The health hazards inherent to commercial meat-based companion animal diets are extensive and difficult to avoid, and can include slaughterhouse waste, supermarket rejects, restaurant grease, fish contaminants, endotoxins, mycotoxins, and toxic chemicals. Unsurprisingly, studies have identified kidney, liver, heart, neurologic, visual, neuromuscular and skin diseases, bleeding disorders, birth defects, immunocompromisation and infectious diseases associated with meat-based diets. There is no scientific reason why a diet comprised only of plant, mineral and synthetically-based ingredients cannot be formulated to meet all of the nutritional requirements of cats and dogs, and several commercially-available vegan diets claim to do so. Health benefits commonly observed include decreased skin parasites and improved coat condition, allergy control, weight and arthritis control, and improved vitality. Correct use of a complete and balanced nutritional supplement is essential, however, to avoid potentially severe health problems, particularly in cats, and monitoring of urinary acidity is strongly advisable. These topics will be explored in greater detail, and are described at www.vegepets.info.

1. Vegan Companion Animal Diets
Vegetarian cat and dog photos:
www.VegePet.com, www.VeganCats.com
ANDREW KNIGHTANDREW KNIGHT
DipECAWBM (AWSEL), DACAW,DipECAWBM (AWSEL), DACAW,
PhD, MANZCVS, MRCVS, SFHEAPhD, MANZCVS, MRCVS, SFHEA

2. Some definitions
Vegetarian = ovo-lacto-vegetarianVegetarian = ovo-lacto-vegetarian
VeganVegan

3. Why veg*n?
 Animal ethicsAnimal ethics
 Food justiceFood justice
 EnvironmentEnvironment
 HealthHealth

4. ‘Little Tyke’
the vegetarian lioness

5. Overview
 Meat-based diets: health hazardsMeat-based diets: health hazards
 Meat-based diets: associated diseasesMeat-based diets: associated diseases
 Animal diets: biological requirementsAnimal diets: biological requirements
 Vegetarian diets: unnatural behaviour?Vegetarian diets: unnatural behaviour?
 Health benefits?Health benefits?
 Dietary transitionsDietary transitions

6. Meat-based diets:
health hazards
US 2007 pet food recall due to melamine US 2007 pet food recall due to melamine
contaminationcontamination
Affected brands: Affected brands:
 http://www.accessdata.fda.gov/scripts/petfoodrecall/
Signs of kidney failure: increased thirst and urination, Signs of kidney failure: increased thirst and urination,
dehydration, inappetence, lethargy, vomiting, deathdehydration, inappetence, lethargy, vomiting, death

7.  Meat meal and byproducts: slaughterhouse Meat meal and byproducts: slaughterhouse
waste, 4-D meat, supermarket rejects and waste, 4-D meat, supermarket rejects and
rendered dogs and catsrendered dogs and cats
 Premium brandsPremium brands
 DigestDigest
 Restaurant greaseRestaurant grease
 Fish contaminantsFish contaminants
 Infectious diseasesInfectious diseases

8.  EndotoxinsEndotoxins
 MycotoxinsMycotoxins
 Hormones and antibioticsHormones and antibiotics
 PreservativesPreservatives
 ProcessingProcessing

9.  Kidney diseaseKidney disease
 Liver diseaseLiver disease
 Heart diseaseHeart disease
 Neurologic diseaseNeurologic disease
 Visual diseaseVisual disease
 Musculoskeletal diseaseMusculoskeletal disease
What are the effects?

10.  Skin diseasesSkin diseases
 Bleeding disordersBleeding disorders
 Birth defectsBirth defects
 ImmunocompromisationImmunocompromisation
 Infectious diseasesInfectious diseases

