Why Does My Dog Smell Like Fish?

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why does my dog smell like fish

The most common root cause of a fishy smell in dogs isn’t actually fish, but rather their anal sacs [1]. In this article, we’re going to elaborate on that and explore other possible causes. 

Why Does My Dog Smell Like Fish? How Does the Anal Sac Emit a Fishy Smell?

The anal sac comprises two glands[2] located on either side of the anus in many mammals, including dogs. The anal glands produce a certain liquid that needs to be excreted regularly by either expression or defecation.

The anal gland liquid naturally produces a subtle fishy smell, and oddly enough, dogs use that smell as a way to identify other dogs and collect important information on them.

If you’ve ever noticed your dog sniffing another dog’s tail, butt, or poop, it is simply trying to find out more about the other dog.

Anal Sac Impaction 

breeds that are most at-risk of ASD

A subtle fishy smell is usually not a source of concern, however, if the smell becomes overwhelmingly hard to ignore, then your dog may have developed anal sac impaction.

Findings show that approximately 20%[3] of dogs are affected by anal sac impaction. This ultimately highlights how common the disease is. 

As I mentioned previously, sac fluid needs to be excreted regularly, but when that doesn’t happen, the fluid eventually fills up inside the glands, hardening over time and causing more serious health complications like anal sac diseases and tumors. 

The following factors are strong triggering agents of impaction:

  • Obesity 
  • Trauma from physical strain
  • Swollen anal sac
  • Irregular stools 
  • Loose stools 
  • Bacterial infections 

Signs of Anal Impaction 

A strong fishy smell doesn’t necessarily mean your pooch’s anal sac is impacted, it could be the result of numerous other things.

A sure-fire way to tell if your dog’s anal sac is in fact impacted is observing if the smell is accompanied by the following symptoms:

  • An abscess around the rectum area
  • An increasingly aggressive behavior
  • Dragging back side across the floor 
  • Red/brown anal discharge 
  • Difficulty passing stool
  • Excessive tail chasing 

How to Treat Anal Impaction 

For the most part, treating anal impaction is a simple process. However, vets warn against taking matters into your own hands, as it can be extremely painful to your hound.

Instead, you should seek professional help and a qualified and trained individual will proceed to drain the sac manually. This is usually done under local anesthesia. 

In addition, impacted sacs can also be treated with a combination of pain relief medications and antibiotics. 

In very rare and extreme cases, your vet will recommend surgical intervention in which your pet will be placed under general anesthesia.

The procedure lasts a couple of hours but it can last even longer if there appears to be non-cancerous tumors inside the anal sac. 

How to Prevent Anal Impaction

Unfortunately, there isn’t much you can do to completely prevent anal impaction, especially since several different factors can trigger the disorder.

For instance, smaller dog breeds and hounds struggling with obesity are more prone to impaction. There are however numerous things you can do to curb the risk factors. Read our article about How Heavy Should My Dog Be to learn more about this.

For example, given that loose stools are a major risk factor, you can try to be as meticulous as possible with your dog’s diet to minimize loose stools. Taking your pet for regular checkups may also prove to be useful.

Taking these safety precautions will not only ensure your dog steers clear of possible anal impaction, but it will also significantly reduce the probability of your dog developing more serious related health complications, i.e. tumors, anal sac disease, and bursting of the anal sac. 

Other Possible Causes of Fishy Smell 

While an impacted anal sac is the most probable root cause, it’s definitely not the only thing that’s making your pup smell like a walking fishery. The culprit could also be one of the following: 

Your pooch ate or rolled in fish 

We’ll start with the most obvious, because sometimes the answer lies right under our noses. Dogs are scavengers by nature; it’s in their DNA to go out of their way in search of food left by others. That said, it could be that your pet stumbled on a piece of fish lying around.

For this one, give your dog a good bath and see if the smell persists. If it disappears then, Voilà! One less thing to worry about. If not, read on to explore other possible sources. 

Gastrointestinal Issues 

What most dog owners fail to realize is that dogs or pets, in general, are intolerant to numerous ingredients.

Common foods like spices and chocolates can be very toxic to them and ingesting these foods often results in a series of gastrointestinal issues.

A typical tell-tale sign of gastrointestinal discomfort is constipation, other signs like excessive burping and regurgitating foods usually follow suit. 

To put it simply when your dog is experiencing intestinal discomfort, he may fart and burp excessively, which could be what’s creating the unpleasant smell. 

Urinary Tract Infection 

The unpleasant smell may be coming from your pet’s urine and this is often a sign of a urinary tract infection(UTI). 

UTIs in dogs are largely caused by bacteria and they affect approximately 14% of dogs[4]. Despite the fact that they’re so widespread, UTIs are quite dangerous and can potentially be fatal. 

Dogs generally contract UTIs from bacteria that penetrate their system through their urethral opening. A weakened immune system as a result of malnutrition may also be the gateway for bacteria.

Bad Breath

Bacteria can also attack the mouth to trigger halitosis and several other periodontal diseases. Plaque is the main catalyst here, it’s a layer of bacteria and food residue in a dog’s mouth.[5]

A small layer of plaque is completely normal, but a thicker layer is a lot more problematic because for one, it will destroy the teeth and gums, and two, it will produce awful fish-smelling acids and gasses. 

With simple dental care, you can help your dog prevent periodontal issues. To get you started, you can incorporate the following tips in your pooch’s dental care routine:

  • Brush your dog’s teeth regularly 
  • Include dry food in its diet 
  • Get your dog chew toys 
  • Take your pup for regular dental check-up 

Home Remedies for Fishy Smell 

Even if your pup’s anal sac is in perfect condition, chances are your dog might still accumulate the smell from partaking in a number of indoor and outdoor activities. 

Remedying the fishy smell your pup’s giving off will require lots of trial and error since there are several possible underlying culprits.

What’s more, sometimes regular shampoo isn’t enough to get rid of the awful stench. If that’s the case, you can use the following home ingredients to rinse your dog: 

  • Lemon juice 
  • White/apple cider vinegar
  • Baking soda

You can use these products separately or together after you’ve given your hound a bath with regular shampoo.

You’ll simply need to spray or spread a generous amount of lemon juice, vinegar or baking soda all over your pet, let it sit for a few minutes then rinse off with warm water. 

When to Seek Professional Help

Dogs are extremely intelligent animals and they have a way of communicating with us. That’s not to say you shouldn’t be observant though.

Something as minor as a fishy smell shouldn’t require professional attention, but if other symptoms pop up, then you should be concerned. 

For starters, if your pup’s behavior, eating pattern, sleeping pattern, and bowel movement coïncide with the appearance of the unpleasant smell, you are definitely dealing with anal sac disease.

Ultimately, you can put on a pair of medical gloves and check your dog’s anal glands. If they’re swollen, contact your vet immediately. Leaving them swollen will only cause them to burst. 

The Bottom Line

To recap, there are several reasons why your dog smells like fish, but the most probable reason is that its anal sac needs to be expressed. 

In the event that you’ve ruled out all other possible factors and you’re sure it’s in fact the anal sac, getting professional help as soon as possible will yield the most favorable outcome.

Photo of author
Larissa Musangu
I'm a seasoned dog lover and companion. I've noticed that there are numerous misconceptions regarding dog nutrition, which is why I've taken it upon myself to share actionable, accurate and research-backed advice on best-practices for feeding our four-legged friends.

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