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Below is a growing list of scientific articles that deal directly or indirectly with feline hyperthyroidism. The articles are sorted by date with the most recent at the top. A brief description of the article follows the title. To follow a link to the abstract page, click on the title. A link to the source of the article is available by clicking on the article title on the individual abstract page. |
| 2007/11 Liver Function in Cats with Hyperthyroidism Before and After 131I Therapy. This study demonstrates that, regardless of a majority of cats with hyperthyroidism (15/19) having significant increases in at least one of their serum activity of liver derived enzymes, liver functional testing was not different between control and cats with hyperthyroidism. High serum liver enzyme activities were not associated with abnormalities in hepatic parenchyma and liver functional variables, regardless of the degree of increase. Serum liver enzyme activities return to normal after control of hyperthyroidism with 131I therapy. Cats with hyperthyroidism have a significantly higher serum fasting ammonia concentration than cats who were euthyroid. These results demonstrate that extensive examination for hepatobiliary disease in most cats with hyperthyroidism is unnecessary. |
| 2007/07 Thyroid Tumors in Dogs and Cats The clinical presentation and biologic behavior of thyroid tumors vary widely among dogs, cats, and human beings. Although thyroid tumors in dogs are rare, they are most likely to be malignant. Clinical signs are usually the result of impingement on surrounding structures, and clinical hyperthyroidism is rare. In contrast, hyperthyroidism resulting from benign thyroid proliferation is relatively common among older cats. Malignant tumors are extremely uncommon but have high metastatic potential. Irrespective of the tumor's ability to produce functional thyroid hormone, scintigraphy is often helpful in the diagnosis and staging of thyroid tumors in all three species. Treatment with surgery is a reasonable treatment option for noninvasive tumors. Iodine-131 is a well-established treatment for thyroid nodules in cats, but its effectiveness in dogs is controversial. |
| 2007/07 Thyroid Surgery in Dogs and Cats Thyroid surgery is indicated for malignant and benign neoplasms or hyperplasia of the thyroid glands. A ventral midline cervical approach allows for bilateral thyroid exploration. Care should be taken to avoid the surrounding neurovascular structures and esophagus. Evaluation of both thyroids should be done before proceeding with partial or complete thyroidectomy. Complications of thyroid surgery include intraoperative hemorrhage and clinical signs associated with damage to the recurrent laryngeal nerves, parathyroid blood supply, or parathyroidectomy. |
| 2007/07 Testing for Hyperthyroidism in Cats Hyperthyroidism remains a common endocrine disorder of cats. Although relatively easy to diagnose in classically presenting cats, the increased frequency of testing cats with early or mild disease has had significant implications for the diagnostic performance of many of the routine tests currently used. Further advances in the etiopathogenesis and earlier diagnosis are only likely with the advent of a species specific feline thyroid-stimulating hormone assay. |
| 2007/07 Feline Thyroid Storm Thyroid storm is a syndrome described in human medicine to define a multisystemic disorder resulting from organ exposure to excessive levels of thyroid hormone. This form of acute thyrotoxicosis, although uncommon, can be life threatening and is a significant cause of mortality in human emergency rooms. Although thyroid storm is a well-recognized clinical entity in human medicine, it has not been described in veterinary medicine. This article discusses the human syndrome and defines a similar syndrome in hyperthyroid veterinary patients. The clinical signs of and treatment modalities for feline thyroid storm are also presented. |
| 2007/07 Etiopathologic Findings of Hyperthyroidism in Cats None of the studies to date have isolated a single dominant factor that could be incriminated in the development of hyperthyroidism in cats. Rather, most of the studies provide further evidence of the widely held view that hyperthyroidism is a multifactorial disease in this species. At this time, the most likely candidates include one or more of the goitrogenic chemicals that have been shown to be present in cat food or the cat's environment. In addition, mutations of the thyroid stimulating hormone receptor gene or mutations of its associated G proteins seem to play an important role in the pathogenesis of this disease. |
| 2007/07 Cardiovascular and Renal Manifestations of Hyperthyroidism In the simplest terms, hyperthyroidism is the clinical syndrome that results from an excess of thyroid hormones. This review considers the effects of hyperthyroidism on the cardiovascular and renal systems by reviewing the available literature on the clinical manifestations of this syndrome in the cat and also considering experimental studies and experience in other species, including human beings. |
| 2007/07 Radioiodine is considered the treatment of choice for hyperthyroidism, but in some situations, methimazole therapy is preferred, such as in cats with preexisting renal insufficiency. Unfavorable outcomes from methimazole are usually attributable to side effects, such as gastrointestinal upset, facial excoriation, thrombocytopenia, neutropenia, or liver enzyme elevations. Because restoration of euthyroidism can lead to a drop in glomerular filtration rate, all cats treated with methimazole should be monitored with blood urea nitrogen and creatinine levels in addition to serum thyroxine (T4) and a complete blood cell count. Transdermal methimazole is associated with fewer gastrointestinal side effects and can be used in cats with simple vomiting or inappetence from oral methimazole. Hypertension may not resolve immediately when serum T4 is normalized, and moderate to severe hypertension should be treated concurrently with atenolol, amlodipine, or an angiotensin-converting enzyme inhibitor. |
| 2007/07 The indications, techniques, and expectations for radionuclide diagnostic studies on canine and feline thyroid glands are presented. In addition, the considerations surrounding radioiodine or external beam radiotherapy for benign and malignant thyroid disease are reviewed. The intent of this article is to familiarize primary care veterinarians with the utility of and outcome of the ionizing radiation-based diagnostic and therapeutic techniques for assessing and treating canine and feline thyroid disease. |
| 2006/06 Thyroid Storm in Cats: Fact or Fiction Thyroid storm is a syndrome described in human medicine to define a multi systemic disorder resulting from organ exposure to excessive levels of thyroid hormone. This form of acute thyrotoxicosis can be life-threatening and is a significant cause of mortality in human emergency rooms. Hyperthyroid cats that present with acute exacerbation of thyrotoxicosis may be described to have thyroid storm. |
| 2006/06 Aplastic anemia in cats - clinicopathological features and associated disease conditions 1996-2004 A retrospective study of 128 feline bone marrow reports identified 13 cases of aplastic anemia. Clinical diagnoses included chronic renal failure (n=5), feline leukemia virus infection (n=2), hyperthyroidism treated with methimazole (n=1) and idiopathic aplastic anemia (n=5). |
| 2006/03 Cloning and sequencing of feline thyrotropin (fTSH): Heterodimeric and yoked constructs. This report constitutes the first cloning and sequencing of the genes encoding the subunits of feline thyrotropin. |
| 2006/02 Thyroidectomy in the Cat Thyroidectomy in cats is most commonly indicated to treat hyperthyroidism because of adenomatous hyperplasia of the thyroid glands. Preoperative stabilization of the hyperthyroid cat with antithyroid drugs is preferred to minimize anesthetic and surgical complications. Multiple surgical techniques for thyroidectomy have been reported, and results of surgery and complications differ between techniques. |
| 2006/02 Thyroid Scintigraphy in Hyperthyroidism. Thyroid scintigraphy is a nuclear medicine procedure that produces a visual display of functional thyroid tissue based on the selective uptake of various radionuclides by thyroid tissue. Thyroid scintigraphy provides valuable information regarding both thyroid anatomy and physiology and can play an integral role in the diagnosis and management of cats with hyperthyroidism. |
