Oral Allergy Vaccine for Treatment of Seasonal Pruritis in a Spectacled Bear (Tremarctos ornatus)
Skin disease affects a large portion of the captive USA spectacled bear population, with female bears often showing pruritis and progressive alopecia. A 21-year-old female spectacled bear (Tremarctos ornatus) at the Houston Zoo had seven episodes of seasonal pruritis over a 10-year period (1997–2006). The episodes occurred between May and October of each year and were characterized by constant scratching and by hair loss on the face, particularly around the eyes, and on the paws and flanks. Treatment with antihistamines, steroids, antibiotic, and antifungal medications occasionally resulted in subjective temporary relief but never resolved the condition. In February 2007 intra-dermal skin testing for 55 local allergens was performed and revealed reactions to multiple pollens, trees, and insects. A custom allergy vaccine was developed based on skin test results. The vaccine was mixed with honey and administered orally slowly via spoon to enhance absorption across oral mucous membranes. The vaccine was given initially twice weekly, frequency was then decreased to once weekly, and currently the bear is treated every other week. An objective scoring system to evaluate scratching was developed and indicated a notable decrease in scratching the first summer and continued marked improvement for the following two summers. The opportunity to administer the allergy vaccine orally, rather than parenterally, greatly enhanced our ability to treat this animal. Consultation with a veterinary dermatologist and intra-dermal skin testing for local allergens is recommended for bears with recurring pruritis and alopecia.