Bulldogs. Pugs. Boston terriers. French bulldogs. There is a term for these widely-loved pups who seem to lack snouts altogether, with their face instead appearing to have been smooshed in through years of inbreeding. That term is "brachycephalic," derived from the Greek for "short head."
Whether you adore these animals or think their very existence is inhumane (a controversial subject indeed), experts from both the dog worlds and the climatology world agree on one thing: Brachycephalic dogs are going to suffer a lot more as climate change worsens. It all comes down to the science.
"Brachycephalic breeds are more susceptible to heat stress (hyperthermia) than non-brachycephalic breeds, especially if they are overweight, and will begin to overheat when temperatures exceed 91º degree F and 62% humidity," Dr. James A. Serpell, professor of Ethics & Animal Welfare at the University of Pennsylvania School of Veterinary Medicine, told Salon by email. "Overheating may lead to collapse or even death."
Dr. Lisa Gunter, an assistant professor of Animal Behavior & Welfare at the Virginia Tech School of Animal Sciences, broke down the biology of why these sweet-natured dogs are unfortunately prone to heat-related health problems.
"Unlike people that sweat as our primary way to stay cool in the heat, dogs pant," Gunter explained by email. "It's their special form of evaporative cooling."
The key is understanding that in order to attain the smoosh-faced look that their fans find aesthetically pleasing, brachycephalic dogs are bred in ways that prioritize style over function. If the nostrils need to be closer to slits to accommodate the reduced facial real estate (i.e., no snout), often that is what happens. If their windpipes are practically crushed inside their necks and their soft palates are elongated, frequently that is simply the way they are bred. The end result is that these breeds suffer from more than the breathing problems one would expect with these structural problems. After all, they also need their faces to thermoregulate.
"These physical limitations make breathing difficult, causing these breeds to be particularly susceptible to heatstroke more so than other dogs, [even] in surprisingly mild weather and humidity," Gunter said. "Struggling to breathe can also limit the amount of oxygen in the bloodstream, straining the hearts of brachycephalic dogs and making them more susceptible to heart problems."
To project what the future will be like for brachycephalic dogs as climate change cooks the planet, Gunter turned to a city that has already begun experiencing the most extreme version of those conditions — Phoenix, Arizona, where she used to live for nearly a decade.
"Scheduling what time you walk your dog, where you walk (is it shaded?), and how long the walks are becomes essential as does carrying water, no matter the outing's duration," Gunter explained. "Heat radiating off paved streets and walkways is much more intense for dogs than it is for people. Often, dog owners will use booties to protect their dogs' feet."
She added, "Seemingly routine activities with brachycephalic dogs, like a mid-day potty break in the backyard or coming along on a car ride, can be deadly in extreme heat if they're accidentally forgotten about or closed in a space without air conditioning for just a few minutes. Overall, owners of brachycephalic dogs need to be much more aware of the heat and its devastating effects than typical dog owners."
While Gunter was merely describing dogs who experience the day-to-day hotter weather that will become a "new abnormal," Molly Sumridge — a PhD candidate in anthrozoology at the University of Exeter — told Salon by email that these breeds can also be expected to fare worse from the natural disasters that these events will make more frequent. Indeed, as compound drought and heatwaves (or CDHW events) become more common, heat-related weather extremes will be more common as well.
"Whether a region experiences higher overall temperatures, or longer stretches of hot weather, these dogs will require access to air conditioned spaces for their health and wellbeing," Sumridge said. "Smoke from wildfires local and miles away can harm dogs of all breeds, however sensitive respiratory symptoms are of increased concern. Exposure of smoke to these breeds where breathing is already compromised can further put them at risk of complications, injury or illness."
Dr. Michael E. Mann, a professor of Earth and Environmental Science at the University of Pennsylvania, who wrote a paper in July about CDHW events, confirmed in an email to Salon that the assessments of the dog experts is correct: Brachycephalic dogs are going to suffer more than other dogs as the weather gets hotter.
"My understanding is that they're very susceptible to heat stress, and so they are especially threatened by climate change," Mann wrote to Salon. He clearly lamented this fact, stating that "as a dog person, I'd hate to see them suffer or vanish altogether as species." His advice to owners of brachycephalic dogs is "avoiding letting them or taking them outside during especially warm periods."
The dog experts had their own tips as well.
"Keeping your dog properly hydrated at home by making sure multiple water bowls are available and easily accessible throughout your house is a simple thing to do," Gunter said. "Whenever out and about, have water with you and a dish that your dog is comfortable drinking from. Dehydration can make a heat-related situation worse."
The same is true of excessive weight, Gunter added — and brachycephalic dogs are prone to weight problems.
"Regular low-impact exercise can benefit your dog's health as well as identify possible breathing problems that need veterinary attention," Gunter said. "For dogs with moderate to severe breathing problems, surgery may be necessary to widen their nostrils and shorten their soft palate for better breathing."
Although Gunter stopped short of saying that brachycephalic dogs should not be bred any more, she urged that they be bred "with less extreme physical features." She also encouraged potential owners to find rescue dogs and research breeders to make sure they are breeding new dogs responsibly.
"As a consumer, it is important to frequent breeders that care about their dogs' physical welfare, including how extreme physical features will negatively impact their dogs' lives," Gunter observed. "Good breeders should have their dogs screened for brachycephalic obstructive airway syndrome (BOAS) and not be breeding those individuals that exhibit BOAS symptoms."
For any owner whose dog does overheat, which can be seen if they are disoriented or vomit or pant excessively, "cool them down as quickly as possible before seeking medical attention," Gunter said. "This can be achieved by pouring cool water over the dog and using a home fan or your car's air conditioning to assist in the evaporate cooling process." Only then should the dog be taken for medical rehabilitation.
Serpell also said that brachycephalic dogs should be kept "lean," adding that they should not be exercised during the warmest times of day: 12 PM to 6 PM. Yet unlike the others interviewed, he was very blunt when asked if the solution might be to stop breeding brachycephalic dogs altogether: "Yes!"
