Signs of Internal Injuries of a Dog

By Karen S. Johnson

Internal injuries can be deceiving; a dog struck by a car may not show any initial symptoms. His seemingly unscathed demeanor could be his body’s response to shock. Accidental poisoning is another, commonly unobserved source of internal injuries. Several symptoms can point to an internal injury, ranging from depression to bloody urine. If you know your dog has experienced physical trauma or observe unusual changes or symptoms, contact your veterinarian immediately. The best way to prevent internal injuries is to constantly know your dog’s whereabouts.

Changes in Demeanor and Eating

A sign of something serious can be as subtle as your dog just “not being himself.” Changes in your dog’s mood, such as depression and lethargy, can signify an internal injury, notes veterinarian Janet Roark of Hill Country Veterinary in Austin, Texas. This is so particularly if he also loses interest in eating. Use these potential early indicators to monitor him carefully, paying close attention to his breathing, bathroom habits and physical comfort or signs of weakness while walking or lying down.

More Obvious Symptoms

Roark advises dog owners to look for changes in breathing and respiration, coughing or vomiting up blood, pale gums and a weak pulse. Observe whether your dog whimpers when you touch him or try to keep him up, or it looks like his abdomen is “tucked up.” Seemingly inexplicable bruising can occur hours after trauma impacts your dog’s body, so contact your vet immediately if you notice any bruising. While most dogs experience the occasional bouts of diarrhea, black diarrhea is a red flag and could indicate an internal injury.

Signs of Physical Trauma

Even if you don’t witness a traumatic collision or injury but see physical signs, take your dog to a veterinarian immediately. In addition to bruising, a scrape or irritated skin could be road rash and a sign that some impact occurred -- even unexplained shortened toenails should make you suspicious. If you see bleeding from a puncture, or a displaced or protruding bone, try to cover the area with a clean cloth but don’t let that significantly delay your trip to the vet clinic or hospital. If your dog actively resists being touched, call your vet; he may have to be sedated for both his and your safety.


Ingesting rodent poison is an unfortunately common occurrence in dogs. Many rat poisons contain anticoagulants that prevent the blood from clotting. Your dog may not show any symptoms until days later; many of the symptoms are identical to a blunt trauma injury, as well as nose bleeds and bleeding from the rectum. Quick diagnosis and treatments is critical. Certain human medications also contain anticoagulants, so keep them out of your dog’s reach.


Treatment for an internal injury can include intravenous fluids for shock and pain relief, sutures and bandages, or even blood transfusions. Follow your veterinarian’s instructions closely; your dog may need several weeks or even months to make a full recovery.