Dog Pee Smells Like Fish: Causes and What to Do
A fishy smell from your dog isn’t something you should ignore. When your dog pee smells like fish, it’s often a sign of a urinary tract infection or other health issue that needs attention. Similarly, when dogs butt smells like fish, the culprit is almost always the anal glands — small sacs on either side of the anus that can become impacted or infected. Whether it’s dogs butt smells, a general dog butt smells situation, or the specific complaint that my dogs butt smells after sitting on the couch, these fishy odors are the body’s way of communicating that something is off. Let’s break down the causes and solutions.
Why Dog Pee Smells Like Fish
Urinary Tract Infections (UTIs)
The most common reason dog pee smells like fish is a urinary tract infection. Bacteria in the urinary tract produce waste compounds that give urine an unusually strong, pungent, sometimes fishy odor. UTIs are more common in female dogs due to their shorter urethra, but they affect male dogs too. Other signs include frequent urination attempts, accidents indoors, blood in urine, or straining to urinate.
Bladder Stones and Other Issues
Bladder stones (uroliths) can cause urine odor changes as minerals concentrate in the bladder. Certain metabolic conditions and kidney disease can also alter urine chemistry enough to produce unusual smells. If your dog’s urine smells persistently different, a veterinary urinalysis is the diagnostic first step.
Diet and Medications
Sometimes a fishy urine smell has a simpler explanation — a high fish-content diet, certain supplements (like omega-3 fish oil in excess), or particular medications can temporarily alter urine odor without indicating disease. If the smell appeared shortly after a dietary change, this is worth considering.
Why Dogs Butt Smells Like Fish: Anal Glands Explained
When dogs butt smells like fish, anal glands are almost always the cause. These sacs normally express naturally during defecation, releasing a fishy, musky secretion that dogs use for scent marking. When the anal glands don’t empty properly — due to soft stools, obesity, or anatomical issues — they become impacted, causing discomfort, leakage, and intense fishy odor.
If dog butt smells strongly and your dog is also scooting (dragging their bottom on the ground), licking their rear excessively, or sitting uncomfortably, impacted anal glands are the most likely explanation. Manual expression by your veterinarian or a professional groomer typically resolves the immediate problem.
If left untreated, impacted glands can become infected (anal sacculitis) and may form abscesses that require antibiotics or surgical drainage. Dogs prone to anal gland issues may need regular professional expression every 4–8 weeks, along with dietary adjustments to produce firmer stools that naturally express the glands.
When to See a Vet
Any time my dogs butt smells intensely of fish and doesn’t resolve after expression, or if your dog’s urine has smelled different for more than a day or two, veterinary attention is warranted. Anal gland infections can become serious quickly, and UTIs left untreated can progress to kidney infections. A simple vet visit with a urinalysis and anal gland examination can resolve most causes within a single appointment.
Pro tips recap: Keep your dog on a diet that produces firm stools to help natural anal gland expression. Monitor urine smell as part of your routine health checks. When in doubt, a urinalysis is inexpensive and provides enormously valuable diagnostic information. Don’t let fishy odors persist without investigation — they’re rarely benign.
