This does not mean that we have all the answers and are infallible. You may have heard by now that the six-month injectable heartworm preventative has been pulled from the market by the FDA because of deaths and other side effects in dogs.

ProHeart 6 has been voluntarily withdrawn under recommendation of the FDA following a large number of adverse drug reaction reports. This product had no claim of efficacy against hookworms and roundworms, either, but then neither does the product you are using.

(Question) I have a six-year-old male yellow Lab that has had two severe reactions to his vaccinations. The first was when he was 12 weeks old and getting his puppy shots. The second time was when he was four years old. In between whenever he came due for shots my vet would give him some kind of shot (I can't remember what) before she gave him the vaccination and he would be fine.

The last time he had a reaction he did not receive this shot prior to his vaccinations, and we gave him Benadryl at home. Last year we did the titer thing and he didn't need any vaccinations. This week we again had titers taken. We should get the results in a couple of weeks. My question is this: Would you vaccinate if the titers are low?

My vet does not think we should vaccinate. I would like your opinion on this. Also, do you know of a place where the distemper vaccine can be obtained by itself and not as a combination vaccine?

(Answer) If your dog is six years old and has good titers to distemper and parvo, then I would consider not vaccinating for two or three years, at least. Be sure the titers are run at a diagnostic lab that specializes in canine titers. I use Cornell University, in Ithaca, New York.

I use a distemper-parvo vaccine from Intervet, Inc. I'm not sure if they have a distemper-only product. This product has given good titers and no reactions. A combination of distemper and parvo is not much of a load for the dog compared to those products that have five to seven antigens.

(Question) I have a seven-year-old German shorthaired pointer that has developed a severe case of bloody stools. This has happened three times in the last few months, each episode lasting about three days. It was so severe the last time that I took him to the vet, where they did extensive testing, had him on IVs for four days but found no clue for what was causing it.

He is doing much better now, but I don't think he's going to survive another episode. I've done some research myself on the Internet with little success. We live in Southern California in a very dry climate. The only thing I found that resembles his symptoms is oomycete infection: gastrointestinal pythosis. It doesn't fit our region at all, but we do have a pond (with algae) in the backyard that he drinks out of regularly. What are your thoughts? (Answer) I would consider the small-bowel problems that resemble Crone's disease in people. Often referred to as lymphasitic/plasmacytic enteritis, this disease is responsive to diet change, prednisalone and metronidazole. Diagnosis is difficult and often requires biopsy to prove.

Contact Tom Holcomb, DVM, by email at h1holco@attglobal.net.