Feline mammary hyperplasia is a benign, progesterone-associated fibroglandular proliferation of one or more mammary glands that may occur in both the female and male cat. This condition is usually seen in young sexually intact females following estrus, and in male and female cats receiving long-term treatment with progestogens.
Etiologia da hipertrofia mamária em felinos
There are two types of feline mammary hyperplasia described: lobular hyperplasia and fibroepithelial hyperplasia.
Epidemiologia da hipertrofia mamária em felinos
There is no breed disposition. Feline mammary hyperplasia can occur in young, cycling, or pregnant cats; aged, sexually intact females and males; and neutered males after treatment with progestins.
Sinais clínicos de hipertrofia mamária em felinos
The clinical finding characteristic of mammary hypertrophy in cats is palpable masses in one or more mammary glands in a sexually intact cat 1–14 years old. The onset of swollen mammary glands is acute.
Mammary hyperplasia in a cat. Note the enlarged glands appear erythematous, and some of the skin is necrotic. Edema of the skin and both hind legs is common, and the condition can easily be confused with acute mastitis.
Courtesy of Dr. Autumn P. Davidson.
The size of the enlarged glands is quite variable, ranging from 1.5 to 18 cm. In chronic situations, ulceration of the mammary glands due to enlargement, skin necrosis, and trauma may be noted. No milk is produced in the diseased glands in pregnant animals.
Diagnóstico de hipertrofia mamária em felinos
Diagnosis of feline mammary hyperplasia is made based on signalment, clinical signs, and history. Histologically, no inflammation or necrosis is noted.
Although a benign condition in cats, biopsy is indicated. Given that 80% of mammary tumors in cats are malignant, any mammary mass in cats has to be addressed with concern.
Differential diagnoses include:
acute mastitis
mammary tumors (mammary adenocarcinoma, mammary carcinoma, mammary adenoma, mammary sarcoma)
Tratamento da hipertrofia mamária em felinos
Feline mammary hyperplasia may spontaneously regress if left untreated.
Treatment of feline mammary hyperplasia involves removal of the progesterone source. This can be through one of the following means:
Administration of antiprogestins
Ovariectomy or ovariohysterectomy for animals in diestrus
Mastectomy in animals not responding to other surgical or medical treatments