| 2006/02 Survival times for cats with hyperthyroidism treated with iodine 131, methimazole, or both: 167 cases (1996–2003) Conclusions and Clinical Relevance—Results suggest that age, preexisting renal disease, and treatment type were associated with survival time in cats undergoing medical treatment of hyperthyroidism. Median survival time for cats treated with methimazole alone was significantly shorter than median survival time for cats treated with I-131 alone or methimazole followed by I-131. |
| 2006/02 Radioiodine Treatment of Hyperthyroidism Radioactive iodine provides a simple, effective, and safe treatment for cats with hyperthyroidism and is regarded by most authorities to be the treatment of choice. |
| 2006/02 Medical Management of Hyperthyroidism Radioiodine is considered the treatment of choice for hyperthyroidism, but in some situations, methimazole therapy is preferred, such as in cats with pre-existing renal insufficiency. |
| 2006/02 Measurement of total thyroxine concentration in serum from dogs and cats by use of various methods Total T4 concentrations determined in dogs and cats by use of 4 commonly used methods provided similar and consistent results. |
| 2006/02 Hyperthyroidism and the Kidney Hyperthyroidism and chronic renal failure (CRF) are both common diseases of older cats. Hyperthyroidism increases GFR by a variety of physiologic effects. Chronic renal failure can suppress total T4 concentrations in cats with concurrent hyperthyroidism. |
| 2006/02 Diagnostic Tests for Hyperthyroidism in Cats The diagnosis of hyperthyroidism, one of the most common disorders affecting elderly cats, is usually straightforward and considered routine by most practitioners. This paper reviews the available tests used to confirm a diagnosis of hyperthyroidism in cats and discusses their overall usefulness. |
| 2005/11 Thyroid to salivary ratios determined by technetium-99m pertechnetate imaging in thirty-two euthyroid cats. A 95% prediction interval based on the natural log of the Thyroid : Salivary uptake ratio was computed to provide a normal range of 0.48–1.66. This range is similar to previous studies, but suggests a slightly higher upper limit than previously reported. |
| 2005/11 Seroreactivity to A-type retrovirus proteins in a subset of cats with hyperthyroidism. These results suggest that it may be possible to develop an animal (feline) model for the role of retroviruses in thyroid autoimmune diseases. |
| 2005/11 Relationship between selected echocardiographic variables before and after radioiodine treatment in 91 hyperthyroid cats. Pretreatment T-4 assessment was not useful in determining which cats may have potentially relevant echocardiographic abnormalities, some echocardiographic abnormalities may emerge after treatment, and that less than 10% of the pre- or posttreatment abnormalities would be considered clinically relevant. |
| 2005/10
Serum Troponin I Levels in Hyperthyroid Cats Before and After Treatment with Radioactive Iodine
These results suggest that chronic exposure to excess thyroid hormone may induce myocyte damage of sufficient severity to raise serum cTnI concentration in a proportion of cats that resolves following establishment of a euthyroid state. |
| 2005/09 Somatic mutations of the thyroid-stimulating hormone receptor gene in feline hyperthyroidism: parallels with human hyperthyroidism. The identification of a potential genetic basis for feline hyperthyroidism is novel, increases our understanding of the pathogenesis of this significant feline disease, and confirms its similarity to TNG. |
| 2005/09 Feline hyperthyroidism. The contribution of nuclear medicine. Radioiodine treatment is considered to be the easiest, the most effective and with fewer complications treatment for FH compared to thyreostatic drugs or surgical treatment. The contribution of nuclear medicine in FH is an interesting challenge for both veterinary and nuclear medicine. |
| 2005/09 Expression of inhibitory G proteins in adenomatous thyroid glands obtained from hyperthyroid cats. A decrease in Gi2 expression decreases inhibition of adenylyl cyclase and allows a relative increase in stimulatory G protein expression. This results in increased amounts of cAMP and subsequent unregulated mitogenesis and hormone production in hyperthyroid cells. Decreased Gi2 expression may explain excessive growth and function of the thyroid gland in cats with hyperthyroidism. |
| 2005/08 Pleural effusion with hyperthyroidism. Generally, most ECG abnormalities resolve with successful management of thyrotoxicosis. |
| 2005/07 Sedating and Anesthetizing Patients That Have Organ System Dysfunction What agents and monitoring devices might be better in these patients? This anesthesiologist tells you how to handle common situations, such as: "Based on the results of physical examination and routine screening tests, what constitutes dysfunction of such severity to warrant a change in routine sedation or anesthetic protocols?" |
| 2005/05 Update on thyroid function tests in cats: Where does TSH fit in? An optimal feline TSH assay system would hopefully distinguish normal from low values. Such sensitivity will be critical as practitioners are already recognizing cats with palpable thyroid glands but normal total and free T4 concentrations. Also, the diagnostic difficulties associated with sick hyperthyroid cats would presumably be alleviated. |
| 2005/05 Thyroid disorders in the geriatric patient. Thyroid disorders are common in older pets. They often present a diagnostic challenge, and reaching a definitive diagnosis can be difficult or impossible in some cases. It is important for the veterinary practitioner to be familiar with the historical, physical examination, and clinicopathologic data findings in each of these diseases and to become comfortable with the treatment, monitoring, and prognosis associated with thyroid diseases in geriatric pets. |
| 2005/05 The role of renin-angiotensin-aldosterone system (RAAS) in the development of systemic hypertension in cats treated for hyperthyroidism. The cause for the development of hypertension in cats that are being treated for hyperthyroidism remains enigmatic. Activation of the RAAS tends to decrease with treatment both in cats that remain normotensive and those that develop hypertension. Although renal function declined significantly with treatment, cats in both NT (3/10) and HT (6/11) groups developed azotemia, and creatinine concentrations were not significantly different between the groups. The role of declining renal function in development of hypertension is worthy of further study. |
| 2005/05 Serum cobalamin and folate concentrations in cats with hyperthyroidism. These findings suggest the presence of significant malabsorption of both cobalamin and folate in cats with hyperthyroidism, although hypermetabolism may lead to increased vitamin requirements. Hyperthyroidism may directly or indirectly lead to vitamin malabsorption, or some hyperthyroid cats may have concurrent small intestinal disease. Whatever the mechanism, concurrent intestinal dysfunction and vitamin deficiencies appear to be common in hyperthyroid cats. |
| 2005/05 G proteins show normal activation in response to thyroid stimulating hormone in feline hyperthyroid cells. G protein activity is not altered in HT cells and a decreased expression of Gi protein and not an alteration in activity is part of the pathogenesis of feline hyperthyroidism. |
| 2005/05 Expression and purification of feline thyrotropin (fTSH): Immunological detection and bioactivity of heteridimeric and yoked glycoproteins. This work constitutes the first report of in vitro expression and purification of recombinant feline thyrotropin. The demonstration of immunological recognition by antibodies generated against pituitary-source TSH, and of bioactivity confirms that the recombinant glycoprotein may be used to standardize and improve clinical assays for feline TSH. |
| 2005/05 Effects of methimazole on thyroid gland uptake of 99mTC-pertechnetate in 19 hyperthyroid cats. Quantitatively, thyroid scintigraphy did not significantly change after methimazole treatment (P>0.1). Evaluation of serum TSH concentration may be helpful in identifying methimazole-induced changes in the scintigraphic features of hyperthyroidism in mildly hyperthyroid cats. |
| 2005/05 EFFECTS OF METHIMAZOLE ON THYROID GLAND UPTAKE OF 99MTC-PERTECHNETATE IN 19 HYPERTHYROID CATS Nineteen cats with abnormally high serum T4 concentrations underwent thyroid scintigraphy using technetium-99m pertechnetate (99mTcO4) before and after 36±6 days of methimazole administration (approximately 2.5 mg PO q 12 h). Quantitatively, thyroid scintigraphy did not significantly change after methimazole treatment (P>0.1). Evaluation of serum TSH concentration may be helpful in identifying methimazole-induced changes in the scintigraphic features of hyperthyroidism in mildly hyperthyroid cats.
