How much testing is enough?

So what happened in the wee hours this morning?  First, the prologue…

When I am presented with an animal who has medical problems, I am also being presented with a mystery.  Sometimes it is much more mysterious to the pet’s owner than it is to me (see future post on emergency diaper rash).  Sometimes the problem is pretty vague: "He just doesn’t feel good."  When you know your pet, you know when he doesn’t feel good, even when you have no idea why.

The investigation starts with a history.  "What’s going on?  What is he doing that’s different or not right? Has anything changed in his life? Diet? Environment? Anything???" If we’re seeing a new patient, then I also have to go back to "How long have you had him?  Inside or outside? Fenced yard? What does he eat? How often?  Heartworm preventive? Flea control? Where does he sleep?  Previous problems?"   Maybe we have some clues now, maybe not.

Next is the physical examination.  I look at everything, front to back, top to bottom.  Scope the eyes, scope the ears, look way back in the mouth, listen to the chest, do an all over touchy-feely, because they won’t take off their fur or roll up their sleeve.  Maybe we have some more clues now, maybe not.  Maybe we’re still at "not feeling good".  Now what?

Now we’re up to diagnostic testing.  Perhaps the history or physical exam have suggested a direction, perhaps not.  For instance, if a young puppy is known to chew on non-food items, and he has begun vomiting solids, but feels okay otherwise, first thing is X-ray for a foreign object in the stomach.  If there’s no real solid direction, then we may have to cast a broader net. How broad? Now we’ve caught up to the title.

How serious is the problem?  I’d really like to run every test known to civilized man on every pet that comes in.  That way I’d miss fewer things, get things handled faster.  In general, I’m big on diagnostic testing.  Knowing that my psychic abilities are limited, I’ve invested in a lot of equipment to "look inside" the pet.  Frequently  I do not "just know".

There are two problems with running that many tests on every patient. The obvious first is the owner’s financial concerns.  If I don’t "really need" the information, can I justify a complete blood count, urine specimen, stool specimen, blood chemistry exam, chest x-rays, abdominal x-rays, ultrasound exam of the abdomen, electrocardiogram and more?   At the University teaching hospital, those first four are considered a "minimum database".  Everybody gets that. Of course, they aren’t seeing anything except seriously ill animals who are being referred by their regular doctor (who is feeling out of his depth).

The second consideration is the stress on the animal. If we’re talking a 2-pound kitten, there’s a limit to how much blood she can give up for testing purposes (though our new equipment can run about 20 tests with about  four drops of blood, thank goodness).

This means that we frequently base the depth of our diagnostic testing program on the apparent severity of the animal’s condition.   The patient who is turning yellow, can’t rise, and is losing fluids on both ends faster than you wipe — that guy is getting the works, just as fast you can run the tests.  He can’t wait.   If you have a young puppy with an occasional mild cough, but he’s happy and running and playing and eating fine, chances are that you’re not going to dive into a big diagnostic workup.  And thereby hangs the tale.

Samson was the beautiful four-months old Rottweiler puppy with the occasional mild cough.  We didn’t really consider doing a chest X-ray on him.  I wish we had.  His occasional mild cough was due to the fact that his heart was the size of a basketball (due to a birth defect) and it was putting pressure on his wind-pipe inside his chest.  Last night, his folks gave him a little Robitussin with a decongestant in it.  Should have been just fine, no problem.  The decongestant was pseudoephedrine, and it was enough of a stimulant to his huge, defective heart to send it over the edge.  He began to have some respiratory distress very soon after taking it.  Then he seemed better and took a nap.  When he awoke, gasping for breath, I got the 3:00 AM call.

His heartbeat was so fast I couldn’t count it.  Chest X-rays showed his lungs filling with fluid.  He didn’t respond to treatment.

True, this guy’s heart was a time-bomb just waiting to go off.  He would have keeled over playing ball or something before he got much older.  That chest X-ray would have just made him into a heart patient waiting for the other shoe to drop.  Maybe it would have dropped in the daytime. Maybe 3:00 AM was in the cards.  I hate Karma.

Does this mean that I’ll be running every test known to civilized man on every patient?  No, this was a "freak thing".  Will I continue to recommend a thorough diagnostic workup to every sick patient?  You bet, because your pet really needs the best I can give him.

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