Finally, I did a rectal exam on him. Put a finger in his bum and "holy s--t!" he's got a huge mass growing in his bum that felt like it was very firmly attached to his pelvis. This guy is way too young for cancer, I thought to myself..... I sighed deeply and explained to his owner what I had found. She was devastated. I told her not to worry, at which she scoffed. I referred her to an internist (yes, this happens frequently) for further diagnostics including a biopsy of the mass.
Not the same mass as that found in the dog's behind.
The dog had a CT scan revealing a very large mass that likely involved the dog's pelvis - already bad news. Biopsy results were pending.....
Briefly having forgotten about this dog for a day or so, I received a copy of the internist's report, including the biopsy report.
"WHOA!" I yelled out loud. I was ecstatic. The firm mass was not neoplastic (cancerous) but rather INFECTIOUS! In the biopsy they found club-shaped bacteria consistent with an infection called Nocardia or Actinomyces. We learn about these things in school but they are relatively quite rare. The bottom line is that this is most likely curative. The dog does not have cancer and will survive. The dog is on a penicillin and trimethoprim-sulfa, two types of antibiotics that should eradicate this infection.
These types of bacteria are usually associated with a penetrating foreign-body (a splinter, for example) in the skin. Perhaps a foreign body penetrated into the wall of this guy's rectum - ouch.
Nocardia bacteria (image to right)
Actinomyces bacteria (image below), similar to Nocardia.....
We are all surprised at the diagnosis and happy with the outcome. This appears to be the theme of the last few posts, eh?
