How Long Can A Dog Go Without Food? Fact Checked By Our Vet

If your dog isn’t eating, you might be wondering how long they can go without food. Well, this is a very valid reason to be worried. Dogs need food to stay healthy, so any changes in eating patterns can cause a lot of trouble.

Here’s what you should know about it.

How Long Can A Dog Go Without Food?

Dogs skipping a meal is just a sign something isn’t sitting well with them. They might work through it and feel hungry for their next meal, or they might not.

As a rule of thumb, if your pup hasn’t eaten regularly in the last 24 hours, or is throwing up everything they eat, consult with a vet.

Be especially cautious with small breeds, since they get dehydrated faster. Usually, a sudden appetite change is the most common sign of your dog not feeling well.

Why A Dog That Won’t Eat Can Be Dangerous

A dog that refuses to eat, or that cannot eat, can have important health consequences. In general, here are some key points to keep in mind if your dog isn’t eating:

• Hydration is critical: Typically, healthy dogs can technically survive up to five days without eating, but only if they drink water. Without proper hydration, fasting dogs are at risk of severe health consequences and it can even be life threatening.

• Size matters: As with children, the smaller the body size, the bigger the risk of suffering from lack of eating. Small breed dogs are more prone to dehydration, hypoglycaemia and general organ failure.

Why Is My Dog Not Eating?

Appetite loss is a non-specific symptom. This means it might be caused by several health issues. In any case, your vet will be able to tell you more. These are some of the reasons why your dog might not want to eat:

Mouth or gastrointestinal issues

Sometimes, dogs don’t eat because they have something stuck on their gums or other parts of their GI system. As a rule, check your dog’s teeth, gums, cheeks, and throat if they refuse to eat. A loose tooth or cavities can be a common reason for loss of appetite. The same with intestinal upsets: dogs with vomit, have diarrhoea, suffer from weakness or lethargy, should get immediate veterinary care. Intestinal obstruction can also induce a lack of appetite. If your dog shows any of these symptoms, call your doctor immediately.

Bacterial, viral, or parasitological infection

It’s very common for dogs to pick up infections. Diseases like salmonellosis, parvoviruses (1) or blood parasites can cause many symptoms, including loss of appetite. If you see your dog is lethargic, call your vet to get your dog checked.

Cancer and organ failure

Not to scare you, but lack of appetite can be an early sign of serious diseases. For instance, different published journal reports mention that owners recognised abnormal drinking, eating and urinating behaviour over half a year before their pet's official diagnosis (2). On the other hand, they also recognised weight loss almost four months in advance. When it comes to cancer, it’s a common fact that dogs that are in pain refuse to eat. Of course, some medication can induce appetite loss.

Anxiety or depression

If something is bothering your dog on an emotional level, it might cause them to lose their appetite. If your dog has other behavioural changes, this might be the root cause of their lack of appetite (3). Sadness, anxiety, being left alone and changing routines can cause your dog to avoid eating, but this should go away in a day at most.

Sudden diet changes

This one ties in with the gastrointestinal distress causes we outlined above. Dogs are sensitive to sudden diet changes, especially if they aren’t used to eating diverse foods. This is very common when changing kibble brands or even recipes within the same brand. If that sounds like you, try to slowly introduce the new food to your dog instead of swapping all at once. This should solve the lack of appetite in no time.

Your dog might be bored

Sometimes dogs get bored of their food or even the flavour. If your dog is picky, this is a likely cause. Try adding a yummy topping like some cut up sweet potato or a few meat pieces. If your dog starts eating again, boredom might have been the reason why.

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What To Do If Your Dog Is Not Eating

The first thing you need to do is make sure there are no underlying medical conditions that might be preventing your dog from eating. In general, a quick at-home once-over can show you whether or not your dog is feeling bad in other ways.

If you think there’s something more serious going on, or if your dog hasn’t eaten in 24 hours or more, rush to the vet. They’ll be able to figure out what is going on with your pup and medicate as needed (4).

On the other hand, if your pup simply refused to eat a single meal, and is behaving normally otherwise, you might want to try these tips:

Keep their feeding area relaxed 

If something scares or distracts your dog, it might cause negative associations with feeding time. Avoid this by keeping your dog’s bowl in a calm, quiet place without loud noises.

Add more flavour 

This works if your dog is bored of their food, or just isn’t a fan of the newest kibble recipe. Here are a few tips:

• Increase moisture: Switching from dry food to a canned or pouched food can make mealtime more appetising.
  
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• Increasing fat: This one is especially useful if you’re trying to sneak medication, or your dog needs to eat less food without lowering calories.
• Warm it up: Lukewarm food is more appetising to your dog than fridge-cold meals. Of course, keep an eye out for the temperature and never give piping hot food to your dog.
• Ask the vet for secondary effects: Some drugs cause a loss of appetite, so if your pup takes medication, your vet might be able to help. They might adjust their dosage or swap for other options altogether.

When To Call The Vet If My Dog Isn’t Eating

We recommend keeping an eye out whenever your dog refuses to eat even a single meal. This, alongside other behavioural changes, can signal other more serious health conditions.

If a dog refuses to eat twice in a row, or hasn’t eaten in 24 hours, you should call your vet. Depending on their hydration levels, their size and overall health status, your dog can need medical attention in as little as 36 hours.

Final Thoughts

If your dog isn’t eating, you should check on their overall health. Most times it’s only because they’re bored with the food and using the tips we mentioned above, your dog will chomp up on their food in no time.

As always, if you think your dog is getting worse or they have something serious, call your vet! They will be better qualified to give you the best advice.

References

1. Decaro, N., et.al. (2005). "Clinical and virological findings in pups naturally infected by canine parvovirus type 2 Glu-426 mutant". Journal of Veterinary Diagnostic Investigation, 17(2), 133-138. https://doi.org/10.1177/104063870501700206 
2. Bartlett, P. C., et al. (2010). "Case-control study of risk factors associated with feline and canine chronic kidney disease". Veterinary Medicine International, 2010. https://doi.org/10.4061/2010/957570 
3. Delaney, S. J. (2006). "Management of anorexia in dogs and cats". Veterinary Clinics of North America: Small Animal Practice, 36(6), 2006, 1243-1249. https://doi.org/10.1016/j.cvsm.2006.08.001
4. Zollers, B., et al. (2017). "Evaluation of the safety in dogs of long‐term, daily oral administration of capromorelin, a novel drug for stimulation of appetite". Journal of Veterinary Pharmacology and Therapeutics, 40(3), 2017, 248-255. https://www.researchgate.net/profile/Linda-Rhodes/publication/317025795_Evaluation_of_the_safety_in_dogs_of_long-term_daily_oral_administration_of_capromorelin_a_novel_drug_for_stimulation_of_appetite/links/5925b911458515e3d44e35d1/Evaluation-of-the-safety-in-dogs-of-long-term-daily-oral-administration-of-capromorelin-a-novel-drug-for-stimulation-of-appetite.pdf