There are many causes of blood in the urine of male dogs, and common diseases include urethritis, cystitis and urolithiasis. Urethritis and urethral stones are more common. Urethritis is an inflammation of the mucous membrane of the urethra and causes include unhygienic catheterisation or the spread of inflammation from adjacent organs. Clinical manifestations include frequent urination and haematuria, along with painful noises during urination and frequent licking of the urethral opening by the dog. The principles of treatment are to eliminate the cause, control the infection and flush the urethra. Urolithiasis causes blood in the urine due to stones or large amounts of crystals that irritate the mucous membrane of the urethra and bladder, resulting in bleeding. The clinical manifestations of urolithiasis include frequent urination, dribbling and haematuria with a strong ammonia odour, and in severe cases, blockage of the urethra, blockage of the urine, bladder distention and even rupture. Causes include low water intake and feeding large amounts of dry food. Mild cases of urolithiasis can be treated by flushing, while severe cases are more often treated by surgery.
