Section 7: Supportive and Symptomatic Care
Top 3 Takeaways
- Thoroughly evaluate the patient—including evaluation for potential comorbidities—when instituting symptomatic care to improve overall quality of life.
- Pain and discomfort may arise from the cancer itself (e.g., pain from osteosarcoma), from side effects of cancer treatment (e.g., RT or chemotherapy), or secondary to another disease process.
- Routinely assess oncology patients’ nutritional status, beginning with diagnosis and continuing throughout treatment.
In This Resource:
The primary objective of symptomatic therapy for oncology patients is to maintain or improve quality of life by mitigating discomfort and resolving or alleviating clinical signs. Supportive and symptomatic care are essential components of patient management and are aimed at enhancing quality of life throughout treatment. Given that clients often prioritize their pet’s quality of life, it is crucial to consider the client’s goals, preferences, and limitations when developing a care plan. Effective case management requires coordinated communication between general practitioners and oncologists, as the former frequently play a vital role in administering care. Comprehensive patient evaluation, including the identification of comorbidities that may affect the treatment protocol, is imperative. Supportive therapies are summarized below and in Table 7.1.
TABLE 7.1 Supportive and Symptomatic Care Options
Vomiting |
Hyporexia |
Diarrhea |
Pain |
Other GI Support |
Bone Marrow Suppression |
|---|---|---|---|---|---|
|
|
|
|
|
|
Common Side Effects of Chemotherapy
Dogs and cats generally tolerate chemotherapy well, but side effects such as vomiting, nausea, anorexia, diarrhea, and bone marrow suppression may occur. These side effects can lead to muscle wasting and weight loss, which clients may perceive as a decline in quality of life.
Supportive Medications
1. Nausea/Vomiting
See Table 7.1 for options to treat nausea and vomiting in patients.
2. Hyporexia Management
Hyporexia may occur secondary to the primary disease process, such as GI lymphoma, or may be secondary to treatment such as chemotherapy. Along with options listed in Table 7.1, the appetite stimulants capromorelin and mirtazapine can be given orally to manage hyporexia in feline and canine patients, 1,2,3,4 and mirtazapine is available as a transdermal ointment for use in cats. If nausea is suspected underlying the hyporexia, treat for nausea first.
3. Diarrhea Management
Therapeutic recommendations for managing diarrhea after chemotherapy have been updated. Because other acceptable treatment options are effective, the current trend is a shift away from empirical antibiotic use to treat acute diarrhea to support antibacterial stewardship and avoid the negative impacts of disrupting the normal GI biome. 5,6,7
Crofelemer-CA1 delayed-release tablets, which the FDA conditionally approved for treatment of chemotherapy-induced diarrhea (CID) in dogs, is one therapy to consider. And in one small study, a highly potent probiotic reduced the incidence of CID in canine patients receiving multiagent chemotherapy and may be considered as an additional supportive care option. 8 Another option is smectite (medical aluminosilicate clay), which in one study led to a faster resolution of clinical signs when compared with metronidazole in dogs with CID. 9
4. Pain Management
Recognizing and alleviating pain in oncology patients is essential for maintaining quality of life. Pain may be caused by the cancer itself (e.g., osteosarcoma pain), a treatment modality (e.g., RT or chemotherapy), or a concurrent disease (e.g., osteoarthritis). To adequately control pain, use a multimodal approach. Refer to the 2022 AAHA Pain Management Guidelines for Dogs and Cats for current recommendations on a multimodal approach to pre-empting and controlling pain.
The most effective pain management is usually achieved by treatment of the underlying disease, so consider the cancer-specific therapies discussed above. When these are not feasible or desired, the second most effective option for the most consistent and durable pain control for most malignant tumors is palliative-intent radiation therapy. Based on studies in humans and animals, between 70 and 90% of patients with cancer related pain will have significantly reduced pain in response to palliative-intent radiation therapy. Response durations vary widely, from a few months to more than a year depending on the tumor type.
New pain management products are available and may complement standard pain therapy. Two monoclonal antibody therapies that target nerve growth factor to manage chronic pain are available for dogs (bedinvetmab) 10 and cats (frunevetmab). 11 Two drugs often used postoperatively in feline patients are injectable buprenorphine, which can control pain for 24 hours, or buprenorphine transdermal solution, which can control pain for 4 days. 12,13,14 Gabapentin or pregabalin have mixed effectiveness in adjunctive pain management in dogs and cats and can also be considered in chemotherapy patients. 15 IV bisphosphonates can help reduce bone pain.
5. Nutritional Support
Routinely assess the nutritional status of oncology patients at the time the diagnosis is made and throughout treatment. Customize diets based on the patient’s cancer diagnosis, any additional health issues (e.g., pancreatitis, renal disease), and nutritional needs. Also consider environmental factors, such as other household pets and the client’s ability to adhere to feeding recommendations.
