Don't Automatically Trust What You Read
Reliable Sources Can Let You Down
So here I am leafing through my dog-eared copy of the February, 2011 edition of the Brazil-based Journal of Venomous Animals and Toxins including Tropical Diseases. Within its pages I come upon a review article that says onions will cause hemolytic anemia in cats.
I’ve written a few times about onion toxicity over the years. It doesn't hurt to raise the flag every now and then.
But in talking with pet owners about feeding table scraps, I often hear the comment, “…but I wouldn’t feed chocolate or raisins or onions.” Most pet owners get it by now. But, I digress.
Actually, I wasn’t going through the above named journal. I was reading the October, 2011 issue of “Catnip,” a publication of the Cummings School of Veterinary Medicine at Tufts University.
The publication quoted the above named Brazil-based journal in its “Mews in the News” section under the headline, “Study validates that cats should not eat onions.” I found what I consider to be an egregious error.
The section’s author quotes the Brazilian journal reporting that onion toxicosis is “consistently noted in animals that ingest more than 0.5 percent of their body weight in onions at one time,” then goes on to add (quoting the Catnip author now), “which translates to a 10-pound feline eating about one-half pound of onion.”
That’s an easy math error to make, I suppose, but it’s a major error that should not have escaped proof readers.
If I did my gozindas correctly, a ten pound cat would only have to eat about eight-tenths of one ounce of onion to exhibit signs of onion toxicosis. A half pound equals 0.5 percent of a 100 pound animal’s weight, not a 10 pound animal.
I remember a similar math error regarding the toxic dose of theobromine, the main toxic agent in chocolate, in a similar publication from a different school of veterinary medicine back in the mid-90s. Back then I wrote to them about the error and it was corrected in a subsequent issue.
So, even highly credible, authoritative sources can make mistakes. But to laypersons who rely on those authoritative sources, it’s a real kick in the gut when they give you a bum steer.
As a practical matter, the realistic dangers of onion toxicity are disputed by some professionals, but the subject won’t go away. Interestingly enough, there have been reports of Heinz-body hemolytic anemia in some dogs caused by skunk spray, because of alkyl mercaptans and disulfides found in the substance a skunk releases when it sprays.
I Googled: skunk spray hemolytic anemia and found a number of sites that talked about it. The 2005 May 1 issue of JAVMA (Journal of the American Veterinary Medical Association) describes a case of Heinz body anemia in a dog that was sprayed with skunk musk.
It’s not unusual for well-credentialed scientists, embracing divergent scientific principals, to disagree. Look at the global warming debate, for instance. One can read the writings of certain experts and learn certain information that one would expect to be able to take to the bank.
Then, one could read the writings of another equally credentialed expert who espouses entirely different principles, and one could rightfully expect to take that information to the bank as well. I find that frequently as I research subject matter for my columns.
When that happens I search around to try to come up with a consensus of opinion and, failing that, I report both sides of the argument and let the reader decide which side to get behind. In my opinion (an opinion? moi?) a publication reporting its position on a debatable subject is fine, but reporting inaccurate information is unacceptable, especially if it's in error.