This can occur in any cat or dog but it is most commonly seen in male dogs and male cats. Some breeds of dogs such as Dalmatians are at higher risk of developing an obstruction. The obstruction is usually caused by mineral plugs or stones that block the urinary outflow tract (urethra). Early signs of a possible urinary blockage may include straining to urinate but producing little to no urine, crying when urinating, small drops of blood, excessive licking at the prepuce or vulva, frequent trips in and out of the litter box (cats) or frequent need to go outdoors (dogs). As the time since blocked increases waste products build up in the blood and the animal may exhibit vomiting, weakness, lethargy, disorientation, collapse and death. In ability to urinate is a life threatening emergency that must be dealt with quickly. If you notice any abnormalities when your pet is urinating go the veterinarian immediately.