Aminopterin Poisoning from Pet Food - What to Do

On March 24, 2007, Menu Foods Issued a pet food recall for its "cuts and gravy" wet pet food. The pet food has been found to be contaminated with aminopterin (4-aminopteroic acid, 4-amino analog of folic acid), a drug and rodenticide that can cause kidney damage and death in pets. There is no reason to suspect other pet foods are contaminated.

There is a lot of information about how dangerous the poison is to your pet, but mainly people are wondering what to do if they think their pet may have been exposed and how they can tell if their pet is safe. I've collected some information and resources to help you out.

What to Do if You Used a Recalled Food

• Discontinue using the food. The toxicity of aminopterin is dose-dependent, so the lower the dose, the better the prognosis.
• Keep the food, in case it needs to be tested. There is no blood test for your pet for aminopterin, though the food itself can be tested. You don't want to risk accidentally using the food, so I would pass the food along to your vet for safe-keeping. The FDA is recommending disposal of opened food (it's perishable), but if your pet is showing signs of poisoning, the vet may wish to submit it for testing.
• Call your vet for the latest advice.
• Look for symptoms of poisoning in your pet, which would include loss of appetite or vomiting, excessive thirst, excessive urination, and possibly diarrhea.
• If you suspect poisoning, contact your veterinarian. Your vet can determine if your pet is suffering from kidney damage, which is the primary damage caused by aminopterin.
• Be sure water is available to your pet at all times.
• If your vet has looked at your pet's bloodwork and determined its kidney function is fine, then relax. Yes, rodenticides are relatively slow-acting, but if there is no apparent effect and there is no possible further exposure, your pet should be fine. The damage from exposure is relatively quick, within a few hours, with the most severe effects usually seen on the third or fourth day following exposure. If it has been longer than a week since your pet ate any suspect food, it should be past the point of showing symptoms had it been exposed.

Although the recall is recent, apparently it has been known since February there was a possible issue with the pet food. If you have fed the recalled food to your pet at any time since December 2006, I would recommend having your pet checked, just for your own peace of mind, whether or not you see any symptoms of kidney damage. There are medications which might be of use in treating confirmed aminopterin exposure, but the primary care will be ensuring hydration and watching the acidity of the blood to prevent crystal formation in the tubules of kidneys (obstructs them and worsens the damage). Kidney damage is believed to be at least partially reversible, but exposure would be expected to carry some long-term health risks.

Resources for Further Reading

• Information for Veterinarians
• Aminopterin Facts
• Pet Food Recall Information
• March 2007 Pet Food Recall FAQs

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