How To Tell If Your Vet Gets It
How To Tell If Your Vet Gets It
The "expert", in any profession, doesn't always know best
Veterinarians do important work. When dogs fall ill or need life saving surgery we all rely on their skills to get our pups and other critters back to health. We value what they do. When it comes to diet, however, we tend to put too much pressure on them to have all the answers.
Most vets are not trained on the vastly different dietary needs of common domestic animals. For example, cats are obligate carnivores and need to eat mostly meat. Dogs are facultative carnivores and can eat a variety of plants, while rabbits and hamsters are primarily herbivores and eat plants, seeds and fruit. It’s easy to forget just how much information they’re expected to know. Unless they’ve specialized in one area, it’s unlikely they are deeply knowledgable in all of them.
If it matters to you that your vet is nutritionally knowledgeable, we have some critical questions you can ask them to see if they know their stuff.
Before that, here’s the recipe for Doggy Swedish Meatballs:
In both veterinary school and (human) medical school, the nutrition curriculum students are required to take is minimal. For medical schools, estimates range from 20 -30 hours over the entire four years of the coursework. Most programs do not require separate nutrition courses. This paper calls nutrition education in medical schools rudimentary. For veterinary schools, it’s highly program dependent, and there is generally more nutrition, about 40-70 hours, but spread across multiple species. This survey suggests the vast majority of veterinary students find nutrition education to be lacking in the US and Canada.
The challenge comes when pet parents expect vets to know the answers to dietary questions. Most people prefer not to sound ignorant. But unless your practitioner is a vet nutritionist, which are only a small percentage of vets, how much a vet actually knows about pet diets depends on how much research they do on their own. Below are questions you can ask to learn how well your vet understands the literature, plus an extra question on statistics. They go from softball to hard.
#1 - Are avocados toxic? How do you know?
The answer is no. If your vet says yes, they haven’t done the research (beyond googling).
In the veterinary literature there is a false belief that avocados are toxic. Several highly cited research papers cite studies that relate avocado consumption to toxicity in dogs. BUT MOST RESEARCHERS NEVER READ THE ORIGINAL SOURCE. This is often referred to as citation layering, where an author cites one paper that cited another and so on, without ever reading the fundamental source. We read it, and it’s an anecdotal account from Kenya in 1994, where two dogs who were “fond of avocados” died at an animal hospital. At that time Kenya was not known for its rigorous scientific research.
Coincidentally, after we shared the link in our previous newsletter it got taken down. Here is a picture excerpt, but the key point is that both dogs were neglected, sick and emaciated for years before dying. The only evidence of avocado toxicity is that they lived on farms with avocados, and it’s possible that it’s all they had to eat.
How and why this paper started a whole myth on avocado toxicity is anyones guess.
Avocados skin and pits contain the toxin persin, but the amounts are minimal in the flesh and perfectly fine for both dogs and humans to consume in moderation.
#2 - How toxic is chocolate?
If your vet says all chocolate is equally toxic, they don’t understand what actually makes it toxic.
The answer to this question is nuanced. It depends on the type of chocolate, but a good analogy is that chocolate is about as toxic to dogs as alcohol is to humans. The toxic compound in chocolate, called theobromine, is most concentrated in cocoa powder, which most dogs are unlikely to find appetizing. Baking chocolate and 90%+ dark chocolate are the most dangerous types with about 30-40% of their weight in cocoa powder. (The rest is sugar and cocoa butter, which contains minimal amounts of theobromine.) Milk chocolate typically contains less than 10% cocoa powder.
To put this into perspective, a small dog weighing about 15 pounds would need to eat one whole 3 oz milk chocolate bar to have symptoms, or 4 milk chocolate bars for a potentially fatal dose. This is like an adult (150 pound) person eating 5 milk chocolate bars for a symptomatic dose or more than 20 milk chocolate bars for a potentially fatal dose. Dark chocolate, like distilled alcohol, can be dangerous, but fatalities from chocolate poisoning are very rare. See this study of 156 dogs who were seen by the vet for chocolate poisoning over four years (already a higher bar as most people don’t go to the vet for small amounts of chocolate). Of the 156 dogs, 112 had no symptoms, 44 showed symptoms, but only one died. The most severe cases were due to dark chocolate consumption.
#3 - What is the false-positive rate of pancreatitis tests?
People are often concerned about their pets developing pancreatitis, but what they don’t know is that pancreas specific lipase tests have a false-positive rate of up to 40%! If your vet doesn’t know this, they may be falsely diagnosing pancreatitis and believe the risk of dogs having it is higher than it actually is.
Healthcare professionals are notoriously bad at understanding statistics. According to research done by the New England Journal of Medicine 50 years ago, up to 80% of medical practitioners incorrectly answered basic statistics questions about the incident of disease. You would expect this to get better over time, but the same questions were asked in 2014 at Harvard University and the results were nearly identical. If Harvard University is this bad what about other hospitals?
BONUS QUESTION — Understanding statistics
If you can ask this question without sounding pretentious, and get a correct answer, your vet has an elite understanding of statistics.
The question is as follows:
“If a disease has an incident of 1 in 1000 and a false positive rate of 5%, a patient with a positive test has what chance of having the disease?”
Less than 20% of healthcare providers surveyed in the above study got this question correct. So if you don’t know, don’t feel bad. The most common answer is 95% because there is only a 5% false positive rate. Most Harvard doctors and medical students answered the same. In case you don’t know, false-positives are positive results while actually being negative, called a type 1 error. False-negatives occur when the sample is actually positive, but the test shows negative, called a type 2 error.
The correct answer is just under 2%. The reason is false-positive rates have nothing to do with the incident of the disease, it only has to do with the test. Rare diseases affect very few people, so similarly, with 5% type 1 errors there will be many positive tests but few actual cases.
Here’s the math. If the incident is 1 in 1000, and 1000 people take the test, on average 50 people will get a false-positive result (5% of 1000). However, because it’s so rare, only one person will get a true positive result. Therefore the likelihood of actually having the disease with a positive test is only 1 out of 51 or 1.97%. This is a huge difference from 95%! Imagine if a doctor told you your chances of having a disease was 95% when it was actually less than 2%. So as we always say, it’s important to understand the science ourselves so that we don’t get fooled by someone else’s misunderstanding.
Conclusion:
Healthcare providers have an extremely important job. There is no replacing this much needed expertise. However, we as consumers should not over-rely on their knowledge, especially in situations where healthcare providers are not specifically trained. We always strive to be your primary source for dog nutrition related information. Unfortunately, because we aren’t “experts” we won’t ever tell you we know something for sure. We can only share with you what we find to be good research. If you ever have any questions or conflicting evidence, please share it with us.
That’s all for now.
All the best,
Joelle and the Precious Creatures Team