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| 2005/05 Cloning and sequencing of feline thyrotropin (fTSH): Heterodimeric and yoked constructs. This work describes for the first time the full coding sequences of the two subunits of fTSH and has produced DNA constructs for its in vitro expression and purification. |
| 2005/05 Association of the risk of development of hypothyroidism after iodine 131 treatment with the pretreatment pattern of sodium pertechnetate Tc 99m uptake in the thyroid gland in cats with hyperthyroidism: 165 cases (1990-2002). Cats with hyperthyroidism that have a bilateral scintigraphic pattern in the thyroid gland before 131I treatment appear to have a significantly higher risk of subsequently developing hypothyroidism, compared with cats with a unilateral scintigraphic pattern. |
| 2005/04 Secondary hypothyroidism following head trauma in a cat. An 18-month-old female neutered domestic short hair cat was examined because of marked polydipsia and stunted growth following head trauma when it was 8 weeks old. A presumptive diagnosis of secondary hypothyroidism and central diabetes insipidus following head trauma was made. |
| 2005/02 Thyrotropin-stimulated DNA synthesis and thyroglobulin expression in normal and hyperthyroid feline thyrocytes in monolayer culture. These data support the idea that feline hyperthyroidism is caused by cell abnormalities, resulting in dysregulated growth and hormone synthesis, and emphasize its importance as an animal model for Thyrotoxic Nodular Goiter. |
| 2005/02 Thyrotropin-Stimulated DNA Synthesis and Thyroglobulin Expression in Normal and Hyperthyroid Feline Thyrocytes in monolayer culture. Feline hyperthyroidism is a common, spontaneous disease in older cats that is similar clinically and histopathologically to human toxic multinodular goiter (TNG). In this study, the functional response of feline normal thyroid (NT) and hyperthyroid (HT) cells grown in monolayer culture to thyrotropin (TSH) was determined. These data support the idea that feline hyperthyroidism is caused by cell abnormalities, resulting in dysregulated growth and hormone synthesis, and emphasize its importance as an animal model for TNG. |
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2005/02
Multivariate Analysis Of Risk Factors For Feline Hyperthyroidism In New Zealand The results of this study support and extend those in several earlier reports and show that cats in New Zealand are, in many respects, similar to cats in Europe and North America in terms of their susceptibility to hyperthyroidism. The finding that female cats are predisposed to hyperthyroidism is at variance with most previously published work. It remains unclear which, if any, of the identified disease associations are causal, so further studies of this increasingly prevalent feline endocrinopathy are warranted. |
| 2005/02 Calcinosis involving multiple paws in a cat with chronic renal failure and in a cat with hyperthyroidism Calcinosis of multiple paws is described in two cats. A metastatic pathogenesis was supported by the laboratory findings of hyperphosphataemia and a calcium x phosphorus solubility product > 7 g/L. Hyperparathyroidism could not be confirmed because a valid feline parathyroid hormone assay was not available at the time. One cat was diagnosed with chronic renal failure and presented initially with an irregular nodular calcification on the chin. Dietary and medical management was unsuccessful and ultimately the animal was euthanased. Hyperthyroidism was diagnosed in another cat by laboratory findings and scintigraphic imaging. In addition, the cat had a hyperphosphataemia in the absence of azotaemia. Intravenous administration of radioactive iodine as (131)I was accompanied by reduction and normalization in serum total thyroxine and phosphorus concentrations and resulted in resolution of calcification in the paws. |
| 2005/01 Feline endocrinopathies Feline endocrinopathies (excluding diabetes mellitus) include hyperthyroidism, hypothyroidism, acromegaly, hyposomatotropism, diabetes insipidus, hyperadrenocorticism, primary sex hormone-secreting adrenal tumors, primary hyperaldosteronism, pheochromocytoma, hypoadrenocorticism, hyperparathyroidism, and hypoparathyroidism. |
| 2004/11 The options for treating feline hyperthyroidism. The options for treating feline hyperthyroidism include surgery, medical therapy, and radioiodine therapy. The choice among these options is based on the animal's clinical status (the severity of clinical signs and the presence of concurrent nonthyroidal illness), the costs, the clinician's experience, and the availability of radioiodine therapy. |
| 2004/11 Examining the pathogenesis of feline hyperthyroidism. No specific etiologies have been identified, but environmental and genetic factors have been studied to help explain the increase in the incidence of hyperthyroidism over the past few decades. |
| 2004/11 Choosing the best tests to diagnose feline hyperthyroidism. Nonthyroidal illness can interfere with the diagnosis of hyperthyroidism, especially in cats with mild increases in total T4. Measuring free T4 by equilibrium dialysis and performing nuclear scintigraphy can enhance our ability to accurately diagnose this disorder in cats, including cats with concurrent nonthyroidal illness. |
| 2004/09 Transdermal methimazole treatment in cats with hyperthyroidism. Although the overall efficacy of transdermal methimazole is not as high as that of oral methimazole at 2 weeks of treatment, it is associated with fewer GI adverse effects compared to the oral route. |
| 2004/09 Efficacy and safety of transdermal methimazole in the treatment of cats with hyperthyroidism. Although the overall efficacy of transdermal methimazole is not as high as that of oral methimazole at 2 weeks of treatment, it is associated with fewer GI adverse effects compared to the oral route. |
| 2004/08 Traumatic partial hypopituitarism in a cat Traumatic hypopituitarism was diagnosed in an 11-month-old male neutered cat. The presenting complaints were polydipsia, polyuria and lethargy of three months' duration. |
| 2004/07 The activity of the feline thyroglobulin promoter is compromised by flanking adenoviral sequence. These results suggest cis acting elements in the flanking adenoviral sequences may compromise the activity of the feline thyroglobulin promoter and thus make Ad5 an unsuitable vector for transcriptionally targeted gene therapy in feline hyperthyroidism. |
| 2004/05 Management of hypertension in a geriatric cat Hyperthyroidism and chronic renal disease occur commonly in geriatric cats, often in association with potentially life-threatening primary or secondary hypertension. |
| 2004/05 Hypertension In Dogs and Cats The veterinary community has been slow to embrace the practice of routine screening for hypertension despite the realization that persistent elevations in blood pressure can have serious and even life-threatening consequences. |
| 2004/05 Effect of dietary soy on serum thyroid hormone concentrations in healthy adult cats. Short-term administration of dietary soy has a measurable although modest effect on thyroid hormone homeostasis in cats. Increase in T4 concentration relative to T3 concentration may result from inhibition of 5'-iodothyronine deiodinase or enhanced T3 clearance. Soy is a common dietary component that increases serum T4 concentration in cats. |
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2004/05
Effect Of Dietary Soy On Serum Thyroid Hormone Concentrations In Healthy Adult Cats Short-term administration of dietary soy has a measurable although modest effect on thyroid hormone homeostasis in cats. Increase in T4 concentration relative to T3 concentration may result from inhibition of 5´-iodothyronine deiodinase or enhanced T3 clearance. Soy is a common dietary component that increases serum T4 concentration in cats. |
