Why does my dog smell like fish?

If you’ve suddenly noticed your dog smelling like fish, you’re not alone — and there’s usually a clear reason for it.In most cases, that fishy odour comes from your dog’s anal glands, but there can be other causes too.

In this article, we’ll explore:

• Why dogs sometimes smell like fish
• Common anal gland problems and warning signs
• What to do if your dog smells fishy
• Other possible causes (like urine, breath, or vaginal infections)

The Most Common Reason: Anal Glands

What Are Anal Glands?

Your dog’s anal glands (also called anal sacs) are two small scent glands located on either side of the anus.

They release a distinctive liquid when your dog goes to the toilet — this helps dogs communicate and mark territory.

Normally, you won’t notice any odour at all. However, if the glands become blocked, swollen, or infected, you’ll start to smell that unmistakable fishy scent.

Anal Gland Problems in Dogs

Anal gland issues are very common and one of the top reasons dog owners visit the vet. Problems range from mild impaction to painful infections or abscesses.

Types of Anal Gland Issues

1. Impaction

When the anal sacs don’t empty properly, liquid can dry up and block them. Impacted glands can be sore and, if untreated, can lead to infection.

2. Infections and Abscesses

If bacteria enter the sacs, they can become infected and swollen. In severe cases, the sacs may rupture, which is extremely painful and needs urgent veterinary care.

3. Tumours or Growths

Though rare, tumours can form around the anal sacs and should always be examined by a vet if swelling or bleeding is seen.

Signs Your Dog Has Anal Gland Issues

Watch for these signs that your dog might be struggling with their anal glands:

• A pungent fishy smell from your dog’s bottom
• Dragging or scooting their bottom on the floor
• Licking or biting their bottom more than usual
• Discomfort or straining to go to the toilet
• Signs of pain or yelping when sitting or pooping
• Blood or Pus in their poo

💡 Tip: Always consult your vet if you notice these symptoms. Treating anal gland problems early can prevent pain and complications.

What to Do If Your Dog Smells Like Fish

If your dog smells fishy, especially around the bottom, your first step should always be a vet visit.

Veterinary Treatment

Your vet will examine the anal glands and, if necessary, express them (manually empty the sacs). Some professional dog groomers also offer this service, but your vet should check for underlying problems first.

Can You Express Anal Glands Yourself?

It is possible for owners to learn to express anal glands at home — but only under veterinary guidance. Doing it incorrectly can cause pain or infection.

How to Prevent Anal Gland Problems

Keeping your dog healthy overall helps reduce anal gland issues. Here are some practical tips:

• Feed a high quality diet with a good fibre content
• Ensure regular exercise
• Maintain a healthy weight
• Plenty of fresh water
• And keep an eye on their poo’s – firm and not too soft

Other Reasons Your Dog Might Smell Like Fish

Sometimes, the smell isn’t from the anal glands at all. Here are other possible causes:

When Your Dog is Scared

Dogs sometimes release their anal gland fluid when frightened or anxious — a normal “fight or flight” response. This causes a brief fishy smell but isn’t a cause for concern.

Fishy breath

If your dog’s breath smells fishy (and they haven’t just eaten fish), it could point to:

• Dental problems (plaque or infection)
• Digestive issues
• Kidney disease or diabetes

🦷 Regular tooth brushing and vet dental checks can help prevent this.

Fishy-Smelling Urine

A strong fishy odour in your dog’s urine may signal a urinary tract infection (UTI) or bladder issue. Persistent smells should be checked by your vet.

Female Dog Smells Fishy

Female dogs may develop a fishy smell due to a yeast or bacterial imbalance in the vaginal area. Again, a vet visit is advised for diagnosis and treatment.

When to Be Concerned

If the fishy smell is persistent, strong, or accompanied by pain, scooting, or unusual discharge, don’t ignore it. These are signs that your dog needs professional help.

Conclusion

So, why does your dog smell like fish?
In most cases, it’s due to their anal glands, and while it can be unpleasant, it’s usually not serious.
A quick vet check, a balanced diet, and regular monitoring can keep your dog comfortable and odour-free.

👉 For more dog health advice and care tips, visit our Oscar & Hooch Dog Health Blog.

Frequently Asked Questions

Why does my dog smell like fish even after grooming?

If your dog still smells like fish after grooming, it’s likely the issue is internal — most commonly the anal glands. Groomers may not always express these glands, especially if they’re impacted or infected. A quick vet visit can identify and treat the root cause.

How often should my dog’s anal glands be expressed?

Most dogs naturally empty their anal glands when they go to the toilet, so they don’t need regular expressing. However, if your dog has recurring issues or is a small breed (like a spaniel or chihuahua), your vet may recommend every few months.

Can diet affect my dog’s anal glands?

Yes! A diet rich in fibre helps produce firm stools that naturally express the glands. Feeding high-quality dog food and ensuring your dog stays hydrated can reduce the risk of blockages.

Do female dogs smell like fish when in heat?

Some female dogs may smell stronger when in heat, but a distinct fishy odour is not normal and could indicate an infection, such as bacterial vaginosis or a yeast imbalance. Always check with your vet if you notice this smell.

Should I be worried if my dog smells like fish once in a while?

A one-off fishy smell, especially after your dog gets scared, is usually harmless — it’s just the anal glands releasing naturally. But if it happens often, or your dog seems uncomfortable, it’s best to get them checked by a vet.