Abstract
This report describes an unusual manifestation of congenital hypothyroidism in a kitten presented for an ileocolic intussusception and chronic constipation. A ten-week-old, undersized, entire male mixed-breed kitten presented for abdominal pain and distension. Radiography and abdominal ultrasound confirmed a small intestinal intussusception. Following successful surgical reduction of the intussusception, the kitten continued to suffer from chronic constipation that was nonresponsive to medical management. Serum free-thyroxine concentration was consistent with hypothyroidism. Administration of levothyroxine sodium resulted in rapid resolution of the constipation. The kitten's mentation and activity levels improved and it grew and gained weight, reaching a normal physiologic weight by 12 months of age. Feline congenital hypothyroidism was the most likely cause of the ileocolic intussusception in this kitten. Underlying endocrine dysfunction should be considered when presented with an undersized kitten with cretinoid features, disproportionate dwarfism, mental dullness and chronic constipation.