| 2004/03 High urinary corticoid/creatinine ratios in cats with hyperthyroidism. The results of this study demonstrate that the urinary C : C ratio may be abnormally high in cats with hyperthyroidism, probably because of increased metabolic clearance of cortisol and activation of the pituitary-adrenocortical axis by disease. Although the clinical features of hyperthyroidism and hyperadrenocorticism in cats are different, hyperthyroidism should be ruled out when cats are suspected of hyperadrenocorticism on the basis of abnormally high urinary C : C ratios. |
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2004/03
Epidemiologic Study Of Relationships Between Consumption Of Commercial Canned Food And Risk Of Hyperthyroidism In Cats These findings suggest that the increasing prevalence of feline hyperthyroidism is not solely the result of aging of the cat population and that canned foods may play a role.Multivariate Analysis Of Risk Factors For Feline Hyperthyroidism In New Zealand |
| 2004/03 Computed tomographic densitometry of normal feline thyroid glands. Normal feline thyroid tissue is easily detected using CT without contrast medium enhancement. This information may be useful for CT evaluation of abnormal feline thyroid glands. |
| 2004/02 Treating Thyroid and Parathyroid Neoplasia in Dogs and Cats Once a diagnosis of neoplasia of the thyroid gland is suspected or confirmed, a variety of treatments are available for dogs and cats. In this article, we first review the available therapeutic options for thyroid neoplasia in dogs and cats. We then describe therapy for parathyroid neoplasia, which is less common in both species. |
| 2003/10 Relationship between orally administered dose, surface emission rate for gamma radiation, and urine radioactivity in radioiodine-treated hyperthyroid cats. Surface emission rates for cats administered I131 appeared useful in determining upper limits (threshold) of urine radioactivity and are a valid method to assess the time at which cats can be discharged after I131 administration. |
| 2003/09 THE PREVALENCE OF HYPERTENSION IN HYPERTHYROID CATS AT DIAGNOSIS AND FOLLOWING TREATMENT. Hyperthyroidism has been reported as an important cause of hypertension in the cat. However systematic studies of blood pressure in hyperthyroid cats have not been reported and, in large case series, signs consistent with hypertensive retinopathy/choroidopathy have been noted infrequently. The aim of this study was to determine the prevalence of hypertension in hyperthyroid cats at the time of diagnosis, and following initial treatment. In conclusion, severe hypertension is relatively uncommon in cats at the time of diagnosis of hyperthyroidism. However, a significant number of cats will develop hypertension following the induction of euthyroidism. It is, therefore, important to monitor cats’ blood pressure following initiation of therapy. |
| 2003/09 LONG-TERM CHANGES IN GLOMERULAR FILTRATION RATE IN HYPERTHYROID CATS FOLLOWING TREATMENT WITH IODINE-131. It is generally believed that there is a decline in renal function following treatment of hyperthyroidism in cats, but no long-term assessment of glomerular filtration rate (GFR) has been performed. Our aim was to assess the effect of iodine-131 treatment on immediate and long-term renal function in cats with hyperthyroidism. In conclusion, most hyperthyroid cats treated with iodine-131 showed a significant decline in GFR within one month following treatment, however, this decline did not continue. Results also indicated that a subnormal TT4 may contribute to this reduction in GFR as normalisation of TT4 resulted in marked increase in GFR. Therefore, a dose of iodine-131 should be used, which does not render TT4 below the normal reference range. If the same is true for medical or surgical management of feline hyperthyroidism needs to be assessed. |
| 2003/09 Effect of measurement method on blood pressure findings in cats before and after therapy for hyperthyroidism. We conclude that the method of measurement may affect BP results in hyperthyroid cats and that within the Doppler method, BP values obtained in a controlled environment by a trained operator are significantly lower than values obtained in a less controlled situation. Blood pressure methodologies used in this small study did not detect a significant change in BP in response to therapy for hyperthyroidism. |
| 2003/07 Cystic thyroid and parathyroid lesions in cats Reports of cystic thyroid and parathyroid masses in cats are uncommon. Herein, the authors describe a series of four cats with cystic ventral cervical lesions, among them thyroid cyst (n=1), thyroid cystadenoma (n=2), and parathyroid adenocarcinoma (n=1). |
| 2003/05 Total thyroxine testing: Comparison of an in-house test kit with radioimmuno- and chemiluminescent assays. Excellent concordance between Snap T4 results and either RIA or Immulite results was observed. All of these technologies can be used to accurately measure serum TT4 concentrations, but because of slight test-associated biases, the most consistent results will be obtained by using 1 test method exclusively. |
| 2003/05 RELATION OF SURVIVAL TIME AND URINARY PROTEIN EXCRETION IN CATS WITH RENAL FAILURE AND/OR HYPERTENSION. Proteinuria is related to survival time in humans with renal failure. The aim of this study was to investigate the relationship of proteinuria to survival time in cats with variable renal function, and with or without systemic hypertension. Proteinuria predicts reduced survival times in cats with CRF. Further studies are now warranted to determine whether interventions that decrease proteinuria, such as treatment with ACE-inhibitors, will improve survival of cats with renal failure. |
| 2003/05 Diagnosis of feline hyperthyroidism using thyroid scintigraphy. This study demonstrates that a palpable thyroid nodule is suggestive of feline hyperthyroidism despite normal serum thyroxine levels. In these cats additional diagnostics such as thyroid scintigraphy or measurement of fT4(ED) is recommended for the diagnosis of hyperthyroidism. |
| 2003/05 Clinical efficacy of transdermal methimazole in cats with hyperthyroidism. The results of this study indicate that transdermal methimazole in PLO gel results in comparable efficacy by 4 weeks of treatment, with fewer GI side effects, compared to the same dose administered orally, and is therefore is a viable alternative in the treatment of feline hyperthyroidism. |
| 2003/04 Evaluation of relationships between pretreatment patient variables and duration of isolation for radioiodine-treated hyperthyroid cats. A pretreatment estimate for duration of isolation could be determined only from an equation based on the orally administered dose of 131I. These findings suggest that administration of the lowest efficacious dose possible is the dominant factor in reduction of duration of isolation for cats treated with 131I. |
| 2003/04 Efficacy and safety of once versus twice daily administration of methimazole in cats with hyperthyroidism. Results suggest that once daily administration of methimazole was not as effective as twice daily administration in cats with hyperthyroidism and cannot be recommended for routine use. |
| 2003/02 Use of recombinant human thyroid-stimulating hormone for thyrotropin-stimulation testing of euthyroid cats. The TSH stimulation test can be performed in cats by IV administration of 0.025 to 0.200 mg of rhTSH and measurement of serum TT4 concentrations at time of injection and 6 or 8 hours later. Clinical validation of the TSH stimulation test would facilitate development of additional tests of thyroid gland function, such as a TSH assay. |
| 2003/01 Juvenile hyperthyroidism in a cat. The cat was diagnosed with hyperthyroidism, and a unilateral thyroidectomy was performed followed by radioactive iodine at a later date. The clinical signs resolved following radioactive iodine, and the cat subsequently developed clinical hypothyroidism. |
