August 6, 2010

My pet’s breed is “sensitive to anesthesia”

“Breed sensitivity” to anesthesia is a common misperception that has spread through the pet community for years. There is no such thing. The rumors have become more rampant since the advent of the internet, with a lot of incorrect information being posted on internet sites. None of these sites quote medical literature, but often refer to anecdotal incidents of anesthetic complications. Usually, these stories end with some version of  “don’t let this happen to you;  Make sure that your vet knows that __________s (fill in the blank for your breed) are more sensitive to anesthesia”. While the loss of any pet during an anesthetic procedure is horrible, these incidents rarely have anything to do with a dog or breed being “sensitive” to anesthesia.

So where does the idea of breed sensitivity to anesthesia come from? Surely there is some basis for so many people to be spreading this misinformation. I think there are likely two reasons for this, detailed below:

  1. 15-20 years ago barbiturates were routinely used for general anesthesia in veterinary patients. While barbiturates are inherently safe drugs when used properly, they are associated with a slower recovery from anesthesia when compared to many of the newer drugs used for veterinary anesthesia. Some barbiturates (pentobarbital) are particularly long lasting. Recovery from barbiturate anesthesia depends partially on the drug moving into the patient’s body fat, where it is slowly metabolized. Patients with low body fat, including greyhounds, whippets, salukis, and other members of the “sight hound” breeds are slow to recover from barbiturate anesthesia because they have no body fat for the drug to move into. As a result, it stays in their bloodstream longer, leading to slow recovery. In some cases these patients can remain groggy for days, leading to a variety of complications, including unfortunately, a higher risk of anesthesia associated fatality. This becomes even more of a problem when the anesthetic is not accompanied by appropriate patient support such as warming blankets, IV fluids, and monitoring equipment. Modern anesthetic drugs are short-acting and/or reversible, leading to much more rapid recovery. Most patients, including members of the sight hound family, are walking within 15-30 minutes of the completion of the anesthetic episode.
  2. Unlike human medicine, in veterinary medicine there is very little oversight regarding the quality of the anesthesia used on patients. Anesthesia can be done very cheaply, or it can be done well. While most clinics and veterinarians use modern drugs and techniques, many are substandard. When problems inevitably arise, these can be dismissed as the pet being “sensitive to anesthesia”. Owners are not generally capable of assessing what level of care their pet received, and accept the statement that their pet “was sensitive”. They tell other people and the myth is propagated.

There really is no such thing as “sensitive to anesthesia”. No two patients are created equal, and anesthetic protocols should be tailored to each pet’s individual needs. For those owners wishing the ultimate in anesthetic safety, we can request our Board-Certified Veterinary AnesthesiologistTM, Dr. Martin Kennedy, to remotely monitor your pet while they are being placed under anesthesia by our in-house anesthesia technician.