The dog days of summer. We’ve all heard this expression used to describe the hottest time of the year. But what most people don’t know when they use this term to complain about the heat is that the phrase is as old as Western culture itself.
“The dog days of summer” was first uttered way back in ancient Rome. In Latin, the expression reads “caniculares dies,” or “days of the dogs.” The Romans dubbed this the time period that spanned from the first week of July to the second week of August.
To understand why the Romans associated summer heat with canines, you have to know a bit about astronomy.
Romans, like their Greek cousins, were masters of the night sky and knew a lot about the heavens. The brightest star visible in the Western hemisphere is Sirius, also known as the Dog Star. Sirius is a star in the constellation Canis Major, one of the hunting dogs of the constellation Orion, the Hunter. In the winter sky, Orion and Canis Major shine brightly, poised for the hunt.
But in the summertime, Sirius is not visible. Ancient astronomers knew that stars that weren’t visible at night didn’t disappear completely. They were instead present in the daytime sky, even though they couldn’t be seen.
So even though the glow of Sirius was overwhelmed by the sun, the Romans knew it was there. They believed the Dog Star was contributing heat to the summer days by shining brightly alongside the sun.
In reality, Sirius is 8.6 light-years from us and way too far away to contribute heat to the Earth. But the Romans were so convinced of Sirius’ ability to throw heat that they persisted in using the expression long enough for it to become part of the vernacular of Western civilization.
Even though Sirius doesn’t actually contribute to the heat of summer, this part of the season is the hottest and, consequently, the most dangerous for your dog.
To keep your dog safe on days when the temperature is high, keep him indoors in the air conditioning and always make sure he has shade available when he’s outside. Hydration is important too, so ensuring your dog always has access to clean, fresh water is essential.
Of course, never leave your dog in the car during the summertime, even with the windows rolled down. The temperature inside a car can rise rapidly to dangerous heights and result in heatstroke and death.
When your dog is playing or hiking in the summertime, keep an eye on him to make sure he’s not suffering from the heat. Signs of heatstroke in dogs include restlessness, heavy panting, a brightly colored tongue and mucous membranes, thick saliva, vomiting and diarrhea.
Should your dog show signs of heatstroke, get him indoors into an air-conditioned building. Take his temperature using a rectal thermometer, and if it’s higher than 104 degrees, submerge him in a bathtub of cool water.
Take his temperature every 10 minutes until it gets down to 100 to 102 degrees, which is the normal temperature range for a dog.
Take him to a veterinarian as soon as you can for an examination to make sure the heat did not cause damage to his internal organs.
Good outdoor activities for canines during the dog days of summer include swimming in a pool, in a lake or at the beach; playing in the spray of a garden hose; or hiking in high elevations where the air is cool and clean.
If you take your dog salmon fishing with you, don’t let him eat any of your catch unless it’s cooked. Salmon and related types of fish can be infected with a parasite that is toxic to dogs, but not to cats, raccoons or bears.
Salmon poisoning is most common west of the Cascade Mountain range, says veterinary parasitologist Bill Foreyt at Washington State University’s College of Veterinary Medicine. Symptoms include vomiting, lack of appetite, fever, diarrhea, weakness, swollen lymph nodes and dehydration.
Dogs can die within two weeks of eating the fish if they go untreated with antibiotics and a dewormer.