| 2002/11 Predictors of response to radioiodine therapy in hyperthyroid cats. There was a significant relationship between pretreatment thyroxine values and post-treatment thyroxine values at all of the follow-up time points (p < 0.001). There was also a relationship between thyroid to salivary gland technetium scan ratio results and serum thyroxine values at pretreatment and at 1 week post-treatment (p = 0.02, 0.005, respectively). A greater scan ratio was associated with higher thyroxine levels at these time points, but not at 1, 3, 6 or 12 months post-therapy. |
| 2002/06 Bioavailability of transdermal methimazole in a pluronic lecithin organogel (PLO) in healthy cats. The results of this study indicate generally low to undetectable bioavailability of methimazole in a lecithin/pluronic gel given as a single transdermal dose to healthy cats, although one individual cat did achieve nearly 100% transdermal bioavailability relative to the oral route. |
| 2002/05 Thyroid Nodules In Euthyroid Cats: A Matter Of Age Or Time? Retrospective studies support the presence of a subset of cats with nodules not inducing clinical hyperthyroidism. Furthermore, new data provided indicate that early surgical removal of the enlarged thyroid glands is frequently validated by abnormal histopathology. |
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2002/03
Percutaneous ultrasonographically guided radiofrequency heat ablation for treatment of hyperthyroidism in cats. The purpose of this study was to evaluate the efficacy of radiofrequency heat ablation for treatment of cats with naturally occurring hyperthyroidism. Unipolar radiofrequency heat ablation is feasible and effective as a short-term treatment for feline hyper-thyroidism, but has not been effective as a permanent treatment like radioiodine therapy. |
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2002/02
Identification And Concentration Of Soy Isoflavones In Commercial Cat Foods Genistein and daidzein are common constituents of commercial cat foods. Predictors of isoflavone content included ingredient labeling, food type, and food cost. Soy isoflavones in some commercial cat foods were detected in amounts predicted to have a biological effect. |
| 2001/06 Selenium Status Of Cats In Four Regions Of The World And Comparison With Reported Incidence Of Hyperthyroidism In Cats In Those Regions Cats have higher Se concentrations in plasma, compared with values for other species. However, Se status alone does not appear to affect the incidence of hyperthyroidism in cats. High Se concentrations may have implications for health of cats if such concentrations are influenced by the amount of that micronutrient included in diets. |
| 2001/05 Functional cystic thyroid adenoma in a cat. Possible causes of cystic ventral cervical masses in cats include thyroid, thyroglossal duct, and parathyroid cysts; however, the possibility that such masses represent cystic thyroid adenomas or cystic thyroid carcinomas should also be considered. |
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2001/04
Use of Percutaneous Ethanol Injection for Treatment of Bilateral Hyperplastic Thyroid Nodules in Cats Percutaneous ethanol ablation of bilateral thyroid nodules as a treatment for cats with hyperthyroidism is not recommended. This treatment is not as efficacious as the medical and surgical treatments presently used. |
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2001/03
Thyrotropin-Releasing Hormone Stimulation Test to Assess Thyroid Function in Severely Sick Cats Based on the results of serum T4 determinations and the TRH stimulation tests alone, it was not possible to document hyperthyroidism in many critically ill cats with severe nonthyroidal illnesses. This study demonstrates the limitations in laboratory evaluations of severely sick cats. In many of these critically ill cats their otherwise elevated thyroid hormone levels were suppressed into the normal range by their concurrent nonthyroidal disease. |
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2001/02
Measurement of Serum Concentrations of Free Thyroxine, Total Thyroxine, and Total Triiodothyronine in Cats with Hyperthyroidism and Cats with Nonthyroidal Disease Results indicate that determination of free T4 concentration is useful in the diagnosis of hyperthyroidism, especially in cats in which hyperthyroidism is suspected but total T4 and T3 concentrations are within reference ranges. However, because some cats with nonthyroidal disease have high serum free T4 concentrations, hyperthyroidism should not be diagnosed solely on the finding of a high free T4 concentration. |
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2001/01
Long-Term Health and Predictors of Survival for Hyperthyroid Cats Treated with Iodine 131 Two hundred thirty-one cats treated with radioactive iodine at the Texas Veterinary Medical Teaching Hospital were followed for a median of 25 months and tables predicting survival after diagnosis and treatment of hyperthyroidism for various age and sex combinations were created. This study provides estimates of duration of survival for cats successfully treated for hyperthyroidism with radioactive iodine, which can be useful in assisting with client treatment decisions. |
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2000/09
Evaluation Of Dietary and Environmental Risk Factors For Hyperthyroidism In Cats This study suggests that cats which eat certain flavors (fish or liver and giblet flavors) of canned cat food may have a significantly increased risk of hyperthyroidism.This study found no link between the development of hyperthyroidism and exposure to regular treatment with flea sprays or powders; exposure to lawn herbicides, fertilizers or powders; or living indoors. |
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2000/08
Altered Expression of G Proteins in Thyroid Gland Adenomas Obtained from Hyperthyroid Cats The finding of decreased amount of Gi[alpha] in thyroid gland adenomas may indicate that G[i] plays a role in the inhibition of growth and differentiation of the feline thyroid gland. Decreased amounts of Gi[alpha] could reduce the overall inhibitory effect on adenyl cyclase leading to abnormally high concentrations of cAMP, resulting in cell growth and differentiation. |
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2000/05
Effects of Methimazole on Renal Function in Cats with Hyperthyroidism The results of this study agree with others that hyperthyroidism increases GFR, and treatment with methimazole, surgical thyroidectomy, or radioiodine decreases GFR. Isosthenuria was present prior to methimazole treatment in the three hyperthyroid cats that developed azotemia after treatment. Thus, hyperthyroid cats with isosthenuria prior to treatment may be at risk for development of renal failure after euthyroidism is established, so a pretreatment urinalysis is indicated in all cases. |
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2000/03
Prevalence of Ocular Abnormalities in Cats with Hyperthyroidism Active retinal lesions were only observed in 3 hyperthyroid cats (3%). The results of this study indicate that hyperthyroidism does not seem to be a frequent cause of abnormalities in the eyes of cats. |
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2000/02
Tissue sources of serum alkaline phosphatase in 34 hyperthyroid cats: a qualitative and quantitative study. In hyperthyroid cats, there was a significant correlation between the serum L-thyroxine concentrations and the SALP concentrations. These findings suggest pathological changes in both bone and liver in most cases of feline thyrotoxicosis. |
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2000/01
Prothrombin, Activated Partial Thromboplastin, and Proteins Induced by Vitamin K Absence or Antagonists Clotting Times in 20 Hyperthyroid Cats Before and After Methimazole Treatment Seemingly, doses of methimazole commonly used to treat hyperthyroidism in cats do not cause alteration in PT and APTT and only rarely prolong PIVKA clotting time. Nevertheless, abnormal PIVKA clotting time may explain bleeding tendencies unassociated with thrombocytopenia in methimazole-treated hyperthyroid cats. |
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1999/11
