A dog's anal glands are located on either side of its rectum. Every time a dog defecates, the anal glands release a distinctive scent. But sometimes these glands will become infected and eventually rupture. If the infection becomes bad, then in order to save the dog's life, the anal glands need to be removed. But complications from anal gland surgery in dogs are low compared to other types of surgeries.
According to "Dog Owner's Home Veterinary Handbook" by Debra M. Eldredge, DVM, et al., small- and toy-sized dogs are most often afflicted with infected or ruptured anal glands. Smaller dogs are more in danger of losing too much blood during surgery than larger dogs. But vets usually keep a large healthy mixed-breed dog in a clinic--often the vet's own dog--to stand by as a donor, according to the "Textbook of Small Animal Surgery" by Douglas H. Slatter.
The dog needs to be unconscious for anal gland surgery and requires general anaesthesia. Any dog in any type of surgery that involves anaesthesia runs the risk of getting complications just from the anaesthesia. These risks tend to go down the healthier the dog is. Toy dogs with very low body fat will feel the effects of anaesthesia more than larger dogs. Dogs with liver or kidney problems will have trouble naturally filtering out the anaesthesia from their bodies.
Another risk in anal gland surgery is that the dog might vomit while unconscious. The dog can choke to death in this way. The dog is supervised during surgery and about an hour afterwards to be sure the dog does not vomit and, if it does, to quickly clear the vomit from the airway.
There is a chance of postoperative infection with this procedure. The anal glands are located in a difficult position to keep sterile. When dogs defecate, urinate or sit down, they may introduce bacteria to the surgical site. This may mean another surgery to drain any large patches of infection.
According to Jon Gellar, DVM, dog anal gland surgery complications can be reduced if the dog owner asks the vet just how experienced she is at doing anal sacculectomies (anal gland removal). However, in the case of emergencies, a dog owner will not have time to ask questions. But often this surgery can be performed when the dog is feeling well in between anal sac infections.