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Why Does My Cat Throw Up After Drinking Water? 2 Possible Reasons Why!

Luxifa Le

By Luxifa Le

cat vomiting

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Reviewed & Fact-Checked By

Dr. Tabitha Henson

DVM (Veterinarian)

The information is current and up-to-date in accordance with the latest veterinarian research.

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“Ack…aaaack…aaaaaaacccckkk…hurk!” Every cat owner knows the sound of their cat’s retching and is about to throw up on something they love. Owners in multi-cat households may even be able to tell their cats apart by the sounds of their retching! But if your cat regularly throws up, this is a massive problem that their veterinarian needs to address.

The most common reason cats throw up after drinking water is that they drank too much, too fast, but they might also experience vomiting from other sources. Here are the most common reasons your cat might throw up after drinking water.

Top 2 Reasons Cats Throw Up After Drinking Water:

1. They’re Regurgitating

orange kitten vomiting on the floor
Image Credit: ThamKC, Shutterstock

This goes back to the “too much, too fast” quip. The difference between vomiting and regurgitation is that vomiting is the expulsion of the contents of the stomach and small intestine. In contrast, regurgitation is the expulsion of the contents of the esophagus.

When you vomit, it’s because something went wrong during digestion. Maybe you were allergic to what you were eating or ate something that didn’t agree with your spice tolerance. Regurgitation is the expulsion of food from your esophagus. When you regurgitate food, it never actually reaches your stomach.

Usually, when you regurgitate food, it’s because you overate. Your stomach fills up, and the food you continue to eat backs up into your esophagus. Your stomach then sends signals to your brain like, “Help! I’m full, but this fool keeps trying to fill me! It must go! All of it!” Then you regurgitate your food because your stomach is too full.

Cats will overeat in captivity because their default structure of meals is “feast versus famine,” and they’re inclined to overeat when presented with the opportunity. Then their bodies are like, “Hey! I need water!” and drink just enough to overfill their stomachs and regurgitate.

The key between regurgitation and vomiting is that regurgitation occurs right after eating. Vomiting can happen at any time during digestion.

2. Hairballs

young cat sitting on wooden table with hairball
Image Credit: RJ22, Shutterstock

Your cat may also have drunk water trying to pass a hairball. Hairballs occur when your cat ingests hair while grooming itself. While cats have been eating hair since before written history, they never evolved to be able to digest it. Usually, the hair comes out the back end without issue but depending on the length of the cat’s fur, and how frequently and vigorously it grooms itself, a buildup of hair that cannot safely pass through the intestines may occur.

When the buildup of hair is too large to pass through the intestines safely, the cat will throw the hairball up to expel it from the body. By the time it reaches your floor (or shoes, or duvet), it probably looks more like a tube of discolored mucus, but it’s composed of hair, and we call it a hairball anyway.

Cats may drink water to move hairballs through the digestive tract. Thus, your cat will sometimes drink water and vomit up the hairball and the water when that doesn’t pan out the way it’d hoped.

How Much Vomiting is Normal in Cats?

Expecting a cat to never vomit in their life is like expecting a human never to vomit in their life. It’s going to happen eventually. However, cats should not be vomiting regularly. Vomiting incidences that occur more than once a month should be investigated as they may be a sign of something more serious going on with your cat’s digestive tract.

Final Thoughts

While vomiting from time to time is no big deal, it can be scary to witness your cat vomiting regularly. If your cat is vomiting after drinking water, there’s probably the reason behind it, and further investigation of your cat’s habits is to ensure that your cat is in good health.

If your cat is vomiting regularly, we recommend that you bring them to the veterinarian immediately. Vomiting can signify several serious illnesses, such as g pancreatitis and cancer. Your veterinarian will have the most holistic view of your cat’s typical health and behavior and be able to diagnose their conditions better than the internet.

As always, it’s better to be safe than sorry regarding our pets’ healthcare!

Featured Image Credit: Tunatura, Shutterstock

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