Serum Fructosamine Concentration in Cats with Overt Hyperthyroidism Serum fructosamine concentrations in hyperthyroid cats were significantly lower than values in healthy cats due to accelerated plasma protein turnover. Diabetic cats have elevated serum fructosamine concentrations proportional to the degree of hyperglycemia present during the preceding two weeks. Hyperthyroid cats with diabetes mellitus should have lowered serum fructosamine concentrations which may fall within the euglycemic range of normal cats, or below. Therefore, serum fructosamine concentration should not be used to diagnose or assess the adequacy of treatment of diabetes in cats with concurrent hyperthyroidism that has not been controlled for at least six weeks. Additionally concentration of serum fructosamine in hyperthyroid cats should not be used to differentiate between diabetes mellitus and transitory stress-related hyperglycemia. |
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1999/09
Surgical Options for the Treatment of Hyperthyroidism in the Cat Since more than 80% of hyperthyroid cats have neoplastic changes in both thyroid glands, bilateral thyroidectomy is necessary for treatment of the majority of hyperthyroid cats. Several different thyroidectomy techniques have been developed in an attempt to minimize potential post-operative complications associated with bilateral thyroidectomy such as hypocalcemia or recurrence of hyperthyroidism. Damage to or removal of all four parathyroid glands during bilateral thyroidectomy causes hypocalcemia, the most common post-operative complication. Recurrence of hyperthyroidism can occur months after initial thyroidectomy if residual adenomatous thyroid tissue is retained in the surgical site. Thyroidectomy is a very effective treatment option for hyperthyroid cats. |
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1999/07
Use of Propranolol and Potassium Iodate in the Presurgical Management of Hyperthyroid Cats Based on the findings of this study, propranolol followed by potassium iodate is an effective alternative preoperative treatment for hyperthyroidism in cats. Liver function should be monitored, particularly when iodate treatment is added to the treatment regime. The finding that propranolol treatment decreases serum T3 is consistent with findings in man that the drug inhibits deiodinase activity, preventing conversion of T4 to the more active T3. |
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1999/07
Evaluation of Environmental, Nutritional, and Host Factors in Cats with Hyperthyroidism The pathologic changes associated with hyperthyroidism (adenomatous hyperplasia, adenoma of the thyroid gland) have been well characterized in cats, but the pathogenesis of these changes remains unclear. Results suggested a 2- to 3-fold increase in risk of developing hyperthyroidism among cats eating a diet composed mostly of canned cat food and a 3-fold increase in risk among those using cat litter. In contrast, the use of commercial flea products did not retain a strong association. The results of this study indicate that further research into dietary and other potentially important environmental factors (e.g., cat litter) is warranted. |
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1999/03
Overexpression of c-Ras in hyperplasia and adenomas of the feline thyroid gland: an immunohistochemical analysis of 34 cases. These results indicated that overexpression of c-ras was highly associated with areas of nodular follicular hyperplasia/adenomas of feline thyroid glands, and mutations in this oncogene may play a role in the etiopathogenesis of hyperthyroidism in cats. |
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1999/03
Medical Therapy of Feline Hyperthyroidism Antithyroid medications and radioiodine constitute the two main medical options. Methimazole and carbimazole are effective in most cats, but monitoring is required to assess efficacy of therapy and development of side effects. Ipodate is an oral agent that may be used as an alternative in some cats. Radioiodine therapy is also highly successful. Although [beta]-adrenergic blockers do not affect thyroid hormone concentration, they reverse some of the effects of the hyperthyroid state and can be used in combination with antithyroid medications or surgery. |
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1999/01
Electrocardiographic and Radiographic Changes in Cats With Hyperthyroidism: Comparison of Populations Evaluated During 1992-1993 vs. 1979-1982 Two populations (1992 to 1993 and 1979 to 1982) of confirmed hyperthyroid cats were compared to determine whether the incidence of certain cardiovascular specific manifestations of feline thyrotoxicosis had experienced similar changes. Sinus tachycardia, which is the most commonly recognized cardiac manifestation of feline thyrotoxicosis, was not as prevalent in the 1993 group when compared to the 1982 group. Thoracic radiographs were deemed necessary in a larger proportion of the 1982 group when compared to the 1993 group. These findings suggest that feline hyperthyroidism is being diagnosed earlier and with less severe clinical signs than when studied a decade ago. |
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1998/09
A First Feline Case of Cardiomyopathy Associated With Hyperthyroidism due to Thyroid Adenoma in Japan A 13-year-old castrated male Persian cat was presented with depression, anorexia, and weight loss. Radiographic and electrocardiographical examinations revealed cardiomegaly and sinus tachycardia. Cardiac ultrasonography indicated hypertrophy of the left ventricular free wall and interventricular septum, and left atrial enlargement. Elevated serum T3 and T4 levels were observed, and thyroid adenoma was confirmed by histopathology. Based on these findings, the cat was diagnosed as cardiomyopathy associated with hyperthyroidism induced by thyroid tumor. This report describes the first feline case of cardiomyopathy associated with hyperthyroidism in Japan. |
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1998/05
Efficacy of Parathyroid Gland Autotransplantation in Maintaining Serum Calcium Concentrations After Bilateral Thyroparathyroidectomy in Cats Feline hyperthyroidism is a multisystemic endocrinopathy. While multiple methods of treatment exist, surgical removal of the abnormal thyroid tissue remains the most widely available curative procedure. The most serious complication of bilateral thyroidectomy is postoperative hypocalcemia. Hypoparathyroidism and associated hypocalcemia result from accidental removal of the external parathyroid glands or disruption of their vascular supply. The hypocalcemia often can be severe and life threatening, requiring intensive monitoring and care followed by prolonged supplementation with calcium and vitamin D analogues. While parathyroid autotransplantation greatly reduces morbidity in the parathyroidectomized cat, transplanted normal thyroid tissue was present in at least three of eight cats with thyroparathyroidectomy and autotransplantation. It may be possible to transplant diseased thyroid tissue in a clinical case. This may lead to an ectopic site of thyroid adenoma or adenocarcinoma. |
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1997/07
Ipodate Treatment of Hyperthyroidism in Cats lpodate may be a feasible alternative to methimazole for medical treatment of hyperthyroidism in cats, particularly those that cannot tolerate methimazole and are not candidates for surgery or radiotherapy. Cats with severe hyperthyroidism are less likely to respond to ipodate than are cats with mild or moderate disease, and cats in which serum T3 concentration does not return to the reference range are unlikely to have an adequate improve merit in clinical signs. |
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1997/05
Changes in Renal Function in Cats Following Treatment of Hyperthyroidism Using 131I It was concluded that significant declines in renal function occur after treatment of hyperthyroidism and this decline is clinically important in cats with renal disease. Pretreatment measurement of GFR is valuable in detecting subclinical renal disease and in predicting which cats may have clinically important declines in renal function following treatment. |
