Why does your dog have fishy breath?

By Rebecca MacMillan BVetMed BSAVA PGCertSAM MRCVS

Your dog’s breath may never be the sweetest smelling. In fact, sometimes it can be undeniably horrible! But if your dog is smelling particularly pungent, and especially if it’s happening often, then you should try to get to the bottom of the issue.

In this post, we take a closer look at four of the most common causes of fishy breath in dogs and the steps you can take to keep them minty fresh…

Dental problems

One of the most common causes of bad breath is dental disease. After eating, a slimy layer of plaque (a combination of saliva, bacteria, and food particles) will start to form on the teeth. Over time, this can harden into a calcified material known as tartar.

Tartar can cause other dental issues – such as inflamed gums, cavities and abscesses, and, eventually, tooth loss. Abscesses or cavities in the mouth and teeth often cause fishy smelling breath. Plus, foreign objects – like food or sticks – can also get lodged in the mouth and cause a foul smell.

Sadly, it’s estimated that 80% of dogs by the age of two are affected with some degree of dental disease. To keep your dog’s mouth healthy, you should take the following measures:

1. Implement a daily routine from an early age

Other oral treatments like rinses or gels are a great addition to brushing, as are dental sticks and chews.

When it comes to brushing, it’s most effective when performed daily. You should always use dog-specific toothpastes – they’re meaty flavoured and are lower in fluoride than human pastes. A soft bristle brush is best and choose a size appropriate for your dog. A more detailed guide to teeth brushing in dogs can be found here.

2. Feed an appropriate diet

Always provide a good-quality diet that’s appropriate for your dog’s age and size. Avoid chews and treats that are too hard, like bones and rawhides, which can cause painful tooth fractures.

You should also keep a close eye on your pet’s weight. In a recent study, being overweight was linked to dental disease, particularly in smaller breeds of dogs.

3. Attend regular veterinary check-ups

Make sure your dog attends regular check-ups. They’re teeth will be examined during annual vaccinations, but if you notice anything fishy (literally!) in the meantime, then you should visit your vet sooner.

4. Follow your vet’s advice

If your vet recommends dental treatment, then make sure you get your dog booked in for this as soon as possible. Delaying treatment will only allow the disease to progress, making tooth extractions more likely.

Anal glands

You might be thinking, this is at the other end of your dog’s body, what does this have to do with their breath? Well, dogs have two small sacs just inside their anus which contain scent-marking material. Sometimes these sacs (known as anal glands) can become overly full, or infected, causing your dog discomfort. This causes your dog to lick at his bottom, possibly transferring some of the fishy anal gland smell into his mouth.

Other symptoms of anal gland issues include:

• Rubbing their bottom along the ground (scooting)
• An increased fishy odour from their bottom
• Anal gland discharge on their bedding
• A red, irritated anus from rubbing and licking at it
• Occasional swelling or bleeding if there’s an infection

Suspect your dog has an issue with their anal gland? Take them for a check-up. Your vet may gently press on the glands to relieve discomfort and may suggest medication if an infection is present.

If your dog has recurrent anal gland issues, consider adding more fibre to their diet or adding a fibre supplement to their food. Your vet will be able to advise further.

Something they ate

Dogs explore the world with their mouths, which means they often lick and eat things we wouldn’t dream of touching! Dogs are also scavengers by nature – this means they often have a good chew on things whilst out walking and exploring.

Eating something unpleasant can give your dog bad breath – whether they raid the rubbish bin, nibble on a fish washed up on the beach, or steal the cat’s food! Usually, this odour will pass by itself, but giving your dog some water and brushing their teeth will help get rid of the smell quicker.

Be aware that fish-based food or a fish-based dietary supplement can make your dog’s breath smell fishy.

Underlying health issues

Sometimes underlying health conditions like kidney failure can cause a change in the odour of your dog’s breath. The term for this is uraemic breath and usually accompanies other symptoms like thirst, changes in appetite, lethargy, dehydration, and fainting.

Another condition called ketoacidosis may occur in diabetic dogs, causing similar signs to kidney failure. Both conditions are diagnosed through blood and urine samples.

The final word on bad dog breath

There are many causes of fishy smelling breath in dogs, with some being more obvious than others. If your dog has recently developed extremely bad breath, then make sure you get them checked out by your vet. The sooner they get seen, the sooner they can go back to giving you nice sloppy kisses again!

Looking for more things dental? Find out whether your dog is naturally prone to dental problems, or check out our guide to cleaning your pet’s teeth.