What’s Causing My Puppy’s Upset Stomach?

Dr. Jason Gagné, DVM, DACVIM
By Dr. Jason Gagné, DVM, DACVIM
Updated: 5/9/20242-4 minutes
Puppy upset

Your puppy’s upset stomach could be the result of several things. Because puppies start teething around 12 weeks of age and use their mouths as a sensory organ for learning, they chew on and may accidentally swallow many things they shouldn’t, like sticks, leaves, furniture, shoes and more.

Being diligent about feeding only puppy food and treats can avoid upsetting his stomach with human food snacks. Foods high in fat and spices, like steak and pizza, can wreak havoc on his digestive tract.  Other foods, like grapes and chocolate, can be toxic to your puppy. If your puppy does get into something that might be unsafe, it’s best to call your veterinarian.

Sometimes, puppies get so excited about the delicious puppy food we offer them that they eat it too fast. This may lead to the food coming back up or excess gas forming in the intestines. Both can be uncomfortable for your puppy.

Knowing the possible causes of your puppy’s tummy ache will help you know how to help him feel better and potentially prevent future stomachaches.

Potential Causes of Your Puppy’s Upset Stomach

Chewing On & Swallowing Items He Shouldn’t

Puppies are a lot of work. They need constant supervision and entertainment. Otherwise, they’ll get bored, and bored puppies will find ways to entertain themselves, which can involve chewing on things like your new shoes, chair legs or other objects around the house.

If your puppy manages to break off pieces and swallow whatever he’s chewing on (even toys), they could potentially cause GI upset, damage or even potential blockage in the stomach or intestines. Watch for symptoms like bloody stool, vomiting, inability to defecate, low energy and even weight loss.

Any of these symptoms warrant a visit to your veterinarian.

To help prevent boredom, make sure your puppy gets plenty of exercise and mental enrichment each day. Playing games and obedience training with your puppy will also help him get plenty of exercise and keep his brain busy too.

Puppy Ate Chocolate or Other Toxic Foods

There are plenty of human foods dogs can eat, but there are also many that are toxic to dogs. If your puppy eats chocolate, onions, grapes or anything with xylitol in it, he could get sick.

If you suspect your puppy has eaten any of those foods, call your veterinarian to find out what to do. They may have you watch for symptoms like decreased appetite, vomiting and/or diarrhea, abdominal tenderness and lethargy or weakness. They may also recommend bringing him in for an exam or advise you to induce vomiting. Do not induce vomiting if your puppy is struggling to breathe.

All of this depends on clear communication with your veterinarian about what your puppy ate.  


Your puppy’s immune system is still developing, so it’s important to avoid public places like dog parks, pet stores and pet-friendly restaurants until he has had all his vaccines and boosters. Infections can spread easily in these places. Your puppy can play with other vaccinated dogs in a safe place, like your backyard, to limit exposure to infectious viruses and bacteria.

Focus on socializing him with people and children of all ages and exposing him to a variety of experiences like a bicycle riding by, the postal carrier delivering mail or a plane flying overhead. This can result in a calmer, more well-adjusted adult dog. 

Intestinal parasites are another potential cause of GI upset for your puppy. Puppies can become infected with the parasites from a number of places—from birth, the dirt, other animals, standing water, etc. Regular deworming and fecal exams by your veterinarian can help keep your puppy safe from infection.

Another serious and highly contagious infection that can cause severe stomach upset is parvovirus. Contact your veterinarian immediately if your puppy shows symptoms of parvo, including loss of appetite, abdominal pain and bloating, vomiting and diarrhea, which may be bloody. The positive news is that with regular vaccinations and boosters, your puppy can be protected from this virus.

Eating Too Fast

Puppies get excited about everything, especially food. If you notice your puppy gets gas after he eats or if he vomits soon after, he may be eating too fast. Try feeding him smaller portions spread over more meals throughout the day to see if that helps.

If he’s still gobbling up his food, you may need to try a puzzle feeder or food bowl designed to help him slow down.

Some puppies have sensitive stomachs and may benefit from switching to a sensitive formula that’s gentler on the tummy.

If you’ve tried a slow feeder dog bowl or switching foods and your puppy’s stomach is still upset, make an appointment to see your veterinarian. They can help determine what might be causing his tummy ache and help him start to feel better.

Given all that your puppy is experiencing and learning at this fun phase of his life, contact your veterinarian when you first notice he has a tummy ache. A thorough conversation and exam can help get you the answers you and your puppy need to get back to playing and living his best life.

To learn more about puppy health, behavior and nutrition from our experts, visit our Pet Expertise page.

Related articles

person holding healthy white puppy
How do I know if my puppy is sick? Learn the symptoms of a sick puppy, what causes sickness in dogs, and when to contact a vet from our puppy care experts.
Puppy barking for attention
Home remedy for puppy cough
MyPurina App - woman with dog

Be Rewarded for Your Purina Purchases

Earn and redeem points for Purina products with myPurina app.