Diet & Supplement Use in Dogs with Cancer

Timothy M. Fan, DVM, PhD, DACVIM (Oncology, Internal Medicine), University of Illinois at Urbana–Champaign

ArticleLast Updated April 20213 min read
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In the Literature

Bianco AV, Abood S, Mutsaers A, Woods JP, Coe JB, Verbrugghe A. Unconventional diets and nutritional supplements are more common in dogs with cancer compared to healthy dogs: an online global survey of 345 dog owners. Vet Comp Oncol. 2020;18(4):706-717.


The Research …

Cancer is a genetic disease in which cells undergo rapid proliferation, enhanced motility and invasion, resistance to death signals, reduced immunogenicity, and altered metabolism during malignant transformation.1 Some of these properties have been exploited for improved cancer detection and management. For example, the Warburg effect is a form of altered cell metabolism that has been leveraged for advanced cancer imaging and enables metabolically active cancer cells to be detected using special imaging technologies that couple glucose analog tracers with positron emission tomography2—an advanced imaging modality that has become more frequently used in dogs with cancer.3-5 Such metabolic properties of cancer cells remain problematic and can globally compromise the host organism. This is highlighted by cancer cachexia, in which the host organism remains in a negative energy balance despite sufficient caloric intake.6,7

The recognized importance of cellular metabolism in cancer progression has generated considerable interest in the role of nutrition in cancer patients. There is solid foundational evidence demonstrating the beneficial effects of good nutrition for maintaining body condition, reducing cancer-related complications, and boosting immune functions in these patients.8 Interest has also increased regarding adjunctive use of supplements (including antioxidants, phytonutrients, and herbs) for cancer management. However, in veterinary cancer patients, more scientifically validated studies are needed prior to recommending routine use of these supplements.

This study describes the findings of a global survey aimed to better understand pet owners’ preferred sources of information about pet health topics, nutrition, diet types, and dietary supplements depending on their pet’s disease state (cancer-bearing vs healthy). Owners of 213 healthy dogs and owners of 132 cancer-bearing dogs answered an online survey on general trends and attitudes about nutrition. Owners of cancer-bearing dogs spent more time researching health, nutrition, and supplement topics than owners of healthy dogs. Although clinicians remained the primary source of information for all owners, owners of dogs with cancer actively engaged with social media groups and blogs more often than did owners of healthy dogs. Type of diet also differed. Owners of healthy dogs tended to feed commercial dry food, whereas owners of dogs diagnosed with cancer tended to feed homemade cooked and raw diets. Owners of dogs with cancer also used more nutritional supplements than owners of healthy dogs. Collectively, these findings highlight the importance and continued need for research in nutritional, behavioral, and social sciences to provide effective, scientifically based guidelines and recommendations for owners who want to maintain their pet’s quality of life, regardless of disease state.


… The Takeaways

Key pearls to put into practice:

  • Owners usually want to actively participate in the care of their pet—both in healthy and disease states—and clinicians should serve as the primary source for nutritional recommendations.

  • Owners of dogs with cancer tend to engage in more spontaneous dialog via online chat or blogs. This could indicate an increased urgency for information gathering or desire to develop empathic relationships with other owners experiencing similar emotions and circumstances.

  • Nutritional supplements are commonly used in dogs with cancer and in healthy dogs. The lack of regulatory oversight and limited scientifically conducted studies assessing the benefit–risk ratios of supplements for disease management underscore the critical and unmet need to advance nutritional sciences in veterinary medicine.