11. 1.1. Bingham AK, Huebner HJ, Phillips TD, Bauer JE.Bingham AK, Huebner HJ, Phillips TD, Bauer JE.
Identification and reduction of urinary aflatoxin metabolitesIdentification and reduction of urinary aflatoxin metabolites
in dogs.in dogs. Food Chem Toxicol.Food Chem Toxicol. 2004 Nov;42(11):1851-8.2004 Nov;42(11):1851-8.
2.2. Boyer CI Jr, Andrews EJ, deLahunta A, Bache CA, GutenmanBoyer CI Jr, Andrews EJ, deLahunta A, Bache CA, Gutenman
WH, Lisk DJ. Accumulation of mercury and selenium inWH, Lisk DJ. Accumulation of mercury and selenium in
tissues of kittens fed commercial cat food.tissues of kittens fed commercial cat food. Cornell Vet.Cornell Vet. 19781978
Jul;68(3):365-74.Jul;68(3):365-74.
3.3. Coleman WE, Tardiff RG. Contaminant levels in animal feedsColeman WE, Tardiff RG. Contaminant levels in animal feeds
used for toxicity studies.used for toxicity studies. Arch Environ Contam Toxicol.Arch Environ Contam Toxicol.
1979;8(6):693-702.1979;8(6):693-702.
4.4. DiBartola SP, Buffington CA, Chew DJ, McLoughlin MA,DiBartola SP, Buffington CA, Chew DJ, McLoughlin MA,
Sparks RA. Development of chronic renal disease in cats fedSparks RA. Development of chronic renal disease in cats fed
a commercial diet.a commercial diet. J Am Vet Med Assoc.J Am Vet Med Assoc. 1993 Mar1993 Mar
1;202(5):744-51.1;202(5):744-51.
5.5. Dobson RLMDobson RLM et al.et al. Identification and characterization ofIdentification and characterization of
toxicity of contaminants in pet food leading to an outbreak oftoxicity of contaminants in pet food leading to an outbreak of
renal toxicity in cats and dogs.renal toxicity in cats and dogs. Toxicological SciencesToxicological Sciences 2008;2008;
106(1): 251-262.106(1): 251-262.

12. 6.6. Dow SW, Fettman MJ, Curtis CR, LeCouteur RA. HypokalemiaDow SW, Fettman MJ, Curtis CR, LeCouteur RA. Hypokalemia
in cats: 186 cases (1984-1987).in cats: 186 cases (1984-1987). J Am Vet Med Assoc.J Am Vet Med Assoc. 1989 Jun1989 Jun
1;194(11):1604-8.1;194(11):1604-8.
7.7. Freytag TL, Liu SM, Rogers QR, Morris JG. Teratogenic effectsFreytag TL, Liu SM, Rogers QR, Morris JG. Teratogenic effects
of chronic ingestion of high levels of vitamin A in cats.of chronic ingestion of high levels of vitamin A in cats. J AnimJ Anim
Physiol Anim NutrPhysiol Anim Nutr (Berl). 2003 Feb;87(1-2):42-51.(Berl). 2003 Feb;87(1-2):42-51.
8.8. Houpt KA, Essick LA, Shaw EB, Alo DK, Gilmartin JE,Houpt KA, Essick LA, Shaw EB, Alo DK, Gilmartin JE,
Gutenmann WH, Littman CB, Lisk DJ. A tuna fish dietGutenmann WH, Littman CB, Lisk DJ. A tuna fish diet
influences cat behavior.influences cat behavior. J Toxicol Environ Health.J Toxicol Environ Health.
1988;24(2):161-72.1988;24(2):161-72.
9.9. Pion PD, Kittleson MD, Rogers QR, Morris JG. Science.Pion PD, Kittleson MD, Rogers QR, Morris JG. Science.
Myocardial failure in cats associated with low plasma taurine: aMyocardial failure in cats associated with low plasma taurine: a
reversible cardiomyopathy.reversible cardiomyopathy. ScienceScience 1987 Aug1987 Aug
14;237(4816):764-8.14;237(4816):764-8.
10.10. Sousa CA, Stannard AA, Ihrke PJ, Reinke SI, Schmeitzel LP.Sousa CA, Stannard AA, Ihrke PJ, Reinke SI, Schmeitzel LP.
Dermatosis associated with feeding generic dog food: 13 casesDermatosis associated with feeding generic dog food: 13 cases
(1981-1982).(1981-1982). J Am Vet Med Assoc.J Am Vet Med Assoc. 1988 Mar 1;192(5):676-80.1988 Mar 1;192(5):676-80.
11.11. Strieker MJ, Morris JG, Feldman BF, Rogers QR. Vitamin KStrieker MJ, Morris JG, Feldman BF, Rogers QR. Vitamin K
deficiency in cats fed commercial fish-based diets.deficiency in cats fed commercial fish-based diets. J SmallJ Small
Anim Pract.Anim Pract. 1996 Jul;37(7):322-6.1996 Jul;37(7):322-6.

13. Requirements of animal diets
 Nutritional soundnessNutritional soundness
 PalatabilityPalatability
 BioavailabilityBioavailability

14.  Gray and colleagues (2004):Gray and colleagues (2004):
 Vegecat KibbleMixVegecat KibbleMix
 Evolution canned diet for adult catsEvolution canned diet for adult cats
 both deficient in certain amino acids, traceboth deficient in certain amino acids, trace
minerals, vitamins, and arachidonic acidminerals, vitamins, and arachidonic acid
 Evolution diet was also deficient in overallEvolution diet was also deficient in overall
protein contentprotein content
Nutritional adequacy?