The primary dietary goal is to ensure that the food is highly palatable and consumed. A complete and balanced diet, whether commercial or homemade, is essential. A newly released therapeutic diet (ONC Care) has high palatability and positively affects body weight in tumor-bearing dogs. 16 Consulting a veterinary nutritionist is advisable, especially if a homemade diet is chosen, as creating a balanced diet is challenging. 17 Feeding raw diets to oncology patients is not recommended because these patients are immunocompromised, and feeding raw meat–based diets poses increased risks of Salmonella and Escherichia coli infections for patients and for caregivers who may touch saliva or fur or clean up after meals. 18,19,20
If anorexia persists despite medical management, discuss feeding tube (e.g., esophagostomy, nasoesophageal, and percutaneous endoscopic gastrostomy) placement with the client. This can be particularly crucial early in the disease or postoperatively to aid recovery while awaiting therapeutic responses. Consideration of the overall goals, quality of life, and prognosis is essential for feeding tube placement in hospice cases.
The 2026 AAHA Oncology Guidelines for Dogs and Cats are generously supported by CareCredit, Hill’s Pet Nutrition, Merck Animal Health, and Zoetis.
Citations
- Johannes CM, Musser ML. Anorexia and the cancer patient. Vet Clin North Am Small Anim Pract 2019;49(5):837–54.
- Rathore M, Das N, Ghosh N, et al. Insights on discovery, efficacy, safety and clinical applications of ghrelin receptor agonist capromorelin in veterinary medicine. Vet Res Commun 2024;48(1):1–10.
- Rhodes L, Zollers B, Wofford JA, et al. Capromorelin: a ghrelin receptor agonist and novel therapy for stimulation of appetite in dogs. Vet Med Sci 2018;4(1):3–16.
- Zollers B, Wofford JA, Heinen E, et al. A prospective, randomized, masked, placebo-controlled clinical study of capromorelin in dogs with reduced appetite. J Vet Intern Med 2016;30(6):1851–7.
- Ellis C, Odunayo A, Tolbert MK. The use of metronidazole in acute diarrhea in dogs: a narrative review. Top Companion Anim Med 2023; 56-57:100824.
- Holden R, Brennan M. Does metronidazole increase the speed of recovery in dogs with acute diarrhoea? Vet Rec 2021;188(1):33–4.
- St€ubing H, Suchodolski JS, Reisinger A, et al. The effect of metronidazole versus a synbiotic on clinical course and core intestinal microbiota in dogs with acute diarrhea. Vet Sci 2024;11(5).
- Jugan MC, Wouda RM, Higginbotham ML. Preliminary evaluation of probiotic effects on gastrointestinal signs in dogs with multicentric lymphoma undergoing multi-agent chemotherapy: A randomised, placebocontrolled study. Vet Rec Open 2021;8(1):e2.
- Fournier Q, Serra JC, Williams C, et al. Chemotherapy-induced diarrhoea in dogs and its management with smectite: Results of a monocentric open-label randomized clinical trial. Vet Comp Oncol 2021;19(1):25–33.
- Gildea E, North C, Walker K, et al. Use of bedinvetmab (LibrelaVR) for canine osteoarthritis in France, Germany, Italy, Spain, and the UK: Quantitative analysis of veterinarian satisfaction and real-world treatment patterns. Animals (Basel) 2024;14(15):2231.
- Walters RR, Boucher JF, De Toni F. Pharmacokinetics and immunogenicity of frunevetmab in osteoarthritic cats following intravenous and subcutaneous administration. Front Vet Sci 2021;8:687448.
- Clark TP, Linton DD, Freise KJ, et al. Multicentered masked placebocontrolled phase 2 clinical study of an extended duration transdermal buprenorphine solution for postoperative pain in cats. J Vet Pharmacol Ther 2022;45(S1)(suppl 1):S40–S51.
- Clark TP, Linton DD, Freise KJ, et al. Multicentered masked placebocontrolled phase 3 clinical study of an extended duration transdermal buprenorphine solution for post operative pain in cats. J Vet Pharmacol Ther 2022;45(S1)(suppl 1):S52–S66.
- Clark TP, Linton DD, Freise KJ, et al. Margin of safety of extendedduration transdermal buprenorphine solution following multiple-dose administrations to cats. J Vet Pharmacol Ther 2022;45(S1)(suppl 1):S67–S84.
- Di Cesare F, Negro V, Ravasio G, et al. Gabapentin: clinical use and pharmacokinetics in dogs, cats, and horses. Animals (Basel). 2023;13(12):2045.
- Anthony RM, Amundson MD, Brejda J, et al. Acceptance of a novel, highly palatable, calorically dense, and nutritionally complete diet in dogs with benign and malignant tumors. Vet Sci 2023;10(2):148.
- Stockman J, Fascetti AJ, Kass PH, et al. Evaluation of recipes of homeprepared maintenance diets for dogs. J Am Vet Med Assoc 2013;242(11): 1500–5.
- Candellone A, Badino P, Girolami F, et al. Concomitant campylobacteriosis in a puppy and in its caregiver: A One Health perspective paradigm in human-pet relationship. Vet Sci 2023;10(4):244.
- Davies RH, Lawes JR, Wales AD. Raw diets for dogs and cats: a review, with particular reference to microbiological hazards. J Small Anim Pract 2019;60(6):329–39.
- Ribeiro-Almeida M, Mour~ao J, Magalh~aes M, et al. Raw meat-based diet for pets: a neglected source of human exposure to Salmonella and pathogenic Escherichia coli clones carrying mcr, Portugal, September 2019 to January 2020. Euro Surveill 2024;29(18):2300561.