Why Does My Dog Smell Like Fish? Anal Glands, Skin, Mouth, and Other Causes

You're watching TV with your dog curled up beside you when you catch a whiff of something awful. You check the blanket, then your dog's fur. Did somebody open a can of tuna?

We know the feeling. And before you put your pup through another bath, it’s worth checking where the smell is coming from. If it’s just anal gland residue left on the fur, our Bootay Spray for rear-end freshness can help with ordinary external odors between baths. It won’t fix a gland problem, though, and that’s an important difference.

First, Find Out Where the Smell Is Coming From

A fishy smell around your dog’s rear usually points toward anal gland fluid. If the odor is strongest near the mouth, skin, or genital area, something else may be responsible.

You don’t have to diagnose it yourself. Just note where the smell starts and whether anything else seems different about your dog.

For example, if your dog smells fine all morning but leaves a fishy patch on the couch after being startled by the doorbell, that points more toward an anal gland release than a dirty coat.

If the smell is there all day, however, or comes with changes in behavior, you’ll want to investigate further.

Why Do Anal Glands Make Dogs Smell Fishy?

Dogs have two small anal sacs, one on either side of the anus. They produce a strong-smelling fluid that helps dogs communicate through scent.

Usually, the fluid is released when your dog poops. It can also escape when a dog gets frightened or excited, which explains why the smell sometimes appears without warning.

According to Cornell University’s College of Veterinary Medicine, anal glands can become impacted when they don’t empty properly. The fluid builds up, thickens, and may eventually cause inflammation or infection.

That’s why an occasional fishy smell and a persistent one aren’t necessarily the same problem.

How Can You Tell if Your Dog’s Anal Glands Are Full?

Dogs with uncomfortable anal glands may scoot across the floor, lick their rear repeatedly, or seem reluctant to sit down. Some strain while pooping or leave small amounts of smelly fluid on furniture.

The famous butt scoot might look funny for a second, but repeated scooting isn’t something we’d ignore.

Redness, swelling, bleeding, or pus near the anus can indicate a more serious problem. Those symptoms need veterinary attention rather than home grooming.

What if Your Dog Smells Fishy but Isn’t Scooting?

A dog can have a fishy smell without scooting. Some dogs release a little anal gland fluid without any discomfort, while others lick the area instead of dragging their rear across the floor.

So if your dog smells fishy after a stressful moment but otherwise behaves normally, you can clean any residue from the fur and monitor for another episode.

If you’re regularly finding fishy spots on the bedding or the smell returns every few days, schedule a veterinary examination. Normal behavior doesn’t completely rule out an anal gland problem.

What if the Smell Isn’t Coming From the Rear?

Not every unpleasant smell comes from anal glands. Where you notice the odor, and what your dog is doing alongside it, can help narrow down the possibilities.

Fishy Breath: Check the Mouth and Diet

If your dog’s breath smells fishy, start with what they’ve eaten. Fish-based kibble, treats, or fish-oil supplements can leave an odor behind.

There’s another possibility: your dog may have licked anal gland fluid from their rear. Not a pleasant thought when they’ve just given you a big kiss, we know.

But persistent bad breath can also mean dental trouble. Check for red gums, visible tartar, drooling, or difficulty chewing, and arrange a dental examination if you notice those signs.

Smelly Skin: Look for Itching and Redness

If the odor seems to come from your dog’s coat, especially around the paws, belly, or skin folds, look for scratching, licking, greasy patches, or redness.

Yeast and bacterial skin problems can produce unpleasant odors, although yeast is more commonly described as musty or sour than fishy. Our guide to recognizing yeast-related odors in dogs explains the difference in more detail.

The Merck Veterinary Manual’s guidance on skin inflammation also identifies itching, scaling, abnormal odor, and excess oil as possible signs of skin disease.

If your dog’s skin is irritated, a veterinarian can help identify the cause. For a dog whose care routine includes appropriate medicated cleansing, our Dog Itch Shampoo contains antibacterial and antifungal ingredients to help clean the skin and remove buildup.

We wouldn’t use shampoo as a substitute for treating an infection. Persistent redness, sores, or itching need more than a good wash.

Why Does My Female Dog Smell Fishy Down There?

If the smell is strongest around your female dog’s vulva, urinary or vaginal problems may be involved. Changes in urination, unusual discharge, or excessive licking are worth discussing with your veterinarian.

For unspayed females, one serious concern is pyometra, an infection of the uterus that often develops after a heat cycle.

VCA Animal Hospitals’ guidance on pyometra describes signs including increased thirst, vomiting, lethargy, loss of appetite, and sometimes vaginal discharge. Some affected dogs have no visible discharge.

Why Does My Dog Still Smell Like Fish After a Bath?

You’ve washed your dog, rinsed out the shampoo, dried the coat, and cleaned the bathroom floor. A few hours later, the fishy smell is back. Frustrating, right?

The bath may have removed the fluid sitting on your dog’s fur without stopping more from being released. If the anal glands aren’t emptying properly, washing the coat won’t solve that issue.

There’s also a difference between fishy gland odor and ordinary wet-dog smell. Thick fur and skin folds can hold moisture, while underlying skin problems may become more noticeable after bathing.

If the smell occurs mainly while your dog is wet, we’ve covered common causes and drying mistakes in our article on why dogs still smell after a bath.

If your dog is completely dry and the fishy odor keeps returning, focus on finding the source rather than washing more frequently.

How Do You Get Rid of Fishy Dog Smell?

The right solution depends on whether you’re dealing with odor left on the fur or something happening inside your dog’s body.

When Gentle Cleaning Is Enough

If your dog releases a little anal gland fluid after getting startled and seems comfortable afterward, you can gently clean the affected fur using a dog-safe product.

That’s where routine rear-end freshening can be useful. You don’t necessarily need to give your dog another full bath just because a small patch of fur smells unpleasant.

Always follow the grooming product’s directions and avoid applying it to broken or inflamed skin. If the area looks swollen or painful, skip the product and contact your vet.

When the Smell Keeps Returning

If the smell returns even after cleaning, have your veterinarian examine the anal glands. They’ll check whether the sacs are emptying properly and whether inflammation or infection is present.

Don’t try to squeeze the glands yourself unless your vet has taught you how. Unnecessary expression can irritate the area, and an infected gland may need treatment beyond emptying it.

For recurring problems, your vet may also review your dog’s stool consistency, diet, weight, and allergies. Chronic diarrhea, constipation, and excess weight can contribute to anal gland trouble.

Some dogs benefit from additional dietary fiber, but there’s no single supplement or feeding change that works for everyone. Your vet can help decide whether a diet adjustment is appropriate.

When Does a Fishy Smell Mean You Should Call the Vet?

An occasional fishy smell in an otherwise comfortable dog isn’t necessarily an emergency. Repeated odor, especially with changes in behavior, deserves a veterinary appointment.

If your dog cannot urinate, seek emergency veterinary care. Suspected pyometra in an unspayed female is also an emergency.

A Little Smell Doesn’t Always Mean a Big Problem

Dogs have a talent for turning an ordinary afternoon into something unexpected. Sometimes it’s muddy paws on the couch. Other times, it’s a fishy smell that leaves you wondering what happened.

If your dog seems comfortable and the odor appeared just once, a gentle cleanup may be enough. If the smell keeps returning or something about your dog seems different, have your veterinarian check it.

Once you know what you’re dealing with, it’s much easier to decide whether your dog needs treatment, a grooming product, or simply a clean blanket.

And hopefully, your next cuddle on the couch won’t involve checking whether someone left tuna under the cushions.