Dog Not Eating

While many dogs with cancer will experience a lack of appetite at some point during the course of their disease, there are many medications, special diets, and lifestyle changes that can help address your dog not eating.

Key Takeaways

  • There are many reasons a dog may not want to eat. Thankfully, most episodes of decreased appetite only last a short time and do not negatively impact your dog’s quality of life.
  • If your dog’s not eating, but otherwise acting normal, you can try withholding food for 12-24 hours. Then reintroduce small amounts of a bland diet.
  • If your dog is running a fever, cannot keep water down, or if inappetence or vomiting persists for more than 24 hours, contact your veterinarian for guidance.
  • There are various medications that can help encourage your dog to eat by controlling nausea, increasing appetite, and managing pain.

Inappetence: Dog Not Eating

Inappetence, or lack of appetite, can manifest in various ways. A dog not eating may have complete anorexia, where they refuse to eat any food offered. Others may show hyporexia, where they continue to eat, but consume less than their normal amount. Others may have changes in the types of food they are willing to eat.1

Sometimes you will notice differences in your dog’s eating habits immediately, but other times these changes can be more difficult to spot. This is especially true in multi-dog households where another dog may help finish up any left-behind food. In certain cases, weight loss may be the first symptom you notice that may indicate that your dog is not eating enough.

Why Dogs Stop Eating

When your dog doesn’t want to eat, one of the first things you need to determine is why they have a decreased appetite. Careful observation at home can help you and your veterinarian determine the possible cause of your dog’s inappetence.

Many things can lead to a decreased appetite in a dog diagnosed with cancer:

  • Certain cancers such as those that affect the mouth, esophagus, or stomach can directly impact a dog’s ability to eat.
  • For dogs on chemotherapy, nausea and vomiting are common side-effects which may lead to a decreased appetite.2
  • Tumor cells can release compounds that decrease appetite and cause weight loss.13
  • Medications your dog may be on, such as opioid pain control, can decrease appetite as a common side effect.2
  • If your dog is painful in some way (even unrelated to their cancer), they may be unwilling to eat.14
  • Like many people, some dogs just don’t have a good appetite when they’re not feeling well.3

Chemotherapy May Make a Dog Not Want to Eat

Dogs on chemotherapies including cisplatin, doxorubicin, dacarbazine, cyclophosphamide, actinomycin, and 5-FU streptozotocin may be more likely to develop nausea and vomiting after treatment.4

It’s important to note that these side effects may not occur until 2-5 days post treatment,4 so if your dog is not eating after chemotherapy treatments – even a few days afterwards – it may be due to chemo.

What You Can Do at Home to Help Your Dog Eat

There are some simple things that you can try at home to encourage your dog to eat. Every dog is different and finding what works for your dog may take some trial and error.

  • Create a calm, distraction-free environment for your dog to eat in.3
  • Try warming the food slightly.
  • Top the food with something extra tasty, such as a bone broth made for dogs or plain, boiled chicken.
  • Offer a variety of foods for your dog to choose from. Offer these separately and also mixed, so that your dog may choose what they prefer.3
  • Try feeding your dog by hand.3
  • Dog bowls may still smell of the last meal they held, so you might try using a paper plate instead of a dog bowl to reduce nausea.

Vomiting and Lack of Appetite in Dogs

If your dog is vomiting, your dog will not feel like eating, and you can withhold food for 12-24 hours.5,6 After this time period, reintroduce small amounts of water.

If your dog can keep down the water, then offer a few bites of a bland diet.5,6 Good bland diet options include commercial gastrointestinal diets and home-cooked foods such as plain, boiled chicken or cooked, plain white rice.5,6

There are also medications that can help stimulate appetite and control nausea. Talk with your veterinarian to come up with a specific plan for your dog.

Pain and Lack of Appetite in Dogs

If you think your dog is not eating because they are in pain, speak with your veterinarian about adjusting your dog’s pain management plan.

Keep in mind that pain can come from many different sources. Arthritis pain, for example, can cause your dog to not eat. It’s important to discover the source of your dog’s pain and address it directly. Once pain is better managed, dogs usually resume eating normally.

When to Call Your Vet About Your Dog Not Eating

It can sometimes be hard to decide when exactly to contact your veterinarian when you notice your dog not eating. Is it an emergency?

You know your dog best, so trust your gut instincts and contact your veterinarian if you are concerned about your dog’s appetite. The sooner you get whatever is wrong addressed, the better.

Certainly, if your dog is running a fever over 103°F, if she cannot keep water down, or if inappetence or vomiting persists for more than twenty-four hours, you should contact your veterinarian.5,6

Things that Help Improve Appetite in Dogs

There are a variety of medications that can help with a lack of appetite in dogs.

