Accepted Answer

The "parasite" illness you are referring to would be mange, which is an infestation of microscopic mites that burrow through the skin and cause hair loss, redness, severe itchiness, and secondary infection. Interestingly, there are two types of mange in dogs, one which is infectious or contagious (sarcoptic mange, known commonly as scabies) or demodectic mange. This article I wrote on mange describes these different kinds of mange in dogs, and outlines how the two are diagnosed, and how they are treated:

http://www.web-dvm.net/mange.html

However, without a skin scraping and analysis of the scraping under a microscope, one cannot really know if the underlying cause for skin disease is necessarily mange. In fact, mange is far less common in dogs then the most common cause for chronic skin disease in dogs - skin allergies.

Therefore, while getting the dog to a vet for a skin scrape prep and examineation is never a bad idea and perhaps even preferable, you may consider approaching this situation as a skin allergy first, then pursue a skin scraping and work-up/treatment for mange, especially if money is tight right now.

The first thing that you should approach in a potential skin allergy situation is to provide your dog relief. You can do this by medicated shampoos and leave in rinses. DVM pharmaceuticals make an excellent shampoo/leave in rinse combination called Relief Shampoo and Relief Spray. This shampoo and spray, respectively, have soothing oatmeal and omega-3-fatty acid components, as well as an effective topical anti-itch medication called pramoxine. You can get these products from your vet, possibly from pet stores, or online through keyword search.

In significantly affected allergic patients, sometimes topical management is not enough to keep them comfortable and to relieve the allergy. Therefore, if the topical shampoo and spray do not help alone, then I would consider additionally treating with the over the counter antihistamine, Benadryl, dosed at 1 mg per pound of body weight, administered orally, 2-3 times daily as needed.

As far as getting to the bottom of the source of the skin allergy, a food trial is a good start to rule out food allergy. While corn, wheat, and other fillers and preservatives can be involved in food related skin allergies, animal source proteins that the dog has been regularly fed are most commonly implicated. Therefore, the food trial should consist of hypoalergenic diet that is filler free, preservative free, and has a primary protein source that is novel, that is, a protein source that the patient has never been fed. You should feed such a diet exclusively for 8 weeks, then see if less topical and oral antihistamine treatment is necessary to keep the patient comfortable, and even be eliminated altogether. If this occurs, then your solution is to feed the diet exclusively indefinately. Some of my favorite choices for prescription, hypoallergenic diets, are IVD Venison and Potato, and Hills Z/D Ultra. Your vet should have these for sale.

If ultimately food is found to not be an issue involved in the skin allergy, then it is assumed that environmental allergy is the main cause of the skin problems. You can choose to manage this symptomatically as needed in the manner I listed above, or, you can talk to your vet about allergy testing to identify the primary allergens causing the reactions. Once this is determined, the allergens can be isolated in an injectable serum, which is regularly injected to desensitize the patient to the offending allergens.

If these allergy management measures do not ultimately help the patient at all, of course it would be a good idea to have a vet examine a skin scrape prep to check for mange. Mange is treatable, and not at great cost, so it would be worth pursuing.

For more detailed information on skin allergies in dogs, please refer to the following article I wrote on the topic:

http://www.web-dvm.net/skinallergies.html

Expert:	Roger L. Welton, DVM
Pos. Feedback:	100.0 %
Accepts:
Answered:	8/18/2009

Veterinarian

Licensed Veterinarian, Practice Owner, And Book Author ("Canine and Feline 101")