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News In January, Jade Guterl joined the staff of the Animal Endocrine Clinic as our Clinical Research Coordinator. We created this new position and h
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In January, Jade Guterl joined the staff of the Animal Endocrine Clinic as our Clinical Research Coordinator. We created this new position and hired Jade in order to have her assist Dr. Peterson in entering, collating, and organizing the research data that we are accumulating from our three current research studies, all of which are going very well. We chose Jade for this position based on her experience in conducting hormonal research as an undergraduate student at Rutgers University.
We have already enrolled 70 hyperthyroid cats into our study entitled, "Monitoring the Effects of Radioiodine Treatment with a Complete Thyroid Panel," and have entered a few cats into our other research studies. Jade will be the main contact person to help address owner and veterinary questions concerning all of these clinical research studies. To find out more about Jade and the clinical research studies we are doing at the Animal Endocrine Clinic, go to the research page on our website by clicking here. |
The November/December 2012 issue of the NYSVMS Veterinary News featured an interview with Dr. Peterson about the updated fourth edition of his Endocrine Textbook and his career as one of the first veterinarians to specialize in endocrinology. Click here to read the article.
We were a little premature in revealing a link to the new book "The Magical Link: Love, Mystery, and Other Secrets About the Bond Between People and Animals" by Barbara Meyers, but now the website features a link to purchase the book online. In case you missed last month's newsletter, Dr. Mark Peterson and the Animal Endocrine Clinic were featured in the book. Purchase it on The Magical Link website or Facebook page. |
Midwest Veterinary Conference
Columbus, Ohio, February 21 - 24, 2013
Topics:
• Testing for Canine and Feline Hypothyroidism: Pitfalls in the Diagnosis
• Feline Hyperthyroid Update: Some Things Old But Everything New
• Insulin Choices for the Diabetic: Which Preparations Work Best?
• Management of the Problem Diabetic: Acromegaly, Cushing’s & Other Causes of Insulin Resistance
• Diagnostic Testing for Canine Hyperadrenocorticism —Confusion or Clarity?
• What's the Best Treatment for Cushing's Disease? Trilostane vs. Mitotane
Association of Veterinary Doctors of Quebec
Montreal, Quebec, Canada, April 19 - 21, 2013
Topics:
• Feline Hyperthyroid Update: Some Things Old But Everything New
• Insulin Choices for the Diabetic: Which Preparations Work Best?
• Management of the Problem Diabetic: Acromegaly, Cushing’s and Other Causes of Insulin Resistance
• Diagnostic Testing for Canine Hyperadrenocorticism —Confusion or Clarity?
• What's the Best Treatment for Cushing's Disease? Trilostane vs. Mitotane
• Typical, Atypical, and Secondary Addison's Disease: How Do We Diagnose and Treat These Three Subtypes?
CE and the City
New York, New York, May 4, 2013
Topics:
• What's New with Thyroid Disease in Cats? |
Patient History and Examination
Sally, a 6-year-old, female-spayed dog of mixed breeding weighing 9.6 kg was examined because of polyuria, polydipsia, polyphagia, and alopecia of 1-year’s duration.
The dog had been diagnosed with hyperadrenocorticism 6 months ago, based on Sally’s clinical features, high serum alkaline phosphatase (262 IU/L), and a “positive” ACTH stimulation test. The results of the ACTH stimulation test showed a high basal cortisol concentration (8 μg/dl; reference range, 1-4 μg/dl) with a greatly exaggerated post-ACTH cortisol response (58.4 μg/dl; reference range <20 μg/dl).
Trilostane (Vetoryl) treatment was started at the dosage of 30 mg once daily in the morning with food (3.1 mg/kg body weight). Recheck at one month after treatment revealed no clinical improvement. Results of a repeat ACTH stimulation test, performed 4 hours after administration of Vetoryl) revealed a basal cortisol of 1.9 μg/dl with a post-ACTH value of 5.1 μg/dl. Both of these values were considered “ideal” for a controlled dog on Vetoryl therapy, so the drug was continued at the same dosage (30 mg once daily). After 2 additional months of therapy (3 total months of Vetoryl treatment), no clinical improvement was noted and the dog was referred for reevaluation of worsening polyuria, polydipsia, polyphagia, and alopecia. |
 Figure 1 |
Referral and Reevaluation
Results of our physical examination revealed that Sally was bright, alert, and hydrated. She had a distended abdomen with palpable hepatomegaly. Marked bilateral symmetric truncal alopecia, as well as hair loss on ears and tail (Figure 1), was also present.
Results of a repeat ACTH stimulation test, performed 24 hours after the last dose of Vetoryl, revealed a basal cortisol concentration of 7.9 μg/dl and a post-ACTH value of 24.6 μg/dl (ideal post-ACTH cortisol values < 7.0 μg/dl). An abdominal ultrasound was also performed, which showed bilateral adrenal gland enlargement, consistent with pituitary-dependent Cushing's disease (PDH).
