Overview of Canine Estrogen Toxicity

Estrogen toxicity is a condition in which a group of estrogen compounds (female hormones), either produced in excess within the body or administered from the outside, become poisonous to the body. Estrogen toxicity is seen most commonly in reproductive-age females and aged male dogs.

Estrogen toxicity can occur due to estrogen-producing tumors or from the administration of estrogen type medications. These medications are often used to treat a multitude of disorders. Examples include diseases of the prostate, anal tumors, and urinary incontinence (inability to control urination).

What to Watch For

Signs of Estrogen toxicity in dogs may include: 

Lethargy

Pale gums (from anemia)

Bleeding associated with the skin, urine, stool, or vomit

Fever

Persistent or recurrent infections

Thin hair coat

Feminization (female sex characteristics) in males

Diagnosis of Estrogen Toxicity in Dogs

A variety of tests may be necessary to diagnose estrogen toxicity and determine the severity. Recommended tests in dogs may include:

Complete blood count (CBC) to reveal a decreased red cell and platelet count, and a normal or increased white blood cell count. Later in the disease, the white cells are decreased as well.

Bone marrow aspirate and cytology to confirm decreased cell content

Radiographs/ultrasound of the abdomen to reveal tumors capable of producing estrogen

Thorough examination of the testicles in intact (un-neutered) males.

Treatment of Estrogen Toxicity in Dogs

Remove source of estrogen

Provide supportive care

Give blood transfusion in the severely anemic animals

Administer antibiotics in the individuals with infections secondary to low white blood counts

Home Care and Prevention

Administer all prescribed medication by your veterinarian. Watch your dog closely for any change in his/her condition. Recovery may take anywhere from several weeks to several months.

Do not administer estrogen containing compounds to your dog unless instructed by your veterinarian and monitored very closely.