Feline Anal Sac Disorders
General information
Other common/scientific names: anal sac impaction, anal sac infection. anal sac abscess, anal sacculitis. Note that the anal sacs are sometimes referred to as the anal glands.
To the left and right of the anus at approximately the 4 o’clock and 8 o’clock positions lay the anal sacs. They lay under the skin and deep to some of the muscles of the anus and they secrete a brownish, oily fluid with a distinctive, sharp odor. Each sac has a small duct that opens near the anal opening. When the anal sacs are healthy and operating properly, defecation will cause compression of the sacs and a small amount of the fluid in the anal sacs will be expelled onto the cat’s feces. It is thought that this distinctive odor on the feces helps the cat mark its territory and helps in social recognition. The sacs may also be expressed by the cat when it is surprised or frightened and clenches the muscles around its anus.
Causes
When an anal sac becomes inflamed, infected or impacted, the contents of the sac cannot be expressed normally. The sac will become distended and swollen with subsequent pain and, possibly, even rupture of the sac.
Diarrhea or chronically soft feces, poor muscle tone around the anus, and excessive anal sac secretions which may become retained all make an anal sac problem more likely to occur. Inflammation and irritation around the anus from allergy or skin infection may also lead to inflammation of the anal sacs and their duct, leading to impaction or infection of the sacs. However, in many cases the cause of the problem remains unclear.
Cardinal symptom
Scooting on the rear end, licking the anus
Symptoms
Scooting on the rear end and constantly licking the anus are the most frequent symptoms of an anal sac problem. Sometimes pain during defecation may be observed, as may redness, irritation and sometimes swelling around the anus. If a sac becomes infected or abscessed then fever may be present. If an abscessed sac ruptures, a small open wound and drainage may be seen next to the anus. Sometimes only one anal sac is involved, but both sacs may be affected at the same time.
Diagnosis
Diagnosis is made by examination of the anal area and palpation of the anal sacs.
Treatment
In most cats, impaction of the anal sacs without infection is present. In this case, manual expression of the anal glands will take care of the problem. While normal anal sacs have a thin brownish or yellowish secretion, impacted sacs have a thick, pasty secretion which may be beige or brown. Because it is often painful to remove this thick, tooth-paste like material from the sacs, sedation is usually necessary.
Infected anal sacs may have a creamy yellow, thin yellowish-green or reddish-brown secretion. Expressing the sacs, flushing them with a disinfectant solution and instilling an antibiotic/corticosteroid ointment into the sacs may be necessary. The cat will need to be sedated for these procedures. The cat will often also be given antibiotics, anti-inflammatories and pain medications.
Abscessed and ruptured anal sacs are treated much like infected anal sacs. If ruptured, the area will be left open to drain after treatment and will heal by granulation, or scarring. After treatment for infected, abscessed, or ruptured anal sacs, your vet may want your cat to wear an Elizabethan collar for a few days in order to prevent the cat from incessantly licking at the area while it is healing.
In rare instances of repeated anal sac problems, or anal sacs that do not seem to heal after repeated treatment, surgical removal of the anal sacs may be necessary.
Prognosis
The prognosis for cats with anal sac problems is good. Most respond well to treatment, and only in rare instances is surgical removal of the sacs necessary.