Appetite Stimulants

An important appetite stimulant is capromorelin (Entyce®), which triggers receptors in the brain which can increase a dog’s desire to eat.7,8

Entyce is available as an oral liquid that you can easily give at home. It is relatively well tolerated with the main side effects being vomiting and diarrhea in a small percentage of dogs.7

Currently, there appear to be limited contraindications for giving capromorelin in dogs with most types of cancer,8 however, further investigation into the interaction between capromorelin and dogs with malignant melanoma and certain types of malignant breast cancer is needed.8

Your veterinarian can advise you as to whether capromorelin is a good choice for your dog. Other commonly used appetite stimulants include mirtazapine9 and cyproheptadine.

Anti-Nausea Medications

Since nausea and vomiting are common causes of inappetence, anti-nausea medications can help improve appetite.

Commonly used anti-nausea medications include maropitant (Cerenia), ondansetron, and metoclopramide.9

Oral forms can easily be given at home, though injectable formulations are also available for those dogs who are unable to keep down oral medications due to vomiting.

Your veterinarian can advise you as to what anti-nausea medications may be useful as part of your dog’s treatment protocol.

Short Term Fasting

In human medicine, evidence is emerging that short-term fasting around the administration of certain types of chemotherapy may help decrease the severity of some side effects including nausea and vomiting.10-12

While further research is needed, this may be a strategy that could prove useful in veterinary medicine as well, and your oncologist may have some suggestions about timing meals on chemotherapy days.

Pain Medications

Pain is another common cause of decreased appetite in dogs.14 If you think your dog may be experiencing pain, talk with your veterinarian about developing a pain management plan.

Is Your Dog Not Eating a Sign They Are Dying?

Dog lovers often associate a lack of appetite in their dogs with a poor quality of life.2,9 In the short term, not wanting to eat for a day or two is unlikely to truly affect your dog’s overall life quality. Since many episodes of inappetence only last a short time and respond well to medications, special diets, and lifestyle changes, you may not need to worry about this.4

However, if inappetence is prolonged, does not respond to treatment, or causes a severe decrease in weight, it may be a sign of a decreasing quality of life. Make sure you have a candid discussion with your veterinarian if you have any concerns about your dog’s quality of life.

  1. Burney D, Cook A, Freeman L, Johannes C. Inappetence: Its many forms and clinical management. Clinician’s Forum.
  2. Ettinger S. Take the offensive with patients fighting cancer and inappetence. DVM 360. 2019; 50(8).
  3. Harper S. How to help your dog with cancer when he won’t eat. Dog Cancer Blog. 2020.
  4. Ettinger S. Top tips for managing chemotherapy patients in your practice. World Small Animal Veterinary Association Congress Proceedings. 2017
  5. Ettinger S. Helping pets through chemo. DVM360.
  6. Cornell University—College of Veterinary Medicine. Managing common side-effects of chemotherapy in companion animals.
  7. Zollers B, Wofford JA, Heinen E, Huebner M, Rhodes L. A Prospective, Randomized, Masked, Placebo-Controlled Clinical Study of Capromorelin in Dogs with Reduced Appetite. J Vet Intern Med. 2016;30(6):1851-1857. doi:10.1111/jvim.14607
  8. Rhodes L, Zollers B, Wofford JA, Heinen E. Capromorelin: a ghrelin receptor agonist and novel therapy for stimulation of appetite in dogs. Vet Med Sci. 2017;4(1):3-16. Published 2017 Nov 6. doi:10.1002/vms3.83
  9. Walden LA. ACVIM 2017: Chemotherapy-Induced Vomiting and Inappetence. DVM 360.
  10. Safdie FM, Dorff T, Quinn D, et al. Fasting and cancer treatment in humans: A case series report. Aging (Albany NY). 2009;1(12):988-1007. Published 2009 Dec 31. doi:10.18632/aging.100114
  11. Bauersfeld SP, Kessler CS, Wischnewsky M, et al. The effects of short-term fasting on quality of life and tolerance to chemotherapy in patients with breast and ovarian cancer: a randomized cross-over pilot study. BMC Cancer. 2018;18(1):476. Published 2018 Apr 27. doi:10.1186/s12885-018-4353-2
  12. Zorn S, Ehret J, Schäuble R, et al. Impact of modified short-term fasting and its combination with a fasting supportive diet during chemotherapy on the incidence and severity of chemotherapy-induced toxicities in cancer patients – a controlled cross-over pilot study. BMC Cancer. 2020;20(1):578. Published 2020 Jun 22. doi:10.1186/s12885-020-07041-7
  13. Porporato PE. Understanding cachexia as a cancer metabolism syndrome. Oncogenesis. 2016;5(2):e200. Published 2016 Feb 22. doi:10.1038/oncsis.2016.3
  14. Hernandez-Avalos I, Mota-Rojas D, Mora-Medina P, et al. Review of different methods used for clinical recognition and assessment of pain in dogs and cats. Int J Vet Sci Med. 2019;7(1):43-54. Published 2019 Nov 18. doi:10.1080/23144599.2019.1680044

Entyce® is a registered trademark of Elanco US

Cerenia® is a registered trademark of Zoetis US


Did You Find This Helpful? Share It with Your Pack!

Use the buttons to share what you learned on social media, download a PDF, print this out, or email it to your veterinarian.

Editor's Picks