Disorder - Primary hypothyroidism

Organ Systems Involved
Endocrine

Alternative disorders described within LIDA

Hypothyroidism

Alternative Names
Congenital hypothyroidism

Presenting Signs

Primary hypothyroidism is caused when the thyroid gland dysfunctions. This causes low levels of the hormone thyroxine (T4) circulating in the body. Thyroxine is essential for postnatal development of the nervous and skeletal system and regulation of the metabolic rate. Characteristic signs in kittens are normal to increased birth weight, with disproportionate dwarfism evident by six to eight weeks of age. Also the teeth may be delayed in erupting, they may walk abnormally, and there may be mental dullness, lethargy, a distended abdomen, weak nursing and a poor coat. Cats with primary hypothyroidism are also sterile.

Cats at Risk

Primary hypothyroidism is the least common endocrine disorder in cats and no pre-disposing risk factors have been associated with the disease.

Breeds Affected
Abyssinian


Treatment

Medical: hormone replacement therapy with levothyroxine will usually have a good clinical response. Four to six weeks later it is important to assess the cat’s clinical response to treatment. A serum T4 level is measured prior to and 4-6 hours after dosing. Based on the T4 level and clinical response an increase or decrease in dose and/or frequency may be necessary. Reassessment would be required in another 4-6 weeks it treatment is adjusted.

PubMed References
Primary hypothyroidism

Contributor
Alison Bumak