Peer-reviewed veterinary case report
Generalised lymphadenomegaly associated with methimazole treatment in a hyperthyroid cat.
- Journal:
- The Journal of small animal practice
- Year:
- 2007
- Authors:
- Niessen, S J M et al.
- Affiliation:
- Queen Mother Hospital · United Kingdom
- Species:
- cat
Plain-English summary
A nine-year-old domestic shorthair cat was diagnosed with hyperthyroidism, a condition where the thyroid gland is overactive, and started on a medication called methimazole. Within two weeks, the cat became very tired, started eating less than usual, and developed swollen lymph nodes all over its body. Tests suggested that the swelling was due to an unusual reaction in the lymphatic system. When the methimazole treatment was stopped, the cat's symptoms improved quickly, and it was later treated with radioactive iodine, which successfully cured the hyperthyroidism. The cat has not had any return of the swelling and is currently healthy.
Abstract
A nine-year-old, domestic shorthair cat was diagnosed with hyperthyroidism and treated with methimazole, which resulted in lethargy, inappetence and marked generalised lymphadenomegaly within two weeks of initiation of therapy. Cytology, histopathology and immunohistochemistry were suggestive of atypical lymphoid hyperplasia. Cessation of treatment resulted in resolution of all clinical signs and physical abnormalities within two days. Subsequent treatment with radioactive iodine cured this cat of its hyperthyroidism. The lymphadenomegaly did not return at any stage and the cat is currently asymptomatic. Although methimazole administration for feline hyperthyroidism has been associated with many side effects, lymphadenomegaly has, to the authors' knowledge, not been previously reported.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/17355609/