There is a common and easily explainable reason why your dog might smell like fish. But there are other reasons also. Here we look at the question “Why does my dog smell like fish” and discuss why you are smelling this odour. We also touch on when to be concerned about it, and what you need to do about it.

Anal Glands

The most common reason for your dog smelling like fish is to do with their anal glands. These glands, or sacs, sit either side of their anus and produce a distinctive smelling liquid. This liquid is secreted when your dog goes for a poo and it acts as a scent marker. It tells other dogs lots of information about your dog. This explains why when dogs meet to do straight to the bum for a sniff! Normally you will be unaware of the smell of these secretions. But if your dog’s anal glands have become blocked, swollen or infected this can cause the distinctive pungent fishy smell.

Anal Gland Problems

It is very common for dogs to have problems with their anal glands. From mild impaction to tumours, problems with anal sacs are a common reason for dog owners to visit the vet. Anal sac issues include:

  • Impaction: where the anal sacs are not emptying completely. Any remaining liquid can dry up and block the sac preventing further emptying. Impacted anal sacs can be very painful. If left untreated they can develop into infections and absesses.
  • Infections and abscesses: by now the scas could be discoloured and/or swollen. In extreme cases the sacs can rupture. This is extremely painful and leads to further complications.

Signs to look out for

There are the signs you need to watch out for that might indicate an anal sac issue: 

  • Pungent fishy smell from your dog’s bottom
  • Dragging their bottom on the floor
  • Licking or biting their bottom more than usual
  • Problems or straining to go to the toilet
  • Signs of pain or yelping 
  • Blood/Pus in their poo

It is so important to speak to your vet if you think your dog has anal sac issues. Address the issue before it becomes anything more uncomfortable or severe for your dog.

My dog smells like fish – What next?

If you notice a fishy small from your dogs bottom area, see your vet. They will be able to assess your dog and give any treatment if required. It may be than your dog’s anal glands need expressing which the vet can do for you. Some groomers also offer this service also.

Can I do it myself?

With advice and guidance from your vet it is possible to do this for your dog yourself. But always see a vet in the first instance to check if there is an issue and if your dog needs their glands expressing.

There are things you can do for your dog to keep them at their healthiest and hopefully prevent anal sac problems:

  • A quality diet with a good fibre content
  • The right amount of exercise
  • Watch their weight
  • Plenty of water
  • And keep an eye on their poo’s – firm and not too soft

Other reasons for a dog smelling like fish

They are scared:

Sometimes when a dog is scared he will naturally empty his anal sacs as a fight or flight response. This will result in a short lived but pungent fishy smell. In this instance there is no need to contact the vet and is totally normal.

Fish breath:

Unless they’ve just eaten fish, if your dog has fishy breath, they may have dental issues. Ideally, brushing your dog’s teeth regularly will avoid dental issues. Other reasons that your dog has fishy breath may be to do with disgestion, kidney disuease or diabetes. So If this fishy breath is a persistent observation, speak to your vet.

Fishy Urine:

If there is a strong smell of fish from your dog’s urine this could be a sign of a UTI or bladder problem. If this persists, speak to your vet.

Female dog smells of fish:

If your female dog smells of fish, they could have an imbalance in their vaginal yeast and bacteria. Again, consult your vet about this.


You should now feel much happier knowing the answer to the question “Why does my dog smell like fish”. In the majority of cases, if your dog is smelling of fish, it will be related to their anal glands. And there is nothing major to worry about. Check with your vet, whether they need emptying and if you need to make any lifestyle modifications. For more health related blogs, head here.