Summer Heat

Dr. Kimberly Brokaw
Walkersville Veterinary Clinic

(8/2012) We all have seen the public service announcements, the signs at the firehouse, and other warnings about the dangers of leaving pets or children in a hot car. Every year people get distracted and forget about their pets, sometimes with disastrous consequences. Unfortunately, every year I see pets who suffer from heat stroke. It is important to know the signs that your pet is overheated, and to have a plan to prevent your pet from getting overheated. Slight increases in body temperature can be corrected by the dog through panting. However when dogs are unable to stabilize their temperatures, clinical signs can progress to confusion, rapid breathing, vomiting, diarrhea, internal bleeding, collapse, and seizures.

Obviously being left in a hot car, even with the windows partially down, is dangerous for the pet but overheating can also occur from just being outside too long. Several of the serious, heat related problems that I have seen have followed similar scenarios to the following.

Coal is a large Newfoundland. He has been the constant companion for a family with two kids. The kids grew up with Coal and while Coal is not a fancy show dog, he is a beloved pet. One afternoon the oldest son came home from school. He let Coal out in the backyard and went back in the house to make himself a snack. The son received a phone call from a friend and they decided to go to the mall. A few hours later the mother returned home from work and found Coal in the backyard. He was laying on the sunny deck and was unconscious. By the time Coal arrived at the vet clinic his temperature was 108 degrees. The mother was hysterical and kept saying "it can't be heat stroke, he was only outside for a few hours and it wasn't even that hot out." Unfortunately while it had only been 85 degrees outside, that had been too hot for Coal, with his large body and heavy hair coat.

I immediately placed Coal on a wet table and had my vet assistant start spraying him off with cold water. I shaved his legs and placed two intravenous catheters to give him lots fluids to further assist in cooling Coal down. As I continued to work on Coal he started having seizures and bloody diarrhea. I administered anti-seizure medications. Since the seizures continued despite moderate doses of medication, I gave more medications to put Coal in a temporary coma to prevent more seizures. I told the owners that Coal had a very poor prognosis for recovery but that we should wait until his temperature was back to normal to fully assess him. To my surprise as his temperature stabilized, so did Coal. By the end of the evening, while Coal was unable to stand or move, he was looking around the room and was aware of his surroundings.

Due to financial constraints, Coal was not transferred to an emergency hospital for the night but was rather released to care of his owners with instructions to come back to the clinic the next morning. The next morning, I received a call from Coal's owners. He was on his feet and acting almost completely normally, so they weren't going to come into the clinic. I had them pick-up some stomach medications to give to Coal and advised his owners to continue to watch him closely. While I would have preferred to do a recheck and make sure he was ok, I was pleased he was doing so well. Coal continued to improve and is currently back to normal although his owners have been cautioned that he is more vulnerable to another episode of heat stroke.

Coal was extremely lucky. I have treated several dogs who did not have happy outcomes. When taking your dog for walks in the hot weather, try to restrict walks to early mornings and late evenings. Do not leave them in cars. Be careful leaving them outside even with shade and water. If you feel hot while standing in the back yard for 15 minutes, your dog was probably ready to go back into the air conditioned house 10 minutes earlier.

Some animals, such as horses, can't be brought into the air conditioning when it gets excessively hot. Fans can be set up in the barns. Horses can be hosed down whenever they are sweaty or breathing hard. Riding should be limited in extreme heat.

If fans are going to be used in a barn, make sure fans that are designed for barn environments are chosen. Agricultural stores like Tractor Supply Company sell fans that are designed for barn usage. Regular house box fans should not be used. As barns are typically dustier than houses, a fan with an enclosed/ sealed motor is preferred to decrease chance of fire. (If you look at the back of the fan and see wires, the motor is not sealed.) When the motors aren't sealed, dust and debris get into the motor. This causes the motor to seize up, over heat, and catch fire. Fans should be cleaned at the start of the season to eliminate any dust that may have accumulated on them. The fan's cord should also be placed where horses can't reach and chew it. Misting fans are also available and can significantly help in keeping livestock cool. My suggestion would be to get an agricultural fan that has galvanized construction, enclosed motors with thermal protection, welded wire guards on the intake and exhaust sides, and a heavy duty power cord that is kept out of reach of the horses.

A couple years ago a farm in West Virginia had 44 horses killed in a fire started by a residential box fan. The farm had taken many expensive preventive measures to prevent a barn fire. The farm had all new wiring, 20 fire extinguishers, and a fire hydrant 100 feet from the entrance. Hay was properly cured and was stored separate from the stable. The fire department was only about two blocks away, but by the time the fire was noticed it was too late. The box fan that started the fire was only two months old. I frequently see barns that have box fans in them or even worse have multiple box fans with extension cords connecting them together. Horse owners take many precautions to prevent barn fires, but often don't think about the fire hazard of using inappropriate fans.

Overheating is usually preventable. Animal owners need to plan carefully to ensure a cool environment for their pet. If you suspect that your pet is overheating, spray him with large amounts of cold water, and call your vet immediately. This is a potentially life threatening situation and rapid action is required.

Read other articles by Dr. Kim Brokaw