Dog Can’t Kick Ehrlichiosis

Q. My dog was diagnosed with ehrlichiosis in the spring of 2007. We did an initial round of doxycycline for probably six weeks. Her blood work looked better, so we took her off the antibiotics. In July 2008, she wasn’t acting like herself so we headed back to the vet. He did blood work, then said, “it looks like the ehrlichiosis coming back,” so we started another four-week round of antibiotics, and her appetite dropped off. My vet wants to continue the antibiotics, but she won’t eat.

A. It is true that doxycycline, the antibiotic used to treat infections from ehrlichiosis, can cause loss of appetite, diarrhea, and occasional vomiting. However, I would not assume that in an 11-year-old Lab that the antibiotics are the source of her appetite change.
 
A key indicator of health in an older dog is body weight. If her body weight is going down, I would want to get her checked out more thoroughly. As you probably know, cancer is one of the most common diseases in older dogs, especially Labrador Retrievers. An ultrasound scan of her abdomen and routine blood testing can help rule out any other underlying disease.
 
Instead of speculating about the presence of an infection from ehrlichia, your veterinarian can submit a blood test for a PCR analysis, which is highly sensitive for the infection’s presence. Although these tests are not inexpensive, they will help you and your veterinarian get to the bottom of your dog’s problem.
 
Ehrlichiosis is an organism that is transmitted from ticks to dogs, and can cause long term infections that are difficult to clear from the body, even with long-term antibiotic usage. The infection is not contagious to other dogs.