From Ferret
Vulva swelling associated with hyperestrogenism in a ferret[1]

Hyperestrogenism is a relatively common hormonal disease of jills.

Normally the adrenal glands of intact or neutered ferrets produce cortisol but only minimal amounts of androgenic steroids such as testosterone or estrogen[2].

Jills have a specialized reproduction physiology which can develop, if unmated, into a persistent oestrus with fatal consequences of hyperestrogenism[3].

The endocrinology of this disorder relates to the elevated levels of estrogen in estrus jills, which causes bone marrow suppression, resulting in anemia and reticulocytopenia. Hemorrhages are a common cause of death. A similar hypersecretion of sex hormones is seen in association with hyperadrenocorticism[4].

Clinically affected jills display clinical signs of inappetence, lethargy, melena, a prominent and swollen vulva and anemia.

Diagnosis is based on blood test confirmation of anemia and hyperestrogenemia.

Treatment depends on the severity of anemia. In mild cases, ovariohysterectomy is curative.

In severely anemic jills, ovulation can be induced with human chorionic gonadotropin (100 IU or 1,000 USP units IM). A repeat injection may be required in 7 - 14 days. A blood transfusion may also be required.

The use of antiestrogen drugs appears to be ineffective in this species in limiting the bone marrow suppression[5].


  1. Tufts Uni
  2. Donovan BT et al (1983) Effect of exposure to long days on the secretion of oestradiol, oestrone, progesterone, testosterone, androstenedione, cortisol and follicle-stimulating hormone in intact and spayed ferrets. J Endocrinol 99:361–368
  3. Wenker C & Christen C (2002) Ferrets in veterinary practice. Schweiz Arch Tierheilkd 144(11):575-584
  4. Rosenthal KL & Peterson ME (1996) Evaluation of plasma androgen and estrogen concentrations in ferrets with hyperadrenocorticism. J Am Vet Med Assoc 209(6):1097-1102
  5. Hart JE (1990) Endocrine pathology of estrogens: species differences. Pharmacol Ther 47(2):203-218