Dog Peeing Blood: Causes, Warning Signs and When It's an Emergency

Other signs that often come with the blood

Blood in the urine (hematuria) is the most common sign of cystitis, and it often comes with others:

Straining to pee, or squatting several times to pass only a little urine.
Peeing very often, sometimes dribbling small spots in several places.
Crying or whining while peeing.
Licking the genital area a lot.
Stronger-smelling urine.
Accidents in the house in a dog who was already house-trained.

When to see the vet

Go to the emergency vet right now if your dog:

Strains to pee and nothing comes out, or only a few drops. In a male, a blockage is even more likely.
Is lethargic, has a fever or won't eat.
Vomits.
Has trouble breathing.
May have eaten rat poison. Bring the packaging.

Make an appointment today if your dog is bright and eating, but:

Pees blood or the urine looks reddish.
Pees very often, only a little each time.
Cries when peeing, licks the area a lot or has accidents in the house.

The most common causes

Only a vet can tell which one it is. These are the usual suspects:

Bladder infection (cystitis). It's the most common cause: bacteria travel up the urethra into the bladder. It's more common in females, who have a shorter, wider urethra.
Bladder stones. They rub against the bladder wall and irritate it, causing blood and straining. They often form after an infection, and the signs look so much like a plain infection that vets don't assume stones without testing. If a stone blocks the urethra, it's a life-threatening emergency: it happens more in males, whose urethra is longer and narrower.
Tumors or polyps in the bladder, urethra or ureters. They cause blood, straining and frequent urination, and they're often linked to infections that keep coming back or don't clear up with treatment.
Underlying diseases that make infections more likely: diabetes, kidney disease or Cushing's disease.
Anatomical abnormalities, more common in females.
Rat poison. Bleeding can show up in several places, including the urine.
Cystitis without an infection. In some cases there are no bacteria.

What to do on the way to the vet

Call the clinic and tell them what you see: when it started, what the urine looks like, whether your dog is straining and whether there's been vomiting. Ask whether they want you to bring a urine sample.
Write down how often your dog pees, how much comes out and whether they're drinking more than usual.
Let them drink whenever they want: drinking more helps dilute the urine.
Don't give human medications or painkillers unless your vet says so.

What the vet will do

They'll examine your dog and, almost always, run a urinalysis, which checks for red and white blood cells, bacteria and crystals. A urine culture identifies the bacteria and the antibiotic most likely to work. If there are other signs of illness, they'll run bloodwork. If they don't find the cause, or suspect stones or a tumor, they'll recommend X-rays or an ultrasound of the bladder.

Treatment depends on the cause: antibiotics for an infection, sometimes with pain medication and a diet change. Some stones dissolve with a special diet and others have to be removed, with surgery or with a non-surgical technique that flushes them out through the urethra. After treatment, a repeat urinalysis is common to make sure the infection is gone.

In the US, an emergency exam averages about $135, X-rays about $172 and an ultrasound about $483. Surgery for bladder stones averages about $2,331, and a hospital stay about $1,323 at an emergency clinic (Synchrony/CareCredit 2025-2026 cost study). Costs vary by region and clinic. More in what a vet visit costs.

Frequently asked questions

Is it always an infection?

No. A bacterial infection is the most common cause, but stones or tumors are also possible, and the signs look alike. That's why the vet runs tests instead of guessing.

Can I wait and see if it gets better?

It's not a good idea. An untreated infection can cause ongoing discomfort and complications, like bladder stones or a kidney infection. And if there's a blockage, every hour counts.

Why does it happen more in females?

Females have a shorter, wider urethra, so bacteria reach the bladder sooner. Males are at higher risk of a stone blocking the urethra.

Can it happen again?

Yes. Infections and stones can come back, especially with an underlying disease like diabetes. That's why vets usually repeat the urinalysis after treatment and look further into infections that persist.

How can I help prevent it?

Plenty of water helps. For some dogs, vets recommend moist or canned food, which dilutes the urine. If your dog has had stones, follow the diet and rechecks your vet gives you.

Sources

This article is for general information and does not replace diagnosis or treatment by a veterinarian. If you are worried about your pet's health, call your vet clinic.