Buddy, a 7-year-old labrador with anal sac abscesses
Anal sac disease
The anal sacs sit to the right and the left of the anus and contain glands that secrete a foul-smelling liquid.
The most common anal sac disease is impaction or inflammation, which can usually be managed by squeezing of flushing out the anal sacs. Sometimes abscesses can develop, most of which can also be managed medically. Surgery is recommended for dogs where impaction or inflammation is frequent and negatively affecting quality of life, or where anal sac abscesses fail to resolve or keep recurring. Anal sacs are sometimes removed in dogs with anal furunculosis where lesions persist over the anal sacs despite medical treatment with ciclosporin. Anal sac disease is extremely rare in cats.
The glandular cells can become cancerous, a condition known as anal sac apocrine gland adenocarcinoma, or colloquially as ‘anal sac cancer’ or ‘anal gland cancer’. Cancer may also be called neoplasia or tumour. Although having a high tendency to spread to lymph nodes, anal sac cancer has one of the longest survival rates of all canine cancers and has a low complication rate during treatment, and so is very worthwhile disease to treat. Dogs with cancer confined to the anal sacs can be cured by surgery alone. Cancerous lymph nodes in the abdomen can be removed at the same time as cancerous anal sacs.
Anal sacs are removed by making a small incision to the side of the anus and separating the anal sac and duct from surrounding tissues. Both sacs are removed, as anal sac inflammation usually affects both sacs, and recent studies have shown anal sac tumours can be present on both sides even if a lump is only felt on one side.
Complications are uncommon. Some temporary faecal incontinence is seen after surgery in up to 13% of dogs, thought to be due to swelling or mild discomfort making it harder to clench to hold faeces in. It is very rare for faecal incontinence to be permanent, and this complication is rarely reported. Other complications are very rare, and dogs are quickly comfortable after surgery.
Buddy's Story
Buddy developed anal sac abscesses that failed to respond to medical management, and he was uncomfortable around his bottom due to fistulas between the anal sacs and the skin. It is typically more difficult to remove anal sacs that have had repeated abscesses, especially if they have previously burst through the skin as Buddy’s had done. With careful dissection, both anal sacs were removed at the same surgery. The anal sacs were sent to a laboratory for analysis and showed he had a small cancerous mass in one of the sacs. The mass was very small and as it is likely to have been caught early in his disease, Buddy has a good prognosis.
A few months after surgery, Buddy’s owner updated me to say: ‘Buddy is doing really well, all healed and looking the best it has in years. He is no longer licking or going at his bottom. Thank you for getting our Buddy back to his normal way and living the life that he deserves. He is definitely back to his normal cheeky ways.’
