Reasons for Cat Pre-Op Fasting: What You Need to Know

Why Do Cats Need to Fast Before Surgery?

Let's first take a look at the structure of a cat's trachea and esophagus:

In a conscious state, cats have an instinctive swallowing reflex that covers the opening of the trachea with the larynx while eating or drinking, preventing food or water from accidentally entering the trachea or lungs.

However, during anesthesia, the muscles of the gastrointestinal tract and the lower esophageal sphincter relax. This increases the risk of passive reflux of stomach contents, and without the swallowing reflex, stomach contents can enter the lungs.

Even if there is no reflux during surgery, postoperative nausea and vomiting (PONV) are common side effects of general anesthesia.

If a cat vomits during the recovery process, food can be aspirated into the lungs through the inguinal canal.

Food, stomach acid, and liquids entering the lungs can cause inflammation or aspiration pneumonia, a lifethreatening lung infection.

If your cat starts coughing after anesthesia, be sure to pay attention! It could be a sign that a foreign object has entered the lungs.

While pneumonia may be mild, if food blocks the trachea, it could even lead to suffocation and death.

Therefore, it is usually necessary to fast before all elective surgeries.

What is an Elective Surgery?

Elective surgery is a term used for nonemergency surgeries that are necessary but can be delayed, such as spaying or dental surgery.

What if there is no fasting before an emergency surgery? If a cat's life is in danger and surgery must be performed immediately, the priority is to save the cat's life.

Specific Fasting Time for Cats Before Surgery

Is the fasting time always 8 hours before surgery, with no food or water allowed? In fact, this time standard is a simplified version. Generally, it applies to healthy adult cats, but not all cats can fast for a whole night.

This is because we need to consider the increased risk of hypoglycemia in diabetic cats, older cats, and kittens. Therefore, it is necessary to consult with the doctor to determine how long to fast before surgery based on the cat's age, weight, health status, and potential risk factors.

According to the American Animal Hospital Association (AAHA), in general:

1. Healthy adult cats should not be fed for at least 46 hours before surgery, and 8 hours of fasting is usually sufficient.

2. Kittens weighing 8 weeks or less than 2 kilograms should not be fed for at least 12 hours before surgery, and it is best to fast for 46 hours.

3. Cats with special conditions, such as pregnancy, diabetes, intestinal obstruction, obesity, and others, should consult with the doctor to determine the fasting time.

4. The minimum fasting time for water should not be less than two hours.

Preoperative Examination

Before a cat undergoes surgery, it is best not to proceed with anesthesia and surgery blindly. Preoperative examination is very important because some cats may appear healthy on the outside, but their actual physical condition is not good. Anesthesia and surgery without examination can be very dangerous.

For example, if a cat has kidney dysfunction, anesthetizing it can cause a decrease in blood pressure and heart rate, reducing renal blood flow and significantly stimulating the kidneys, leading to further deterioration of kidney function. Additionally, if the kidney dysfunction is not recognized and drugs that increase renal burden are used, this can lead to serious consequences.

The death of a cat due to a neutering surgery is often due to a lack of preoperative examination, as spaying is a very mature surgery with a low risk of death. The death is usually caused by other reasons. And this is just an example; other organs like the lungs, heart, and liver can also face risks.

Therefore, preoperative examination is necessary. What kind of examination should be done? Here are some options:

① Routine examination: This includes visual, auditory, and tactile examinations to initially assess the cat's condition, but the effectiveness of the examination depends on the doctor's clinical experience.

② Blood tests: These can determine if the cat has anemia, inflammation, blood diseases, or blood parasites, which are important and necessary, as some diseases may not be suitable for surgery.

③ Biochemical tests: These check liver and kidney function, blood sugar, and total protein, including ALT, ALKP, TP, BUN, CRE, and GLU. If a cat has diabetes, it means that the wound will be difficult to heal. A low total protein level is also a concern.

The first three tests are necessary, while Xrays and ultrasounds are determined based on the surgery's needs. There are also some special tests that may be required based on the cat's condition, such as checking blood oxygen and blood pressure in cats with heart disease before surgery, providing oxygen therapy, and administering antihypertensive medications. Since heart disease cats are on longterm treatment with lowsodium and diuretic drugs, which can easily cause water and electrolyte imbalances, these should be corrected before surgery.

Lastly, as responsible cat owners, we must strictly follow the doctor's instructions before our cats undergo surgery. Fasting is crucial, and we must not give in to our cats' pleading for food. Indulgence can harm our feline friends!