Debunking the myth: Dog Days of Summer

By Pat Pratt

July 29, 2014

Sores and boils brought on from swimming in lakes and rivers, canines going mad, and fish refusing to bite are just a few of the many myths associated with the “Dog Days” of summer, but is there any real truth behind the stories of these strange occurrences?

Local experts say “likely no,” but add there are some elements of fact to many popular folktales. This is especially true for Dog Days.

“What you find is, a lot of these myths have some little bit of truth associated with them. But generally they get passed down. One person had this happen, or two people had this happen, and it ends up in the lore of a community,” said Pettis County Health Center Administrator JoAnn Martin.

Dog Days are usually known as the later part of July and beginning of August. The name for this period has roots in ancient Rome, as this is the time when Sirius, the Dog Star, conjoins with the sun. Many in medieval times thought the star and sun combined to bring on the sweltering heat associated with high summer.

For years in Missouri, yarns have been spun that swimming during this period will cause the water enthusiast to develop sores on their body. Astrological events certainly have little to do with this, but Martin offered some insight, explaining that the lack of rain and hot humid conditions offer bacteria ideal conditions for growth.

“The thing about swimming in the rivers, when the water gets sluggish and there is not a good flow going through, there is more opportunity for some of the contaminants that are in water to build up a little more,” Martin said.

“Theoretically, if you have open cuts, sores, mosquito bites, and you’re in the water and you come in contact with more bacteria, it could lead to more infections. But, there is nothing in the literature that I know of that says it’s an absolute given.”

Agricultural runoff may also play a role in this part of the myth.

“In any body of water that has agricultural runoff there are some parasites, particularly Giardia and Cryptosporidium,” Martin said. “If people get river water or lake water in their mouth, they run a risk of contracting these parasites and they cause diarrhea.”

Supposedly, dogs sometimes go into a “Cujo” like rage during this time of the year. Does Fido or BowWow really sense the position of celestial bodies in the nighttime sky and break out in a fit of madness, or is it something else? The family pet is likely unaffected by the sun’s conjunction with the “Dog Star,” but there may be a logical explanation.

“We see in increase in dog bites when the summertime happens. It’s not that the dogs are mad. It’s because the people are out,” Martin said. “Think about it. When it’s cold, you don’t have kids outside playing. You don’t have dogs outside. They go out and do their business — they go back inside. You don’t have as many bikers, walkers, people simply out. It’s not that the dogs are any grumpier in the summer.”

Another part of the Dog Days legend says the fish won’t bite during this period. Missouri Department of Conservation officials said there is no truth to this myth whatsoever.

“I think it’s totally a myth that the fish won’t bite during the Dog Days of summer,” said MDC spokesperson Bill Graham. “Fish will bite anytime of the year that they are hungry and the water conditions settle them down and keep them feeling OK.”

Graham added that August offers some better than average fishing for certain species.

“Sure, it gets hot and yeah some things go for deeper water or are difficult to catch. But in August, even though you get a lot of days where it’s hot, the temperature and barometric pressures sort of stays steady,” Graham said. “Down where it’s cool in the water, the steadiness of things keeps the fish active and on the move. It’s one of the best months for Crappie fishing at Truman Lake.”

Regardless of the myths of snakes going blind, moonshine turning to water, or whatever other legends have been passed down through the generations, the truth is, the Dog Days of Summer are usually just plain hot and miserable. Still there is no reason not to enjoy the lakes, rivers and bountiful water recreation Missouri offers.

Remember to bring the family dog. He’s not an almanac reader, he’s just hot.