Photo credit: Shutterstock.com Studies have shown malignancies and their treatments can significantly impact a cat’s quality of life (QoL).1 Some cats are notoriously finicky eaters, and when faced with the physical decline and organ dysfunction often caused by malignancies, their feeding behaviors and needs become even more complex. My team and I conducted a study to address a critical question: Can therapeutic nutrition improve the quality of life for cats with malignancies? Our goal was to demonstrate therapeutic nutrition specifically designed for cats2 with malignancies could provide measurable benefits in terms of their physical condition and overall well-being. The results of our study confirmed our hypothesis. This article features the findings and discusses how veterinary professionals can incorporate nutritional strategies into feline oncology care to help both cats and their caregivers during this challenging time. The challenges of nutritional management in feline oncology Both veterinary professionals and pet parents face unique challenges when introducing therapeutic diets into the care plan of a cat with malignancies. These could include: Clinic barriers. Veterinarians and veterinary technicians operate under significant time constraints. While medical treatments and diagnostics take precedence, key nutritional assessments can become an afterthought. Owner barriers. For pet parents, the emotional toll of a malignancy diagnosis can lead to behaviors like “pity feeding,” where they offer unbalanced treats or human foods to comfort their pets. Multi-pet households add another layer of complexity, as managing different diets for multiple animals can be challenging. The additional cost of a therapeutic diet can also be concerning pet parents. Patient barriers. Cats are creatures of habit, often resistant to dietary changes. They can develop strong preferences for, or aversions to, specific textures or flavors. Cats with malignancies may also experience appetite loss, nausea, or pain, further complicating the transition to a therapeutic diet. Proving the impact of a therapeutic diet The central question of our study was whether a therapeutic diet could improve QoL for cats with malignancies. We designed a single-arm, non controlled observational study to evaluate the impact of a therapeutic dry diet on cats diagnosed with malignancies. Study objectives Our primary goal was to demonstrate that therapeutic nutrition could provide measurable benefits for cats with malignancies. Specifically, we sought to assess the impact of therapeutic nutrition as a component of malignancy management protocol on indices of QoL,3 body weight (BW), body condition score (BCS), muscle condition score (MCS), eating enthusiasm,4 stool quality, and facial expression of pain (measured using the Feline Grimace Scale).5 Study design The study was conducted over a 70-day period and included 39 client-owned cats with various types of malignancies. Thirteen cats successfully completed the entire 70-day feeding period. The cat owners were provided with the study food free of charge in white (i.e. not branded) bags, along with scales to measure food intake and body weight. Data were collected through a combination of owner-reported assessments via a study app and video consultations with veterinarians. Key results The study revealed significant improvements in several clinical parameters, demonstrating the positive impact of the therapeutic diet on the cats’ physical condition and overall well-being: Body weight and body condition score. Cats showed a significant increase in BW by Day 42 (0.15 kg, P=0.02) and further by Day 70 (0.20 kg, P<0.01). BCS also improved significantly, increasing by 0.70 points on a 9-point scale by Day 70 (P<0.01). Muscle condition score. The average MCS of the population showed significant improvement by Day 42 (P<0.01) and continued to show positive trends by Day 70. At the start of the study, the study population exhibited mild muscle loss, but by the end of the study, their MCS showed a shift toward normal muscle mass. Quality of life. Owners reported statistically significant improvements in QoL related to clinical signs and healthy behaviors on both Day 42 (P≤0.05) and Day 70 (P<0.01). Overall QoL scores also improved significantly by the end of the study (P<0.01). Eating enthusiasm and pain levels. Cats maintained consistent eating enthusiasm throughout the study, with no significant changes in their grimace scores, indicating stable pain levels or the absence of increased discomfort. These findings provide evidence that a therapeutic diet can improve the quality of life for cats with malignancies, offering physical benefits. Dr. Becvarova's study showed that a therapeutic diet demonstrated significant improvement in body weight, body condition score, and muscle condition scores in cats with malignancies, over a 70-day period. Photo courtesy Hill's Pet Nutrition Inc. Dr. Iveta Becvarova during her presentation at the 2025 Hill's Global Symposium in Phoenix, Ariz. Photo courtesy Hill's Pet Nutrition Inc. The role of nutrition in enhancing quality of life Malignancies and their treatments can significantly impair a cat’s QoL.1 Clinical signs such as anorexia, vomiting, diarrhea, weight loss, and muscle wasting are common and can lead to a decline in physical health. These signs are not just side effects of the disease but are also useful prognostic indicators. Studies have shown weight loss in cats with lymphoma within the first month of treatment is associated with poorer outcomes and shorter survival times.6 Nutritional support is critical for maintaining body weight, BCS, and MCS, all of which are key indicators of a cat’s overall health and prognosis. Cats with neoplasia with optimal BCS lived significantly longer compared to those with poor nutritional status.7 For pet parents, ensuring their cat is comfortable and