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Why Does My Dog Smell So Bad?

Check your dog out from nose to tail to find the source of the offensive odor.

Muddy coats are great places for smelly bacteria to thrive. By: aaandreasss

It’s an old joke that’s worth repeating: “My dog’s got no nose.”

“How does he smell?”


When your dog has a lingering bad odor, the smell is unpleasant, but it can also be a clue your pet pal has a health problem. Take a nose-to-tail approach to sniff out where that offensive odor is coming from. This isn’t always obvious, so be prepared to lift and sniff” all over the dog.

It helps to be methodical, so let’s start at the front end and work our way tail-ward.

1. Dental Disease

An extreme example is this one dog admitted for a dental. I entered the kennel room, and the smell nearly knocked me off my feet. This dog had an exceptionally bad mouth with tartar that had caused a gum infection and gravy-like pus soiling his lip folds.

Basically, dirty teeth are just that — coated with a cement made up of old food, minerals and bacteria. Then, when infection sets in, the smell becomes really bad.

If your dog smells, then, lift the lips and take a long look at the teeth.

2. Bad Breath

Bad breath (halitosis) isn’t just down to teeth.

Unstable diabetic dogs may have a characteristic lingering odor on their breath of acetone-based nail polish remover. Also, dogs with kidney disease have a whiff of ammonia about them. In both cases, this is due to volatile toxins in the bloodstream released on the breath.

If your dog has bad breath, especially if she’s off-color, then see a vet swiftly.

Halitosis and dental disease could cause your dog to smell unpleasant. By: tinabasgen

3. Ear Infections

If the bad smell seems worse at the head rather than the rear, be sure to check the ears.

For example, the heavy ear flaps of spaniel breeds predispose them to ear infections. You may get an unpleasant waft from time to time when the dog moves in a certain way, so take a moment to check both ears, comparing one with the other.

4. Skin Infections

Closely related to ear problems are skin infections. This could be a patch of sore skin anywhere on the body or a skin fold, such as around the lips, under the chin or around the private parts.

Use your nose to localize the source of the bad smell, lifting and separating any skin folds, until you see right down to the skin. Redness, stickiness, a greasy feel or hair loss are all potential signs of infection.

5. Dirty Coats

Mud contains bacteria, and a heavily soiled coat can smell musty, doggy or downright unpleasant. Again, check out where the smell is worst and then try to identify the odor.

This can also include a smelly coat where a dog with bad teeth groomed herself. The foul-smelling saliva is smeared all over when the dog licks.

Older dogs can be prone to urinary leakage when deeply asleep, and this can soil their coat between the back legs or rear end. As well as seeking medical help for the leakage issue, regular bathing with a mild, moisturizing dog shampoo should keep things sweet-smelling.

Try these tips to sweeten the offensive breath of your dog:

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6. Anal Sac Issues

If your dog is haunted by a lingering fishy smell that is downright stomach churning, their anal sacs might be the culprit. The anal sac secretion is so unpleasant it could almost be used as a biological weapon.

The bad news is that when the anal glands are full, they can leak, leaving small, ripe deposits of nastiness where the dog sits or lies down.

Speak to a groomer, vet tech or vet to get the dog’s anal sacs emptied.

7. Flatulence

Flatulence is the result of bacterial fermentation in the large bowel. This can be due to:

  • Diet (e.g., a carbohydrate is too hard to digest)
  • Bacterial overgrowth (i.e., smell-producing bacteria take over from their more nose-friendly cousins)
  • Disease of the gut wall (i.e., food isn’t digested properly and passes into the large intestine, where it ferments)

If the answer isn’t a simple change of diet, speak to your vet so primary health problems can be ruled out.

8. Upset Stomach

Garbage gut or infections with bacteria or parasites can lead to unpleasant-smelling upsets. A common cause of bad smell is feces caught in the feathering around the rear — so keep those butts clipped short.

So there we have it. Front to back, lift and sniff, and you’ll detect the source of the offensive odor.

Happy hunting!


This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed March 24, 2017.