With this recent heat wave I thought July would be a good time to talk about heat stroke in pets. The following is a true story:
It was a hot summer day last July with temperatures in the 90's when an emergency came in mid-day. Schance, a 12 year old German Shorthaired Pointer had been running errands with his owner that morning, and then taken on a walk during which he collapsed and started breathing very hard. His owner rushed him to SWVH where he was unable to walk into the hospital on his own.
On exam Schance was laying on his side, breathing very hard and loud, and was not mentally responsive. He was dehydrated and his temperature was too high to read on our thermometer, meaning that it was over 108 degrees. It was apparent he was suffering from heat stroke.
Emergency treatment was started. In order to lower his body temperature, we placed cool, damp towels on him and directed a fan towards his body. We placed alcohol on his paws which cools them as it evaporates. A technician placed an IV catheter and IV fluids were started. He was given a sedative to calm his breathing and relax him. Forty minutes after intake, Schance’s body temperature returned to normal and we were able to discontinue cooling.
Unfortunately, Schance was not out of the woods. Bruising was starting to develop on his abdomen. Excessive heat can disrupt the body’s blood clotting abilities. He was still mentally depressed and his eyes developed nystagmus – fast, jerky movements of the eye up and down. We became concerned that as a result of the heat stroke his brain was beginning to swell. A medication called Mannitol was given in an attempt to pull fluid out of the brain and decrease swelling. One hour after giving this medication the abnormal eye movements stopped however, Schance had now developed bloody diarrhea.
Still in critical condition, Schance was transferred to Animal Emergency Center (AEC) for overnight care. Although initially his lab work had been normal, recheck blood work at AEC showed that his blood clotting times were becoming prolonged, correlating with the bruising on his abdomen. Schance also continued to have bloody diarrhea. The good news though was that he was progressively becoming more mentally alert overnight and was able to walk to the car for transfer back to SWVH the next morning.
The next day at SWVH Schance continued to improve. His bowel movements became more normal and his blood clotting times normalized. He continued to become more mentally alert, and was able to go on potty breaks with minimal assistance. We were pleased with his recovery and were able to discharge him that evening.
Heat stroke is a potentially fatal condition in which excessive heat causes body temperature to rise, resulting in damage to cells. The cells lining blood vessels are particularly prone to injury and this is why bleeding problems often occur. The kidneys, lungs and heart can all fail due to damage.
The first signs of heat stroke are often subtle. Dogs will seek shade, pant excessively and may appear weak. It is important to seek veterinary treatment immediately. On the way to the vet put the A/C on high and offer your dog water to drink. Dousing your pet in water can also help, especially the ears and paws where blood vessels are close to the surface and evaporation will cause the most cooling. Do NOT use ice water as it can cause blood vessels to restrict which in turn inhibits cooling the core body temperature down.
The prognosis associated with heatstroke varies widely and largely depends on how severely affected the patient is when arriving at the hospital. The faster the pet is seen by a vet, the better. The good news is that pets that recover from heatstroke generally do not have any long-term side effects.
Prevention of heat stroke is key! During hot summer days restrict walks and physical activity to early mornings and late evenings when it is most cool. Avoid hot pavement and never leave pets unattended in cars. Special care should be taken with animals with pre-existing heart conditions, and short or snubbed nose breeds like bulldogs.