When warmer weather hits, it never fails that emergency veterinarians everywhere see an increase in the incidence of trauma caused by accidental vehicle collisions with pets. More dogs are out on walks, and more cats are let out of the house to roam once the temperature improves and it stays lighter longer. Sadly, this all puts pets at greater risk for being hit by cars.
The types and severity of the injuries we can see from vehicle trauma vary widely. As expected, visible injuries such as fractures or skin wounds are often the reasons animals present to the hospital. Though serious and important to overall patient recovery, it isn’t always the external injuries that cause the most concern. Internal injuries such as bleeding can take time to develop after the initial trauma, and may not be detectable on an initial physical examination. A surprising number of patients can appear quite normal following an injury, but even short hours later, they can be in serious condition from injuries we can’t see from the outside. Internal injuries aren’t just limited to bleeding either. One of our biggest concerns for up to the first 24 hours after an injury is pulmonary contusions. This is essentially bruising of the lung that is caused by damage to the small blood vessels of the lung. If this bruising is significant, the lungs can fill with blood and inflammatory fluid to the point that oxygen exchange is compromised. The unfortunate part about this condition is that it can become progressive after the initial injury and worsen over a very short period of time. Minor contusions are often managed simply with supplemental oxygen (such as in an oxygen cage or by nasal oxygen lines) along with rest and time to allow the condition to resolve. More serious cases can require manual ventilation under anesthesia to force air into the airways and allow the lungs to expand. Sadly, pulmonary contusions can claim the lives of severely traumatized patients, even with aggressive care.
Another internal injury that can cause breathing difficulty is a ruptured diaphragm (a tear in the muscle separating the chest and abdominal cavities). Known as a diaphragmatic hernia, this injury can allow abdominal organs to enter the chest and reduce lung space. Surgery is needed to repair the diaphragm in these cases. Air in the chest or pneumothorax (air within the pleural space that surrounds the lungs) can also occur with blunt-force trauma. Air around the lungs prevents proper expansion during inhalation and leads to breathing difficulty. The treatment includes removing the air from around the lungs with a sterile needle across the chest wall. More serious cases may require the placement of a temporary chest tube to continuously remove air until the lungs can heal. These types of injuries can often be detected using a simple chest x-ray. Your emergency veterinarian will likely recommend chest x-rays even in the most minor trauma cases as surprisingly limited forces on the body can create significant internal injuries that would otherwise go undetected.
Even if no significant injuries can be found on an initial physical assessment after a trauma, we often recommend in-hospital monitoring for the first 12-24 hours after an accident. Not only is this important to watch for progressive breathing problems or slow internal bleeding, but other internal injuries can also develop. Cardiac arrhythmias (electrical conduction abnormalities of the heart) can be caused by blunt-force to the heart wall. Some may require specific medication to prevent them from worsening to the point that the heart could stop. A small tear in the bladder wall may not be initially detectable, but if a patient isn’t urinating in the hospital, starts vomiting, or having worsening abdominal pain, a condition called uroabdomen (urine leaking from the bladder into the abdominal cavity) may be suspected. Overall, even if no external or internal damage has occurred in a trauma from a moving vehicle, we know many of these patients experience pain from this type of injury. Animals can often hide pain better than we would expect, so even if your dog doesn’t look sore, he or she could be acting brave. By keeping them under observation, we also have the opportunity to treat patients with more potent pain relievers than those we can send home with owners; so we know that at the very least, they will have a comfortable stay in the hospital!
As much as it can be rewarding as an emergency veterinarian to save the lives of animals injured by cars, I would be much happier if I never had to treat an animal for a wholly preventable injury in the first place. There are ways that owners can think ahead to prevent collisions involving vehicles and pets. Even if you trust your dog to stay close by, distractions are out there – wild rabbits, playing children, another pet running by – all of these could serve to provoke even the most loyal companion into chase. If we could teach “look both ways before crossing” the way we could teach “sit” and “stay”, it wouldn’t be an issue. But a two-dollar leash is an easy way to prevent $2000 in life-saving vet bills or even priceless loss of life. Another way to prevent injury is as simple as spaying and neutering of your pet – the instinct to breed is a strong one and intact male and female dogs and cats can sometimes have a greater drive to run after another animal, even crossing busy roads to do so. Finally, though cats enjoy the outdoors as much as any pet, an enriched indoor environment, supervised leash-restricted playtime outside, or development of an outdoor enclosure for your cat can ensure that vehicle accidents aren’t a concern for their health in the future.
So, happy summer, and here’s to hoping you and your pet stay healthy and safe! But if the unthinkable does happen, Guardian’s doors are always open for you.