Health Topics  >  General  > Smelly or Bad Odor

What causes strong odors in dogs?

Haircoat contamination

Not a health issue per se, but a common reason for a smelly dog is haircoat contamination. This is a fancy way of saying ‘your dog rolled in something gross’.

Dogs love to roll in strong scents including other animals’ feces, animal carcasses, and even garbage. This is the first thing to rule out if your dog comes in from outside with a terrible smell. Fortunately a good bath is usually the only treatment required.

If your dog has been sprayed by a skunk, it can be a little trickier to get the smell out completely. There are lots of good techniques and products out there that can help you.

Rolling around in strong scents is often the culprit for sudden stinkiness.

Anal sac impaction, infection or inflammation

Perhaps one of the most common (and powerful) stinks that dog owners encounter is that of the anal glands. If you’ve smelled it once, you won’t forget it. Anal glands have a unique, very strong odor that many people describe as ‘fishy’.

Anal glands are normal structures located on either side of the anus in dogs. Their normal function is to help your dog leave their scent, and they should be expressed a little bit with every bowel movement.

In most dogs, they never cause an issue. If you’re lucky, you’ll never have to smell them in your lifetime. However, if anal glands become infected or inflamed, they may not empty normally leading to a build up of this stinky secretion.

When anal glands become overly full, they tend to be uncomfortable and smelly. Your dog may also show signs of scooting (dragging) their bum on the ground or excessive licking.

When anal glands become overly full, it tends to be uncomfortable for dogs. They may show symptoms of excessive licking of their bum, or scooting (dragging) their bum along the ground. You may also notice swelling or pink, inflamed skin around the anus. In severe cases, anal glands can become abscessed and rupture to the outside, leaving a dramatic open wound just next to the anus.

Any of these symptoms merit a trip to the vet. Your vet can assess your dog’s anal glands and express them if needed. They may also prescribe antibiotics or pain medication. In some cases, your dog may need to be sedated so that the glands can be treated appropriately (it’s a sensitive area!).

Finally, some dogs will also release their anal glands suddenly if they are scared. This usually doesn’t require any treatment other than a good bath.


Dogs with severe diarrhea can start to smell quite strongly. Diarrhea with blood has an especially distinct and unpleasant odour. Unlike a regular healthy poop, diarrhea can get stuck in the fur around their bum causing that poopy odor to carry with them wherever they go. 

Take a good look under your dog’s tail if you can’t quite place that stinky odor in your home (make sure to check the bottom of your shoes too!)

Pro Tip: Bloody stool is a cause for concern, especially if there’s more than a few drops. If your dog’s diarrhea lasts longer than 24-48 hours, it’s a sign of a more serious situation that needs prompt veterinary attention.

Ear infections

If you own a dog who is prone to ear infections, you probably know the tell-tale smell even before other symptoms arise. In addition to that funky scent, dogs with ear infections will scratch their ears and shake their heads excessively.

Ear infections can be caused by yeast or bacteria, and will require prescription medication from your veterinarian. If your dog is a repeat offender, talk to your vet about preventive steps you can take, and products you can use at home. The best products for your dog will depend on the type of infection and underlying cause. 


Seborrhea is a fancy term for a dog with excessive flaking or scaling of the skin. It can be a primary condition in breeds like the Cocker Spaniel or Basset Hound, or can develop secondary to another condition.

Seborrhea can be dry or greasy/oily. The latter form tends to be stinkier. The smell associated with seborrhea can be made worse if secondary bacteria or yeast infections set it. Talk to your veterinarian about appropriate shampoos that can be used to manage this condition.

Skin infections

One of the most classic smelly dogs at the vet is a Golden Retriever with a hotspot in the summertime.

Hot spots’ are acute (sudden) moist areas of inflamed skin caused by bacterial infection. They can be located anywhere on the body but a popular spot is just beneath and behind the ear. They are predisposed by allergies, fleas, and swimming without drying off thoroughly. These can happen in any age or breed of dog. Because they are itchy, the dog will usually scratch or chew at the area which only worsens the lesion. 

Because hot spots are itchy, dogs will usually scratch or chew at the area, which only worsens the lesion.

Aside from hot spots, more gradually developing skin infections can also cause your dog to smell. These can be caused by bacteria or yeast, and all can be predisposed by allergies and parasites like fleas. 

If you believe your dog has a skin infection, a veterinary visit is merited. In some cases medications like antibiotics or antifungals will be prescribed.

A clip and clean of the affected area is usually required, and a t-shirt or e-collar to prevent your dog from licking is essential. Your veterinarian can often arm you with appropriate shampoos and other topical treatments to help prevent recurrence of this issue. 


In some cases, tumors on the surface of the body get large enough that they break open. When this happens they are a prime spot for infection to develop and this can be malodorous. Unfortunately, antibiotics are usually only a band-aid solution and removal of the tumor (where possible) is required. 

Oral issues

Most pet owners will admit to not brushing their dogs’ teeth on a regular basis. Because of this, and because dogs are not the most discriminate eaters, we can expect their breath to be not-so-fresh.

That being said, if your dog’s breath is so bad that they clear the room, or if it suddenly becomes foul smelling, they should be checked out by their vet.

Severe or suddenly bad breath can indicate severe periodontal disease, an abscessed tooth, or even an oral tumor.

If your dog's bad breath has a sudden onset or is very strong, it's a sign of a more serious issue.

References for smelly or bad odor