15. Eric Weisman, Evolution Diet CEO (2004):Eric Weisman, Evolution Diet CEO (2004):
““We have ten to twenty thousand healthy and longWe have ten to twenty thousand healthy and long
living dogs, cats and ferrets living on the Evolutionliving dogs, cats and ferrets living on the Evolution
Diet. … Major animal sanctuaries use our productsDiet. … Major animal sanctuaries use our products
and stand behind them. These sanctuaries use ourand stand behind them. These sanctuaries use our
products because they have lower rates of illness andproducts because they have lower rates of illness and
mortality when their animals are placed on our foods.mortality when their animals are placed on our foods.””

16. 3 possibilities
1.1. The sample tested was nutritionally inadequate, but theThe sample tested was nutritionally inadequate, but the
great majority of samples sold and used are adequate.great majority of samples sold and used are adequate.
Due to: formulation error at the factory, or degradationDue to: formulation error at the factory, or degradation
of an old sample. However, it is unlikely that an oldof an old sample. However, it is unlikely that an old
sample would have been retained for testing.sample would have been retained for testing.
2.2. The laboratory results were significantly in error forThe laboratory results were significantly in error for
several nutrients tested. However, a professional,several nutrients tested. However, a professional,
accredited laboratory was used, and the samples wereaccredited laboratory was used, and the samples were
tested blind to decrease bias.tested blind to decrease bias.

17. 3.3. The AAFCO cat food nutrient profiles for theThe AAFCO cat food nutrient profiles for the
maintenance of adult cats are highly conservative, and,maintenance of adult cats are highly conservative, and,
although Evolution Diet pet food does not meet thealthough Evolution Diet pet food does not meet the
AAFCO requirements, it does meet the actual theAAFCO requirements, it does meet the actual the
nutrient requirements for the maintenance of the greatnutrient requirements for the maintenance of the great
majority of adult cats.majority of adult cats.
 But if only 10% of cats required the nutrient levelsBut if only 10% of cats required the nutrient levels
specified by AAFCO, given thatspecified by AAFCO, given that “ten to twenty thousand“ten to twenty thousand
healthy and long living dogs, cats and ferrets [live] onhealthy and long living dogs, cats and ferrets [live] on
the Evolution Diet”the Evolution Diet” (Weisman 2004), this would have(Weisman 2004), this would have
resulted a large population of cats showing signs ofresulted a large population of cats showing signs of
nutritional deficiency following chronic feeding on thenutritional deficiency following chronic feeding on the
Evolution Diet, but this has not been detected.Evolution Diet, but this has not been detected.

18.  Most likely possibility: the sample tested was nutritionallyMost likely possibility: the sample tested was nutritionally
inadequate, but the great majority of samples sold andinadequate, but the great majority of samples sold and
used are adequate, and that a formulation error occurredused are adequate, and that a formulation error occurred
at the factory.at the factory.
 Harbingers of a New Age (2004):Harbingers of a New Age (2004):
““We were frankly shocked by the analysis of the kibbleWe were frankly shocked by the analysis of the kibble
made from Vegecat KibbleMix. I talked with our mixingmade from Vegecat KibbleMix. I talked with our mixing
personnel about the report and tried to understand howpersonnel about the report and tried to understand how
such a situation could have occurred. Isuch a situation could have occurred. I’’m convinced thatm convinced that
this particular batch of Vegecat KibbleMix was madethis particular batch of Vegecat KibbleMix was made
improperly, and have stressed to our personnel theimproperly, and have stressed to our personnel the
importance of paying attention to the mixing process andimportance of paying attention to the mixing process and
if any errors are made to notify me immediately ratherif any errors are made to notify me immediately rather
than pass on incorrectly mixed product.… We willthan pass on incorrectly mixed product.… We will
reformulate our products in light of these unsettlingreformulate our products in light of these unsettling
facts, and submit to a lab for analysisfacts, and submit to a lab for analysis””

20. However…
 ““samples were collected at 1 time pointsamples were collected at 1 time point
and from 1 batch of each productand from 1 batch of each product
 ““substantial variations in resultssubstantial variations in results
attributable to laboratory methods wereattributable to laboratory methods were
possiblepossible
 ““no assessment of the animals …no assessment of the animals …
evaluation of blood AA concentrationsevaluation of blood AA concentrations
would provide valuable information”would provide valuable information”

