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What happens if a dog eats pizza with onions?

Dogs have a way of sneaking their favorite foods, whether we want them to or not. You may know that your dog shouldn’t eat onions, and that pizza isn’t really healthy for them either. If your pooch sneaks a piece of pizza, are they in danger? What happens if they eat pizza with onions? 

What happens if a dog eats pizza with onions?

You realize your pooch just helped themselves to a slice of pizza with onions. You may be concerned, or even scared. Aren’t onions toxic to dogs? What about the other ingredients? The good news is, your dog is likely not in any danger. 

Onion Toxicity 

It’s true, onions are toxic to dogs. However, they would need to eat a lot of onion to have any problems. Onions are a member of the allium family. 

They contain N-propyl disulfide. This is fine for humans, but it causes the dogs red blood cells to break down. This is also present in garlic, but in higher amounts. 

Onion and garlic can make your dog sick. The good news is that it takes a lot of onion to make them ill. A 45 pound dog would need to eat 1 medium to large onion to have serious toxicity. 

Even if your dog ate an entire pizza, it’s unlikely there’s enough onion on the pizza to make them ill. However, if the pizza contained both onions and garlic or garlic powder, this makes it more likely they will get a harmful dose. 

The signs of onion or garlic toxicity include difficulty breathing and an elevated heart rate. They may also have stomach pain and discolored pee. Their gums can become pale, yellow, or brown.

Gastointestinal Upset 

The most common problem dogs experience after eating pizza is gastrointestinal upset. This occurs due to the high fat content of the food. Certain ingredients like spices and dairy can also contribute to the condition. 

Dogs have a snesitie system. In fact, any change to their regular diet, even switching dog foods, can trigger stomach upset. If they aren’t used to eating pizza, it’s normal for them to have some issues. 

The signs of stomach upset include vomiting, diarrhea, and loss of appetite. These symptoms will typically appear within a few hours of dietary indiscretion. 


Simple stomach upset is certainly inconvenient for you and tough for your dog, but there are no long term consequences. Pancreatitis, however, is more concerning. 

Dogs can develop pancreatitis when eating a diet high in fat, carbs, or both. So a meal like pizza can certainly trigger the condition. Pancreatitis is caused when the pancreas becomes inflamed. 

It’s role is to release digestive enzymes. When functioning properly, these enzymes activate in the intestines, where they digest food. Pancreatitis causes the enzymes to activate when they are released. The enzyme then damage the pancreas and surrounding organs. 

This causes intense pain, and repeated vomiting. Your dog may also adopt a praying position. This means they put their paws on the ground, and their rear in the air. This helps relieve the pain temporarily. 

What to do if my dog eats pizza with onions?

 If your dog has eaten pizza with onions, there are steps you should take. Most dogs end up with an upset tummy, if they have any problems at all. However, some develop pancreatitis. 

Remove the Temptation 

The first thing you should do is remove any remaining pizza from your dog’s reach. The last thing they need is more pizza. 

Take Notes 

Your dog will probably be fine, but just in case, take notes. Write down how much pizza they ate, the time, and the ingredients. As you monitor them, write down any symptoms that develop, and the time. 

If you do need to seek veterinary treatment, this information can be vital. 

Monitor Your Pooch 

Now you’ll need to monitor your dog. Keep an eye out for stomach upset and signs of pain. If they are vomiting repeatedly, vomiting or pooping blood, or very lethargic, you should contact your vet or bring them in for treatment. 

If they are in severe pain, whining, or in the praying position, these are also signs they need treatment. 

If your pooch has signs of onion toxicity, you’ll need to get them to the vet immediately. These signs include lethargy, discolored urine, troubled breathing and a rapid heart rate. Gums that are yellow, brown, or pale are another sign. It’s highly unlikely for this to occur from pizza, but you should be aware of it. 

Bland Diet 

If your pooch only has symptoms of an upset stomach, and appears fine otherwise, you can treat them at home. This starts with a bland diet. Vets recommend withholding food for 12 to 24 hours.

Then, you’ll feed them a bland diet of boiled chicken and rice. You should give them 2 parts rice to 1 part chicken. If they eat 1 cup of food, for example, you will give them 1/3 cup chicken and 2/3 cup rice. 

After 1 to 2 days, begin transitioning them back to their regular food. Feed them 1/4 regular food and 3/4 bland food. Every 1 to 2 days, increase the regular food by 1/4. 

If your pooch has stomach upset during this transition, move back a step. If you were giving them 1/2 regular food and 1/2 bland, go back to 1/4 regular food and 3/4 bland for a few more days, then try increasing the regular food again. 

Over the Counter Medications 

In addition to a bland diet, over the counter medication can be helpful for treating your dog’s upset stomach. They will help manage the symptoms until your dog’s stomach settles.

Famotidine is an antacid that can be bought over the counter. 

It can help calm your pooch’s tummy. You’ll give them .5 mg per pound of body weight. This means a 20 pound dog would take 1 10 mg tablet. You can repeat the dosage as needed every 12 hours. 

Peptop bismol might be what you reach for if you overeat or have other stomach woes. It works for your pooch just as it does for you. You can give your dog 1 teaspoon per 10 pounds of body weight. This can be repeated every 6 to 8 hours as needed. 

Natural Solutions 

Pumpkin can help soothe your dog’s stomach. It’s highly digestible and contains plenty of fiber. Unless they are constipated, a few teaspoons is all they need. It can be served plain, and most dogs enjoy it this way. It can also be mixed with chicken and rice, or with their dog food.