Blood in Cat's Urine: Causes & What to Do

Blood in the urine usually means there is irritation, inflammation, bleeding, or damage somewhere in the urinary tract. In cats, one of the most common reasons is feline lower urinary tract disease (FLUTD). This is a group of conditions that can cause blood in the urine, straining, frequent trips to the litter box, and urinating outside the box. Within that group, feline idiopathic cystitis (FIC) is especially common. FIC is bladder inflammation without a bacterial infection, and stress often plays a role.

Other important causes include bladder stones or crystals, urinary tract infection, and urethral plugs or obstruction. Stones can scrape the bladder lining and cause bleeding. UTIs are less common in younger healthy cats but become more likely in older cats and in cats with conditions such as kidney disease, diabetes, or hyperthyroidism. A urethral blockage is most common in male cats because their urethra is narrower, and it is a true emergency.

Less common but still possible causes include kidney disease, trauma, bleeding disorders, and urinary tract tumors. Sometimes what looks like blood in the urine can also be pigment from blood breakdown products rather than active bleeding from the bladder. Because the causes overlap so much, your vet usually needs urine testing and sometimes imaging to sort out what is happening.

See your vet immediately if your cat is straining with little or no urine coming out, crying in the litter box, vomiting, hiding, acting weak, or has a painful, firm belly. These signs raise concern for a urinary blockage, which can quickly lead to dangerous electrolyte changes, kidney injury, and death if not treated. This is especially urgent in male cats.

You should also arrange a prompt same-day or next-day visit if you notice pink, red, or rust-colored urine, frequent urination, accidents outside the litter box, excessive licking of the genital area, or obvious discomfort while urinating. Even if your cat still seems fairly comfortable, blood in the urine is not something to ignore.

Home monitoring is only reasonable while you are arranging care and only if your cat is still passing normal amounts of urine, eating, and acting comfortable. Do not give human pain relievers or leftover antibiotics. Keep notes on litter box trips, urine amount, appetite, and behavior so you can give your vet a clear timeline.

Your vet will start with a physical exam and a careful history. They will want to know whether your cat is producing normal urine, how long the signs have been going on, whether there have been stress changes at home, and whether your cat has had urinary problems before. In male cats, your vet will check right away for a distended bladder and signs of obstruction.

The first-line test is usually a urinalysis, which looks for blood, inflammatory cells, crystals, urine concentration, and other clues. Depending on the case, your vet may also recommend a urine culture to check for bacterial infection, especially in older cats or cats with other medical conditions. Bloodwork may be added to assess kidney values, hydration, and electrolyte changes.

Imaging often helps narrow down the cause. X-rays can identify many bladder stones, while ultrasound can help evaluate the bladder wall, kidneys, sediment, masses, or stones that do not show well on radiographs. If your cat is blocked, treatment may include sedation or anesthesia, urinary catheter placement, IV fluids, pain control, and hospital monitoring. If your cat is not blocked, treatment depends on the underlying cause and may range from pain relief and hydration support to diet changes, antibiotics when infection is confirmed, or stone management.

Home care should support your cat while following your vet’s plan, not replace it. Encourage water intake with canned food if your vet approves, fresh bowls in multiple rooms, or a pet fountain. Keep litter boxes very clean and easy to access. Many cats with lower urinary tract signs do better with less stress, so try to keep routines predictable and provide quiet resting areas, hiding spots, and enough litter boxes for the household.

Watch the litter box closely for urine volume, frequency, and effort. A cat who is visiting the box often but producing only drops, or no urine at all, needs urgent care. If your vet recommends a therapeutic urinary diet, use it consistently and ask before mixing in other foods or treats. Sudden diet changes can make some cats eat less, so transition only as directed.

Do not give human pain medicines, leftover antibiotics, cranberry products, or supplements unless your vet specifically says they are appropriate for your cat. These can delay proper treatment or even be dangerous. If signs return after seeming to improve, contact your vet promptly because recurrent episodes are common, especially with feline idiopathic cystitis.