What Are Anal Glands and Where Are They Located?
Every dog has two anal glands, also known as anal sacs, positioned on either side of the anus at roughly the four o'clock and eight o'clock positions. These small, pouch-like structures sit just beneath the skin and are lined with specialised glands that produce a strong-smelling, oily secretion. The scent is unique to each dog and serves an important biological purpose — it is a form of chemical communication that carries identity information when dogs meet and sniff one another.
Under normal circumstances, the glands are expressed naturally each time a dog defecates. The pressure of a firm stool passing through the anal canal causes the sacs to compress and release a small amount of fluid. This is why stool consistency plays such an important role in anal gland health. Dogs eating a high-fibre diet with well-formed stools tend to have far fewer problems than those producing soft or loose motions.
Signs That Something Is Wrong
When the glands fail to empty properly, the secretion thickens and builds up inside the sac, a condition known as impaction. This is uncomfortable and can progress to infection or abscess if left unaddressed. Knowing the early warning signs can save your dog considerable pain.
- Scooting — dragging the bottom along the floor or grass
- Persistent licking or chewing at the base of the tail or around the hindquarters
- A distinctly fishy or musty odour, particularly noticeable when the dog sits near you
- Reluctance to sit down or sudden discomfort when sitting
- Turning to look at or bite at the rear end without obvious cause
- Visible swelling or redness on one or both sides of the anus
Scooting is the most widely recognised sign, though it is worth noting that it can also indicate other issues such as worms or skin irritation. If your dog scoots repeatedly over several days and you notice the fishy smell, anal glands are the most likely culprit.
Manual Expression: External vs Internal Techniques
When the glands are not emptying naturally, manual expression is required. This can be performed by a veterinary professional, a trained groomer, or — with proper instruction — by the owner at home. There are two approaches: external and internal expression.
External expression involves placing a folded piece of tissue or cloth over the anus and gently squeezing upwards and inwards at the four and eight o'clock positions simultaneously. This technique is less precise and may not fully empty impacted glands, but it is far less invasive and suitable for routine maintenance in dogs prone to mild build-up.
Internal expression is carried out by a veterinarian. A lubricated, gloved finger is inserted into the rectum to locate each gland individually and apply direct pressure to empty it completely. This method is more thorough and is the preferred approach when impaction has already occurred. It also allows the vet to assess the consistency of the secretion — thin and pale is normal, whilst thick, paste-like or bloody material indicates a problem requiring treatment.
It is generally advisable not to attempt internal expression at home unless you have received direct training from your vet. Done incorrectly, it can cause discomfort or injury.
When Impaction Progresses to Abscess
If an impacted gland is not treated, bacteria can multiply within the accumulated secretion, leading to an abscess. This is a painful condition that develops rapidly and requires urgent veterinary attention.
Signs of an anal gland abscess include a noticeably swollen, hot, and painful area on one side of the anus. The overlying skin may appear reddish-brown or purple. In more advanced cases, the abscess can burst through the skin, forming an opening called a fistula that discharges pus and blood. Dogs with abscesses are often visibly distressed, may cry when touched near the area, and may refuse to defecate due to the pain involved.
Treatment typically involves lancing and flushing the abscess under sedation or anaesthesia, followed by a course of antibiotics and anti-inflammatory medication. In recurrent or severe cases, surgical removal of the affected gland — a procedure called anal sacculectomy — may be recommended.
Breeds Most Commonly Affected
While any dog can develop anal gland problems, certain breeds appear to be predisposed to recurring issues. These include:
- Cocker Spaniels — one of the most frequently affected breeds, possibly due to soft coat and body conformation
- Basset Hounds — their low muscle tone and distinctive build may contribute to reduced natural expression
- Cavalier King Charles Spaniels — prone to chronic anal gland impaction throughout their lives
- Miniature and Toy breeds generally — smaller dogs tend to have narrower ducts relative to gland size
- Overweight dogs of any breed — excess fat tissue around the anal area can impede natural expression
If your dog falls into one of these categories, speak to your vet about a monitoring schedule and whether regular preventative expression is appropriate.
The Role of Diet in Anal Gland Health
Because natural gland expression depends on the pressure of firm stools, diet has a significant influence on how well the glands function. Dogs fed a high-fibre diet tend to produce bulkier, more formed stools that exert sufficient pressure to empty the glands during each bowel movement.
Practical dietary adjustments that may help include adding a teaspoon of plain canned pumpkin to meals (not pumpkin pie filling), switching to a high-fibre kibble, or incorporating safe vegetables such as carrots or green beans. Always introduce dietary changes gradually to avoid gastrointestinal upset, and consult your vet before making significant changes, particularly if your dog has underlying health conditions.
Dogs prone to recurring issues despite a good diet may benefit from fibre supplements recommended by their vet, or from more frequent gland checks — typically every four to eight weeks.
When to See a Vet
Any dog scooting repeatedly or showing signs of discomfort around the hindquarters warrants a veterinary assessment. Early intervention prevents simple impaction from escalating into a painful abscess. If you notice swelling, heat, redness, or any discharge near the anus, treat this as urgent and contact your vet the same day. Prompt treatment not only relieves your dog's discomfort but significantly reduces the risk of complications requiring surgery.