Page 225 - Small Animal Clinical Nutrition 5th Edition

228 Small Animal Clinical Nutrition

Some advocates of raw food claim that dogs should be fed raw ment with Salmonella enterica have occurred in greyhound facil-
VetBooks.ir meat because their wild canine ancestors survived and present ities in which raw meat was fed (Morley et al, 2006). Unlike
raw food advocates in the dog-racing industry, pet owners share
day relatives survive on uncooked food.There is no evidence to
their household and food-preparation area with their pet. The
support dogs evolved from jackals, foxes or coyotes (Wayne,
1993). Comparisons of mitochondrial DNA indicate that dogs FDA “does not believe raw meat foods for animals are consis-
most likely descended from wolves. However, the mitochondr- tent with the goal of protecting the public from significant
ial DNA patterns of modern dogs and wolves are distinctly dif- health risks, particularly when such products are brought into
ferent, and there is no single wolf ancestor that is common to the home and/or used to feed domestic pets.” Thus, the FDA
all dogs (Semyenova et al, 2002). No compelling scientific evi- has drafted guidelines for companies selling raw meat diets to
dence based on evolution supports statements that dogs should pet owners (2000).
eat uncooked food as did wild canids. Claims that dogs are car- Often, pet owners will refer to the quality of their raw home-
nivores, rather than omnivores, are likely due to confusion of made diet ingredients as “all natural,” “whole food” “or organ-
taxonomy (Carnivora) with feeding behavior (carnivore). Dogs ic,” none of which decreases the potential for microbial con-
belong to the order Carnivora, but their eating habits are those tamination. Numerous studies have demonstrated the presence
of an omnivore (Chapter 12). Panda bears, for example, are her- of bacterial pathogens in retail meat for human consumption
bivores in their feeding behavior, but are included in the order (Sinell H-J et al, 1984; Fenlon et al, 1996; Tamplin et al, 2001;
Carnivora taxonomically. Duffy et al, 2001; Whyte et al, 2001; Zhao et al, 2001; White
Advocates of raw food emphasize the importance of ingredi- et al, 2001; Villani et al, 2005; O’Keefe, 2005). Raw meat diets
ents (Billinghurst, 1993; Schultze, 1998; Volhard and Brown, prepared by pet owners fed to dogs and cats have been docu-
2000) with less emphasis on nutrient balance. Advocates claim mented to contain pathogenic Yersinia enterocolitica 4/O:3,
the nutrients from commercial moist or extruded pet foods are Salmonella spp. and Escherichia coli O157:H7 (Fredriksson-
less or not available or even absent (Pottenger, 1939; Ahoma et al, 2001; Joffe and Schlesinger, 2002; Freeman and
Billinghurst, 1993; Schultze, 1998; Volhard and Brown, 2000) Michel, 2001; Chengappa et al, 1993). Commercially available
when compared with feeding raw ingredients. Although no raw meat diets (beef, lamb, chicken and turkey), sampled over a
digestibility studies of a complete raw diet have been published two-month period, cultured positive for non-type specific E.coli
to date, average apparent digestibilities of nutrients in commer- and S. enterica (Strohmeyer et al, 2006). Of 25 commercial raw
cial pet food have been published. Opponents to feeding raw meat diets (beef, lamb, quail, chicken and ostrich), 64% were
food point out that some nutrients actually are more readily positive for E. coli and 20% were positive for Salmonella spp. In
available from cooked ingredients (Zia-ur-Rehman and addition, 20% were contaminated with Clostridium perfringens
Salariya, 2005), and that overall nutrient availability and balance and a toxigenic strain of C. difficile was isolated from one food
are more significant than for certain individual ingredients. a (Weese et al, 2005). Any claims that a finished pet food is
Advocates of feeding raw food report coat and/or dental ben- “human grade,” or any connotation that a pet food is derived
efits (Pottenger and Simonson, 1939; Billinghurst, 1993; from raw ingredients “like, or similar to, what your own human
Schultze, 1998; Volhard and Brown, 2000) based upon empir- family members eat” is considered false and misleading under
ical and anecdotal evidence (Billinghurst, 1993; Schultze, 1998; current AAFCO rules and regulations. a
Volhard and Brown, 2000); however, some who recommend Advocates of feeding raw meat, bone and eggs claim that
raw meat recognize the limits of using such evidence (Silver, pathogenic organisms in raw meat do not affect dogs and cats
2004).The high fat content (>50%) of raw food diets compared due to the lower stomach pH and shorter GI transit times in
to that found in most dry kibble (<30%) often can account for these species. Stomach pH and GI transit times are in fact sim-
owners’ reports of improvement in the appearance of their pet’s ilar among people, dogs and cats and do not lower the risk to
coat (Dunn, 1999). The incidence of periodontitis and frac- pets. Dogs and cats succumb to foodborne pathogens and
tured teeth, however, increased with age in 67 dogs eating raw exhibit clinical signs similar to those in people (Fredriksson-
animal carcasses with bones in a dental health study (Robinson Ahomaa et al, 2001; Gayle, 2003; Remillard and Wynn, 2005).
and Gorrel, 1997). None of the homemade and commercially Neither freezing raw meat before feeding nor purchasing
available raw food diets analyzed were appropriate for long- freeze-dried commercial foods eliminates pathogens; freezing
term feeding (Freeman and Michel, 2001, 2001a), which is and freeze-drying are ineffective means for killing bacteria. In
consistent with the clinical experience of one editor of this text- fact, both methods are used for long-term preservation of valu-
book (RLR).To date, no scientific evidence exists that demon- able stock bacterial cultures in laboratories. Grape seed extract
strates raw food diets provide additional or exceptionally unique itself does not kill microorganisms and does not render meat
nutrients that cannot be obtained from cooked food. safer. The antimicrobial activity attributed to grapefruit seed
Professionals at zoos and racing greyhound kennels, who extract is merely due to the synthetic preservative agents added
have historically fed raw meat, recognize the potential for con- to the product. Natural grape seed appears not to have antimi-
tamination and attempt to decrease risks of foodborne illness. crobial activity (von Woedtke et al, 1999).
Raw meat may make up 50 to 75% of the food consumed by Opponents to feeding raw food point out that meat and egg
racing greyhounds in the United States (Chengappa et al, supplies for people are contaminated with microorganisms and
1993). Sporadic fatalities and contamination of the environ- that feeding raw meat increases the likelihood of exposure of