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1997/01
Investigation of the effects of hyperthyroidism on renal function in the cat. This study evaluated the effects of thyroxine on renal function in the cat. Administration of high doses of exogenous thyroxine to cats results in significant stimulation of renal function. |
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1996/12
Study of calcium homeostasis in feline hyperthyroidism. Hyperparathyroidism occurred in 77 per cent of hyperthyroid cats, with parathyroid hormone concentrations reaching up to 19 times the upper limit of the normal range. The etiology, significance and reversibility of hyperparathyroidism in feline hyperthyroidism remains to be established but could have important implications for both bone strength and renal function. |
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1996/12
Alkaline phosphatase bone isoenzyme and osteocalcin in the serum of hyperthyroid cats. This study concluded that hyperthyroid cats do have altered bone metabolism, although it is usually clinically insignificant. |
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1996/03
Effect of treatment of hyperthyroidism on renal function in cats. Reduction of serum T4 concentrations after treatment of hyperthyroidism may result in azotemia in older cats with chronic renal disease. Treating azotemic hyperthyroid cats with methimazole until it can be determined whether correction of the hyperthyroid state will exacerbate the azotemia may be prudent. |
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1996/01
Feline Hyperthyroidism: Efficacy Of Treatment Using Volumetric Analysis For Radioiodine Dose Calculation The administration of a dose of radioiodine based solely on the volume of hyperfunctioning thyroid tissue as estimated from the pertechnetate scan may be inadequate for those patients with extremely elevated serum thyroxine levels or large thyroid glands, and oral administration of radioiodine is not recommended for the treatment of feline hyperthyroidism. |
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1995/12
Radioiodine treatment of 524 cats with hyperthyroidism. Results of the study confirms that subcutaneous administration of radioiodine provides a safe and effective means of treating hyperthyroidism in cats. |
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1995/10
Response to high-dose radioactive iodine administration in cats with thyroid carcinoma that had previously undergone surgery. There were no complications associated with 131I treatment, and clinical signs resolved in all cats. All 7 cats became hypothyroid after treatment. |
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1995/02
Changes in clinical and laboratory findings in cats with hyperthyroidism from 1983 to 1993. Overall, the frequency and severity of many clinical features of hyperthyroidism in casts has decreased over the past 10 years since the first cases of the disease were reported. |
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1994/12
Prospective randomized comparison of intravenous versus subcutaneous administration of radioiodine for treatment of hyperthyroidism in cats. When compared with IV administration, SC administration of radioiodine appeared to be as effective for treatment of hyperthyroidism, safer to personnel, and less stressful to the cats. |
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1994/12
Ocular disease associated with hypertension in 16 cats Between 1990 and 1993, 16 cats were referred with acute onset blindness or intraocular haemorrhage. Blood pressure assessment, using the Doppler ultrasonic recording technique in 11 of the cats, proved these cases to be hypertensive. Fifteen cats underwent further investigation, revealing 13 with some degree of renal impairment and one as hyperthyroid. Five underwent cardiac ultrasound and all showed evidence of cardiac hypertrophy. The eyes from four of the cats were examined histologically and showed serous or haemorrhagic retinal detachments with varying degrees of retinal degeneration and a range of ocular hypertensive vascular changes. Two cats had full post mortem examinations which revealed evidence of renal and thyroid pathology. |
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1994/12
Changes in renal function associated with treatment of hyperthyroidism in cats. This study provides further evidence that treatment of hyperthyroidism can result in impaired renal function. In addition, this study suggests that, in some instances, thyrotoxicosis might mask underlying chronic renal insufficiency. |
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1994/11
The Prevalence of Retinopathy in Cats with Systemic Hypertension and Chronic Renal Failure or Hyperthyroidism - Thirty-six cats with either chronic renal failure or hyperthyroidism were examined. Indirect systemic blood pressure and ophthalmic findings were recorded for each cat. Fifteen of 23 cats (65%) with chronic renal failure had blood pressure readings consistent with hypertension. Twelve of these 15 (80%) had hypertensive retinopathy. Three of 13 cats (23%) with hyperthyroidism had blood pressure readings consistent with hypertension. One of these three cats (33%) had hypertensive retinopathy. The most common findings of hypertensive retinopathy were hemorrhages and intraretinal serous exudates. |
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1994/07
Use of the Thyrotropin Releasing Hormone Stimulation Test to Diagnose Mild Hyperthyroidism in Cats As a diagnostic test, the TRH stimulation test compares favorably with the T3 suppression test but requires less time and is more convenient to perform. |
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1994/07
Quantitative Aspects of Thyroid Scintigraphy With Pertechnetate (99mTco4 ) in Cats It is concluded that the optimal time for visualization of the thyroid by 99mTcO4-scanning is 60 minutes after IV injection of the radionuclide. |
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1994/07
Acute onset of hypokalemia and muscular weakness in four hyperthyroid cats Hyperthyroid cats may be prone to disturbances in potassium homeostasis. Clinicians should be aware of potential changes in potassium homeostasis during the treatment of cats with hyperthyroidism. |
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1994/06
Radioactive iodine therapy for feline hyperthyroidism: Efficacy and administration routes There was no difference in the outcome between the cats injected intravenously or subcutaneously and the latter was considered to be safer and simpler. The administration of an approximated dose of 131I proved to be an effective treatment for hyperthyroidism in 47 (94.0 per cent) of the cats and obviated the need for sophisticated nuclear computer facilities. There may be a lag period in some cases before euthyroidism is achieved and this should be considered before the administration of a second dose. 131I can be administered subcutaneously without untoward effects. |
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1994/05
Thyroid Hormone Metabolism: A Comparative Evaluation Knowledge of thyroid hormone and iodide metabolism is derived from a combination of in vivo and in vitro studies in a variety of mammalian species. Each species provides a unique opportunity to investigate various aspects of normal or altered thyroid hormone physiology. This article compares thyroid hormone and iodide metabolism in dogs, cats, and humans, with emphasis on similarities and differences as well as on areas in which data are not currently available. |
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1994/05
