Making Veterinary Decisions

Many patients in many countries don’t pay the full cost of their medical care, which makes cost a less important factor in medical decision making, for both many patients and many physicians.

On the other hand, nearly everyone pays the full cost of their veterinary care, and taking your pet to the vet is a good time to think about how medical decisions should get made.

This came up for me recently. I have an 11-year-old Labrador retriever.  My wife took her to our usual vet practice because she had a strange swelling on her flew (upper lip). On this particular day, she saw a new young vet who we hadn’t seen before. He made three findings:

  1. The swelling was an infection, and antibiotics were indicated. He prescribed Simplicef, which the manufacturer describes as “the first and only once-daily oral cephalosporin that’s FDA approved for veterinary use in the treatment of canine skin infections. It’s designed to be convenient and a good value for your large dog.” (from simplicef.com)
  2. Her weight was 57 pounds, about 10 pounds lower than a year ago. He suspected a metabolic disorder (and probably also considered cancer, but didn’t say that), and ordered a panel of blood tests.
  3. He heard a heart murmur, left-side, grade 2-3/6, which had been documented in her chart for several years. He recommended an ultrasound, chest x-ray, and ekg.

I like veterinarians. I think they’re good people with the interests of animals at heart. That said, in this particular consultation, several avoidable errors were made that illustrate some key principles of medical decision making (for humans as well as dogs):

  1. The dog improved on the first 14-day course of Simplicef, as we all expected, but these infections typically require multiple courses. Readers of this blog will not be surprised to hear that while once-daily dosing may be more convenient than twice-daily dosing, a 14-day course of Simplicef was about $50; the equivalent course of generic cephalexin is about $8. There is no evidence of any difference in effectiveness, and cephalexin has been around a long time, and our dog has taken it before with no ill effects. We pointed this out to the vet, who was surprisingly reluctant to switch for the second course, but agreed. The infection continued to improve on cephalexin. Attention to principles of rational prescribing would have been beneficial here.
  2. The blood tests were all normal, as I had predicted, because I knew something that the vet didn’t — but should have. About 10 months earlier, we changed to a prescription dog food (our dog has arthritis, the combination of glucosamine and omega-3’s we were adding to her regular dog food seemed to be helping, and the new dog food had that all built-in and was cheaper that the cost of the supplements). When we changed food, we continued to feed at the same volume, without considering differences in the caloric content of the food, which turned out to be lower. She was losing weight because she was simply not getting enough calories. I had the vet calculate the appropriate feeding amount and she was gaining weight within two weeks (although that requires titration too — her joints are less painful when she’s lighter, so we don’t want her to gain it all back). The key decision point here – one echoed by many expert human diagnosticians -  is that lab tests can’t take the place of a good history. Had this vet asked “have you changed her food?”, we would have embarked on this trial of increasing her food without the costly blood tests — which, given that she had no clinical fatigue or other symptoms, could certainly have been postponed a few weeks anyway.
  3. Everyone likes to know what’s going on. Naturally, the vet would like to know the cause of the heart murmur. As we point out in the book, however, the main purpose of gathering information is to drive a decision (allaying worry might be a secondary purpose, but that should be the patient’s — or owner’s — worry, not the doctor’s). So I asked the vet what he expected to learn, and how that would affect subsequent treatment. He indicated that they would learn if her murmur was amenable to medical treatment. I pressed for exactly which drugs he was referring to, and he mentioned diuretics and ACE inhibitors. I asked if there was any evidence of benefit for an asymptomatic dog, and he assured me there were several studies. I asked where to find them; he couldn’t specifically cite any, but suggested I search Medline for canine heart murmur studies. Which I did, finding two medium-to-large trials, one showing no benefit and one showing ambiguous benefit (and with several methodological flaws). Now, the veterinary literature is considerably smaller than the human medicine literature, and many fewer well-designed large-scale randomized trials are conducted in dogs. I haven’t yet brought these studies with me to see if (a) I didn’t find some important study that the vet had in mind, (b) he was thinking of these studies and interprets the findings differently, (c) he was thinking of studies in dogs with documented heart disease, in which ACE inhibitors do appear to prolong life by several months, or (d) he was passing along a vague memory of reading these or being told that evidence supported the drugs without checking for himself. Moreover, his recommendation did not consider values in the decision beyond the value of gaining knowledge. Cardiac ultrasound requires sedation, which is a procedure that is not without risk in an older dog. Moreover, medications can have side effects that can diminish quality of life, and these may not be worth extending our dog’s life by a few months. These are crucial considerations in this decision, and this particular vet, on this particular day, missed them.

My wife is a very smart person, but, like most people, not a decision scientist – and she shouldn’t have to be. A veterinarian, like a physician, has far greater expertise and experience in health care than their clients do. When they make a recommendation, it will usually be followed – often without question. That’s one reason why veterinarians (and physicians) also need to become experts in decision making, and why owners (and patients) need to ask good questions and seek out providers who demonstrate a commitment to good decision making.

Comments

  1. gina

    Interesting comments. I would say that the reason the vet used Simplicef is that they have a responsibility to use drugs that are FDA-approved for animals before they can use the human equivalent generic. And yes they do cost a lot more! And if your dog had had a reaction to that generic brand of cephalexin (and had not been on Simplicef, he (the veterinarian) would not have had a legal leg to stand on. Which is why vets tend to shy away from generics

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