 Ultrasounds of animals who have eaten the contaminated food in most cases show cortical echogenicity, perirenal fluid and pyelectasia.One of the largest veterinary hospital chains in the U.S., Banfield, has released statistics on the recent rates of pet kidney failure.Banfield's veterinarians treat an estimated 6 percent of the nation's cats and dogs, and their findings provide "the most authoritative picture of the harm done by the tainted cat and dog food," according to the FDA.