Weimaraner Skin problem - bumps/pimples

Question
I have a one year old weimaraner that developed what looks to be a skin allergy over the past two months. She has small bumps all over her body (> 50 or so, mostly her back and chest). The bumps are red when they form and then turn into pustules (pimples). They usually rupture (a creamy fluid and then a little blood) and then dry out. A lot of times she will lose the hair where the pimple developed.

The bumps are small (smaller then a dime in diameter) and she does not seem to be too bothered by them - they don't itch and her behavior seems fairly normal. If you look at her from the side or from above, because her coat is short, you can easily see the bumps because her hair is raised where they occur. If you pet or rub her coat, you can also easily feel the bumps.

She has been to the veterinarian twice and neither visit has produced results. She was given a medicated shampoo (I forget the name) the first visit and after a few washings, the bumps seemed to get progressively worse. The next visit the vet took a skin scraping that came back clean. She was given Dexamethasone Solution 2mg/ml as well as Cephalexin 500mg. Still no results after 3 weeks.

Any thoughts as to what this is or what the next step should be? I don't want this to turn into something worse, as it certainly has not got any better over time.

A little more background...We got our puppy at three months and fed her Eukanuba Natural Lamb & Rice Puppy (0-12 months) food. At around 10 months, we began mixing in some Eukanuba Puppy Large Breed (0-24 months) food. The main ingredient in the newer food is chicken. I thought it might be a food allergy, as I have heard dogs can be allergic to chicken, so I have slowly been trying to get her back on lamb & rice.  We have used the same laundry detergent since we got her.

Thank you in advance for any help you can offer.
Drew.

Answer
This is most likely a bacterial infection on the skin. Ask your vet for a 2 week supply of an antibiotic for the skin.  If it is a pyoderma, then there is some kind of underlying problem that allows the bacteria to infect the skin.  In a young dog,it could be a food allergy and your vet can help you with a food elimination diet trial.