Pet Food Recall Update – Melamine Information
Dr. Ernest Ward, Jr.

 The recent pet food recall has left both pet owners and veterinarians confused and concerned. The recent implication of melamine as the potential toxic compound found in wheat gluten has raised questions about what it is and how did it get in pet foods. Continue checking the official manufacturer’s website, www.menufoods.com/recall, for the latest information.

 What is Melamine?
Melamine is a cyclic amino compound which is part of the triazine family of chemicals. It is produced from urea and exists as a monomeric powder.

What is melamine used for?
Melamine is chemically crosslinked with formaldehyde to form plastic laminates, the most common of which is Formica. It is used in plastic utensils. It is also used as a flame retardant and a non-protein nitrogen source (fertilizer), when combined with appropriate microorganisms that can metabolize the compound into urea or ammonia.

Is melamine toxic?
As far as we can ascertain, melamine is minimally toxic. In chronic dosing studies, rats developed cystic calculi (bladder stones) and consequent carcinomas of the bladder after 6 months of administration. There is virtually no mention of nephrotoxicity in the published literature. It is considered a mild ecological toxin, and generally safe in a work environment (inhalation and dermal or mucosal contact). Surprisingly, melamine has a diuretic action.

Is melamine present in the affected foods?
Yes. Studies by the FDA have confirmed that melamine is present in the affected foods. It is not present in other foods tested. It is present in the gluten used in the manufacture of the affected foods.

How does this translate into dietary toxicity?
If extrapolated from toxicity studies in rats (and assuming cats have the same acute toxicity doses as rats), cats would need to consume about 4kg (almost 2 lbs) of food per day to approach the rat LD50. Thus, we are skeptical of the ability for melamine to produce toxicity that is being reported.

Can melamine act as a marker for affected individuals?
We believe so. Since it appears to be present only in the contaminated foods, and is relatively easily detected in urine and kidneys of affected animals, melamine may be a reasonable marker of exposure to affected diets. This may help rule out dietary causes of acute renal failure. However, more information is needed to determine the validity of this hypothesis.

How can melamine be detected?
Currently, melamine is detected by mass spectrometry, which is not routinely available. However, if testing options become available, we will update this information.

What is wheat gluten?
Gluten is a shapeless mixture of proteins found combined with starch in some cereals, notably wheat, rye, and barley. It constitutes about 80% of the proteins contained in wheat, and is composed of the proteins gliadin and glutenin. Gluten is responsible for the elasticity of kneaded dough, which allows it to be leavened, as well as the "chewiness" of baked products like bagels. It is commonly used a thickening agent for gravy and broth.

How did melamine get into pet food?
The wheat gluten was reportedly made in China, transported to Kansas City and then distributed to Menu Foods plants in New Jersey and Kansas by ChemNutra. The contamination allegedly occurred in China.