The 4-month-old Doberman pinscher puppy I saw last month was beautiful. He was muscular, and his coat was shiny and sleek. Heart, lungs, eyes, ears and teeth all checked out fine. We reviewed his history and previous vaccinations. Diet and feeding schedule were discussed.
The only part of his exam that bothered me were a few patchy spots around his muzzle. Just to be sure, I used a surgical blade and some oil and did a skin scraping. A microscopic exam revealed a small mite that caused a condition called demodectic mange. Demodex, as it is often referred to, is a tiny mite that lives in the hair follicles of dogs and other species. They are microscopic mites that look like a cigar with legs at the front end.
The mite can be frequently found in young dogs and is often self-limiting. The good news is that it is generally considered non-contagious to other dogs and non-transmissible to people. Dogs frequently have localized mites that create just a few small areas of patchy hair loss, and they will recover in a short time without treatment.
The mite can be present in the skin, but the immune system keeps the population below what would be seen clinically. When the immune system does not function properly, the population increases and causes bald patches, giving the pet a moth-eaten appearance.
Genetics plays some part in the disease as some breeds are more commonly affected. Bull dogs, Dobermans and a number of other breeds are genetically more susceptible.
When the areas of hair loss are larger or more numerous, demodex becomes a much more serious disease. We make sure everything else is normal in the condition of the pet. Nutrition and other parasites are considered, and steps are taken to address other health considerations if needed.
Treatment options include topical or oral medications. The most common current treatments include a farm animal injectable parasite medication given orally. The drug most frequently recommended is Ivermectin, the active ingredient in one of the commonly used heartworm preventative medications. This drug must be used carefully in some breeds of dogs as they can be sensitive to it. Collies and similar breeds must avoid high doses of Ivermectin.
I expected the Doberman puppy to do very well as there were just a few mites on the scraping, and the area of involved skin was small. Two weeks later he came in for an eye issue and his skin looked worse. His face was crusty and looked scabby. His scraping was improving as we saw fewer mites, but he appeared to have Pyoderma, a bacterial skin infection common in young dogs. A puppy's immune system is often immature and fails to respond to both bacteria and demodex. Once we started oral antibiotics for his skin, he was on the road to recovery.
Cats have recently been reported to have demodex, but felines have a different species of mites. One species is similar to that of dogs and may be a normal inhabitant of skin. It is not often diagnosed. A second species, a short mite, may spread to other cats.
The prognosis for canine Demodex is generally good. On rare occasions the infection becomes overwhelming. In an older animal, it can indicate a more serious condition. Any bald spot on a pet should be examined by a veterinarian. Proper diagnosis and treatment will usually get a pet back to normal quickly.
Lawrence Gerson is a veterinarian and founder of the Point Breeze Veterinary Clinic. His biweekly column is intended to educate pet owners. Consultation with a veterinarian is necessary to diagnose and treat individual pets. If you have a question you'd like addressed in Pet Points, email firstname.lastname@example.org. Please include your name and municipality or neighborhood.