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News Day-Long CE Program Features "Advances in Treatment of Feline Hyperthyroidism" & more Sunday, August 11, 2013 New York Metro Area Veterinary S
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Day-Long CE Program Features "Advances in Treatment of Feline Hyperthyroidism" & more
Sunday, August 11, 2013
New York Metro Area Veterinary Specialists Featured at Day-Long Veterinary & Technician CE lectures
One hour CE lectures run from 10:00 AM—7:00 PM. Program will be held at Leonard's Palazzo 555 in Great Neck, New York.
Veterinary and technician CE topics to include: Critical Care, Oncology, Pharmacology, Surgery, Ophthalmology, Dermatology and Endocrinology. Doctors and technicians can earn up to 7 NYS-approved CE credits through this CE program.
Dinner Lecture: 5:30 PM - 7:00 PM
Dr. Mark Peterson presents: “Advances in the treatment of feline hyperthyroidism: a strategy to slow the progression of CKD”
For information. or to register, e-mail: livmahelp@gmail.com. Please put "August 11, 2013 CE" in subject line. |
All-Day Continuing Education Seminar
Sponsored by the Long Island VMA and the Westchester-Rockland VMA
Great Neck, New York, August 11, 2013
Topic:
• Advances in the Treatment of Feline Hyperthyroidism: A Strategy to Slow the Progression of CKD
Continuing Education by the Sea
Corpus Christi, Texas, September 6, 2013
Topics:
• Treating Dogs With Cushing's Syndrome
• Diagnostic Testing for Hyperthyroidism in Cats: More Than Just T4
• Endocrine Potpourri: Various Case Studies
Syracuse Veterinary Medical Association
Syracuse, New York, October 17, 2013
Topics:
• Update on Feline Endocrinology (Diabetes, Hyperthyroidism and Hypercalcemia)
• Diagnosing and Treating Dogs With Cushing's Syndrome
North American Veterinary Conference
Orlando, Florida, January 18 - 22, 2014
Topics:
• Canine Cushing's Disease: Confusion or Clarity? |
At the annual American College of Veterinary Internal Medicine (ACVIM) conference held last month in Seattle, Washington, two of Dr. Peterson's research abstracts were presented. They are listed below, along with his comments:
Broome MR, Peterson ME. Use of L-thyroxine supplementation after radioiodine therapy helps blunt the worsening of azotemia in hyperthyroid cats with pre-existing kidney disease. J Vet Intern Med 2013;27:685-686.
Hyperthyroidism develops in cats secondary to 1 or more autonomously functional thyroid adenomas. The progressive thyrotoxicosis that ensues causes the chronic suppression of endogenous TSH release and ultimately the atrophy of normal thyroid tissue in these cats. This thyroid atrophy can lead to a period of transient hypothyroidism following curative radioiodine therapy. Once T4 values fall, circulating TSH levels increase, leading to reactivation of the previously suppressed and atrophied thyroid tissue in the large majority of these cats. Between 30-40% of cats with hyperthyroidism have pre-existing chronic kidney disease (CKD). Iatrogenic hypothyroidism has been shown to contribute to worsening of azotemia and shortened life expectancy in cats with pre-existing CKD (Williams et al, J Vet Intern Med. 2010;24:1086). In hyperthyroid cats with concurrent azotemia, the transient hypothyroidism that follows radioiodine therapy may contribute to additional renal function decline and worsening of the cats’ CKD stage.
The purpose of this study was to evaluate if prevention of this transient hypothyroidism would blunt the progression of azotemia commonly seen following the resolution of thyrotoxicosis in these cats with preexisting CKD.In this study, 195 hyperthyroid cats with concurrent CKD (IRIS stage 2 to 3) were treated with radioiodine (range, 1-10 mCi, median, 3 mCi). Of the 195 CKD cats, 85 cats were discharged on L-T4 (0.1 mg, PO q24 h), whereas the remaining 110 cats served as controls (no L-T4 supplementation). In both groups, total T4, BUN, and creatinine levels were recorded before treatment and then again at 1, 3 and 12 months following radioiodine therapy. Following successful radioiodine therapy, both groups of cats with preexisting CKD demonstrated increases in serum BUN and creatinine levels that gradually progressed over the 12-month period (Table 1). However, the percent rise in median creatinine concentrations in the 85 cats treated with L-T4 was significantly less than the rise in the 110 cats not supplemented with L-T4 (12.5% vs 33.3%; P < 0.05). These results suggest that L-T4 supplementation of radioiodine-treated cats with CKD may help limit progression of azotemia, presumably by avoiding the transient hypothyroidism that commonly develops after radioiodine therapy.
Comments—Iatrogenic hypothyroidism (even temporary) has been shown to contribute to worsening of azotemia in cats with pre-existing CKD (Williams et al, J Vet Intern Med. 2010;24:1086).
The results of this study suggest that L-T4 supplementation of radioiodine-treated cats with concurrent CKD may help limit progression of azotemia by avoiding the transient hypothyroidism that commonly develops after radioiodine therapy. Further research is in progress, but short-term L-T4 supplementation has become an integral part of the protocol for treating hyperthyroid cats with renal disease at our practice. |
Broome MR, Peterson ME. Ectopic sublingual thyroid neoplasia in the dog: 25 cases (1995-2012). J Vet Intern Med 2013;27:685-686.
