Case History and clinical Examination

JBVC

The Journal of Bombay Veterinary College

0971-1643

An Official Organ of Bombay Veterinary College Alumni Association

jbvc-14-1and2-048

Clinical Article

Hypothyroidism in sloth bear (Melursus ursinus) – A case report

Salvekar

S. P.

Chauhan

A. R.

Sarkate

L. B.

Khandekar

G. S.

Department of Surgery & Radiology, Bombay Veterinary College, Parel, Mumbai - 400 012 (M.S) India.

6–122006

141–2148148

Case History and clinical Examination

A captive male sloth bear (Melursus ursinus), age 8 years, was presented at Katraj Snake Park, Pune with the complaint of intermittent anorexia and hair loss for over a period of two months. On the examination the skin seemed to be dry and flaky with rough, lusterless hair coat. Bilateral non inflammatory alopecia was observed on neck, chest, ventral thorax and inner aspects of arms. The bear appeared dull, sluggish, lethargic and less energetic in the movements than the other bears in the enclosure. The bear was obese as a result of reduced activity. The clinical examination revealed temperature 100oF, respiratory rate 35 breaths/min, and slight tachycardia although the values were in the normal physiological limits.

Skin scrapping was collected from three different alopecic sites which showed no evidence of mange mites and fungi. Stool examination was carried out using sedimentation technique. No abnormality was detected in routine stool examination.

Blood was examined for complete blood count and serum chemistry for liver and kidney function, fasting serum cholesterol and thyroid hormone estimation. The hemogram values revealed Haemoglobin 15.5 gm%, R.BC. Count-6.27 mil/Cu.mm, PCV – 32.6%, TLC-11800/cmm, Differential Leukocyte count: Neutrophills – 68%, Eosinophil – 1%, Lymphocyte – 38% and monocyte – 1%. Thrombocyte count – 5.16 lakhs/cu.mm. All the values were within the normal physiological limits.

SGPT – 25 IU/L, BUN – 14 mg%, serm creatinine – 0.8 mg%. Whereas marked hypercholesteraemia (Serum cholesterol – 257mg/dl) and low levels of T₃ (36.53 ng/dl) & T₄ (0.94 mcg/dl) were observed confirming the diagnosis.

The age, origin of the bear, Clinical findings and the hematology as well as serum chemistry were indicative of this entity, so it was decided to start with the thyroid replacement therapy and observe subsequent changes. The deficiency of thyroid was thought to be due to idiopathic atrophy of thyroid gland owing to the above circumstances (Ettinger & Feldman, 1995)

Treatment

Replacement therapy with sodium levothyroxine (synthetic T₄) was administered orally at the rate of 20mcg/kg twice a day (Tablet Eltroxin 100mcg). The bear appeared considerably active with the second week after the initiation of treatment. The dermatological condition Alopecia and hair loss was resolved in sixth week of the initiation of treatment. The coat appeared lustrous and shiny later in 9^th week. Similar dermatological findings, weakness and hypophagia were also stated by Sastry (1983) in hypothyroidism. The food was designed to obtain as far as possible with low cholesterol diet. Three months later routine hemograme and serum chemistry was performed again where significant increase in T₃ (59.23 ng/dl) & T₄ (1.3 mcg/dl) levels were observed. Where as, the other hematological parameters were in normal physiological limits. After this the Eltroxin dose was altered to 16 mcg/kg once a day and was fortified with another vitamin preparation containing vitamin A (440 IU) and Vitamin E. The bear has been kept on the replacement therapy for the life time.

Thyroid hormone acts on virtually all the organ systems of body. Hence the effects of decreased levels of thyroid hormone are varied. Hypothyroidism usually occurs due to decreased production of thyroxine (T₄) and triiodothyronine. Most of the hypothyroidism cases are attributed to idiopathic atrophy of thyroid gland or lymphocytic thyroiditis. Some times bilateral thyroid neoplasia or invasion of metastatic neoplasms may also contribute to hypothyroidism. The signs of hypothyroidism are varied and non-specific in the initial stages and hence it is mostly misdiagnosed. It is usually diagnosed at 5–7 years of age. The incidence of this condition as recorded by Chastain and Panaciera (1995) is about 1:156 to 1:500. In Asia it is more prevalent in regions of Himalayas (Dukes, 1955).

ReferencesChastain

C. B

Panaciera

D. L

, (1995) Hypothyroid Diseases: In “Textbook of Veterinary Internal Medicine” Pp: 1487.Dukes

H. H

, (1955) Endocrine organs: In “The Physiology of Domestic Animals”. 7th Edn. Pp 850–856.Ettinger

S. J

Feldman

E.C.

, (1995) Hypothyroidism In Textbook of Veterinary Internal Medicine, pp 1535.Sastry

G. A.

, (1983) The endocrine glands. In: Veterinary Pathology, 6th Edn. Pp 490.