Deer with Hair Loss

Observation by B. Holter, Jr.:

We have been seeing Sitka black-tailed deer with large patches of fur hanging from their bodies and bald spots the size of place mats. Some deer also have multiple growths the size of baseballs all over their bodies. We have noticed this going back over the past four years. When they are shot, people have brought them in to help with identification. The US Forest Service has taken some of the deer, but I am not aware of any findings yet. Deer is one of our traditional food sources and we are concerned that it could cause cancer, infection, or other illnesses in people.

Kimberlee Beckmen, Wildlife Veterinarian with the Alaska Department of Fish and Game (ADF&G), writes:

It is not uncommon to get reports of patches of hairloss in deer. The reports have not seemed to increase recently, but are sporadic each spring. When we get access to an affected animal, we will check for potential causes such as invasive, exotic ectoparasites, including moose winter tick or exotic lice that may spread to Alaska with the changing climate and animal movements. As far as the multiple growths up to the size of baseballs, as mentioned, these are papillomas, a viral wart. They will resolve (drop off and heal) with time. The warts are not cancerous and are not known to be contagious between species and, therefore, generally not a concern for causing illness in people.

To determine what is causing the hairloss, or if it is just a seasonal molt, we need to closely examine deer with the condition during a time when the causal factor is present. If it is moose winter tick, the ticks will have dropped off by April and nothing would be found now. If it is lice, they might still be identifiable. It would be helpful for the public to be aware that if they see a sick or abnormal deer, call the nearest ADF&G office as soon as they observe the animal. That will expedite the possibility that one of the biologists may be able to either dart the deer to get a closer look and collect blood/skin biopsies, or euthanize if it has an exotic ectoparasite infection. At a minimum, it would help us better understand the frequency of observation and location information. Photos are still helpful, but quality has been very poor. We also need to know the distribution of the hairloss (pattern) and what the skin looks like underneath, and the general body condition, age/sex of the deer.

Dr. Helen Schwantje, Doctor of Veterinary Medicine from the British Columbia (BC) Ministry of Forests, Lands, Natural Resource Operations and Rural Development writes:

There is a syndrome on Vancouver Island and into Washington and Oregon deer called hairloss syndrome. In our deer, I think they have adapted over time to some degree so although some times the deer die from exposure and poor body condition, most live and grow new coats. We have lots of winter ticks in parts of BC but I have never heard of deer being affected as you describe. I have copied this to one of our biologists in Smithers to see if he has heard of this in deer in his area. I have very little info about Sitka deer on the coast and it would be most interesting to ask more of our friends around Prince Rupert, etc. if they have seen this or if the occurrence is localized.

Bill Jex, Regional Wildlife Biologist at the BC Ministry of Forest, Lands, Natural Resource Operations and Rural Development, Skeena Region, writes:

We haven’t had any reports of severe tick infections on our coastal black-tails or our inland mule & white-tailed deer; that’s not saying there isn’t any parasitism, but it’s not at a level where we are hearing about wildlife health issues or die-offs. As Helen also noted, lice infestations could also cause a hair-loss issue so perhaps it was a particularly bad louse year and the deer simply rubbed more aggressively.

Comments from LEO Editors:

According to a 2016 Alaska Daily News article, Whats wrong with this Anchorage moose? The Internet, as always, has some ideas, Anchorage residents observed an ailing moose in the summer of 2014 with an appearance similar to that of above-mentioned deer. Neighbors believed the animal had been attacked by a grizzly bear, but Fish and Game biologists, as well as Internet commenters, have offered alternate theories as possibilities.