Thyroid embryology defines the normal migration of thyroid tissue from its origin as an epithelial proliferation in the floor of the pharynx at the base of the tongue (ie, the foramen caecum) along the path of the thyroglossal tract. The embryologic path of the thyroid gland includes the tongue and hyoid apparatus. Failure to associate fully with the embryologic aortic sac leads to the incomplete descent of the thyroid and the presence of sublingual ectopic thyroid tissue. Ectopic thyroid tissue in this location can occasionally become neoplastic.
Two previous reports describe a total of 9 cases of sublingual thyroid carcinoma in dogs (JAVMA 1989;195:1606; ASVS Veterinary Symposium 2011;217). No reports of benign thyroid neoplasia developing in this location have been identified. Medical records reviewed between 1995-2012 revealed 519 dogs with thyroid carcinoma, confirmed by thyroid scintigraphy. During that period, 25 dogs with ectopic sublingual thyroid neoplasia were identified (5% of all thyroid carcinoma cases). The dogs ranged in age from 4-15 years (median, 9 yrs), with 13 neutered males and 12 spayed females. Breeds included mix (6 dogs), Golden Retriever (4), American Staffordshire Terrier (2), and Labrador Retrievers (2). Eight dogs (32%) had high serum T4 levels, consistent with hyperthyroidism. Twelve dogs had normal total T4 levels, 4 dogs had low values, and 1 dog’s T4 value was not available. Four dogs had pulmonary metastases confirmed by scintigraphy and 4 had concurrent cervical disease, and 1 dog had both concurrent cervical disease and pulmonary metastasis. Seventeen dogs had histopathologic confirmation and 7 dogs had cytologic confirmation of thyroid malignancy.
Fourteen dogs were treated with surgery; of these, 9 had excision of the basihyoid bone. All tolerated surgical intervention, including hyoid bone resection. Gross surgical excision of thyroid disease was confirmed scintigraphically in 7 dogs, 5 of which required hyoid bone resection. Thirteen dogs were treated with high-dose radioiodine (dose range, 40-130 mCi; mean, 95 mCi). No lasting complications following radioiodine were identified. Radioiodine therapy resulted in a marked response, as measured by percent decreased radionuclide uptake (range 42-100%, mean, 80%) in 8 dogs with gross disease. Radioiodine was also successful in ablating normal thyroid tissue in 3 dogs without persistent gross disease. Nine dogs were treated with both surgery and radioiodine. Surgery was performed prior to radioiodine therapy in all 9 dogs. One dog with a thyroid tumor deemed initially surgically unresectable had a successful surgical excision following radioiodine therapy.
Comments— Until this report, however, only 9 cases of sublingual thyroid carcinoma have been reported in the dog. This study reveals that ectopic sublingual thyroid carcinoma is not uncommon in dogs and is diagnosed at a rate of 5% of all thyroid carcinomas in our practices. Thyroid scintigraphy, however, plays a key role in confirming the location of this tumor and is determining if the carcinomatous tissue is functional.
Partial surgical excision of the hyoid apparatus is usually indicated for gross resection of sublingual thyroid carcinoma and is well tolerated in the dog. Adjunctive high dose radioiodine or chemotherapy therapy may also be useful with incomplete surgical excision and/or with metastatic or multicentric disease |
Peterson ME. Diagnostic testing for feline thyroid disease: hyperthyroidism. Compendium 2013;35:E1-6.
Peterson ME. Diagnostic testing for feline thyroid disease: hypothyroidism. Compendium 2013;35:E1-6.
Bargellini P, Orlandi R, Paloni C, et al. Contrast-enhanced ultrasonographic characteristics of adrenal glands in dogs with pituitary-dependent hyperadrenocorticism. Veterinary radiology & ultrasound: 2013;54:283-292.
Broome MR, Peterson ME: Ectopic sublingual thyroid neoplasia in the dog: 25 cases (1995-2012). Journal of Veterinary Internal Medicine 2013; 27:685-686.
Broome MR, Peterson ME: Use of L-thyroxine supplementation after radioiodine therapy helps blunt the worsening of azotemia in hyperthyroid cats with pre-existing kidney disease. Journal of Veterinary Internal Medicine 2013; 27:686.
Peterson ME. Diagnostic testing for hyperthyroidism in cats: more than just T4. Journal of Feline Medicine and Surgery 2103; (in press).
Peterson ME: Hyperthyroidism, In: Greco D, Davidson A(eds), Blackwell’s Five-Minute Veterinary Consult Clinical Companion: Small Animal Endocrinology and Reproduction. Ames, Iowa, Wiley-Blackwell. 2013 (in press). |
The Animal Endocrine Clinic is the only clinic of its kind in the country that specializes in the diagnosis and treatment of cats and dogs with endocrine disorders. Dr. Peterson has set up two NY clinics (Manhattan and Bedford Hills) to service clients from New York City, Long Island, Westchester County, New Jersey and Connecticut.
This Clinic is separated into three divisions: the Endocrine Clinic, dedicated to diagnosing and treating dogs and cats with endocrine disorders; the Hypurrcat treatment center designed for treating hyperthyroid cats with radioactive iodine (I-131); and Nuclear Imaging for Animals, a state-of-the-art medical imaging facility where we use radioactive tracers to perform nuclear scanning (scintigraphy) for diagnosing of thyroid, bone, liver, and kidney diseases in dogs and cats.
The Animal Endocrine Clinic is a referral-only hospital, and does not offer prophylactic or routine care. We can be reached by phone at (212) 362-2650 or (914) 864-1631; by email at info@animalendocrine.com or on the web at www.animalendocrine.com. |
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