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Why Has My Dog Lost Their Appetite?

Written by Anna Hollisey


English cocker spaniel sitting next to full food bowl

Has your dog lost interest in their dinner? There are many potential reasons for this alarming behavior. Let’s cover the main possibilities.

#1: Gastrointestinal Upset or Infection

Sometimes (naming no names, Louie/learn/dog-diaries/the-puppy-diaries-4-the-1000-pack-of-chewing-gum), dogs eat terrible, horrible things… and we don’t know why – maybe they tasted good at the time.  But certain human foods (including onion and garlic, chocolate, and xylitol sweeteners) are toxic to our dogs. They can cause effects including:

  • Loss of appetite
  • Diarrhea
  • Vomiting. 

If your dog’s an everything-eater then you’re probably familiar with these occasional bouts of stomach upset. And you know that it’s important to observe your dog for additional symptoms. 

If your dog has a bad stomach, runny feces, or vomiting – and those are not accompanied by any other symptoms, mental or physical – then you’ll want to seek vet advice if there’s no improvement after 48 hours. 

But be aware that vomiting and diarrhea can also be signs of underlying illness or infections. So it’s important to watch closely for any other warning signs, including changes in personality. If you have any doubt, get straight to the vet. 

#2: Mental Health 

Mental health can affect your dog’s appetite, too. If they suffer from separation anxiety, they may be disinterested in food during the time while you are away from them. Some dogs will only eat when their owner is nearby; that’s when they feel relaxed.

Anxiety of all types – including stress caused by fireworks, travel by car, or a visit to the vet – can result in a lost appetite. Your vet can provide advice about day-to-day management, including medication.

#3: Just Back From the Vet 

Certain canine medications (including anesthetics and some regular prescriptions) are known to cause loss of appetite. If your dog’s just had an operation or veterinary treatment, or started a new medication, check the directions on the pack. Then observe them carefully and call your vet if they’re not hungry again within a day or two. 

#4: Tired Of Their Food 

Imagine you had the exact same meal for breakfast and dinner every day. Would you lose your appetite?  When that happens to our dogs, sometimes they get labeled ‘fussy eaters’. That’s not fair. Test your dog’s appetite by offering them one of their favorite foods (if you didn’t already). Sometimes our dogs just need a change in diet, and you can achieve that by adding toppers to their standard food or by trying something totally new. 

#5: Dental Infection 

A dental infection can be difficult for owners to notice. But loss of appetite is an early indicator, as your dog is likely to experience pain when they chew. Dental infections/learn/dog-health/periodontal-disease-in-dogs-symptoms-causes-and-treatments start with gum disease but can become very serious, affecting the tooth’s root. It is vital to get your dog to the vet very quickly if you suspect that their teeth are causing pain. 

#6: An Imbalance in The Gut

The gut is an important part of your dog’s overall health system. It affects their immune levels, mental health, and skin condition. The gut also contains the chemicals which tell your dog when they’re full or hungry. This means that an imbalance can cause loss of appetite.

Your vet will recommend a course of action to test and identify the cause of imbalance. You can also try giving your dog a supplement which contains postbiotics to support a healthy gut microbiome/learn/dog-supplements/what-are-the-best-digestion-supplements-for-dogs.  

#7: Your Dog is Pregnant 

Pregnancy hormones arrive in waves, which can cause nausea (in humans and dogs!). Monitor your dog closely to see that she eats enough and call the vet if you need advice. If your dog has been pregnant for some time and has suddenly lost her appetite, it might be the first sign of labor./learn/dog-health/why-wont-my-pregnant-dog-eat-anything

#8: Another Health Issue 

Loss of appetite is one of the first symptoms of a wide range of conditions, infections, and viruses. Many dogs will lose interest in food when they’re feeling wrong. For example, kidney disease will manifest in a loss of appetite accompanied by more frequent urination. So if your dog’s persistently off their food, get them off to the vet for testing.

Further Reading

Here’s all you need to know (and more) about dog poop./learn/dog-health/dog-poop-everything-you-need-to-know If your dog needs something to eat which is tasty and gentle on their stomach, try making some homemade bone broth/learn/dog-health/can-i-feed-my-dog-bone-broth. On the same topic, read some interesting facts about dogs’ digestive systems!/learn/dog-health/1.-dogs-are-built-to-cope-with-cholesterol