Raw meat diet: not enough scientific validity to support use
Jan 1, 2004
By: Walt Ingwersen, DVM, DVSc, Dipl. ACVIM
Aside from the current debate over vaccination protocols, few topics engender such controversy as the nutrition we provide to our companion animals (or ourselves, for that matter).
It seems at times that pet owners are more inclined to make decisions based on anecdotal information, personal opinion and the latest "fad" rather than the substantial and growing body of science-based nutritional data that has contributed to the longer life span that our companion animals currently enjoy.
While no one would disagree that the motivation to provide for a healthier life is common regardless of which diet is chosen, the choices made can have significantly different outcomes.
The November/December 2003 issue of the Journal of the American Animal Hospital Association provides a case report detailing the occurrence of septicemic salmonellosis in two cats fed a raw meat diet (Stiver et al. Septicemic Salmonellosis in Two Cats Fed A Raw-Meat Diet. J Am An Hosp Assoc 203;39:538-542. Accessible via www.jaaha.org).
The two cats were part of a cattery environment and demonstrated clinical signs of gastrointestinal upset, weight loss, and anorexia that quickly progressed to a moribund clinical state and death. Postmortem examination confirmed septicemic salmonellosis as the underlying etiology with tissue cultures identifying Salmonella typhimurium in one cat, and Salmonella newport in the other. Similar culture results were obtained from the raw food fed to the latter cat.
While this report is the first to describe the occurrence of salmonellosis in cats secondary to a homemade raw-food diet, the results, at first glance, may appear to hold little clinical significance as salmonellosis has been identified in other species under similar circumstances. Raw food diets have been associated with a variety of infectious agents common to both pets and people, including Salmonella spp., Campylobacter spp., Escherichia coli O157, Yersinia enterolitica, Listeria monocytogenes, Clostridium perfringes, Clostridium botulinum, Staphylococcus aureus, and Bacillus cereus (LeJune et al. Public Health Concerns Associated With Feeding Raw Meat Diets to Dogs. J Am Vet Med Assoc 2001;Vol 219, No. 9:1222-1225.) The feeding of these diets has been a relatively common practice in dogs, particularly racing Greyhounds and sled dogs, but is also a growing trend for some pet owners. Sources include commercially available diets, homemade diets (e.g., bones and raw food [BARF]), as well as through supplementation (whether provided by the owner or secondary to outdoor hunting/scavenging.) There are reports of raw food diets resulting in clinical salmonellosis in the canine and this has prompted a health advisory regarding dog treats made from pig's ears, rawhide, and cow hooves (Food and Drug Administration. FDA issues a nationwide public health advisory about contaminated pet chews. Health and Human Services News. Available at: www.fda.gov/bbs/topics/NEWS/NEW00692.html).
However, what is of emerging clinical significance is the growing body of information that demonstrates these diets pose a health risk not only for the pets that consume them but to their owners as well.
Other than a small number of Salmonella spp. (S. typhi and S. paratyphi A and B), all other species are considered to pose a zoonotic concern.
The Centers for Disease Control and Prevention (CDC) reports that most cases of human salmonellosis are caused by four serovars: S. enterica ser Enterididis, S. ser Typhimurium, S. ser Newport, and S. ser Heidelberg (Sanchez et al. Animal Sources of Salmonellosis in Humans. J Am Vet Med Assoc 2002; Vol 221, No. 4:492-497). These Salmonella spp. have been commonly identified in companion animal salmonellosis, with the zoonotic potential clear. There are multiple potential sources of human exposure that can be traced to companion animals including a pet with clinical salmonellosis, a pet with asymptomatic salmonellosis shedding the organism via its stool, and as a result of raw-food diet preparation. The feeding of raw food diets has recently garnered the FDA's attention, and they have been identified as a potential public health risk. This has resulted in the establishment of guidelines to protect both pets and their owners (Guidance for industry #122 available at www.fda.gov.cvm/guidance/published.htm#published_3). Also, those counseling the immunocompromised on safe pet ownership have consistently recommended that raw-food diets not be fed, but rather a commercially available or cooked diet be used instead (Greene. Pet Ownership for Immunocompromised People. In Current Veterinary Therapy XII. W. B. Saunders Co.: 271-276).
“Some people are really into a raw-food diet for pets, but it’s a huge public health hazard. Think about it: You have raw meat, you’re touching it, your dog touches it, and then your dog goes and licks the baby. I’ve had two patients die and two patients get really sick from it.”—Amber Andersen, DVM, a vet at Point Vicente Animal Hospital in Rancho Palos Verdes, California.