Vomiting and Diarrhea in Dogs and Cats - First AID Advice

Herb Rovay
Mar 12
4 min read

Brown dog with a plastic cone rests on white bedding, looking sad. The background is neutral gray, adding a calm atmosphere. — A small, fluffy dog rests on a bed, wearing a protective cone to prevent it from licking its wounds, gazing forward with a thoughtful expression. Hilltop / Top Care

First Aid Advice Before You Reach the Vet

Vomiting and diarrhea are common problems in dogs and cats, but they should not always be dismissed as a simple stomach upset. In some pets, especially the very young, the very old, or those already unwell, vomiting and diarrhea can quickly lead to dehydration, weakness, and electrolyte imbalance.

Mild cases may settle with supportive care, but more severe cases can become serious very quickly. Knowing what to do first can help protect your pet while you arrange veterinary advice.

Why Vomiting and Diarrhea Can Become Serious

Fluid Loss Is the Main Risk

Vomiting and diarrhea cause the body to lose water and important electrolytes.

This means pets can become dehydrated faster than many owners realise, especially if:

vomiting happens repeatedly
diarrhea is severe or frequent
both vomiting and diarrhea occur together
the pet is very small, young, old, or already sick

The biggest concern in many cases is not just the stomach upset itself, but the fluid loss and weakness that follow.

What to Do First

Rest the Stomach

If your dog or cat is vomiting, it is often safest to withhold food and water for a short period at first so the stomach can settle.

If vomiting has stopped, small amounts of clear fluids can sometimes be offered after 6 to 8 hours. If these fluids are tolerated, bland food may be introduced the following day in small amounts.

This approach may help in mild cases, but it is not appropriate for every pet. Pets that are weak, continue vomiting, or seem very unwell should be seen by a veterinarian sooner.

Offer Fluids Carefully

Small Amounts Only if Vomiting Has Stopped

If your pet has not vomited for several hours, you may be able to offer small amounts of clear fluid.

Do not allow gulping or large amounts at once, because that may trigger vomiting again.

If vomiting returns after fluids are offered, the pet should be assessed by a veterinarian.

Reintroducing Food

Start With Small Amounts of Bland Food

If fluids are tolerated and vomiting has not returned, bland food can usually be offered the next day in small, frequent amounts.

The aim is to give the stomach a chance to recover without overloading it.

If your pet refuses food, vomits again, or worsens after eating, veterinary advice is needed.

Keep Your Pet Separate

Isolation Helps Protect Other Pets

If you have more than one pet at home, it is sensible to isolate the sick pet until the cause of vomiting and diarrhea is clearer.

Some causes may be infectious, especially in puppies, kittens, or pets with recent exposure to other animals.

Keep food bowls, bedding, and toileting areas separate until your veterinarian advises otherwise.

Do Not Give Medications Unless Advised

Some Human or Pet Medicines Can Make Things Worse

Do not give medications unless your veterinarian has specifically advised you to do so.

Some medications can make vomiting and diarrhea worse, hide important symptoms, or be unsafe for pets.

It is safer to speak with your veterinarian before giving any treatment at home.

When Vomiting or Diarrhea Is an Emergency

Signs Your Pet Needs Veterinary Attention Quickly

You should contact a veterinarian promptly if your pet:

vomits repeatedly
has frequent or severe diarrhea
seems weak or lethargic
cannot keep water down
has blood in the vomit or stool
has abdominal pain
is a puppy, kitten, elderly, or medically fragile
becomes dehydrated
stops improving within a short time

Vomiting and diarrhea together can become serious quickly, especially when fluid loss is significant.

What Your Veterinarian May Need to Know

Useful Information to Track

If possible, make note of:

when the vomiting or diarrhea started
how often it is happening
whether there is blood present
whether your pet has eaten anything unusual
whether other pets in the home are affected
whether your pet is still drinking

This information can help your veterinarian decide how urgent the situation is and what treatment may be needed.

Vomiting and Diarrhea Care in Kalamunda

When Your Pet Needs Veterinary Attention

If your dog or cat has vomiting, diarrhea, or signs of dehydration, the team at Hilltop Veterinary Hospital in Kalamunda can assess your pet and recommend the safest next steps.

Early treatment is especially important if your pet is weak, cannot keep fluids down, or is losing a lot of fluid.

Concerned About Vomiting or Diarrhea?

We Can Help

If your pet is vomiting, has diarrhea, or seems unwell, book a consultation with Hilltop Veterinary Hospital so our veterinary team can assess the problem and provide the right treatment.