In a recent article published in PLOS One, researchers surveyed 1,418 cat guardians to gather information about the effect of a meat-based or vegan diet on feline health for at least a year.
Study: Vegan versus meat-based cat food: Guardian-reported health outcomes in 1,369 cats, after controlling for feline demographic factors. Image Credit: Sergio Photone/Shutterstock.com
Pet food sales have surged internationally; the United Kingdom (UK) pet food market rose 16% since 2015, and United States (US) pet food sales touched US$ 42 billion by 2020.
This drove considerable research and product development; consequently, companies selling pet food launched 6,000+ new pet food products and 4,000 new pet snacks globally between January 2013 and October 2014, implying there is increased availability of new pet foods, including raw meat, in vitro meat and novel protein sources, such as seaweed, terrestrial plants, yeast, to name a few.
However, this growth has raised concerns that these pet foods might be inadequate (suboptimal) to meet the nutritional requirements of cats. In 2020, the British Veterinary Association claimed that felines are obligate carnivores and should not be feeding a vegan diet.
Although evidence for ingredient bioavailability and interactivity of non-animal and animal-based ingredients is lacking, researchers even claimed that an owner feeding pet cats a vegan diet could be committing an offense.
Thus, assessing the hazards of vegan diets for cats is crucial. There are two ways to evaluate the nutritional adequacy of vegan diets for cats.
The first involves examining whether pet food manufacturers are making quality products. The second, feeding trials, however, are more appropriate to ensure the nutritional adequacy of new pet food products.
Only a few studies have described the health status of cats given different diets. Dodd et al. published findings of a Canada-based survey in 2021 where 1,026/1,325 cat guardians described their cat(s) diet, of which 187 (18%) were vegan cats. Cats fed vegan diets were in good health, and fewer had hepatic or gastrointestinal disorders than those fed meat.
Likewise, Semp examined 59 cats in Germany, Switzerland, and Austria, who, per their guardians, were fed vegan diets for 6-6.5 years. They found that 38/59 cats had shinier coats after switching to vegan diets, and some even overcame dermatological problems.
These studies had several limitations, such as smaller sample sizes, use of nutritionally deficient diets, and not performing blood tests, that limited their predictive value for cats fed vegan diets.
In addition, no large-scale study has described how health indicators varied between cats maintained on meat- or vegan-based diets.
About the study
In the present study, researchers asked cat guardians to inform about themselves and one cat resident in their household for at least one year.
Specifically, they revealed the main ingredients of their pet's day-to-day diet, including conventional, raw, or in vitro meat, fungi, algae, insects, vegan, vegetarian, or other.
Notably, they had to pick only one option. They also furnished information on whether they fed their pet any snacks or supplements.
Further, guardians provided information regarding seven illness indicators, e.g., the number of veterinary visits in the previous year. In a subset of cat guardians who had recently seen their veterinarians to ensure their pet's health, the team calculated the proportion of unwell cats and the median number of cases of health disorders per cat.
In this way, they computed the prevalence of the 22 specific health disorders in the previous or the year before initiating a therapeutic diet, if given any.
Furthermore, guardians reported the frequency of veterinary visits and medication use other than vaccinations and routine treatments for parasites.
The researchers also inquired about information sources guardians relied on when choosing their pet food.
Other data points were related to feline demographics, including role (companion/working animal), age, sex/desexing (neuter) status, activity level, health status, etc.
The team piloted the survey to 25 respondents in April 2020 and finally in May-December 2020 with improved structure and questions to minimize bias.
'Health & Nutrition' was the most important factor, cited by 85% of respondents, and 'maintenance of pet health' was the most key sub-factor when making pet food purchasing decisions, reflecting the concern for pet health in the general population.
Interestingly, 51% of survey respondents feeding raw meat-based diets to their pet cats stated they would realistically consider alternatives, and a striking 83% considered it necessary that alternative diets provided 'Confidence about pet health.'
Both meat- and vegan diet-fed study groups had cats with a median age of eight years overall. Similarly, the sex/neuter status within the study sample appeared broadly representative of normal cats, of which 52% were female.
Two, three, or more veterinary visits could indicate a health concern. In this study, cats fed meat-based diets were more likely to fall ill based on this criterion than those fed vegan diets (31% vs. 27%).
Generalized additive regression models (GAMs) used in this study controlled for feline demographic factors. It was apparent that cats fed a vegan diet were at 10.3% lower odds of having two or more veterinary visits, on average.
Likewise, on average, cats fed a vegan diet were at 19.6% lower odds of receiving medication. Even though statistically insignificant, these findings indicated a tendency for better health.
Vegan diet cats in this study were, on average, 1.9 years younger than cats fed a meat-based diet. This study used seven separate regression models that controlled the same control variables: age, sex, neuter status, and feline location.
Further, cats fed a vegan diet had, on average, were at 56.5% lower odds of progressing onto a therapeutic diet.
They, on average, were at 6.4% lower odds of being considered unwell in a veterinary assessment. Although not statistically significant, this indicated a marginal tendency toward this indicator of better health.
Overall, cats fed on a vegan diet had better health outcomes for every health indicator studied. In addition, the likelihood of suffering from a disorder appeared higher in cats fed meat-based versus vegan diets (15 vs. 7).
The cumulative evidence from this and other prior studies suggests that cats fed nutritionally adequate vegan diets might be healthier than those fed meat-based diets.
Regardless of their type, vegan, vegetarian, and meat-based, pet diets should be nutritionally balanced to avert any health disorder in pets.