Treatment of Feline Mammary Fibroepithelial Hyperplasia Following a Single Injection of Proligestone

Vitásek R. , H. Dendisová: Treatment of Feline Mammary Fibroepithelial Hyperplasia Following a Single Injection of Proligestone. Acta Vet. Brno 2006, 75: 295-297. A case of fibroepithelial hyperplasia of the mammary gland in the cat is reported. A seven-monthold female cat was presented for diffuse enlargement of all of the mammary glands. The cat was treated with proligestone (Covinan®) for the suppression of estrus. Four weeks later all 8 mammary glands were asymmetrically enlarged. There was ulceration of one gland. Sonographic imaging of the affected mammary glands showed homogeneous and granular structures. The patient was treated with subcutaneous injections of 10 mg/kg aglépristone (Alizine®) on days 1, 2, 7, 14 and 21. Within six weeks the mammary glands had completely regressed. No side effects were observed. It is the first case of fully documented feline mammary fibroepithelial hyperplasia and its treatment in the Czech Republic. Queen, progestin, antiprogestin, progesteron Feline mammary fibroepithelial hyperplasia is a growth disturbance of cats characterised by rapid, non-neoplastic proliferation of ductal epithelium and stroma of the mammary gland resulting in enlargement of one, several or all of the mammary glands (Allen 1973). Other terms for the same condition can by found in literature, including feline mammary hypertrophy, feline mammary fibroadenomatosis and fibroadenoma (Nimmo and Plummer 1981). The condition occurs spontaneously in young, sexually intact queens at the time of puberty, during the first oestral cycle, pregnancy or pseudopregnancy and may regress spontaneously or require ovariectomy. Feline mammary fibroepithelial hyperplasia can be induced by administration of progesterone-containing compounds including synthetic progestins such as megestrol acetate and medroxyprogesterone acetate (Hayden et al. 1989; Gorl inger et al. 2002; MacDougal l 2003; Loret t i et al. 2004). In most cases, fibroepithelial hyperplasia can by diagnosed based on typical clinical findings such as diffuse, firm swelling of one or more glands without signs of inflammation (Wehrend et al. 2001). The purpose of the present study is to report the symptoms, history, clinical and ultrasound findings and treatment of a cat that developed mammary fibroepithelial hyperplasia after a single injection of proligestone. Materials and Methods History, examinat ion and therapy A seven-month-old female cat (Maine Coon) was presented with diffuse enlargement of all of the mammary glands. Two months earlier 0.75 ml pro toto proligestone (Covinan®, Intervet) had been used for prevention of oestrus. The owner found out enlargement of all mammary glands four weeks after injection of proligestone. At inspection and palpation, the cat had oedematous and distinct asymmetrical enlargement of all 8 mammary glands, with diameters ranging from 10 to 12 cm (Plate XIII, Fig. 1). There was ulceration of one gland. At clinical examination, body temperature, respiration and heart rates were normal. The cat was lethargic and anorectic. Sonographic imaging of the affected mammary glands showed characteristic homogeneous and granular structures (Plate XIII, Fig. 2). ACTA VET. BRNO 2006, 75: 295–297 Address for correspondence: MVDr. Roman Vitásek, Ph.D. Small Animal Clinic, Unviersity of Veterinary and Pharmaceutical Sciences Palackého 1-3, 612 42 Brno, Czech Republic Phone: + 420 541 562 324 E-mail: [email protected] http://www.vfu.cz/acta-vet/actavet.htm Differential diagnoses included mammary adenocarcinoma or carcinoma, mammary adenoma, or mammary sarcoma or mastitis. Due to the recent history of progestin administration and the involvement of more than 1 gland, mammary hyperplasia was the most likely diagnosis. Patient was treated with subcutaneous injections of 10 mg/kg aglépristone (Alizine®, Virbac) on days 1, 2, 7, 14 and 21. The length, width and height of glands were measured. We calculated the content of the mammary gland (V = l × w × h).