Congenital hypothyroidism in a cat

Crowe A.

Can Vet J 2004;45:168, 170.

A n 18-month-old, 2 kg, intact female domestic short- hair was presented for a 2-day history of decreased appetite and lethargy. The owner had also noted that there was a decrease in the amount of urine and stool being passed. Further conversation revealed a history of chronic intermittent constipation since the age of 8 wk. On examination (day 0), the cat was found to be very small in stature with a round body shape, short legs and neck, and a large, broad head (Figure 1). Deciduous teeth were still evident in the dentition and the coat was soft and fluffy. Abdominal palpation revealed an empty colon and a very small bladder. Rectal body temperature was 37.7°C and the pulse 180 beats/min. She was estimated to be 3% to 5% dehydrated on skin tent.Blood was taken for a complete blood cell (CBC) count; biochemical profile, including electrolytes; and a total T4 and free T4 by equilibrium dialysis. An elevated blood urea nitrogen (BUN) and creatinine greater than 3 times the normal value, with a urine concentration of 1.010, supported a diagnosis of acute renal failure. Subsequent failure to produce urine following IV administration of 0.9% NaCl fluids suggested oliguric renal failure. Dopamine HCl (Inotropin; Dupont Pharma, Mississauga, Ontario) was added to the IV fluids at a rate of 2 g/kg bodyweight (BW)/min, along with furosemide (Lasix 5% solution; Hoechst Roussel Vet, Regina, Saskatchewan), 4.2 mg, IV; cephalexin (Kefzol; Eli Lilly, Toronto, Ontario), 60 mg, IV, q8h; famotidine (Apotex, Toronto, Ontario), 2.5 mg, PO, q12h; and baytril (Enrofloxacin; Bayer, Toronto, Ontario), 10 mg, PO, q24h