Do Antibiotics Cause Bleeding in Dogs?

Like any drug you may give your dog, antibiotics carry the risk of side effects, which can sometimes be severe. While most antibiotics won't cause bleeding in your dog directly, side effects include toxicity and allergic reactions, which when severe enough, can lead to bleeding. You should always work closely with your veterinarian when giving your dog antibiotics to prevent side effects that may lead to bleeding.

  1. Side Effects

    • Before you give your dog antibiotics, ask the veterinarian if she is absolutely sure the dog's sickness is bacterial and that the veterinarian has carefully selected the type of antibiotic prescribed. If an antibiotic is given for the wrong reason, or in the wrong dose, your dog is more likely to experience severe side effects.

      While none of the antibiotics appropriate for dogs list general bleeding among the side effects, the antibiotics erythromycin and metronidazole can cause blood in the urine. This can indicate a more serious problem with the dog's kidneys, so if your dog has blood in its urine, you should go to the veterinarian immediately. The antibiotic rifampin can cause discolored tears and urine, which may lead you to believe that your dog is bleeding when it's really not.

    Other Problems

    • If your dog begins to bleed while on an antibiotic, the most common cause is some underlying problem. Before leaving the veterinarian's office, be sure he has exhausted the possibilities of any other condition your dog may have that needs attention. Sometimes, the underlying condition shows itself while the dog is on the antibiotics, making the dog very sick. According to Shelter Medicine, the most common reason for toxicity while on antibiotics is an underlying kidney problem, which can cause blood in the urine.

      If an antibiotic is administered in the wrong dose, the bacteria making the dog sick may become resistant to the medicine, and make your dog sicker than it was in the first place. Bleeding may result from the dog's worsening condition.