21. What should we do?
 ““all 3 veterinary diets assessed in the study reportedall 3 veterinary diets assessed in the study reported
here met current nutritional adequacy and labelinghere met current nutritional adequacy and labeling
requirements, compared with only 5 of 21 over-the-requirements, compared with only 5 of 21 over-the-
counter diets that met the nutritional adequacy andcounter diets that met the nutritional adequacy and
labeling requirementslabeling requirements
 ““For all animals and regardless of diet, general routineFor all animals and regardless of diet, general routine
monitoring and assessment are necessary for adequatemonitoring and assessment are necessary for adequate
nutritional evaluation and to enable clinicians to providenutritional evaluation and to enable clinicians to provide
recommendations for individual animals”recommendations for individual animals”

22. Vegetarian diets & natural behaviour
!?

23. Health benefits?
 Decreased ectoparasites (fleas, ticks, liceDecreased ectoparasites (fleas, ticks, lice
and mites)and mites)
 Improved coat conditionImproved coat condition
 Allergy controlAllergy control
 Improved weight controlImproved weight control
 Arthritis regressionArthritis regression
 Diabetes regressionDiabetes regression
 Cataract resolutionCataract resolution

24.  Increased overall health and vitalityIncreased overall health and vitality
 Decreased incidence of cancerDecreased incidence of cancer
 Decreased incidence of infectionsDecreased incidence of infections
 Decreased hypothyroidismDecreased hypothyroidism

25. 1st large-scale study of
the long-term health of vegetarian cats
WakefieldWakefield et al.et al. J. Amer. Vet. Med. Assoc. 2006; 229: 70-73J. Amer. Vet. Med. Assoc. 2006; 229: 70-73

26.  34 cats maintained on vegetarian diets for 1+ yrs34 cats maintained on vegetarian diets for 1+ yrs
 52 cats maintained on meat-based diets for 1+ yrs52 cats maintained on meat-based diets for 1+ yrs
Variable Vegetarians Carnivores P value
Age (mean +/- SD) 7.0 +/- 4.7 7.8 +/- 4.8 0.48
No. of years diet fed (mean +/- SD) 4.6 +/- 4.1 6.5 +/- 4.7 0.06
Sex distribution (spayed female; castrated male [%]) 38;62 56;44 0.13
Kept strictly indoors (%) 65 69 0.80
Reported to be in ideal body condition (%) 82 65 0.17
Reported to be healthy or generally healthy (%) 97 96 0.38
•No significant differences in age, sex, body condition, housing, orNo significant differences in age, sex, body condition, housing, or
perceived health status.perceived health status.
•Most cats described as healthy or generally healthy.Most cats described as healthy or generally healthy.

27. Sprint-racing sled dogs
BrownBrown et al.et al. Brit J Nutr.Brit J Nutr. 2009; 102: 1318-232009; 102: 1318-23

28.  12 sprint-racing Siberian huskies were fed either a12 sprint-racing Siberian huskies were fed either a
commercial diet recommended for active dogs (n 6), or acommercial diet recommended for active dogs (n 6), or a
meat-free diet formulated to the same nutrient specificationsmeat-free diet formulated to the same nutrient specifications
(n 6)(n 6)
 Sole nutrient intake for 16 weeks, including 10 weeks ofSole nutrient intake for 16 weeks, including 10 weeks of
competitive racingcompetitive racing
 Blood samples were collected at weeks 0, 3, 8 and 16, andBlood samples were collected at weeks 0, 3, 8 and 16, and
veterinary health checks were conducted at weeks 0, 8 and 16veterinary health checks were conducted at weeks 0, 8 and 16
 Haematology results for all dogs, irrespective of diet, wereHaematology results for all dogs, irrespective of diet, were
within normal range throughout the studywithin normal range throughout the study
 The consulting veterinarian assessed all dogs to be inThe consulting veterinarian assessed all dogs to be in
excellent physical conditionexcellent physical condition

29. Dietary change
 Easing the transitionEasing the transition
 Safeguarding healthSafeguarding health
1.1. Use a complete and balanced nutritionalUse a complete and balanced nutritional
supplement or complete dietsupplement or complete diet
2.2. Prevent urinary alkalinization and urolithiasisPrevent urinary alkalinization and urolithiasis
(the formation of urinary crystals and stones)(the formation of urinary crystals and stones)

30. Conclusions
We choose vegan diets for ourselves forWe choose vegan diets for ourselves for ethical,
environmental and health reasons. The samereasons. The same
benefits apply to vegan companion animal diets,benefits apply to vegan companion animal diets,
which provide the best choice for both ourwhich provide the best choice for both our
companion and so-calledcompanion and so-called ‘food’ animals.‘food’ animals.

34. Veterinary opinions