A Haunting Case of Blastomycosis
Yesterday I talked about how a recent news report about a girl in Colorado recovering from bubonic plague reminded me of one of my veterinary success stories. Wouldn’t you know that just a few days later I saw another article, this time about dogs in the Chicago area developing the fungal disease blastomycosis, which brought back memories of a case that did not go so well.
This happens frequently to vets (or at least to me). Just when I’m starting to get a little over-confident in my abilities, a patient will come along that knocks me back down to size.
In this case, it was a yellow lab named Harley. He was summering in the part of Wyoming where I practiced (must be nice!) and had started limping on his right front leg, developed a mild, intermittent fever, and was generally not his normal exuberant self. At our first appointment, his physical exam and diagnostic work-up didn’t result in any specific diagnosis. I was able to localize his pain to about midway up his right antebrachium (forearm, if dogs had arms), but the X-rays were inconclusive. We treated Harley symptomatically with an anti-inflammatory, rest, and antibiotics in case his fever indicated a bacterial infection. He improved a little, probably just because of the pain relief from the anti-inflammatory, but relapsed quickly when treatment stopped.
To make a long story short, after many weeks of rechecks and continued diagnostic testing I was suspicious that we were dealing with blastomycosis, a disease we did not see in our part of Wyoming, but Harley was from Chicago, and he could have picked it up there. Unfortunately, none of his test results were definitive for blasto. The changes that eventually were visible on repeat X-rays fit with a fungal infection affecting his radius, but also could be explained by a bacterial infection or even cancer.
His serology indicated exposure to blastomycosis, but not necessarily that he was suffering from an active infection. If he did have blastomycosis, we were going to have to treat him for a long time with high doses of an expensive antifungal medication that had some potentially serious side-effects. Harley’s owners were understandably reluctant to embark on this course of treatment without a solid diagnosis, so we decided to biopsy the affected bone, and the results were … nondiagnostic.
Believe me; I was just as frustrated as the owners by this result. The sample revealed lots of inflammation, but no cause for it. We spoke about the pros and cons of going back in to get another sample, but the owners decided against it and elected to start the anti-fungal medication instead. We did not expect to see quick improvement and we didn’t, but by the time Harley was getting ready to head back to Chicago, his limp was slightly improved and he seemed to be feeling better. We were cautiously optimistic but still had a long way to go. I called the family once in Chicago to check on Harley. He hadn’t yet had his first exam with his regular veterinarian but was continuing to improve, albeit slowly. After that, Harley was "lost to follow up," as researchers say.
I’ve always wondered what Harley’s Chicago veterinarians thought when they looked over the tome that was the dog’s Wyoming medical record. If they had been out of school long enough, I’d be willing to bet that they were sympathetic and could look back on a few of their own cases that did not go as smoothly as everyone involved had wished.
Dr. Jennifer Coates
Image: Blasto / via Tom Volk, University of Wisconsin