well-nourished provides peace of mind and reduces the guilt often associated with a malignancy diagnosis. Seeing their cat eat, engage in activities, and maintain a semblance of normalcy can help owners focus on creating meaningful moments with their pets during this challenging time. Photo courtesy Hill's Pet Nutrition Inc. Nutritional strategies for cats with malignancies A therapeutic diet designed for many cats with malignancies should meet several key nutritional criteria: High energy density. Cats with malignancies often experience fluctuating appetites. High-energy foods allow them to meet their caloric needs with smaller portions, reducing the risk of malnutrition. High-quality protein. Essential amino acids, including taurine and L-carnitine, are critical for maintaining muscle mass and supporting overall health. Omega-3 fatty acids. EPA and DHA from fish oil can help manage inflammation and interrupt the cycle of muscle wasting driven by disease associated cytokines. Palatability and digestibility. Cats are more likely to eat foods that are highly palatable and easy to digest, so allowing pet parents some flexibility is key for optimal nutrition such as offering a variety of textures and flavors, warming food to enhance aroma, and adding palatable toppers like low-sodium broth. In our study, the diet demonstrated significant improvements in body weight, BCS, and MCS in cats with malignancies over a 70-day period.2 Owners also reported improvements in their cats’ quality of life, including clinical signs and healthy behaviors. Practical implementation in veterinary practice For busy veterinary clinics, integrating nutritional support into malignancy care requires a team effort, but it is essential to improve the quality of life for cats with malignancies. Veterinary technicians also play a vital role in discussing nutrition with clients, especially when veterinarians are pressed for time. Regular nutritional assessments should be part of every visit, with a focus on BCS, MCS, and BW. Educating pet parents about the importance of nutrition in cancer care is equally critical. When owners understand how proper nutrition can improve their cat’s quality of life, they are more likely to adhere to dietary recommendations. This, in turn, can enhance the human-animal bond and provide owners with peace of mind during a difficult time. Addressing misconceptions There are several common misconceptions about therapeutic diets for cats with malignancies that should be addressed: “Reduced-Carbohydrate Diets Starve Malignancies Cells”: This outdated and unsubstantiated belief suggests that restricting carbohydrates can deprive malignancies cells of glucose, their primary energy source. However, research shows that many malignancies can adapt to utilize other energy sources, such as fatty acids and amino acids. Instead, our nutritional focus should be on providing a balanced diet with sufficient protein, fat, complex carbohydrates with lower Postprandial Glycemic Response and essential nutrients. “Homemade or Raw Meat Based Diets Are Better”: While well-intentioned, homemade and raw diets often lack proper nutrient balance. Further, raw meat-based diets can introduce foodborne pathogens, which are particularly dangerous for immunocompromised patients with malignancies. “The Perfect Diet Must Be Fed Exclusively”: Flexibility is key. Even the best therapeutic diet is ineffective if the cat refuses to eat it. Veterinary teams should work with pet parents to find creative ways to encourage food intake, such as warming food, offering variety, and managing nausea and pain. Iveta Becvarova, DVM, MS, DACVIM (Nutrition), is the former senior director of Global Academic and Professional Affairs at Hill’s Pet Nutrition. With more than 20 years of experience in veterinary nutrition, Dr. Becvarova is a board-certified veterinary nutritionist and a Diplomate of the American College of Veterinary Internal Medicine (Nutrition). She has authored peer-reviewed articles and is a frequent speaker at international veterinary conferences. Becvarova is passionate about advancing the role of nutrition in veterinary medicine to improve the quality of life for pets. She can be reached at ibecvarova20@gmail.com. References Tzannes S, Hammond MF, Murphy S, Sparkes A, Blackwood L. (2008). Owners’ perception of their cats’ quality of life during COP chemotherapy for lymphoma. Journal of Feline Medicine and Surgery; 10 (1): 73-81. DOI: 10.1016/j.jfms.2007.05.008 Amundson, M. D., Motsinger, L. A., Brejda, J., & Becvarova, I. (2025). Nutritional support for cats with malignancies shows improvements in clinical indices of quality of life. 29th Congress of the European Society of Veterinary & Comparative Nutrition (ESVCN) Proceedings, p. 64. Tatlock S, Gober M, Williamson N, Arbuckle R. (2017). Development and preliminary psychometric evaluation of an owner-completed measure of feline quality of life. The Veterinary Journal; 228: 22-32. DOI: 10.1016/j.tvjl.2017.10.005 Vanchina MA. (2023). Marrying Taste and Nutrition to Transform the Lives of Pets, Hill’s Global Symposium 2023 Proceedings, Sep 25-26, 2023 Lisbon, Portugal, page: 23-27. Evangelista MC, Watanabe R, Leung VSY, Monteiro BP, O’Toole E, Pang DSJ, Steagall PV. (2019). Facial expressions of pain in cats: the development and validation of a Feline Grimace Scale. Nature Scientific Reports; 9: 19128. DOI: 10.1038/s41598-019-55693-8. Krick, E, Moore, RH, and Sorenmo, KU. (2011). Prognostic Significance of Weight Change During Treatment of Feline Lymphoma. Journal of Feline Medicine and Surgery. 13 (12): 976-83. DOI: 10.1016/j.jfms.2011.08.002 Baez JL, Michel KE, Sorenmo K, Shofer FS. (2007). A prospective investigation of the prevalence and prognostic significance of weight loss and changes in body condition in feline cancer patients. Journal of Feline Medicine and Surgery; 9 (5): 411-417. DOI: 10.1016/j.jfms.2007.02.005