Because of the persistent clinical signs of hyperadrenocorticism, as well as high post-ACTH cortisol concentration at 24 hours after Vetoryl administration, the total dose of Vetoryl was divided into two doses of 15 mg administered every 12 hours with food. Because Vetoryl capsules are not offered in a 15-mg capsule size, a trained pharmacist reformulated the licensed Vetoryl product into this novel capsule size.
Twice Daily Vetoryl Treatment, Dose Adjustments, and Monitoring
On recheck at 1 month after twice daily Vetoryl (15 mg, BID), history revealed that Sally’s polyuria and polydipsia was much improved; however, she remained quite polyphagic and no hair regrowth had been noted. Results of an ACTH stimulation test done 4-hours after the morning feeding and dosing showed a high basal cortisol value (7.9 μg/dl) with a post-ACTH cortisol value (14.6 μg/dl) that was higher-than-desired for Vetoryl treatment (we want the post-ACTH cortisol to be < 7.0 μg/dl). Based on the incomplete clinical response and the high cortisol values, the Vetoryl was increased to 20 mg twice daily (total dose, 40 mg/day or 4.1 mg/kg/day) with a follow-up scheduled for 4-8 weeks later. |
 Figure 2 |
At a 3-month recheck on twice daily Vetoryl, history revealed that the dog much improved, with resolution of increased thirst and urination, a normal appetite, and early hair regrowth (Figure 2).
An ACTH stimulation test showed a basal cortisol value of 4.1 μg/dl, with a post-ACTH cortisol concentration of 6.3 μg/dl. This was considered good control of the hyperadrenocorticism, so the Vetoryl was continued at the twice-daily dosage of 20 mg, given with food. |
At 7 months, the dog continued to be clinically normal with complete hair regrowth. However, a change in coat color was evident (Figure 3). On further questioning, the owners stated that this was the dog’s “puppy-coat” color.” An ACTH stimulation test confirmed good control of the hyperadrenocorticism, so the Vetoryl was continued at the twice-daily dosage of 20 mg with food. |
 Figure 3 | |  Figure 4 |
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Follow-up over the next 20 months revealed that Sally continued to do well on twice-daily Vetoryl (20 mg, BID), with maintenance of a good hair coat and normal thirst and urination. Within a few months, her hair coat color changed back to her normal adult color (Figure 4).
Discussion
Vetoryl was very effective in controlling the signs of hyperadrenocorticism in this dog. This case illustrated that dosage adjustments are commonly required during long-term Vetoryl treatment.
In about 20% of dogs, once daily treatment will not be adequate in controlling the clinical signs and twice-daily administration will be needed. Performing an ACTH stimulation test 24 hours after once daily administration can be useful in documenting this short duration of trilostane action when a dog is not responding to SID treatment.
Alternatively, in dogs that fail to respond clinically to once daily dose administration, the daily dose can simply be divided and given twice daily with food. The dog should then be reevaluated in 4 weeks to check clinical improvement. |
Diagnosing Cats with Borderline or Occult Hyperthyroidism
My patient is a 12-year-old, female, DSH that presented for hematuria. Routine blood work was normal but her serum T4 value was slightly high at 4.6 μg/dl (reference range, 1-4 μg/dl).
Should Hill's y/d Diet Ever Be Used to Manage Cats with Hyperthyroidism?
I consider the feeding of Hill's y/d diet to be a fourth-line of treatment for hyperthyroidism.
Steroid-Induced Diabetes In Cats
Timmy is a 9-year-old, DSH, male cat who is very obese. He has a 9/9 body condition score and weighs 9.5 kg (20.9 pounds).
Is Fine-Needle Aspiration Helpful in Diagnosing Thyroid Carcinomas in Cats?
I have a 15-year old, DSH, male hyperthyroid cat that can no longer be controlled adequately with methimazole, despite an increase in the dose to 10 mg twice daily.
Treating Dogs with Hyperthyroidism and Thyroid Carcinoma
I have a 12 year-old, spayed, female, Chocolate Lab named "Coco" who was diagnosed with hyperthyroidism. Coco has lost 2.5 pounds of weight over the last 6 months but otherwise she was asymptomatic.
Interpreting the ACTH Stimulation Test in Dogs with Suspected Addison's Disease
I am hoping you may be able to offer me some insight/information about testing for hypoadrenocorticism (Addison's disease) in dogs.
Favorable review of Dr. Peterson's BSAVA Manual of Canine and Feline Endocrinology
Dr. Peterson's BSAVA Manual of Canine and Feline Endocrinology was favorably reviewed in the December 15 issue of the Journal of the American Veterinary Medical Association. |
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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