Monday, February 15, 2010

Mystery case...

At 2am last night, a small family walks in, a young couple (early 30s/my age). Both are polite, well-spoken, and obviously educated. The woman is very, very pregnant. They toted along with them a very sick small breed dog.

For 2 days, he had been progressively more lethargic, had begun vomiting, and having black, tarry diarrhea. They had at first assumed a nasty bout of gastroenteritis (vomiting and diarrhea due to non-specific GI upset). He wasn't getting better, though. They brought him to me.

I did my physical exam and found a depressed, dehydrated dog with melena (digested blood diarrhea). I figured we were dealing with something relatively run-of-the-mill: a nasty pancreatitis case, perhaps a raging hemorrhagic gastroenteritis (HGE), or a foreign body lodged somewhere, since he was a little Hoover dog (ate anything from the floor).

Imagine my surprise and confusion when I saw the labwork: marked thrombocytopenia (low platelets). The normal range is 175-250,000. This dog had 53,000 platelets. On top of that, he was very dehydrated and possibly suffering renal insufficiency (kidney values were elevated, he was very dehydrated, yet his urine was very dilute). He also had mild liver enzyme elevations. A canine pancreatic lipase assay to test for the presence of pancreatitis was normal - much to my surprise.

I was left with a very ill dog that was inexplicably thrombocytopenic, depressed, with vomiting and diarrhea.

My differentials? possibly tick-borne illness of some flavor, early immune-mediated thrombocytopenia (body destroying its own platelets), perhaps leptospirosis, a foreign body that had been present for a while, and now the dog in early/low-grade DIC? I ran clotting times to determine if DIC was present, and the clotting times were elevated (aPTT) and high end normal (PT). WTF? Xrays of the abdomen were non-specific.

In the end, I gave the dog a plasma transfusion to help in case this was early DIC, started IV fluids, pain medications, anti-emetics, and an antibiotic. I felt like an idiot, and I was very stressed about the case. I was tired, and I was afraid there was something huge and obvious that I was missing. The owners were flabbergasted. They had expected to find out that something simple was wrong with the little guy - like I had. When I told them that I didn't know what it was but that it was serious, they were just not prepared. I spent probably 2 hours talking to them and trying to explain my various differentials, but in the end, I was left with more questions than answers.

I sent him to the internal medicine specialist the next day. Last I heard, they have no clue what is wrong with him either...and are doing a barium study to rule out a foreign body -- even though I saw nothing on xrays to indicate a foreign body.

It made me feel a lot better that the specialists are currently stumped. Not for the dog, but at least I don't feel like I failed my clients...