LOGAN — Animals in most parts of Utah have been under pressure from high temperatures this summer, and that’s likely to continue into late August and even September.
Kerry Rood, associate professor of veterinary medicine, animal health and management at Utah State University’s School of Veterinary Medicine (USU-SVM) and USU Extension veterinarian, wants people to understand the scope of the problem.
“All animals are at risk during a heatwave,” said Rood. He added that young, old, pregnant and obese animals are especially likely to experience extreme heat stress.
High temperatures have measurable effects on the health of domesticated animals, which in turn harms the productivity of farmers and ranchers. The impact is especially felt in cattle, and not always in the ways people expect.
“Reproductive performance in bulls and cattle can decrease significantly with high temperatures,” said Rood. “The estrus cycles are more ‘silent,’ and bulls are less active due to the heat. Reproductive percentages can decrease dramatically.” He also noted that younger and older bulls can overheat quickly.
According to Rusty Stott, USU-SVM clinical assistant professor of bovine reproduction and herd health, dairy cows are even more vulnerable.

“Dairy cattle working hard to make milk are at high risk for heat stress,” said Stott. He explained that because a cow’s first stomach, called the rumen, generates significant amounts of heat as it breaks down food. The more fiber a cow has in its diet, such as from grass, the more heat the milk cow produces. When temperatures get too high, milk production suffers, which in turn hurts farmers’ livelihoods, and can ultimately impact prices for dairy products. 
However, there’s one group of animals feeling the heat even more acutely: llamas and alpacas. While they’re not the most common farm animals in the state, they are raised here, and they’re not having a good time.
“South American camelids are native to high elevations and cool temperatures of the Andes Mountain Range,” said Stott. “Our temperatures in the summer are much warmer than summers in the Andes. Llamas’ and alpacas’ long fiber coats decrease their ability to manage body temperature.” That makes shearing them all the more important in summer.
Other animals lack ways of getting rid of body heat on their own, so they depend on outside sources and the help of humans to stay cool.
“Some species, such as dogs, pigs and poultry, do not use sweat as a primary way to thermoregulate,” said Rood. “It’s important to provide ways for these animals to cool themselves. Pigs, for example, require some sort of mud bath or water misting to use evaporation to cool themselves.”
Dogs also need special care during heatwaves.
“Working cattle dogs can get heat stress quickly on dry, hot days,” said Rood. “Make sure you stop for frequent water breaks and try to provide opportunities for dogs to jump into water troughs, pools, creeks or ponds to cool off. You should also watch out for surfaces being too hot. If the dogs are asked to work cattle on hot concrete or blacktop surfaces, they can experience burn-blisters on their pads. I’ve seen this personally in several working dogs.”
As bad as burn-blisters can be, they’re only one of many health problems that can arise from overexposure to heat.
“Most of us think of production losses, rate of gain, milk production and poor pregnancy rates, but death can also be a result of extreme heat stress,” said Stott. “Heat stress suppresses the immune system, and mastitis and pneumonia are common diseases of cattle that can increase during heat stress events.”
Because of the danger extreme temperatures pose, producers need to be vigilant when it comes to signs of heat stress in animals.
“The most common sign is when an animal is less active than usual,” said Rood. “It may be laying down, reluctant to rise and not as responsive. Some species start to breathe through their mouths when they become overheated. This is normal in dogs, but in other species, like birds and cattle, open-mouth breathing is uncommon.”
Several things can be done to protect animals from the heat. Constant access to clean water is important for hydration, while shade can keep animal temperatures from rising in the first place. Shelters should ideally be 10-feet tall and aligned north-south, although natural sources of shade, like trees and large plants, also work. Stott also recommends sprinklers or misters over feed bunks as well as increased airflow in confined spaces.
In temperatures like Utah and surrounding states have seen this summer, these preventative measures may not always be enough. Placing portable shelters over a heat-stressed animal and applying water to its skin can help, but if it either can’t stand up on its own or has a high temperature (usually over 104 degrees Fahrenheit) that won’t go down, a vet may need to be called.  
“The prognosis is generally poor for these animals since they are likely in severe heat stress,” warned Stott. “However, veterinarians can provide intravenous (IV) fluids or other cooling mechanisms to help the animals overcome the stress. They can also evaluate the animal for underlying diseases that can be treated and alleviate their pain and suffering.” 
Timely treatment can help animals recover when heat stress is discovered and treated in time. Even so, prevention remains the best way to avoid loss of both life and money for anyone who raises animals for a living.