When a dog has a bladder infection, he or she will likely pass small amounts of urine much more frequently. This can cause dehydration, as well as uremic poisoning and acidosis, all of which can lead to death.
Make sure to give him plenty of water and keep the food intake steady so as not to cause the digestive system any addded stress. Bladder infections should also be monitered to ensure there is no blood in the urine. Just try and keep your dog as comofortable as possible.
It is painful, will cause frequent urination and should be treated with
prescribed antiobiotics for two weeks. Try to get the dog to drink a lot
of water during treatment. A week after finishing the last pill, the dog's
urine should be checked again to be certain the infection is gone.
If your dog is urinating frequently or had trouble urinating it probably has an infection. If the dog has bloody urine that isn't due to heat then I would suggest visiting a vet as soon as possible. The vet will give your dog antibiotics.