Sensitivity to Anesthesia in Dogs
Anesthetics are drugs used to block the sensation of pain. Anesthetics are divided into two categories.
- Local – Local anesthetics are used to numb the surface of the body.
- General – These anesthetics render the dog unconscious.
Certain breeds have an increased sensitivity to barbiturates and other anesthetics and that must also be taken into account prior to surgery. Pre-surgery testing and blood work will help the anesthesiologist determine the safest drug and dose for your puppy or dog.
The greyhound, whippet, Italian greyhound, Afghan hound, Borzoi, Irish wolfhound and the Saluki are examples of sighthounds. Sighthounds, especially greyhounds, are genetically inclined to metabolize drugs differently than other dog breeds. Sighthounds need comprehensive blood work prior to any procedure requiring anesthesia.
Brachycephalic dog breeds such as bulldogs, pugs, boxers and Boston terriers must be closely monitored during anesthesia due to their restrictive airways. They must be closely monitored and cared for before, during and after surgery.
Herding dogs like the collie, border collie, Australian shepherd and the sheltie often have a genetic mutation in the ABCB1 (formerly MDR1) gene that allows certain drugs to accumulate in the brain. The smaller the dog the higher the risk when administering any kind of anesthesia. Toy dogs must be carefully weighed and the appropriate dose of anesthetic given based on their small size.
Extra Large Breeds
Newfoundlands, Doberman Pinschers and Great Pyrenees and other extra-large breed dogs need higher doses of anesthesia prior to surgery. However, big dogs often over-respond to normal doses so it’s vitally important that these dogs are dosed according to lean body mass or surface area rather than actual body weight.