Diagnosing a Case 1

One question I get a lot is how we can figure out what’s going on with an animal when they can’t talk to us. I often compare our diagnostic challenges to those of a pediatrician. The pet’s owner (or child’s parent) knows something is wrong, but doesn’t know what. It’s our job to piece together all the clues from multiple sources to come to some type of differential diagnosis list from which to pursue the case.

Very early in my career I came to the conclusion that 70% of a diagnosis comes from the history and the physical exam. When I first approach a case my first mission is to try to figure out what the client has seen that makes them think the pet is not normal. Things like duration, whether the condition is getting better or worse, and what other conditions the owner has seen during the same time frame all help to us to try to determine which problems are causes and which are effects.

Many times when I first enter an exam room I end up asking the client the very same questions my technician has already asked. That may seem tedious and monotonous and a bit disorganized, but there’s actually a reason for it. Many times – sometimes I feel it’s most times – the client will give me a somewhat different answer than they told the technician. Sometimes, I’ll get two different answers to the same question from two members of the family in the room – say, a husband and wife.

When discrepancies like this occur it actually helps me to narrow down my questions to specific areas that I’m zeroing in on. By asking specific, non-leading questions I can usually start to get an idea of the overall condition of the pet. For instance, if we see a dog that is vomiting but has no diarrhea, it’s a very different list of differentials than it would be if the pet had vomiting and diarrhea together. And if that’s the case, then I have to craft my questions very specifically to try to determine whether the problem seems to be generated in the stomach, small intestine, large intestine, or in more than one place. And only through thorough questioning can I determine whether I think the diarrhea and vomiting are related.

For instance, let’s say a 5 year old spayed female Maltese comes in for vomiting of three days duration, with an acute onset. Let’s also say that the dog has diarrhea on presentation. My technician might get from the owner that the pet has vomiting and diarrhea. However, through thorough questioning I might find out the pet has a chronic on-again, off-again diarrhea which it has had for years. If that’s the case then I definitely want to know whether the pet also had any vomiting during that time frame, and if she did what the frequency and durations were. This is very important because if the pet has on/off loose stools but never had any vomiting, then this current episode of vomiting might be completely unassociated with the diarrhea. As stated earlier, that presents an entirely different set of differential diagnoses than if we see vomiting and diarrhea together.

And just as the history is very important, so too is the physical exam (PE). And in some cases there is so little history, or conflicting stories, or just otherwise absence of information that the physical exam is just about all we have to go on. It’s because of this that I always try to do a thorough physical on all of my cases.

My general PE’s are almost always the same. First, the technician gets the pet’s weight and temperature and a brief overview of the history. Once I get in room, and after I’ve tightened up the history as outlined above I’ll then start my physical exam. I always start my PE’s from the pet’s rear and work toward the head. The reasons for this are several fold:
• First, by starting at the pet’s rear I have to point the pet away from me. This allows the owner to stay at the pet’s head and reassure the pet, helping to keep them calm.
• Second, I don’t ever want to go to the pet’s head until I think they are comfortable with me. For instance, looking in a dog’s eyes is a threatening motion. I have to do it, of course, as part of a thorough physical. However, if I can delay it until the end of the PE then that helps the pet relax.
• Third, my palpation of the abdomen and other structures is more easily accomplished, and thus much more informative, from behind the pet than from in front.

The History and PE are ultra important in getting to an accurate diagnosis. In our next blog post I’ll discuss exactly what I’m looking for during the PE.