What to Know Before Your Pet Gets Anesthesia

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Dogs and cats may require anesthesia for various reasons throughout their lives. Many pets undergo planned surgical procedures, such as spaying or neutering at a young age. Pets also need anesthesia when they’re getting dental cleanings, which are essential not only for oral health but to help prevent health problems throughout their bodies as well. Some pets may require emergency surgery to repair broken bones or to remove something from their digestive tracts that they shouldn’t have eaten.

People often are apprehensive about their pets undergoing anesthesia. This fear may even cause them to skip procedures that they don’t think are essential for their pets. Unfortunately, this means cats and dogs might not get all the care they need. To help assuage your fears, we're taking a closer look at anesthesia and exploring how you and your veterinarian can work together to ensure the best outcome for your pet.

What Is the Risk My Pet Won’t Wake Up?

Veterinarians take numerous precautions before deciding to anesthetize a pet, and technological and pharmaceutical advancements have made veterinary anesthesia safer than ever before. Even still, anesthesia comes with some risk, as does any medical treatment. Veterinary scholars wanted to quantify this risk for pets as best they could. So in a 2006 study called the Confidential Enquiry into Perioperative Small Animal Fatalities (CEPSAF), researchers collected data from more than 98,000 dogs and almost 80,000 cats over two years to generate the most comprehensive information available today.

The researchers recorded health outcomes until 48 hours after the end of the procedure that required anesthesia. Results showed that 0.17 percent of dogs and 0.24 percent of cats passed away due to complications from anesthesia. If pets were sick when they underwent anesthesia, the risk increased to about 1.4 percent.

Further analysis of the CEPSAF study revealed that most problems occurred after anesthesia, with the most critical time being the first three hours after the end of the procedure. For this reason, your veterinary team will monitor your pet carefully during recovery and will keep him at the clinic until he is fully awake.

Preanesthetic Evaluation

To help minimize the risk that your pet will experience anesthesia-related problems, it is important for your veterinarian to perform a thorough physical examination, run some blood tests and discuss your pet’s health and medication history before administering anesthesia. This preanesthetic evaluation assists the veterinarian in assigning your pet an anesthetic status, usually on a scale of I to IV, which is similar to what’s done for people. This status helps the veterinarian determine your pet’s risk for anesthesia-related complications. A blood test helps determine if there are problems in your pet’s liver and kidneys, which are important for metabolizing and excreting anesthetic drugs. A blood test also helps the veterinarian choose the right anesthetic drugs for your cat or dog. If your veterinarian is concerned about your pet’s heart or lungs, more tests may be needed, such as an electrocardiogram, an echocardiogram or thoracic radiography. If any of the test results worry your veterinarian, she will talk with you about whether it’s safe for your pet to undergo anesthesia.

Preanesthetic testing and evaluation are particularly important for the following groups of pets, which are more likely to have health conditions that need to be addressed before, during and after a procedure that requires anesthesia. Even still, it’s often best for these pets to be anesthetized in order to get the treatment they need. Your veterinarian will evaluate your pet to help you make the right decision.

  • Senior pets. Dogs and cats older than 12 face a higher risk of anesthesia-related complications, because they are more likely to already suffer from an organ problem or disease that might make it more difficult for them to tolerate anesthesia. Preanesthetic evaluation will tell your veterinarian which health issues need to be addressed to help avoid anesthesia-related complications during the procedure.
  • Small pets. Veterinary teams deal carefully with dogs weighing less than 11 pounds and cats weighing less than 4 pounds. Your veterinarian needs an exact weight for these smaller pets in order to accurately dose the anesthesia drugs. Small pets also are more likely to get cold during anesthesia, which can cause problems. Therefore, veterinary team members carefully monitor pets’ temperatures and use equipment, such as warming blankets, to prevent hypothermia.
  • Obese pets. Obese cats and dogs can experience compromised heart and/or lung function, which may make it more difficult for anesthetic drugs to work properly. Again, your veterinarian will carefully evaluate obese pets to ensure they’re healthy enough to undergo anesthesia.

Preparing Pets for Anesthesia

In addition to examining and testing your cat or dog before anesthesia, your veterinary team will ask about your pet’s general health and any medications he’s taking. It is important to tell your veterinarian if you are giving your cat or dog any nonprescription drugs such as aspirin — which can cause excessive bleeding during surgery — or any herbs or supplements, including fish oils or other joint products. People often assume that since herbs and supplements are "natural," they cannot cause any problems, but veterinarians are learning that this isn’t true. Herbs such as St. John’s wort, kava kava and ginkgo biloba can decrease the safety and efficacy of anesthetic drugs and surgical procedures, and should be discontinued before anesthesia.

Many veterinarians will ask that you drop your pet off on the day of surgery in order to avoid unnecessary stress from staying overnight at the veterinary clinic. If you’re dropping your pet off on the same day — usually in the morning — you may be asked not to feed your dog or cat after his last meal the day before. This helps ensure your pet does not vomit any food that could get into the lungs before, during or after anesthesia. If your pet did accidentally have access to food, don’t be embarrassed. These things happen. Just be sure to tell your veterinarian this important information. Your veterinarian may need to take extra precautions or change the schedule so that your pet has his procedure later in the day after the food has had time to be digested.

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