Why Does My Dog Smell of Fish?
Why Does My Dog Smell of Fish?
If your dog suddenly smells like fish, and you haven’t just fed them a seafood treat, it’s usually a sign something needs attention. A strong, fishy odour often points to issues with your dog’s anal glands, although it can also come from dental problems, ear infections, or even diet. It’s not a scent that should be ignored, especially if it happens regularly or seems to bother your dog. While unpleasant, the fishy smell is your dog’s way of signalling that something isn’t quite right.
Anal Glands: The Most Common Culprit
The most frequent cause of a fishy smell in dogs is anal gland secretions. These two small glands are located on either side of your dog’s anus and release a strong-smelling substance used for marking territory. Normally, these glands empty when your dog poos, but sometimes they become impacted, infected, or don’t drain properly. When this happens, fluid can leak out—or get expressed manually—releasing a pungent, fishy smell. Dogs with anal gland issues may also scoot, lick their rear, or seem restless.
Dental Problems and Bad Breath
Fishy breath is another common complaint. If your dog’s mouth smells like something out of a fish market, it could be down to plaque, tartar, or gum disease. Bacteria in the mouth can produce foul odours, especially if your dog has a dental infection or something stuck in their teeth. Regular dental care, including brushing and check-ups, can prevent this and keep your dog’s mouth healthier overall.
Ear Infections Can Also Smell Fishy
Dogs with floppy ears or those prone to ear infections may carry odour in their ears that can be mistaken for a fishy smell. Yeast and bacteria love warm, moist ear canals, and when they multiply, the smell can become quite strong. If your dog is shaking their head, scratching their ears, or they smell odd around the head and neck, it could be an ear issue rather than anything rear-end related.
Can Diet Cause a Fishy Smell?
Yes, especially if your dog eats fish-based food or supplements like fish oil. These are often great for coat health and joints, but if your dog is on a high-dose regime or not digesting the oil well, it might cause their skin, breath, or stools to take on a fishy smell. If the smell starts after a diet change, it’s worth reviewing the ingredients with your vet.
When to See the Vet
An occasional whiff of fish isn’t unusual, but if the smell is persistent, sudden, or comes with other symptoms—like scooting, licking, swelling, or discomfort—it’s time to get your dog checked. Anal glands can become infected or abscessed, which can be painful and require antibiotics or even surgical intervention. The sooner you catch the issue, the easier it is to treat.
Can You Express Anal Glands at Home?
Technically, yes—but it’s not for everyone. Expressing anal glands is a messy job, and if done incorrectly, it can cause pain or injury. Many groomers offer this as part of a regular grooming session, and some vet nurses can teach you how to do it safely if needed. For most owners, it’s best left to the professionals.
How to Prevent Fishy Smells in Dogs
Keeping your dog’s anal glands healthy starts with their diet. A fibre-rich diet helps produce firm stools that naturally press on the glands and keep them empty. Regular exercise, grooming, dental care, and ear checks also go a long way in preventing bad smells. If your dog is prone to gland issues, your vet might suggest adding fibre supplements or reviewing food options.
Could a Urinary Tract Infection Cause a Fishy Smell?
Yes. While less common than anal gland issues, urinary tract infections (UTIs) can sometimes cause a strong, fishy or sour smell—especially in female dogs. If the smell seems to come from the dog’s back end, and they’re urinating more frequently, straining, or licking their genital area, a UTI could be to blame.
Can Female Dogs Smell Fishy When in Heat?
Not usually—but some owners report a change in odour during a female’s heat cycle. This isn’t usually described as “fishy” though. If your female dog smells strongly of fish, it’s more likely an anal gland issue, infection, or possibly a vaginal infection (known as vaginitis), especially if there’s discharge.
How to Tell Where the Smell Is Coming From
It’s not always easy to tell whether the smell is coming from your dog’s mouth, ears, rear, or skin, especially if the odour lingers in their fur. To narrow it down:
- Smell their breath and ears individually
- Lift the tail and check for swelling or discharge
- Check for any wet patches on bedding that smell
A quick sniff test isn’t glamorous—but it can help you pinpoint the source.
Is Fishy Smell a Sign of a Dirty Coat?
Sometimes. Dogs with greasy coats or those who’ve rolled in something (like fox poo or dead fish—classic dog behaviour) might carry a fishy scent even after a bath. If the smell lingers after grooming, it’s probably internal—such as from anal glands or digestion—not just a surface issue.
Do Older Dogs Smell Fishy More Often?
They can. Ageing dogs may develop weaker muscles around the anal area, making it harder for the glands to empty naturally. They may also have more dental problems or reduced grooming habits, all of which contribute to stronger or more unpleasant odours.
Is It Ever Linked to Flatulence or Digestive Upset?
Yes. Some dogs with sensitive stomachs, dietary intolerances, or gut bacteria imbalances may produce fishy-smelling flatulence or stools. If the smell seems to come from their bottom but they’re not scooting or licking excessively, it could be diet-related rather than gland-related.
Summary
A fishy smell from your dog is usually a sign of something going on below the surface—most commonly, anal gland issues. It can also be linked to dental problems, ear infections, or diet. While it might be unpleasant, it’s also a useful signal that your dog needs a little help. Keep an eye (and nose) out for changes, and don’t hesitate to contact your vet if the smell becomes regular or is paired with discomfort. With the right care, you can get your dog smelling fresh again in no time.