Anal sac disease is a condition in cats that occurs when the two anal glands, located one on each side of the rectum, become infected, abscessed or impacted with fluids that are normally expressed during defecation. While this condition occurs in dogs and cats, cats most often experience anal disease due to impaction, while dogs can experience infection, abscess or impaction.
How Anal Sac Disease Affects Cats
The clinical signs of feline anal sac disease include scooting, licking and biting at the rear end as the cat attempts to relieve the discomfort, pain and itchiness associated with this condition. Cats may rub and lick their rectal area for reasons other than impacted anal glands, such as allergies (inhalants or food), intestinal parasites (tapeworms) or tumors. Most cats empty their anal glands naturally whenever they have a bowel movement or during exercise. With impaction, this normal emptying cannot occur.
Causes of Anal Sac Disease in Cats
Cats may have anal gland problems because they are being fed a diet that is too low in fiber. A fiber-rich diet results in voluminous stools, which tends to naturally express the anal glands during bowel movements. Obesity and/or a lack of exercise can result in impacted anal glands because the glands do not get expressed naturally as well. Chronic diarrhea and poor muscle tone are thought to contribute to this condition.
Preventing Anal Sac Disease
There is no definitive way to prevent anal sac impaction in cats. A good, healthy diet and lifestyle are probably the best ways to prevent this disorder in cats.
The prognosis for cats with anal sac disease is good to excellent. Obese cats should be placed on a weight loss diet to reduce risks of further incidence, and as long as the anal sacs are kept clean and well maintained the risks of scarring and anal sac rupture are very low.
The "anal sacs" are pockets between the internal and external anal sphincter muscles on either side of the anus of carnivores. The walls of these sacs are lined with large sebaceous glands that secrete a smelly discharge for territorial marking or during times of fear or anxiety. Anal sac disease includes anal sac blockage, impaction, hypersecretion, inflammation, abscess and neoplasia. Anal sac problems are rare in cats, but when they do occur they normally involve impaction.
Symptoms of Anal Sac Disease in Cats
When the anal glands fail to empty, most cats will scoot their rear ends along the ground, which helps to squeeze and empty the secretions from their anal glands. If this is unsuccessful, affected cats tend to become increasingly uncomfortable, begin straining and excessively lick and bite at their anal area. If left untreated, cats commonly develop a rash around their anus due to self-trauma. Some cats may chase their tails and/or undergo changes in temperament. Cats that require constant manual anal gland emptying should be thoroughly assessed by a veterinarian to make sure that there is no underlying medical cause for this problem.
There is no single test that can conclusively diagnose anal sac disease in cats. Instead, this condition is diagnosed based upon the cat's history, clinical signs, results of veterinary physical examination and microscopic examination of the anal sac contents. Anal sac problems are uncommon in cats.
Diagnosing Anal Sac Disease in Cats
Most cases of anal sac disease in cats are caused by impaction of these paired pockets near the cat's anus. When the anal sacs become blocked, cats cannot express their normal secretions during bowel movements. Cat's with anal sac impaction normally will constantly lick or bite around their anal area and scoot their hind end along the ground.
Definitive diagnosis is made by digital palpation of the anal sacs/glands. The veterinarian will palpate the area by placing a finger in the cat's rectum, and if impaction is present the veterinarian will feel small hard masses in the anal sacs. At this point, the veterinarian must apply a good amount of pressure to the glands to express the material. In cases of impaction, the material that comes out of the glands often looks like a thick, pasty brown solid ribbon of material. Anesthesia or sedation is normally necessary due to the pain associated with the examination. If it appears that the anal glands may be infected, most veterinarians will perform a microscopic examination of the material expressed from the glands.
Virtually all cases of anal sac problems in cats are due to impactions of the anal glands. The therapeutic goals are to empty the impacted anal sacs, control any possible infections, and assess whether cancer is involved in the clinical presentation. Impaction occurs when the liquid secretion sits in the anal sacs for an inordinately long time and becomes dried and pasty.
Treating Anal Sac Disease in Cats
Once the gland is swollen and irritated, the increased digital pressure needed to express the gland can bother the cat both during and after the event. Impacted glands are prone to infection and thus can be the source of residual pain. If the cat continues to lick the area, a follow-up appointment should be scheduled.
In most cases, gentle manual expression of the anal glands is possible in companion cats. It may be appropriate for the veterinarian to flush the sacs with sterile saline, antibiotics and/or corticosteroids. Sedation and pain medication are often necessary to complete these treatments in cats. Expressing a cat's anal glands can cause residual irritation, especially if the glands are impacted.
The anal glands are normally emptied during regular bowel movements. If this isn't happening normally, a diet change may help to resolve the situation. Increasing the fiber content to produce a bulkier stool may result in fecal material that is more effective at promoting the emptying these glands during defecation.
For chronically infected anal glands, the only viable alternative may be surgical removal. Management through non-surgical means should be the first choice.