by Jaime Rudd, WIL Scientific Aid
In July, Fish and Game responded to a call from a homeowner in San Luis Obispo who reported something was in the backyard. When game wardens arrived, they found a young black bear cub with a very unusual problem – she had no hair.
After determining that the cub appeared orphaned, Fish and Game officials captured the cub and transported her to the Wildlife Investigations Lab (WIL) where she was examined by veterinarians Ben Gonzales and Deana Clifford. The cub was about six months old, 20 pounds underweight, dehydrated and she had a severe skin infection. Diagnostic tests were run including a complete blood panel, skin scraping, fungal culture and intestinal parasite exam. Her blood results were typical of a malnourished, dehydrated young animal with a compromised immune system. Her culture grew a fungus and microscopic examination of the fungus identified the culprit as Trichophyton mentagrophytes – ringworm, a highly contagious and zoonotic (meaning, it can be transmitted from animals to humans) disease. Skin scraping results also revealed the bear cub was heavily infested with Ursicoptes sp., a mange mite known to infect bears.
Mange, also known as scabies, is a skin disease caused by a microscopic mite that parasitizes the top layer of skin. Depending on the species of mite, mange can be highly contagious between mammals, and sometimes from mammals to people. As far as we know, Ursicoptes sp. is not zoonotic. As the mites burrow into the skin, they cause an allergic reaction which leads to crusting of the skin and intense itching. Severe infections cause hair loss (alopecia), thickening and scabbing of the skin. Secondary fungal and bacterial infections commonly occur, which cause deep and superficial pyoderma (skin infection), leading to further degradation of the skin, the body’s first defense against disease.
Mange has been reported in numerous wildlife species and it can also afflict domestic animals and humans. Animals that are severely infested typically show signs of poor health. While spontaneous recovery can occur, this disease can be fatal as the infection progresses. In the past few years, wildlife biologists have observed a rise in mange cases affecting local wildlife populations. Bighorn sheep, bobcats, mountain lions, foxes, coyotes, squirrels, and bears are a few of our valuable species that are vulnerable to mange mites.
Our veterinarians had a big decision to make. If we treated this little bear, she would not be a good candidate for rehabilitation and eventual release. It can take animals with infections this severe many months to regrow all their hair. Intensive treatment and care would be required over a long period of time, during which time she could become habituated human caretakers. Also, both mange and ringworm are contagious to other bears, so she could not be housed with other cubs for company. However, if we decided not to treat her and release her back into the wild, her chances of survival were extremely poor – especially with the coming winter.
After careful consideration, WIL veterinarians decided the best course of action was to treat the cub until we could transfer her to an approved zoo. Because this little cub had been sick for so long, her natural defenses to ward off disease and infection were shut down.
So, how would WIL go about treating such a heavily parasitized little bear? There is limited literature about how to successfully treat wild black bears with infections this severe. We knew we had to treat her parasite, fungus and bacterial infections all at the same time.
She was given an antibiotic for her bacterial skin infections that was specially made to be peanut butter-flavored. She was also given an injection for the mites but her systemic treatment for the ringworm infection was postponed for a week due to potential side effects that could result because of her poor overall health. She was bathed using a specially medicated shampoo to clean and soothe her skin and dipped in lime-sulfur – a treatment that would help kill both the parasitic mites and the ringworm. Subcutaneous fluids were given to boost her hydration.
Each week, the cub would need to receive a bath and a dip as well as an anti-parasitic injection (which should be given for up to 6 weeks). Twice a day she would receive an antibiotic for her bacterial skin infections and once she was healthy enough, she would require twice daily antifungal medication. Not to mention round-the-clock care and feedings until she could maintain a healthy body weight … and the WIL staffers all signed up!
After 3 months of intensive care; this cub has tripled in size and is starting to develop a fine coat of new hair. Her blood chemistry has improved and for the past three weeks tests have detectged no mites. She has made giant leaps toward recovery and is doing well on systemic antifungal treatment. Her fungal culture has not had any growth for more than a week. She will continue to be treated until we are confident her infection has resolved and she has completed the medication regimen. It will be months, possibly more than a year, before she has a complete hair coat but to us she is a beautiful baby bear.
So what will become of the little bear? When we feel confident she is not contagious and is healthy enough for travel, she will be transported to her new home at the Gladys Porter Zoo in Brownsville, Texas, where the bear keepers are anxiously awaiting her arrival.
The decision to treat this little bear has contributed to our understanding of mange and ringworm in bear cubs. At WIL, it is our hope that what we have learned will lead us and others to better understand the impact of mange and related diseases and contribute to more effective treatment of future cases.
Special thanks to the WIL staff and volunteers who have given this little bear extraordinary care. Also thank you to Dr. Larry Buntrock and the staff at San Juan Veterinary Hospital in Citrus Heights for donating medications to the lab, Douglas Feed and Pet Supply, and to Raley’s for donating produce – especially those grapes she loves so much!