Case Reports

Was this patient's transdermal Tx making her dog sick?

Author and Disclosure Information

► Hot flushes, night sweats
► Concern about estradiol effects on pet
► Nipple, vulvar enlargement in pet


 

References

THE CASE

A 56-year-old postmenopausal woman with a history of anxiety, depression, alcohol abuse, fatigue, insomnia, and mental fogginess presented to the family medicine clinic with concerns about her companion animal because of symptoms possibly associated with the patient’s medication. Of note, the patient’s physical exam was unremarkable.

The patient noticed that her 5-year-old, 4.5-lb spayed female Chihuahua dog was exhibiting peculiar behaviors, including excessive licking of the abdomen, nipples, and vulvar areas and straining with urination. The dog’s symptoms had started 1 week after the patient began using estradiol transdermal spray (Evamist) for her menopause symptoms. The patient’s menopause symptoms included hot flushes, insomnia, and mental fogginess.

The patient had been applying the estradiol transdermal spray on her inner forearm twice daily, in the morning and at bedtime. She would let the applied medication dry for approximately 2 hours before allowing her arm to come in contact with other items. She worried that some of the hormone may have wiped off onto her couch, pillows, blankets, and other surfaces. In addition, she often cradled the dog in her arms, which allowed the canine’s back to come in contact with her inner forearms. To her knowledge, the dog did not lick or ingest the medication.

The patient had taken the dog to her veterinarian. On physical exam, the veterinarian noted that the dog had nipple and vulvar enlargement but no vaginal discharge, vaginal bleeding, skin changes, or urine abnormalities.

THE (PET’S) DIAGNOSIS, THE PATIENT’S Rx

The veterinarian diagnosed the Chihuahua with vaginal hyperplasia and vulvar enlargement secondary to hyperestrogenism. The animal’s symptoms were likely caused by exposure to the owner’s hormone replacement therapy (HRT) medication—the estradiol spray. The veterinarian advised the woman to return to her family physician to discuss her use of the topical estrogen.

The patient asked her physician (SS) to change her HRT formulation. She was given a prescription for an estradiol 0.05 mg/24-hour transdermal patch to be placed on her abdomen twice weekly. After 2 weeks of using the patch therapy, the patient’s menopausal symptoms were reported to be well controlled. In addition, the companion animal’s breast and vulvar changes resolved, as did the dog’s licking behavior.

DISCUSSION

Estrogen therapy, with or without progesterone, is the most effective treatment for postmenopausal vasomotor symptoms.1 Given the concerns raised in the Women’s Health Initiative (WHI) and other clinical trials regarding hormone therapy and cardiovascular and breast cancer findings, many clinicians look to alternative, nonoral dosage forms to improve the safety profile.

Continue to: Safety of nonroal estrogen therapy

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