Visiting Veterinarian

Not fit for man nor beast

By Michele Gerhard Jasny V.M.D. - May 10, 2007

What a mess! How did it all begin? Seems an unnamed pet food company was having a new flavor of cat food produced by Menu Foods. Wait a minute. Before we go any further, who or what is Menu Foods? It doesn't sound like a well-known pet food brand like Purina or Iams or Eukanuba. That's because Menu Foods is kind of like a big ol' factory kitchen that "cooks" for lots of different pet food companies. Since it takes special equipment to slice and dice those tasty morsels just right, many companies give their recipes to manufacturers, like Menu Foods, and say "Here! Buy some groceries and whip us up a batch of Yummy Gummy Kitty Goulash."

So before this undisclosed company released their new flavor to the general public, they did feeding trials. I'm not clear if these trials were for palatability or nutritional evaluations, but it doesn't really matter. What matters is that a bunch of the kitties sampling Yummy Gummy Goulash developed kidney failure. Everyone involved assumed the problem was specifically related to Yummy Gummy Goulash, so they stopped the trials and threw away the recipe. Problem solved.

Only then something scary happened. Pets began getting sick, even dying, with kidney failure after ingesting certain pet foods, specifically some of the "cuts and gravy" style products. The Food and Drug Administration (FDA) got on the case and began recalling pet food. Initially the problem seemed limited to a small number of canned and pouch moist foods all produced at Menu Foods.

Focus falls on melamine

The FDA tested samples of the recalled food, looking for what might be causing the kidney failure. Toxins like antifreeze, heavy metals, and several pesticides were quickly ruled out. A New York State laboratory reported that they had isolated a compound called aminopterin, a product used as rat poison in some countries, but this was quickly discounted when the FDA's Forensic Chemistry Center was unable to confirm this finding. Continued testing eventually did turn up something unusual and repeatable. Melamine.

What's melamine? Well, it ain't supposed to be in food. Melamine is a small, nitrogen-containing molecule that is used as a fertilizer in Asia. In the United States it is used as an industrial binding agent, flame retardant, and part of a polymer in making cooking utensils and plates. But there it was - melamine in Yummy Gummy Kitty Goulash, where it was not supposed to be. Further research narrowed the melamine contamination to one specific ingredient. Wheat gluten.

Okay, so what's wheat gluten? It's a protein derived from wheat flour used as a filler and binder in gravy-style pet foods... like when Grandma mixes a pinch of flour in the gravy to make it thicken. Here's where we run into a little mystery. Wheat gluten is not toxic and, although there has not been a lot of research done on melamine, what little there is does not suggest that it is highly toxic. Yet melamine seemed to be the absolutely consistent factor, found in all the recalled foods, as well as in the urine and tissues of affected pets. Currently scientists are not 100 percent sure that melamine is the causative agent, but it is clearly a marker for the toxic substance.

So how did melamine get in the wheat gluten? The source was rapidly traced to wheat gluten imported from a specific company in China. There is speculation that the melamine was added intentionally to boost the nitrogen content of the wheat gluten, thus making it appear to have more protein, which might increase the market value, but this is just a theory. No one knows for sure. All the shipments of potentially contaminated wheat gluten were traced, the pet food companies informed, and the pertinent products voluntarily recalled.

"Well, there!" we all thought. The problem has been located and contained. Thank God that's taken care of." When clients called, I told them if they wanted to be extra careful, avoid any foods that contained wheat gluten, and they should be fine. But then something else occurred. Melamine was found in some rice protein concentrate (also imported from China) in the United States and in corn gluten in South Africa.

Definitive answers elusive

Owner after owner called in a panic. What should they do? Was the brand they used safe? What if their pet had eaten some of the recalled product? What should they feed their pet? Should they start home-cooking?

It has been difficult to answer these inquiries definitively. We still don't know for sure what is causing the problem, although the correlation with melamine contamination is obviously significant. We still don't know the long-term implications, nor can we say with complete assurance that all sources have been identified. On the other hand, we don't want to throw the baby out with the bath water. The recall actually involves a very small percent of the available pet food on the market today. There are still many safe diets out there. Here's what I am currently advising my clients, and what I am doing for my own pets.

Check several web sites daily for updates. Initially we advised relying on www.menufoods.com but not all recalled foods are noted at this site. Other sites to check include www.avma.org and www.fda.gov. If your usual brand is not on the list, it should be fine to feed. If you want to be extra paranoid (like me), avoid all wheat gluten, corn gluten, or rice protein concentrate. (Although as of this writing the FDA has banned importation of wheat gluten from China and is testing several other different foodstuffs to make sure they are free of contaminants.) Do not feed anything that is on the recall list! They should all be off the shelves by now but check carefully. Only certain lots are affected. Do your homework. Check the "Best by" dates and the UPC codes. Please do not call my office and ask us to do this. We just cannot do the footwork for everyone. If you definitely have unopened recalled food, you can return it for a refund.

If your pet ate recalled food, initially we were not suggesting any tests unless your pet showed signs of illness. This recommendation has changed. I now advise a baseline chemistry profile, complete blood count, and urinalysis. If your pet is sick, call your veterinarian immediately and save all pet food packaging. Cats and small dogs seem to be affected more frequently than larger dogs. Symptoms may include loss of appetite, lethargy, vomiting, sudden changes in water consumption or changes in frequency or amount of urination. (Remember these symptoms can also be caused by many other diseases.) There is no specific antidote for melamine, but your veterinarian can provide treatment for kidney failure.

Home-cooked complications

If you decide to home cook, beware. It won't do your pet any good if you avoid commercial pet food but then create a serious nutritional deficiency or give him food poisoning by home cooking. Pets' nutritional needs and preferences are different from humans. Dogs are different from cats. Formulating a complete and balanced diet is tricky. If you are determined to play chef, get veterinary advice. Try www.petdiets.com/ or www.balanceIT.com for recipes. Do not substitute or leave out ingredients because you can't find them. Do not feed homemade diets for more than two months. Hopefully by that time, this whole mess will be cleaned up.

A worrisome recent development is the news that melamine-tainted pet food has been fed to hogs destined for human consumption. As I write this, the FDA says there is no indication that melamine-contaminated products have been shipped directly to any facility that produces food for human consumption, but they are now testing all wheat gluten, corn gluten, rice protein concentrate, corn meal, rice bran, and soy protein imported from China. So much is still unknown. By the time this goes to press, the details may have changed again. Food recalls are nothing new and most cases of kidney failure we are seeing are unrelated to pet food consumption, but this has been a frightening and uncertain time for pet owners. Don't ignore the risks. Don't overreact. Educate yourself. Make informed decisions based on fact, not fear, but keep checking the facts.

This column is dedicated to Horatio. We are waiting on the final test results to determine if melamine-tainted pet food caused his fatal kidney failure.