Congenital Thyroid Hypoplasia and Seizures in 2 Littermate Kittens

Hypothyroidism

“…Naturally acquired hypothyroidism is a rare clinical entity in the cat, and most clinical descriptions of feline hypothyroidism in the veterinary literature have been case reports of either primary congenital or adult onset hypothyroidism (Arnold et al, 1984;Sjollema et al, 1991;Jones et al, 1992, Rand et al, 1993Mellanby et al, 2005;Traas et al, 2008;Blois et al, 2010;Quante et al, 2010). In contrast, iatrogenic hypothyroidism following any of the three common treatments for hyperthyroidism is well recognized (Nykamp et al, 2005;Williams et al, 2010).…”

“…Reported causes of congenital hypothyroidism include thyroid dyshormonogenesis (Sjollema et al, 1991;Jones et al, 1992), thyroid dysmorphogenesis (Traas et al, 2008), and TSH resistance. Reported causes of congenital hypothyroidism include thyroid dyshormonogenesis (Sjollema et al, 1991;Jones et al, 1992), thyroid dysmorphogenesis (Traas et al, 2008), and TSH resistance.…”

“…Additional findings include lethargy, mental dullness, constipation, hypothermia, bradycardia, and prolonged retention of deciduous teeth (Arnold et al, 1984;Peterson, 1989;Sjollema et al, 1991;Jones et al, 1992;Traas et al, 2008;Fig. Affected kittens typically appear normal at birth, but a decrease in growth rate usually becomes evident by 6 to 8 weeks of age.…”

“…Affected kittens typically appear normal at birth, but a decrease in growth rate usually becomes evident by 6 to 8 weeks of age. Two littermate kittens with hypothyroidism had a concurrent seizure disorder but whether the seizures were related to hypothyroidism was unclear (Traas et al, 2008). Additional findings include lethargy, mental dullness, constipation, hypothermia, bradycardia, and prolonged retention of deciduous teeth (Arnold et al, 1984;Peterson, 1989;Sjollema et al, 1991;Jones et al, 1992;Traas et al, 2008;Fig.…”

Goiter with Vascular Anomalies in a Litter of Polish Lowland Sheepdogs

“…CGH has been reported with thyroid organification defects in toy fox terriers and rat terriers, Abyssinians, and domestic shorthairs as a result of a thyroid peroxidase deficiency. 1,2,5,6,13,14 Although the puppies in this report had serum thyroid concentrations below the reference ranges and one puppy also had a serum TSH concentration mildly above the reference range, those three puppies did not show the classic clinical features of CH (known as cretinism), such as dwarfism, dullness, and skeletal deformities.…”