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Ask Yvette

Dear Yvette

I read a study that said that Vitamin C cures certain diseases in dogs. Is this true?

Sandy

I'm not sure which study you are referring to, so I cannot offer any comments specifically to Vitamin C and dogs. I do know that there is some conflicting evidence on this topic. What I can offer is some advice on studies and their interpretation. Here are a few tips to help people better judge the validity of a study.

Sample size:
Most people have heard something such as, “Eight out of ten veterinarians asked would serve Krunchy Bits dog food to their own pets.” What you need to ask is, “Exactly how many veterinarians did you ask?” If the company only asked 10 veterinarians, this means that most professionals did not give an opinion. The sample size is not large enough to be accurate. The numbers may still be correct, but they do not accurately represent all veterinarians.

Bias:
Everyone carries a bias. By everyone, I mean everyone. A good researcher asks questions in a way that aims at truth. They set out to disprove a theory. They aim for honest answers. Let's go back to our ten veterinarians and Krunchy Bits. You need to ask, “Who conducted the study and how did they ask the questions?” If management at the pet food company was paying for the study, do you really think you're getting an unbias survey? Not impossible, but not likely.

Random/Blind sampling:
If you want a survey or study to reflect a large group of people, you need to ask a random sample. That means that everyone is represented in some way. If Krunchy Bits only asks veterinarians they employ, we do not know about veterinarians elsewhere. Do you really think that the veterinarian who designed the food is going to feed something else?

Many medical tests are also done double blind. This means that the person giving the test does not know who is getting the drug/vitamin and who is being given a sugar pill. Since they do not know what they are giving, they are not influenced into subtly influencing results. Double blind is usually a good thing.

Interpretation:
How do those researchers present the data? Some are very precise. That is the way it should be. Be careful of conclusions that leap from point A to point B. Good scientists are incredibly picky to say what they mean. Whenever someone quotes a study, ask to see the source.

Correlation does not mean Causation:
It's a rule in psychology. Just because two things are tied together does not mean one causes the other. It is not uncommon to read the certain vitamins might be a “miracle cure.” If you go back to the study, chances are you will find that people who eat lots of a certain vitamin are less likely to get a particular disease. But is the vitamin a miracle cure? Or is it that people who eat lots of food with vitamins generally eat healthy? Is healthy eating the bigger story? You be the judge.

Statistics don't lie. But there are some pretty creative ways to spin numbers out there. If you look at the source documents most of the spin doctoring starts to stand out fairly quickly.

Yvette is an award winning pet writer and pet behavior columnist. She also is the author of Meeting Milo, a North American dog bite prevention program to reduce the approximately 2 million children bit by dogs annually. She is the owner of AwesomeDogs.ca and works as a behavior consultant in London, Ontario.

This column was originally featured in The Londoner
See more of Yvette... www.awesomedogs.ca
www.meetingmilo.com

Yvette has 2 dogs of her own, KIKI and KAYA. Take a look...

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