Why Can’t My Pet Eat Before Surgery?

Author: Emi Kooyman | Founder

When it comes to surgery day, one of the most important safety steps we ask of you is simple: no breakfast for your pet.

We know it can feel tough to skip their morning meal, but there’s a good reason behind it — and following these instructions helps us keep your pet safe during anesthesia.

At Spay Neuter Vets, every protocol we follow is designed with your pet’s comfort and safety in mind. Let’s talk about why fasting matters, and how you can help us make anesthesia as safe as possible — including a simple optional add-on that offers even more protection.

Why Fasting Matters

When your pet is placed under anesthesia, their muscles completely relax — including those that normally keep food and fluids inside the stomach. The esophagus and the sphincter between the stomach and throat lose tone, which makes it easier for stomach contents to travel backward.

If your pet has recently eaten, that material can regurgitate into the throat and be inhaled into the lungs, leading to a serious complication called aspiration pneumonia.

Aspiration pneumonia can require:

• Hospitalization and oxygen therapy

• IV fluids and antibiotics

• A long, unpredictable recovery period

The safest (and simplest) way to prevent this is by starting surgery with an empty stomach.

Our Fasting Guidelines

Here’s how to prepare your pet safely for anesthesia:

• No food after midnight the night before surgery.

• A small snack (10–25% of their normal meal) of wet food or pâté only is recommended between 8 PM and midnight. This helps prevent excess stomach acid that can form with prolonged fasting.

• No dry kibble or treats after midnight.

• Water is OK overnight — please do not withhold.

• Puppies and kittens 5 months old and under may have a small portion (10–25% of their normal meal) of wet food by 6 AM the morning of surgery. No food after 6 AM. 

If your pet eats after the cutoff time, please let us know right away. The veterinarian will decide if it’s safe to proceed or if we should reschedule for another day.

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Learn more about what to expect when you book a spay/neuter surgery with us.

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The Role of Anti-Nausea/Antiemetics: An Optional Add-On for Extra Safety and Comfort

Even when pets have fasted appropriately, some are still prone to nausea or reflux under anesthesia. To help protect against this, we offer an optional Anti-Nausea/Antiemetic injection at check-in.

This Anti-Nausea/Antiemetic injection is a medication that helps:

• Decrease stomach acid production

• Reduce the risk of vomiting or regurgitation under anesthesia

• Make the post-surgery recovery smoother and promote getting back to eating faster

While Anti-Nausea/Antiemetics are not required for every patient, it’s a smart precaution for owners who want to add an extra layer of safety — especially for pets who are sensitive, anxious, or known to have sensitive stomachs.

We do require Anti-Nausea/Antiemetic injection for certain cases, such as:

• Brachycephalic (BOAS) breeds like Bulldogs, Pugs, Shih Tzus, and Persians

• Pets that recently ate outside the fasting window (if the veterinarian approves surgery to proceed)

• Pets with known reflux issues or prior vomiting during anesthesia

In these specific circumstances, the veterinarian has determined that he Anti-Nausea/Antiemetics injection is required for safety. Otherwise, it remains an optional add-on that many owners choose when their budget allows — simply for the added peace of mind it brings.

💡 As a bonus, when owners elect to add the Anti-Nausea/Antiemetic injection, we also include a complimentary Vitamin B12 injection to support energy and recovery.

Elective Surgery Means Safety First

Spay and neuter procedures are elective, which means they can be safely postponed if your pet isn’t fully ready for anesthesia.

If your pet eats after midnight, or if anything seems off the morning of surgery, we’re happy to reschedule rather than take unnecessary risks.

Why risk a preventable complication when waiting one more day helps ensures a smooth, lower stress procedure?

At Spay Neuter Vets, our team takes every precaution to keep your pet safe — before, during, and after surgery. Thank you for helping us make anesthesia as safe and worry-free as possible by following fasting guidelines and considering preventive care options like adding the Anti-Nausea/Antiemetic injection.