Dogs can smell like many things, depending on what they have most recently rolled in, but one of the more unpleasant aromas dogs commonly develop is one of fish.
If your dog smells like fish, it is probably not because he figured out how to spray himself with Eau de Sardine. A fishy odor is usually the result of secretions from the anal glands.
What Are Anal Glands?
Anal glands, which are also called anal sacs, are small sacs located on either side of your dog’s anus. These sacs are full of specialized sweat glands that produce an unpleasant smelling secretion that acts as a scent marker for your dog. When your dog poops, these secretions pass onto the feces, letting other dogs know important chemical information about your dog. This explains why your dog is so interested in other dogs’ poop, not to mention the tail sniffing that goes on when two dogs meet.
Dogs also “express” their anal sacs when they are scared, which is perfectly normal, if a bit odorous. Anal gland secretions have a distinct smell that many people describe as fishy. If your dog smells like fish, chances are there may be something going on with her anal glands.
Anal Sac Disease
Normally, your dog’s anal glands are naturally expressed in small amounts each time she defecates. Sometimes, however, the anal sacs are not emptied completely of fluid, and the fluid becomes dry and causes impaction. Impacted anal sacs cannot express properly, which is very painful for your dog. The sacs feel hard to the touch, and when expressed manually by a veterinarian or other professional, produce a thin ribbon of pasty, brown material. If impacted anal glands aren’t treated, they can become abscessed.
Impactions can happen for several reasons. There could be an abnormality in your dog’s anal sacs, or your dog could have soft stool, which is not firm enough to express your dog’s anal glands when she defecates. Obese dogs are at an increased risk of impacted anal glands, as their sacs do not empty well.
Infections and Abscesses
Anal glands can also get infected, and in this case, they can also become abscessed if left untreated. Infected and abscessed anal sacs are very painful, and the area may appear discolored or swollen. If left untreated, these abscesses can rupture through the skin.
“Abscesses need prompt attention,” says Dr. Jerry Klein, AKC chief veterinary officer. “They are painful and sometimes require surgery. The dog also usually needs antibiotics and pain medications.”
Anal Sac Tumors
Anal gland tumors limit your dog’s ability to express his anal glands himself, and they make the anal glands feel firm and enlarged. In most cases, anal sacs with tumors will not express at all, and your veterinarian may take a biopsy and perform an ultrasound to diagnose the problem.
Symptoms of Anal Sac Disease
There are other symptoms of anal sac disease besides a fishy smell. Dogs with irritated anal sacs may scoot on the floor, bite or lick at their anus, or have difficulty defecating. They may even vocalize when they defecate because it is painful. You might also feel a hard lump near the rectum, or notice blood and/or pus on your dog’s stool. Although scooting is a fairly common sign that may seem laughable, it is a helpful symptom and warning of anal sac disease. If you notice any of these signs, or any discoloration around the anus, call your veterinarian and get your dog in for evaluation.
There are certain conditions your dog may have that can increase the chances of anal sac disease. These include: being overweight or obese, food and environmental allergies, hypothyroidism, skin mites, and bacterial or yeast infections of the skin.
What to Do About Your Dog’s Fishy Smell
If you notice a fishy smell, call your veterinarian. Your dog may simply need his anal glands manually emptied, or expressed, which should resolve the odor.
Some dogs, especially small dog breeds, require that their anal glands be expressed regularly. Veterinarians and groomers both perform this service, and you can even learn how to do it yourself if you don’t mind the odor. However, be aware that manually expressing the anal glands too frequently can cause inflammation and result in scar tissue, so it should only be done when they are not emptying naturally.
Compacted anal sacs require your veterinarian’s assistance. These are carefully expressed, and your veterinarian may need to use a softening agent or saline rinse if the compaction is particularly dry. Once the compacted material is removed, your veterinarian may recommend a higher fiber diet for your dog to help him express his anal sacs naturally.
Infected or abscessed anal sacs are cleaned with an antiseptic and are then typically treated with antibiotics. Your veterinarian may recommend hot compresses applied to the area if she suspects an abscess, and it may take a few flushings for the infection to resolve.
In some cases, your veterinarian will remove the anal sac or sacs. Anal sac disease that does not resolve with treatment, as well as anal sac tumors, usually need to be dealt with by surgical removal. While there are potential complications, such as incontinence, most procedures are successful and do not negatively affect your dog’s quality of life.
Preventing Anal Sac Disease
While anal sac disease is not always possible to prevent, there are a few things you can do.
- Feed your dog an appropriate diet with the right amount of fiber.
- Keep an eye on your dog’s stool to make sure it is well-formed.
- Exercise your dog regularly and keep an eye on his weight.
- Provide your dog with plenty of fresh, clean water.
Luckily, anal sac problems are relatively easy to treat. Once the underlying issue is resolved, the fishy smell should go away. If your dog requires regular anal gland expression, that fishy smell is a reminder to get your dog into the veterinarian’s office or to the groomer.