Etiopathology of Feline Toxic Nodular Goiter The basic lesion appears to be an excessive intrinsic growth capacity of some thyroid cells. The factors enhancing the transformation of a normal thyroid into a nodular hyperfunctioning goiter over many years are still unknown. Immunological, environmental, and nutritional factors are the focus of ongoing studies, but an infectious agent can not yet be excluded. |
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1994/05
Effects of Thyroid Hormone and Thyroid Dysfunction on the Cardiovascular System Hyperthyroidism is common in the cat andc linically significant cardiovascular manifestations are common and often dramatic. Hyperdynamic systolic function and mild myocardial hypertrophy are common manifestations which may lead to overt congestive and high output heart failure. If signs of congestive heart failure or significant arrhythmias are not evident, specific therapy need only be directed toward restoration of the euthyroid state. In most cases the cardiovascular changes associated with thyroid dysfunction are completely reversible. |
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1994/03
Agarose Gel Electrophoresis of Alkaline Phosphatase Isoenzymes in the Serum of Hyperthyroid Cats Cats with hyperthyroidism [(increased serum thyroxine (T4)] commonly have increased serum alkaline phosphatase (ALP) activity in addition to other serum biochemical abnormalities. Hyperthyroid cats had increased ALP activity in bands corresponding to isoenzymes originating in the liver, bone, and an unidentified tissue source. |
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1994/01
Ultrasonographic Examination of the Thyroid Gland of Hyperthyroid Cats: Comparison to 99mTc04 Scintigraphy High-resolution ultrasonography was evaluated as an alternative to 99mTcO4 scintigraphy for examining size and appearance of thyroid glands in hyperthyroid cats. This preliminary study indicates that thyroid ultrasound examination may provide information that is useful for diagnosis and treatment of feline hyperthyroidism. Although ultrasound provides accurate evaluation of the thyroid glands, it cannot replace 99mTc04- scintigraphy for screening of metastatic lesions and ectopic glands. |
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1993/12
Altered platelet indices in dogs with hypothyroidism and cats with hyperthyroidism Changes in platelet size reported in human beings with thyroid endocrinopathies also are found in animals so-affected. The pathogenesis of platelet abnormalities in animals with thyroid derangement is unclear and likely is multifactorial. |
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1993/09
Radiographic and Scintigraphic Evidence of Focal Pulmonary Neoplasia in Three Cats With Hyperthyroidism: Diagnostic and Therapeutic Considerations Increased radionuclide uptake in focal pulmonary lesions and cytologic evaluation of tissue obtained by fine-needle aspiration are not specific for thyroid tissue. |
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1993/05
Influence of Systemic Nonthyroidal Illness on Serum Concentration of Thyroxine in Hyperthyroid Cats This study's results show that nonthyroidal illness can be associated with normal serum T4 concentrations in cats with apparent hyperthyroidism. |
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1991/12
Use of the triiodothyronine suppression test for diagnosis of hyperthyroidism in ill cats that have serum concentration of iodothyronines within normal range. Concluded that the triiodothyronine suppression test is a safe and accurate test for diagnosis of hyperthyroidism in cats with suggestive clinical signs of the disease but lacking high serum concentration of iodothyronines. |
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1990/09
Triiodothyronine [T3] suppression test--An aid in the diagnosis of mild hyperthyroidism in cats Advantages of the T3 suppression test are that the drug and assays are readily available and relatively inexpensive. The disadvantage is that the test relies on owner compliance for administration of the liothyronine. Serum T3 levels increased in all cats following treatment with liothyronine. Thus if post- liothyronine T3 levels are not increased compared with baseline values, owner compliance is questioned and the test may be invalid. Adequate suppression of serum T4 following administration of T3 rules out hyperthyroidism. However inadequate suppression of T4 following administration of T3 has been reported in euthyroid humans with disorders other than hyperthyroidism.
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1990/09
Serum thyroxine concentrations following fixed-dose radioactive iodine treatment in hyperthyroid cats : 62 cases [1986-1989] The authors feel that radioactive iodine given at a fixed dose of 4 mCi/cat IV is an effective treatment for feline hyperthyroidism. |
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1990/07
Recurrence of hyperthyroidism after thyroidectomy in cats RECURRENCE OF HYPERTHYROIDISM occurred in 4/40 cats treated surgically by thyroidectomy. Regrowth of abnormal tissue at the site of the originally affected gland was found in 3/4. |
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1989/09
Occurrence of problems after three techniques of bilateral thyroidectomy in cats The incidence of recurrence was significantly higher in cats treated with the intracapsular dissection technique than the modified intra- or extracapsular dissection techniques. |
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1989/05
Metabolic and endocrine myopathies of dogs and cats Metabolic and endocrine myopathies are discussed including those associated with skeletal muscle storage diseases [glycogen storage diseases, muscle triglyceride storage diseases, and mitochondrial myopathies], malignant hyperthermia, exertional rhabdomyolysis, hyperthyroidism, hypothyroidism, hyperadrenocorticism, hypoadrenocorticism, primary aldosteronism [Conn's syndrome], Nelson's syndrome, hypopituitarism, hyposomatotropism, acromegaly, primary hyperparathyroidism, hypercalcemia, hypoparathyroidism, diabetes mellitus, hypokalemia, and hyperkalemia. |
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1989/04
Effect of glucocorticoids on thyroid function in normal cats and cats with hyperthyroidism A significant decrease in T4 levels occurred 24 hours post prednisone in the normal cats but not in the hyperthyroid cats. T4 levels were not significantly different than baseline levels at 1 and 2 weeks post methylprednisolone. |
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1988/08
Thyroid carcinoma causing hyperthyroidism in cats : 14 cases [1981-1986] All cats treated with high dose radioiodine therapy became euthyroid following treatment. |
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1988/07
Methimazole treatment of 262 cats with hyperthyroidism Methimazole is shown to be an efficatious therapy for hyperthyroidism in the cat requiring at least daily treatment. Adverse effects developed in 18.3% of the cats treated, usually within the first month of treatment. Adverse reactions seen included anorexia, vomiting, lethargy, facial and neck excoriations, thrombocytopenia , and hepatopathy. |
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1988/06
Echocardiographic findings in 103 cats with hyperthyroidism Echocardiographic abnormalities of numerous types commonly occur in cats with hyperthyroidism but usually improve following a return to euthyroidism. |
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1988/02
Predictive value of tracer studies for 131I Treatment in hyperthyroid cats Tracer kinetics of radioiodine do not accurately predict post therapy radioiodine kinetics in many cats. |
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1988/01
Serial determination of thyroxine concentrations in hyperthyroid cats Although concentrations did vary, no significant variation in T4 levels was seen with time, and all T4 levels remained above normal during the study. |
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1988/01
Assessing degree of hyperthyroidism in cats Total T4 and T3 levels appear to correlate with the degree of hyperthyroidism in cats. |