Peer-reviewed veterinary case report
Cat mammary gland swelling after one shot of contraceptive injection
By Loretti, Alexandre Paulino et al.·Published in Journal of feline medicine and surgery·2005·Department of Veterinary Clinical Pathology, Brazil·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: Clinical, pathological and immunohistochemical study of feline mammary fibroepithelial hyperplasia following a single injection of depot medroxyprogesterone acetate.
- Species:
- cat
Plain-English summary
Eight young female cats developed swollen mammary glands after receiving a single injection of a contraceptive hormone called depot medroxyprogesterone acetate (MPA). Despite the injection being given at the recommended dose, the cats showed high levels of progesterone weeks later, indicating the hormone was still affecting them. Tests revealed that the hormone may have caused changes in the mammary tissue, leading to the swelling. It's important for pet owners to be aware that overdosing on this medication can lead to such issues. Treatment options may include monitoring and possibly adjusting hormone therapies.
People also search for: cat swollen mammary glands · depot medroxyprogesterone acetate side effects · feline mammary hyperplasia treatment
Abstract
Feline mammary fibroepithelial hyperplasia (FMFH) following a single injection of depot medroxyprogesterone acetate (MPA) was observed in eight intact young queens. The repository compound is marketed as a veterinary product by a local pharmaceutical company with an indication for contraception in cats. The drug was administered according to the recommended doses and injection frequencies. Serum hormone assays performed immediately before neutering and 3 weeks after neutering detected persistently high levels of progesterone suggesting that depot MPA was still exerting its influence. No corpora lutea were found in those cases ruling out ovaries as the main site of progesterone. Immunohistochemistry performed on the hyperplastic mammary glands detected progesterone receptors in the nuclei of ductal cells, and growth hormone (GH) and insulin-like growth factor-I (IGF-I) in the cytoplasm of ductal epithelium. Overdosing should be considered here as the animals received at least 10 mg/kg of depot MPA in a single injection. Progestin-induced local synthesis of GH and IGF-I in mammary epithelial cells is suggested as one of the pathogenic mechanisms involved in the development of FMFH.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/15686973/