Diligence should eliminate puppy’s recurring parasites
Q Our 11-month-old puppy suffers from seemingly never-ending loose bowel movements. He came to us by way of adoption online from the South and arrived with several parasites, including roundworm, hookworm and giardia. Our vet made the diagnoses even though the adoption papers stated that the pup had been treated for worms several times and had tested negative before coming to us. We were frustrated, but with initial treatments, he showed no more eggs or cysts. However, we were told that he still tested positive on another test. We treated him again and just when we thought he was negative, cysts appeared again! How can he continue to get the same thing? Wouldn’t he become immune after awhile? Our vet thinks he is getting re-exposed in the local environment and so the fight goes on.
A What you have experienced is not that uncommon. Unfortunately, a good amount of dogs adopted through online sites, especially coming from the South into New England, seem to have various health issues, and parasitism is one of the most common. Luckily, all of the parasites you mentioned, and intestinal parasites in general, can be treated and eliminated. Dogs do not develop immunity to them despite prior exposure. For many years, veterinary practitioners tested fecal samples by flotation, and chances are that giardia was often missed since this small protozoan parasite is hard to detect.
In my practice, we send our samples out to a lab that does a better job of detecting this parasite with higher magnification as well as running a test called an ELISA test, which I believe you may have been referring to. This is an antigen antibody test that measures if a patient has been exposed to giardia. We always treat these dogs initially with fenbendazole and metronidazole, and usually one treatment suffices. I would agree with your veterinarian that your dog is getting re-infected by either eating his own feces, other animal feces or drinking water carrying the cysts. I see a lot of dogs that seem to love eating rabbit or goose droppings, and this is often a source. As you have witnessed, clinical signs often include diarrhea as well as vomiting, lethargy and lack of weight gain. Yet many dogs show no signs at all. This is why we recommend testing annually, and more often if dogs are at risk. I suggest you watch where your dog hangs out and what he eats or drinks outside. Pick up his droppings and dispose of them properly. As long as he’s otherwise happy and healthy, he should be OK.