DEAR PAW’S CORNER: We lost our Landseer Newfoundland to myositis. “Katie” was under a vet’s care for many months, but only in the later stage of her illness was the condition recognized. The vet told us myositis can be caused by a virus or by parasites. Could you explain to me how it could have been caused by parasites, and if so, how we could have known? – Helga G., Fairpoint, NY
DEAR HELGA: First, my condolences on your loss. It’s never easy to lose a pet, and Katie went through a tough time.
Myositis is a condition in which a dog’s muscles are damaged by inflammation. The most common form is masticatory myositis, in which the muscles involved in chewing are affected. Its cause can be hard to determine. Myositis can develop after a parasitic infection like toxoplasmosis, or as a secondary issue in pets with cancer. Pets with immune disorders may develop myositis. But often, no underlying cause is found.
The condition tends to set in suddenly. In masticatory myositis, affected dogs may exhibit swelling of the facial muscles and bulging eyes; they may run a fever and will show a reluctance to eat or whimper when chewing. In general myositis, dogs may exhibit a stiff-stilted gait and suffer muscle pain and weakness. They will tire easily.
If caught early, acute myositis can be treated using steroid therapy and supportive nutrition. If an underlying cause is found, like parasites, a wound or illness, the vet will treat that as well. Owners should keep a close eye on dogs that have been treated, in case symptoms return.