DEAR READERS: The Clean Label Project completed a study of over 900 pet food products from 71 brands. Products were screened for over 130 toxins. See cleanlabelproject.org/product-ratings/pet-food for more information and handy infographics about the results.
In my opinion, the high and concerning levels of lead, cadmium, arsenic, pesticides, nickel, chromium and mercury in some pet foods, and the low levels in others, can be traced to the kinds of animal parts and byproducts being recycled into pet foods.
I am referring to the vast tonnage of factory- and feedlot-raised animals and fish killed and discarded as unfit for human consumption; remains of euthanized horses; and hundreds of thousands of worn-out milk cows, exhausted breeding sows and spent laying hens. The older the animal, the greater the bioaccumulation in the bones, livers and other body parts. By inference, the safest animal parts come from those killed at an early age. This enormous fraction from the animal industries is widely used by the pet-food industry to recycle the low-cost animal remains of a carnivorous culture that still refuses to accept the adverse health and environmental consequences of including beef as a dietary staple.
The Clean Label Project's rating of pet foods, according to pet-food consumer advocate Susan Thixton, raises some suspicion by giving many waste-ingredient pet foods high ratings. Regardless, this is an alarm bell to the pet-food industry and to pet owners and veterinarians. The older the farmed animals are and the higher in the marine food chain the fish are, the more loaded with these and other toxic chemicals they will be. This is a classic example of environmental and food-chain contamination due to our continued, collective sins of omission and commission with regard to social responsibility and effective planetary stewardship.
DEAR DR. FOX: Large dogs have larger brains than small dogs. Are large dogs potentially smarter than small dogs? -- R.P., Washington, D.C.
DEAR R.P.: It would be logical to assume that the bigger the brain, the greater the intelligence, but biologically, it has more to do with the ratio between body size and brain size.
Small dogs have more compact bodies and brains than large dogs and are relatively equal in terms of overall intelligence. Intelligence tests, as I detailed in my book "Superdog," are compounded by animals' motivation and cognitive abilities, attention span and how easily they are distracted.
Domesticated animals generally have smaller brains than their wild counterparts of similar body size. Poor nutrition in early life and prenatally can impair brain development and later cognitive abilities in humans and other animals.
Being raised in physically, emotionally and intellectually stimulating environments may, as biologist Charles Darwin theorized, account for the larger brains seen in some species compared to their domesticated counterparts.
CATS FED DRY FOOD ONLY MAY HAVE ELEVATED DIABETES RISK
A survey of the owners of more than 6,700 cats in Sweden found a higher risk of feline diabetes in cats fed primarily dry food than in cats fed mostly wet food, researchers reported in the Journal of Veterinary Internal Medicine.
Obesity was a key risk factor, but the dry food link to diabetes held among normal-weight cats, and the animals were also more likely to have feline diabetes if they ate a lot of food, primarily stayed indoors and got minimal exercise.
(Send all mail to email@example.com or to Dr. Michael Fox in care of Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.
Visit Dr. Fox's website at DrFoxVet.net.)