Anal Gland Disease in Dogs: A Common but Often Overlooked Source of Discomfort

Anal sac disease is one of the most common causes of perianal discomfort in dogs, yet is frequently undertreated or managed with repeated expression rather than addressing underlying causes.

Key Facts

Dogs have two anal sacs positioned at 4 and 8 o'clock relative to the anus; these sacs produce secretions used for scent marking and released during defecation.
Anal sac impaction occurs when secretions accumulate rather than expressing normally; impacted sacs cause discomfort manifested as scooting, excessive licking, and sitting discomfort.
If untreated, impaction progresses to infection (sacculitis) and ultimately abscess formation with painful rupture through the perianal skin.
Small breeds are disproportionately affected; obesity, soft stools, and anatomical variation all contribute to impaction risk.
Manual expression by a veterinarian or groomer provides relief but does not address underlying causes; many dogs require repeated monthly expression indefinitely.
Dietary fiber supplementation to firm stools can help many dogs express naturally during defecation, reducing the need for manual expression.
Recurrent anal sac disease that does not respond to dietary and medical management may ultimately require surgical removal (anal sacculectomy).

Welfare Considerations

Anal sac disease causes chronic perianal discomfort that significantly affects quality of life. Impacted or infected anal sacs cause pain that worsens with sitting and defecation — activities that cannot be avoided. The characteristic scooting behavior seen in affected dogs reflects active attempts to relieve discomfort through external pressure. Abscessed anal sacs cause acute, severe pain; the rupture through perianal skin, while providing temporary relief, leaves an open wound that requires treatment and causes further discomfort during healing. The welfare impact of chronic anal sac impaction in dogs requiring monthly manual expression is often underestimated — regular discomfort between expressions, and the discomfort of expression itself, represents ongoing welfare compromise. Addressing root causes through dietary modification and weight management, rather than perpetual manual expression cycles, provides better welfare outcomes for many dogs.

What You Can Do

Recognize anal sac discomfort signs: scooting, perianal licking, reluctance to sit, or visible swelling near the anus.
Have impacted anal sacs expressed by a veterinarian and discuss root cause management rather than just repeated expression.
Consider high-fiber dietary supplements if your dog requires frequent expression — firmer stools aid natural emptying.
Maintain a healthy weight — obesity is a significant risk factor for anal sac disease.
Seek prompt veterinary care if you notice a discharging wound or severe swelling near the anus — abscess requires treatment.