Notoedric mange in an Eastern gray squirrel
A case of notoedric mange was diagnosed in an Eastern gray squirrel in Montreal in June. This animal was debilitated, emaciated, and showed a significant hair loss. Notoedric mange is a parasitic disease caused by the presence and multiplication of a microscopic mite called Notoedres centrifera in the skin. This parasite digs microscopic “tunnels” in the skin, which creates irritation. Scratching then induces wounds, hair loss, and progressive weakening of the animal, as noted on the submitted specimen. It should be mentioned that this parasite is species specific and is not known to infect either domestic animals or humans.
Although this parasite appears to be quite common among squirrels in some areas of the United States and may, in some situations, cause significant mortality, it has been rarely documented in Canada. Of more than 450 Eastern gray squirrels submitted for evaluation over the years at the CWHC, only half a dozen cases of mite infestation have been reported, essentially in Ontario and Quebec. The potential effect of global climate change on the geographic distribution of this parasite is uncertain. As the transmission of this parasite is undoubtedly favored by an increase in squirrel densities, the growth of some urban squirrel populations may also play a role in the occurrence of this parasitic condition in Canada.
We regularly receive pictures of squirrels with hair loss. Although notoedric mange is one of the possible causes of this clinical presentation, other conditions, such as fungal infections (dermatomycosis), post-stress molting problems and genetic abnormalities, may also be associated with loss or absence of hairs in this species. Therefore, the diagnosis of mange should be based on an examination of the animal. However, the documentation of squirrels with hair loss from pictures can allow us to detect cases of probable infections. We therefore remain interested in receiving this type of photographic materiel.
Dr. Stéphane Lair, CWHC-Québec