Unconventional diets and nutritional supplements are more common in dogs with cancer compared to healthy dogs: An online global survey of 345 dog owners

Abstract

This survey aimed to investigate and compare diet type and supplement use between dogs (Canis lupus familiaris, L.) with cancer and a population of owner-reported healthy dogs and to assess the sources of information dog owners consult. Respondents were mainly from English-speaking countries. Dogs were considered healthy (N = 213) if owners reported them to be in good health. Dogs were included in the cancer group (N = 132) if the owner reported that their dog had been diagnosed with cancer. An online survey was distributed to clients presenting to a tertiary oncology service, clients presenting to a local primary care veterinary practice, and through social media. Owners of dogs with cancer spent more time researching pet health (P < .001), pet nutrition (P < .01) and nutritional supplements (P < .001) than owners of healthy dogs. While veterinarians were most commonly reported to be an information source for both groups, owners of healthy dogs more likely consulted pet stores and owners of dogs with cancer tended more to social media groups and blogs. Healthy dogs were more likely fed commercial dry food (P < .001), whereas homemade cooked (P < .001) and raw diets (P < .05) were more prevalent among dogs with cancer. Supplement use, especially cannabidiol products, mushroom extracts or turmeric/curcumin, was also more common for this group (P < .001). Alternative diets and supplements were more popular among owners of dogs with cancer compared to owners of healthy dogs. These findings highlight the need for nutritional counselling and education of pet owners regarding nutrition-related topics, especially when their dog is diagnosed with cancer.

Changes in diet and supplement use in dogs with cancer

“…Mushroom-based and CBD/THC supplements were added at the highest rates after a cancer diagnosis; this is consistent with these supplements being more commonly given to dogs with cancer when compared to healthy dogs. 11 This helps to confirm that some of these differences are attributable to a cancer diagnosis, rather than solely because of other factors such as age. Although mushrooms have anticancer potential in mice, 19,20 this has not been shown in dogs.…”

“…12 For total number of dogs receiving supplements, our data showed no significant change after a cancer diagnosis. Dogs with cancer are more likely to receive supplements than healthy dogs in the general population, 11 which was not evaluated in this study. Our findings might also reflect the owner's focus on supporting their dog during chemotherapy and other treatments during the period of time close to diagnosis.…”

“…[8][9][10] Dogs with cancer are more likely to receive home-prepared foods, with more than half of diet alterations after a cancer diagnosis involving the addition of home-prepared components. 11,12 Owners of dogs with cancer are more likely to give supplements. 12,13 Given the importance of nutrition in dogs with cancer, and because owners might change the diets after diagnosis, it is important that clinicians collect information on what owners are feeding their dogs and how a cancer diagnosis affects this.…”

Thinking outside the lab: Can studies of pet rats inform pet and laboratory rat welfare?

“…In sum, self-report owner surveys have been used in both veterinary and behaviour-problem contexts to investigate potential predictors of clinical or behaviour-problem morbidity, as well as highlighting broader welfare concerns associated with poor husbandry practices amongst some owners. For example, a number of studies have considered owner reports of diet and behaviour management in relation to dog obesity [15][16][17] while Oxley et al (2019) investigated the ways in which owners (and other caregivers) reported handling their pet rabbits 18 , a feature of husbandry with known importance for rabbit welfare. Pet owner surveys clearly have a role to play in informing health, husbandry and welfare improvements for domesticated species.…”

Should we be discouraging use of ‘anticancer’ supplements in dogs and cats with cancer?

“…OVER the past few years, numerous nutraceutical products with claimed ‘anticancer’ properties, such as chondroprotective agents, turmeric, curcumin, mushroom extracts and various immune support medications, have been available on the market, and a recent survey highlighted that there has been a rise in their use by owners of dogs with cancer 1 . However, there is limited to no evidence on the safety or effectiveness of these products, and also no indication about any possible interaction with chemotherapy drugs, and so we argue that their use should be discouraged.…”