General Anesthesia and Your Pet

It can be a little scary when you hear that your pet needs to go under general anesthesia for a procedure. Learning what you can about what's going to happen can help decrease any anxiety you might have.

What Is General Anesthesia?

General anesthesia is when your pet is rendered unconscious, so they don't move or feel pain while they are undergoing a procedure. Pets are put under general anesthesia for many reasons, including:

• To have spay/neuter procedures done
• For dental cleanings, x-rays, and extractions
• To undergo MRI or CT scans
• For other types of surgery
• Sometimes, for restraint to do a thorough exam, x-rays, or laceration repair

General anesthesia in pets is achieved by using medication which can be in an inhalant form or an injectable form. When injectable is used, the pet is then often placed on inhalant anesthesia to maintain unconsciousness, especially if anesthesia is needed for more than a few minutes.

What Are the Risks of General Anesthesia for Pets?

There are risks to general anesthesia, as there are for any medical procedure. In general, most pets handle anesthesia quite well unless they have an underlying medical condition. The most common side effects seen with general anesthesia are:

• Vomiting upon waking up. This can be decreased by fasting the pet before anesthesia.
• Aspiration of vomit resulting in aspiration pneumonia. As pets are waking up from anesthesia, they don't have control of their swallowing mechanism right away, and if they vomit, they risk aspirating it into their lungs. This risk can be mitigated by keeping the pet intubated until he is beginning to move around and careful monitoring by veterinary staff, who can help the pet hang his head if he starts vomiting so gravity can bring it out.
• Prolonged sedation/difficulty waking up. This can occur if the pet's liver isn't functioning correctly. It's also common in sighthound breeds of dogs.
• Cardiac and respiratory arrest. This is not common, but it can occur, usually due to a hidden underlying condition.

How Are the Risks of General Anesthesia in Pets Mitigated?

Your veterinarian can decrease the risks to your pet of general anesthesia by:

• Performing a complete physical exam beforehand to look for any problems that might indicate anesthesia could be risky.
• Looking through your pet's medical history, especially considering any past anesthetic events, to determine whether there was a problem.
• Pre-anesthetic blood tests may be performed to look for indications that the pet's kidneys or liver might be struggling and less likely to deal well with anesthesia.

Additionally, steps can be taken during your pet's anesthesia to decrease the risks. These include:

• Intravenous fluids before, during, and after anesthesia to support blood pressure and help the organs flush out the medication. The IV catheter also allows the quick administration of life-saving medicines if your pet suffers an adverse anesthetic event.
• An endotracheal tube placed in the pet's windpipe can help the veterinarian more strictly control the amount of inhalant anesthesia and oxygen your pet is getting. It also allows the veterinary staff to manually breathe for your pet if he stops doing so himself.
• Pets can be kept warm with electric pads or towels and blankets. When a pet's temperature drops during anesthesia, complications are more likely to occur.
• Human and machine monitors can closely watch your pet's blood pressure, heart rate, oxygen saturation level, respiratory rate, gum color, anesthetic level, and temperature. Small or large adjustments can be made to the anesthesia, medications given if needed to combat problems, and the procedure hastened or ended early, if necessary, based on this monitoring.

Follow your veterinarian's instructions carefully before anesthesia.