A few weeks ago I was petting my dog when I noticed that his abdomen seemed somewhat distended. As the dog was showing no other signs of discomfort or disease I decided to wait for a few days to see whether it might clear up on its own. After all, I thought, he has been known to eat the hooves of dead deer and then vomit them up again days later.
After a few days with no apparent change, I called the veterinarian office. "My dog's abdomen seems to be distended, although he is not showing any other signs of distress. Should I be worried?" The animal tech said, "I don't know what it is; potentially it could be serious. You should bring the dog in and let the doctor look at it."
So we came into the office and the veterinarian looked at the dog and palpated his abdomen. "I don't know what it is," the vet said. "You should bring him back tomorrow morning for an xray."
So we returned the next morning and Buddy had his xray. Later in the day, the vet called me. "He did fine; he's coming out of the sedation now with no problems." I expected the next sentence to be a diagnosis but he said, "We don't know what it is. I think you should take the dog to the animal referral center" 30 miles away.
So we settled into the truck and took a drive. At the referral center one of the veterinarians told me, "We'll do an ultrasound examination while you are having lunch. Then we'll call you." I went off to eat a late lunch, during which the referral center called to say only that I should return so that someone could talk to me. This time the vet said, "We don't know what it is, but we do know where it is: There is a growth on the spleen. I think you should have his spleen removed."
So the dog settled in for surgery while I drove back home again. Later the surgeon called and said, "He did fine; he's coming out of the anesthesia now with no problems. When we took out the spleen we saw that there was a growth on it. We don't know what it is, but we sent it to the pathologist. You can bring the dog home, but first I think you should talk with our rehabilitation veterinarian."
So I drove the 30 miles to the animal referral center and spent some time talking with the rehab vet about some symptoms they had noticed following surgery. She had several suggestions for ways to prevent those symptoms from becoming a disability, but I was watching the dog and saying to myself, I don't think she knows what it is.
So the dog and I bundled back into the truck and headed for home.
Days later one of the vets called me from the referral center. "The histology report is back and it is good news. There is no malignancy in the tissue we removed, so it is not cancer ... although we don't know what it is."
And so after several days (and several thousand dollars) the dog and I had the same experience in animal health as people do with human health (although at only 10% of the price). We ruled out the worrisome possibility, the one which would have made the entire episode moot. We underwent inconvenience and trauma and became poorer and (in the dog's case) a bit lighter.
But in actual reality we did it all on speculation. We don't have a diagnosis, let alone an etiology. Our speculations have become more refined and better informed since the days when the best guess was to bleed the patient to death, but it is an improvement in degree more than in kind.