A dog attending the veterinary practice for advice on sickness

Help! My dog is being sick. Identifying the causes of dog vomiting

No one likes being sick, and it can be distressing to see your dog or puppy vomiting. While one-off vomiting may be no cause for alarm – your dog may vomit simply because they’ve eaten too much or too fast, for example – there are numerous reasons for a dog being sick.

Your local vet will help you establish the cause and recommend treatment, if necessary. Always seek help from your vet if your dog or puppy keeps being sick, if you suspect they’ve been in contact with a toxic or harmful substance, or if you spot blood in their vomit.  Other concerning signals are bloating, recurrent vomiting, retching, white foam or in your dog’s vomit and vomiting water.

Sickness in dogs: the warning signs

If your dog is sick once and is otherwise alert, active, and showing no other symptoms, there’s likely to be nothing to worry about. If your dog is lethargic, persistently vomiting, has diarrhoea, loses his appetite, or displays any other symptoms, don’t delay – get him to your local vet, fast. Prolonged vomiting can quickly lead to dehydration, so always be vigilant.

Common causes of a dog being sick

There’s a vast range of possible causes for sickness in dogs. While it’s impossible to cover all of these here, we’ve listed some of the most common reasons. (This list is no substitute for the advice and expertise of your local vet, so always get in contact if you have any concerns about your dog’s health.)

  • Worms
  • Sensitive stomach
  • Stomach infections (gastritis)
  • Ingestion of a foreign body
  • Colitis
  • Serious conditions
  • Poisonous or harmful substances

Reasons for a dog vomiting

An infestation of worms, such as roundworm or tapeworm, can cause your dog to vomit. As always, prevention is better than cure, and it’s important to get into a regular worming routine to keep your dog worm free.

If your dog has a particularly sensitive stomach they may be unable to tolerate certain foods, and this can trigger vomiting. Have you changed your dog’s diet? Your vet can advise you on a suitably bland diet – such as chicken with rice, or fish with pasta – for dogs with a sensitive stomach. 

Stomach infections (gastritis) are a common cause of sickness in dogs – and are often marked by both sickness and diarrhoea. A bland diet (see above) and plenty of water can help clear up the problem in a few days, but always consult your vet if your dog doesn’t recover quickly.

Sickness accompanied by diarrhoea may be a sign of colitis in your dog. Colitis is often eased by feeding your dog a bland diet (see above) after 24 hours without food.

A number of serious conditions can cause sickness in dogs, including congestive heart failure, disease of the central nervous system, cancer, liver and kidney diseases. Your vet will test your dog to rule out these conditions if necessary, and to establish the best course of treatment to get your dog back in tip-top health.
Ingesting poisonous or harmful substances can cause your dog to be sick. If you believe your dog has come into contact with a toxic substance, get him to your vet as quickly as possible. 

Did you know? 

Vomiting isn’t the same as regurgitation, which happens after a meal and contains visible lumps of undigested food. 

“Your vet can advise you on a suitably bland diet – such as chicken with rice, or fish with pasta – for dogs with a sensitive stomach.” 

Need help and advice for your dog?

For expert advice on vomiting in dogs, get in touch with your local vet. To find your nearest recommended vet or pet clinic, use our Find a Vet page.