Why Does My Dog Smell Like Fish?
[All you need to know]

Aaron Rice Expert Dog Trainer
Written: January 17, 2022

There are times when strange odors sneak upon us, and we are confused to discover that those are coming from our dog! Is there a reason why your pet might be so stinky? And why do they sometimes smell like fish? They might be caused by the typical flora that lives in and on your dog, but they can also be a symptom of a medical problem.

In this post, we’ll go through all of the reasons why your pet can emit that may or may not be natural, and we’ll try to answer the question, “why does my dog smell like fish?

If your dog has a fishy smell, it’s a very regular occurrence, and it has nothing to do with what they ate or rolled in. Some breeds are more likely to have a strong sense of smell than others. When it comes to developing a fish smell, factors like gender, age, breed, and morphology (the shape of the body) can all have an effect.

Dogs with oily coats are more prone to emit a fishy smell due to their increased oil production.

Reasons Why Your Dog Smells Like Fish

Anal Sacs

So, precisely what are a dog’s anal sacs? Anal sacs are particular sweat glands on each side of your dog’s anus that produce a smelly discharge. The odor functions as their smell identifier, and it is secreted every time your dog poops. 

That is why dogs are often oddly interested in each other’s feces – sniffing it supplies them with crucial chemical information about the other dogs. However, some dogs’ anal glands can be expressed and unexpectedly let out a dark, oily, stinky fluid when they are scared, anxious, or quickly relax in specific situations.

On the flip side, this stinky smell can be produced if these glands are not emptied; the fluid gets dried and impacted. Anal sac tumors, cysts, and abscesses in your dog’s anal glands can be troublesome and prevent them from correctly releasing fluids from their anal glands because they make the anal glands feel tight and swollen.

Signs Of Anal Sac Diseases

If you notice your dog smelling like fish, this is an early sign of an anal sac problem, so make an appointment with your veterinarian right away. That way, we can immediately address the issue and recommend minimizing anal glands issues in the future.

Aside from a fishy smell, there are other signs of anal sac disease. Dogs with inflamed anal sacs may slide (scoot) around on the floor, bite or lick their anus, or have trouble defecating. Because defecation is uncomfortable, they may even vocalize. You may also detect a firm mass near the rectum, as well as blood and/or pus in your dog’s feces.

Although scooting is pretty standard and amusing, it is a symptom and warning of anal sac disease. If you observe any of these symptoms or discoloration around the anus, contact your veterinarian immediately and evaluate your dog.

Preventing Anal Sac Diseases

Here are some tips you could use to prevent diseases that affect said glands:

  • Examine the area for traces of blood, puss, or any other abnormality
  • Engage them in intense yet mild exercises to reduce weight gain
  • Feeding your dog with food containing an ample amount of fiber
  • Give them clean and fresh water to drink.

Vaginal Infections

Fishy odor can also be caused due to vaginal infection in the case of a female dog. Their fishy smell and appearance can detect infected vagina and/or anal sacs in female dogs. Unless your veterinarian treats these infections with medication, they could develop into abscesses or ruptures, which can be pretty painful. 

After ruling out anal gland disorders, if you see a light-colored discharge coming from your female dog, it could be a sign of vaginitis, bacterial, or yeast infections.

The female dog’s uterus can become infected, leading to the secretion of a white-yellowish substance from the vagina. Pyometra is the medical term for uterine infection, and this is a severe problem that demands quick action. Please take your dog to the vet promptly if you feel they have a Pyometra. 

Bad Breath

The primary cause of bad breath causing fishy breath is because they might have eaten stinky stuff like animal/insect droppings, fish food or treats, etc.

Strange odors originating from the mouth may be caused by renal or kidney disease, diabetes, or dental problems. Bad breath from periodontal diseases is due to the bacteria’s production of volatile sulfur compounds. Other origins of bad breath include results of bacterial metabolism from bacteria residing on the gums, top of the tongue, and plaque on the teeth.

Brushing your puppy’s teeth 2-3 times per week with toothpaste containing active enzymes will help reduce plaque buildup and bad smells. Using dental treats or ones that brush away dental plaque and tartar, such as bully sticks, will also naturally clean your dog’s teeth.

Urinary Tract Infection

Even if your dog eats a somewhat different diet than you, their pee should smell similar to yours. If you notice a strong stench that was not previously present, this is most likely an indication of a urinary tract infection, aka UTI. This is caused by bacteria in your dog’s urine that does not belong there, causing the urine to smell fishy.

Contact your vet to conduct a urinalysis to check for stones, RBCs, proteins, white blood cells, and any other signs of a urinary problem when you notice this bad smell. If an infection is found, your pup shall be given medications to cure the infection, which will subsequently eliminate the odor.

How To Tackle These Problems?

Call your veterinarian if you get a whiff of a fishy smell from your pup. Your dog’s glands may be needed to be manually cleared or released; that should eliminate the odor. Most dogs, exceptionally tiny breeds, require their anal glands to be emptied regularly. 

Vets and groomers also provide service, and if you don’t bother with the stench, you also can learn how to do it yourselves. Yet, it should be noted that physically releasing the anal glands frequently can cause inflammation and scar tissue. Thus this should only be done when they are not emptying normally.

Hardened or impacted anal demand the immediate intervention of your vet. If this is the case, the veterinarian may apply a loosening agent or rinse the area with a saline liquid. Once your dog has been treated, you might be advised by the vet to feed your dog with fibrous food that helps in natural secretion from the glands.


Now that we’ve addressed how many reasons can cause your dog to smell like fish or have what appears to be a stench, knowing what’s causing them to smell can explain a lot about your dog’s behavior and nutrition, as well as warn you about any health issues.

Fortunately, anal sac disorders are usually simple to cure. The stench should be gone after the core problem is treated. If your dog requires regular anal gland expression, the fishy odor is a reminder to take them to the vet or the groomer.