by Merciel » Wed Jul 18, 2012 2:47 am
Here is how hot spots work:
-- your dog gets irritated by something. This could be flea bites, allergies, self-inflicted overgrooming from OCD, bad reaction to a topical anti-flea/tick ointment, a nip at the dog park that broke the skin and healed up itchy, a knot of moist hair rubbing against the skin, whatever. There are infinite possible causes.
-- your dog messes with the irritation and makes it worse.
-- licking and chewing enables bacteria to get into the skin and the wound becomes infected. Also the licking and scratching and chewing is keeping the hot spot moist (encouraging bacteria to breed) and is worsening the wound and preventing it from healing.
Treatment usually involves clipping or shaving away hair if that seems to be irritating the wound, then cleaning the wound and using an antibiotic to control the bacteria in there. You also have to keep the dog from scratching or chewing the wound as it heals, though, because otherwise you're just going to get the whole cycle all over again and new bacteria will be introduced and the wound will stay aggravated and it won't get better.
Ultimately you need to figure out what caused the underlying irritation and address that, though, and for that you need a (good) vet because that is way out of my area of expertise.
If it's a food allergy, the most common culprits are wheat, corn, chicken and beef. You can find limited-ingredient foods (or make them at home yourself, it's not that hard) and go through various elimination diets to narrow down the possible culprits, but this is a long and painstaking process because you have to keep your dog on each food for at least 6 to 8 weeks to see if the symptoms are abating, and if the dog gets a treat or sneaks a piece of garbage that could have one of the suspect ingredients, you have to start that part of the trial all over again.
Fortunately actual food allergies are very rare. Intolerances (where the dog has a bad reaction from eating lots of the ingredient all the time, but doesn't react to a single exposure to a small amount, which is what a true allergy would be) are more common but still not something I see that often.