Wednesday, May 4, 2011

The case of the jaundiced terrier

It was 6:30 am on the last Saturday of my small animal medicine rotation. I had one patient in the hospital to care for that morning, but I was also scheduled to take pick-ups that day — taking on as new patients half of the animals who were transferred to the medicine department that morning from the emergency and critical care department. A rotation mate of mine would take the other half. The transfer list had two animals on it, and since I had gotten to it first, I could pick which I wanted. Feeling relatively bright-eyed and bushy-tailed after a slow week with not many cases, I chose the Boston terrier whose one-word problem (about all the transfer list has room for) was that she was “jaundiced.” Jaundice, or having yellow skin and mucus membranes, suggests a liver problem, as the liver is failing to process your yellow bile acids. I hadn’t had a liver patient yet, and figured it was a good chance to learn something new.

The Boston was in A ward, the ward for sick animals. (Healthy animals who are in for elective surgery and the like end up in B ward. Animals on the other end of the spectrum go into the intensive care unit.) I read her chart. She had come in to the ER the previous morning for lethargy, not eating, and not acting like herself. No blood work had come back from the lab yet. The ER had ultrasounded her abdomen and seen no free fluid in there, which suggested that any liver disease was not far advanced. They had heard a heart murmur, and she had looked yellow to them.

I did my own physical exam. Yellow: hmmm. Maybe I could see that her inner lips looked a little yellow. Maybe not. I chalked this up to my inexperience and wrote “mild jaundice” on the physical exam form. Heart murmur: hmmm. Maybe I could hear it, maybe not. It was a little hard to hear over the sound of her breathing. I thought I could hear some swish to her heart, though. Come to think of it, her breathing was awfully loud. Now, Boston terriers have very flat faces, which makes breathing difficult for them at the best of times. But looking at the depth of her breathing, I thought I saw “increased respiratory effort.” It isn’t something you’d necessarily expect in a liver patient, but I wrote it on the physical exam form with a question mark after it.

The resident on the case, Dr. Crow, took a look at the Boston next. “Did you appreciate jaundice?” he asked. I hemmed and hawed. “Maybe she’s a little jaundiced... I’m not sure,” he said. Oh. Um, good. “Did you actually hear her heart murmur, or just write it down because the ER heard it?” I said I sort of thought I heard it but it was difficult. He nodded. “I’m not really sure I hear it either,” he said. Emboldened, I asked about her respiratory effort. “Yes,” he said matter of factly, “that’s elevated respiratory effort.” I was unsure whether to feel good that I’d noticed, or bad that there had been any question in my mind.

We talked about why a dog with liver disease might have trouble breathing. Dr. Crow walked me through the idea that since the liver is involved in clotting, the dog might have thrown a blood clot into her lungs. We sent her off for x-rays of her lungs. While she was gone, her blood work came back: all of her liver enzymes were significantly elevated. This happens when the liver is so unhappy that it starts to leak enzymes, and when the bile backs up because the liver isn’t processing it properly.

When the Boston came back from radiology, Dr. Crow asked me, “So what do you think about her radiographs?” Her lungs looked terrible. She was having even more trouble breathing, so we put her in an oxygen cage. Dr. Crow called an emergency and clinical care faculty member over to talk through the case. The problems with her lungs were spread too far for him to still suspect one clot. We had submitted a request for clotting tests, but weren’t going to hear back for several hours, as it was a weekend. Dr. Crow and the faculty member decided to do a quick ultrasound of the Boston’s heart. Heart failure can also cause fluid to get into your lungs and make it hard to breathe.

We took the Boston out of her oxygen cage, put her on her side, and put the probe on her chest. And there it was: a big lump on her heart. “Well,” the faculty member said, “I think you just found her problem.” Cancer.

Dr. Crow suspected that the mass was a chemodectoma, a type of cancer to which Boston terriers are particularly prone. However, the cardiology service did a consult on her, and they thought it was more likely to be hemangiosarcoma, because of the speed with which it had appeared and because of its exact location on the heart. Hemangiosarcoma is a very bad diagnosis; animals don’t live very long even if it is excised, and it was going to be impossible to cut it off of this dog’s heart. It is not very responsive to chemotherapy, either.

I asked the cardiology faculty member why he thought the dog’s liver enzymes were elevated. We batted around some ideas, but in the end he shrugged: this was not the dog’s primary problem. And cancer, as the saying goes, can do anything it wants.

The Boston’s owner came in to visit her, and Dr. Crow explained the situation. He said that she was having trouble breathing because fluid (probably blood) from the mass had built up inside her pericardium, the sac around her heart. We could drain that fluid (do a pericardiocentesis) and send her home. If it was actually a chemodectoma, she might do well for a while. If it was hemangiosarcoma, she was likely to have some very serious issues in the next few days.

The owner, after a great deal of soul searching, elected to euthanize the dog. If she had chosen the pericardiocentesis, she would still have had to leave her dog in the hospital for at least 36 hours, to make sure that the pericardium did not fill right back up with blood. If she had then taken the dog home, she would have had to deal with the possibility that the dog would have had little to no time before something else bad happened. Few owners want to deal with the chance of their dog being unable to breathe, and having to rush back in to the hospital with a dog in the car that might go into respiratory arrest. I suspect I would have chosen the same thing.

I learned from this case, as I had from so many others during my medicine rotation, that the one-word summary of an animal’s problem can lead you down the wrong road. And yet every time I am drawn in by the easy answer. I suspect that learning to keep an open mind is part of learning to be a good clinician.

2 comments:

  1. It seems to me like "hermangiosarcoma" is the problem that all dogs have when they go to the hospital. I think we should just one-word diagnose all dogs with that condition.

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  2. Heh. Well, it is definitely true that at a referral hospital like my school, crammed with specialists, we get the cases that primary care vets can't or don't want to handle, and I imagine that the ways that hemangio tends to present would make it high on the list of things that get referred. I have been somewhat horrified at the amount of hemangio I have seen during my short time in the hospital so far. It is not a nice cancer and I wish it happened less often.

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