Cluster of cases of congenital feline goitrous hypothyroidism in a single hospital

Abstract

To describe the clinicopathological findings and outcomes of cases of feline congenital hypothyroidism diagnosed in a single veterinary hospital in Santiago, Chile. Materials and MethOds: Medical records were searched for cases of congenital hypothyroidism over an 18-month period. Inclusion criteria were a diagnosis of congenital hypothyroidism based on consistent historical and clinical findings, a low or low-normal serum total T4 and elevated serum canine TSH (cTSH). results: Six unrelated cats ranging in age from 4 to 19 months met the inclusion criteria. The most common historical signs were small stature and lethargy. All cats had disproportionate dwarfism, delayed tooth eruption, retained deciduous teeth, bilateral palpable goitres and low rectal temperatures. Other findings were bradycardia, obesity, poor hair coat and focal alopecia on the ventral aspects of the elbows and hocks. In all cases, cTSH was markedly elevated. Sequential changes noted after the initiation of therapy included normal T4 after 6 weeks, improved hair coat and increased physical activity by 8 weeks, normal cTSH by 10 weeks and normal physical appearance and dentition after 4 months. Goitres shrank markedly but remained palpable. Hypothyroidism was well managed clinically in all cases 2 years after diagnosis except for one cat that died of unrelated causes. clinical significance: This is the first report to describe a cluster of congenital hypothyroidism cases in non-related cats that were presented over a short period of time. Growth defects resolve with treatment, even in cats diagnosed after puberty. Larger, prospective multi-centre studies are warranted to determine the incidence of congenital hypothyroidism in cats.

Evaluation of Weight Gain, Clinicopathological and Radiographic Changes after Early Diagnosis and Treatment of Congenital Hypothyroidism in Cats

“…Congenital hypothyroidism (CH) is a relatively uncommon disease in cats, with about 70 cases reported in the literature [ 1 , 2 , 3 ]. It has been suggested that CH is an under-recognized disorder as a significative proportion of cases are not diagnosed or die at birth or when juvenile, without the cause of death being established [ 1 , 4 , 5 , 6 ].…”

“…These signs include an enlarged broad head, a short neck and short limbs [ 1 ]. Additional findings are lethargy, mental dullness, constipation, hypothermia, bradycardia, prolonged retention of deciduous teeth, cold intolerance and retention of kitten hair, with the result that the coat remains soft and fluffy [ 1 , 3 , 4 , 5 , 6 , 7 ]. Clinicopathological abnormalities are non-specific and can include mild anemia, hypercholesterolemia, and azotemia [ 1 ].…”

“…The main reasons for this postulate are two: (1) high concentrations have been reported in all of the congenitally hypothyroid cats previously described, and (2) falsely high values for TSH are not generally seen in cats with non-thyroidal illness [ 1 ]. Although the pathophysiological mechanisms, clinical aspects, diagnostic methods, and initial treatment for CH cats have been investigated in several reports [ 3 , 4 , 6 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ], a complete long-term follow-up has rarely been described [ 3 , 6 , 10 , 16 , 25 ].This case series describes the body weight, clinicopathological and radiographic changes after early diagnosis, and the one-year treatment follow-up of three kittens with CH.…”

Case Report: Human Recombinant Growth Hormone Therapy in a DSH Cat Presented With Dwarfism

“…Congenital hypothyroidism was very unlikely since the dwarfism was not disproportionate, and the kitten was not mentally dull ( 10 ). The level of the thyroid hormone was in the low reference range at the beginning and normal while on therapy.…”

“…Hypothyroidism is caused by a developmental failure of the thyroid gland or by impaired thyroid hormone production. Clinical signs include disproportionate dwarfism (short body and limbs, big head), delayed tooth eruption, mental dullness, and lethargy ( 9 , 10 ). Hypoadrenocorticism was described in one dwarf kitten with clinical signs of neurological disorders, with behavioral changes characterized by excessive fear, recurrent episodes of tremors, weakness, severe hypothermia, dull and scruffy fluffy hair coat, dysorexia, and pica ( 11 ).…”