On April 17, 2007, Natural Balance Pet Foods recalled all of its venison products for dogs and the Venison & Green Pea Dry Cat Food after melamine was discovered during laboratory tests. A new ingredient - rice protein concentrate - was contaminated with melamine, according to company reports. The initial announcement included dry dog and cat food but company officials have extended their voluntary recall to include all venison products for dogs, including treats. The voluntary recall was prompted by complaints that pets were vomiting and experiencing kidney problems after eating the food, according to a press release posted on the Food and Drug Administration (FDA) website. The products are sold in specialty pet stores and in PetCo locations nationally.

Throughout North America, toxicologists continue to look for a causative agent in the death of pets that consumed recalled food that contained melamine and byproducts.

To aid in that search, practitioners and pathologists have begun entering data into an online survey designed to identify criteria for pet food related nephrotoxicosis (renal failure caused by a chemical agent). Pathologists have seen tissues and cadavers from cats and dogs that consumed recalled food and had kidney lesions and unique crystals, but the survey designed by the American Association of Veterinary Laboratory Diagnosticians (AAVLD) will clarify the picture, said Barb Powers, DVM, AAVLD president.  At press time, 224 practitioners and pathologists had submitted case data to the AAVLDs online survey.

The overriding question remains: Is melamine the culprit or is it a marker for something else? Diagnostic laboratories are looking at compounds derived from or related to melamine, said Steven Hansen, DVM, a board-certified toxicologist and vice president of the American Society for the Prevention of Cruelty to Animals (ASPCA).

About 20 laboratories in the U.S. and Canada are investigating whether melamine metabolites (including cyanuric acid hydrolase) that occur during production could cause lesions in the kidneys, said Brent Hoff, DVM, DVSc, a clinical pathologist and toxicologist at the Animal Health Laboratory at the University of Guelph. Although the theory has not been proven, scientists question whether an impure melamine product was used in recalled food and is causing death in pets, Hoff explained. “Melamine itself shouldn’t cause the lesions we’re seeing,” he added.

Existing pathology includes “unique” crystals found in urine and tissue of pets that ate recalled foods and lesions in the distal tubules of the kidney. Powers said the crystals are a yellow green color with birefringent properties. They are round with concentric rings.

Doctors suggest acute renal failure therapy for patients that present with recall-related symptoms, Hansen added. Treatment suggestions are published on the American College of Veterinary Internal Medicine website in a PDF format.

Although exact numbers have not been tallied, Hoff believes about 50 pets in Canada were affected by the recall – with 30 deaths – and that about 200 pets in the United States were affected. Hoff has seen two dogs at the University of Guelph and had heard about three others in Canada.
AAVLD survey questions, which cover pet breed, age, sex, and predisposing conditions, will help veterinary toxicologists understand why more cats than dogs were killed by the contaminated food and may provide other answers, Hoff said.

Criteria for cases and the use of a standardized toxicological assay, modified for body tissues, should provide answers to mounting questions about the recall as the number of brands affected continue to increase. [A full article on the survey is published in Take Note.]

Manufacturer announcements on April 5 and 10, 2007, expanded the pet food recall to include one Royal Canin Canada cat food product, Sunshine Mills dog biscuits, and Menu Foods products made in November 2006. Several brands made at the Menu Foods plant Ontario were also added to the list, which is available on the FDAs website. A recall update is also available online.

Sundloff confirmed melamine as the contaminant in food and linked it to crystals found in urine and tissues from pets, but added that toxicologists cannot identify a direct link between melamine and at least 16 pet deaths. He said the FDA figure may be low and acknowledged that some organizations – including the Veterinary Information Network – show that thousands of pets have been affected by recall-related illness and death.

As the recall unfolds and the investigation continues, FDA officials face criticism from politicians who say the government’s response was too slow, that safety measures should be higher, and question a time lag between deaths reported to Menu Foods and the announced recall on March 16, 2007.

On April 12, the U.S. Senate held an oversight hearing with FDA officials and veterinarians to address those concerns.

The same day, the Pet Food Institute (PFI) announced the creation of a National Pet Food Commission that comprises veterinarians, toxicologists, state and federal regulators, and nutritionists. The charge of commission members is to investigate the recall and “build on safety and quality standards already in place,” according to the PFI.

Prior to the PFI announcement, at least one consumer group called for an independent review of pet foods since PFI represents pet food manufacturers.

Hansen said the ASPCA would prefer to see the creation of an FDA-based commission, but added “I presume they will produce good information.”

Recall Information
As recall announcements continue – with Sunshine Biscuits, Royal Canin Canada and more brands produced at Menu Foods facilities – the FDA has emphasized the safety of 99 percent of commercial pet food.

“There is plenty of safe food,” said Stephen Sundloff, DVM., PhD, director of the FDA’s Center for Veterinary Medicine. “The public should feel secure purchasing food not on the recall list at this time. We think we have it all traced out,” he said, referring to wheat gluten imported from China that contained melamine.

Patricia Kennedy Arrington, DVM, owner of Jefferson Animal Hospital & Emergency Center in Kentucky, emphasized a calm approach to the recall during the 19 television interviews she has conducted. A member of the Veterinary News Network, Kennedy recognizes the public relations nightmare that the pet food industry faces and believes that veterinarians can help by emphasizing the ease of testing pets for kidney disease and by talking with clients about the quality of most pet foods.

"The general public seems to think all pet foods are made in the same kitchen now," she said. "They dont understand that there are different recipes, and thousands of facilities. Veterinary medicine has the best nutrition for animals. There are excellent foods out there."

Recall List
On April 10, 2007, Royal Canin Canada recalled Medi-Cal Feline Dissolution Formula canned diet, sold by veterinarians, “because one production lot (Jan. 8, 2009) contains contaminated wheat gluten,” according to a company press release. As of April 12, 2007, the website for Royal Canin USA carried the following message: “Royal Canin USA wishes to assure pet owners that our dry and wet pet food products are not involved in the ongoing FDA investigation related to the recent nationwide pet food recall initiated by Menu Foods and other companies.”

The FDA is now sampling 100 percent of the wheat gluten imported from China and news reports indicate that melamine may have been added to boost protein levels in the products.

During a press conference on April 5, 2007, FDA officials emphasized that their investigation began 24 hours after Menu Foods alerted the agency to a problem on March 15, 2007, amid questions about when Menu Foods first recognized a problem with food products.

In response to questions about a timely response to the recall, FDA professionals cited a lack of resources. Professionals referred to fact that there is not a veterinary equivalent to the Centers for Disease Control and Prevention, which helps trace human-related incidents. Yet Powers said that a similar organization exists.

The AAVLD works with the United States Department of Agriculture to identify livestock diseases through the National Animal Health Laboratory Network, a group that was considering the addition of toxicology to its mission several weeks before the recall was announced.

Powers has offered to share data from the survey with the FDA and said the recall illustrates the need for more partnerships between veterinary and governmental organizations.\

“We’re all just getting to know each other,” Powers said. Although the National Animal Health Laboratory Network focuses on agricultural issues, Powers said that the addition of toxicology to its purview could make sense. “This could easily have happened to the agricultural food supply,” she added.