Pet Vet: Pug's skin issues likely caused by common mite

May 19, 2014

Hadley is a 7-month-old pug living in Durham, N.C. He is the pride of his caretakers, Mattie and Greg, and has been with them since he was 7 weeks old. He is fully vaccinated, on heartworm prevention medication and is fed strictly Science Diet Maintenance dog food. He has been neutered. His daily routine includes a 3-mile walk through his neighborhood and time in a local dog park. It is these trips to the dog park that Greg and Mattie think might be responsible for a skin problem he is having.

Over the last couple of weeks, Hadley has developed areas of hair loss over much of his body. Mattie states the spots are mostly roundish in shape with virtually no hair and flaking skin. Most recently he has begun to scratch some of the spots as well. Greg and Mattie are convinced Hadley picked up something from his dog park adventures.

The skin of dogs has a finite amount of manifestations to a myriad insults. In other words, it is most often not possible to diagnose the underlying cause of a skin problem simply by looking. There are cases of course that are obvious, fleas for example come to mind, but in Hadley’s case, diagnostics are in order.

My suspicion is that Hadley is dealing with a case of Demodectic mange. To diagnose this disease, we commonly use a skin scraping technique followed by a microscopic exam of the material scraped from the skin. If I am correct, the microscopic study will reveal the presence of one or many cigar shaped mites with stubby legs, six of them.

These mites burrow into the victim’s hair follicles and set up in households where they breed and can spread. The hair shafts fall out, hence the hair loss being described with Hadley. Demodectic mange is not always itchy though the generalized form, where much of the skin of the patient is involved, can cause pruritis.

An interesting note about Demodex is that these mites are considered a normal inhabitant of a dog’s skin. They can be found in small numbers on virtually any dog without incident. It is theorized that a dog’s immune system keeps the Demodex population in check. In fact it is very rare to see a case of Demodectic mange in an adult dog unless there is some compromise to the dog’s immune system.

It occurs far more commonly in younger dogs as their immune systems develop. It is usually self-limiting, in other words, it does not spread and is contained by the immune system and eradicated as an apparent skin problem. These dogs will show a spot or two of hair loss often around the face and ears.

Topical treatment is sometimes used to aid in treatment and these cases almost always resolve. Generalized Demodectic mange however needs more aggressive therapy. If I am correct with Hadley’s diagnosis, he has the generalized form of this disease. Incidentally, Demodex is not considered a communicable disease so Hadley would not have contracted the disease from hanging with his bros in the dog park.

In the interest of hedging I must admit that I may be wrong in my suspicion that Hadley has generalized Demodectic mange. He could have ringworm, a type of fungal disease or, as I stated above at the beginning of our discussion, a myriad other possible causes.

One thing is for sure in my mind, it does not appear likely Hadley’s skin issues will resolve on their own. He needs a trip to his veterinarian.


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