Canine Stomach Problems Explained: From Digestive Upset to Vet Diagnosis

Common causes of canine digestive upsets

There are lots of things that can cause a stomach upset in dogs but the most common ones are:

• Dietary indiscretion. Characterised by eating unusual items, such as rubbish, foreign objects, food or faeces, this is by far the most common cause of acute digestive issues in dogs. As we said at the beginning, dogs will eat just about anything, and it doesn’t always agree with them. 
• Adverse food reactions (AFRs) are allergies and intolerances. 
• Parasites.
• Bacterial or viral infections – some of these can be fatal, so always keep your dog’s vaccines up to date.
• Gastric dilatation and volvulus (also referred to as ‘bloat’).
• Toxins.
• Pancreatitis.
• Foreign bodies.

Beware of festivities!

Some of the most dangerous times for your dog are when you are celebrating. Birthdays and any of the usual festive periods like Christmas or Easter can be especially dangerous. This is partly because the house is often chaotic, so your dog might be less supervised than usual, and partly because some of the most dangerous foods for dogs are in the house at these times. Lots of human food is toxic to dogs, and some of the most common ones are:

• Chocolate. The darker the chocolate, the more dangerous it is.
• Onions and garlic.
• Grapes and raisins.
• Artificial sweeteners such as xylitol.
• Alcohol.
• Macadamia nuts.
• Avocado.

As you can see, lots of our festive foods are very problematic! Try to be extra vigilant in festive periods and keep these foods away from your dog. Keep chocolate off the tree or high up and out of reach. 

When to see a vet if your dog has stomach issues

You’ve probably experienced an upset stomach yourself, and you probably didn’t need to see a doctor. The same can be true for mild cases of stomach upset in dogs, especially if they’ve eaten something that is not toxic and simply does not agree with them. If your dog is fairly active and bright but has some mild vomiting and diarrhoea, you can probably give it a day or two and see if it settles. When in doubt, consult your vet.  You can also ask your vet for some highly digestible gastrointestinal recovery food to feed your dog for a few days and then gradually reintroduce their normal food if all is well. Don’t withhold food unless your dog is actively vomiting. Nutrition is very important for gut healing.

You do need to see a vet, however, if any of the following applies:

• Your dog has been vomiting for more than 24 hours.
• Your dog is lethargic, depressed or not eating.
• Your dog is dehydrated. A good way to know this is the ‘skin tent test’. Gently pull the skin over your dog’s shoulders up in the air and let go of it. It should snap back into position immediately. If it’s slow to return, your dog is dehydrated. If it stays up, your dog is dangerously in need of intravenous fluids and veterinary help. 
• You see blood in their vomit or faeces. Also look out for vomit that looks like ‘coffee grounds’ or dark or black faeces. This can be a sign of intestinal bleeding.
• Your dog is trying to vomit but can’t. This can be a sign of a twisted gut and is a surgical emergency.
• You know your dog has eaten foreign material (other than food) or something toxic.
• Your dog seems to be in pain – which may manifest as hunching, whining, reluctance to move or adopting the play bow position for no reason.

How are digestive upsets treated in dogs?

This will depend on the underlying cause. Your dog may need medication, such as drugs to soothe the stomach lining, antacids, antiemetics (drugs to stop vomiting), anti-inflammatories, or treatment for parasites. In some cases, your vet may need to do further tests, such as blood work, imaging or even biopsies in some cases. One thing is for sure, though – nutrition is really important in treating canine stomach issues. In many cases, a change in food is the best approach and no long-term medication is needed.

For acute issues, your vet will probably offer you the recovery food we mentioned before. These foods are highly digestible, with high-quality protein and carbohydrates and added omega fatty acids and antioxidants. They also have good prebiotic fibre sources to help nourish the ‘good’ bacteria  and restore important microbes in the gut microbiome. Your dog may just need this for a few days or weeks until their gut is fully recovered. 

Some dogs that are prone to stomach issues do well on these foods longer-term. If your dog has a food sensitivity, they may need a food elimination trial and a therapeutic food for food allergies or intolerances. Some dogs with recurrent bowel issues may do best on a higher-fibre diet that has much higher levels of prebiotic fibre to keep their stool formed and normal.

Sometimes, it can take a little trial and error to get your dog’s digestive tract back in tiptop shape, but the sooner you seek veterinary advice, the better. Your dog will feel better more quickly and the damage to the gut will be as minimal as possible. Upset stomachs are a fact of life for most of us mammals, including dogs and humans, but with prompt intervention, great nutrition and some tender loving care, the vast majority will soon be a thing of the past.

Dog stomach problem FAQs

What causes stomach issues in dogs? 

The most common cause is eating something that has disagreed with them, such as a carcass or other food from the bin or something rotten. Other causes include food sensitivities, poisoning, parasites and infections. Always keep your dog’s vaccines up to date.

Can digestive problems in dogs be serious? 

Yes. Dogs can become dehydrated and ill quickly if vomiting is unchecked. Twisted stomachs, poisonings and intestinal obstructions are also emergencies.

What foods are best for dogs with sensitive stomachs? 

This depends on the cause of the sensitive stomach. If your dog has an adverse food reaction, they may need a hydrolysed or novel protein diet. They may simply need a diet that is highly digestible and high quality to keep the gut microbiome healthy.

* A Multi-centre Feeding Study of the Influence of Dietary Intervention in Dogs with Gastrointestinal Disorders. Hill's Pet Nutrition, Inc. Pet Nutrition Centre, 2003.

Written by Emma Milne, BVSc FRCVS, and reviewed by Karen Shenoy, DVM.