Avoid heat stress in cattle, horses and dogs when moving cattle
Cattle readily overheat on a hot summer day if they have to exert. Gathering or moving cattle is always safer if you can start early in the morning when it’s cooler.
Dr. Ray Randall, veterinarian in Bridger, Mont., said that if it gets hot before you get the herd to their destination, you may have to stop and let them rest awhile, preferably in an area where they might have some shade and water. “Black cattle don’t handle the heat as well as red or white cattle so you need to take even more precautions to avoid heat stress in black cattle. The important thing when moving cattle is to let them go their own speed, with no chasing or yelling,” he said.
Signs of overheating in cattle include panting open-mouthed, excessive slobber or trying to lie down. A person needs to slow down or stop awhile and give them a rest before they get to that point. “Some ranchers do that routinely; they move the cattle for a couple hours then let them stop and rest awhile before moving on,” he said.
“If it’s going to be a really hot day and it’s a move you don’t absolutely have to make today, it would be better to postpone and do it another day. It’s expensive if you get cattle too stressed, especially if you lose one,” Randall said.
Respiration rate in cattle can be a clue as to how hot they are, according to Don Spiers, professor emeritus at the University of Missouri. If you are moving cattle and give them a chance to stop for a rest, check the respiration rates on some of them. It’s easy to just count for 15 seconds and then multiply by four to get respiration rate per minute or count for 30 seconds and double it. Anything below 40 breaths per minute is healthy.
“Anything above 80 breaths per minute is a sign of heat stress,” Spiers said. “When they get up to 120 it’s more serious, and by the time they get up to 160 breaths per minute with their tongues sticking out and drooling, they have a real problem,” he said. If you are moving cattle on a hot day and some start panting with mouths open and drooling, it’s time to halt and let them rest.
“Dr. John Gaughan in Australia developed a panting score index to evaluate heat stress, using scores from 0 to 5. This involves counting respiration rate. At 0 there is no panting and breathing rate is below 40. Score 1 is 40 to 70 breaths per minute (and it’s easy to see chest movements) but mouth is closed and there’s no drooling,” Spiers said.
Animals at score 2 are breathing 70 to 120 breaths per minute, they have a little drool, but the mouth is still closed. At score 3 there is drooling, open mouth panting (120 to 160 breaths per minute), the neck is extended and head held upward. At panting score 4 the tongue is fully extended out of the mouth for long periods, with excessive drooling, the head is still extended upward, with breaths more than 160 per minute. The respiration rate can’t even be counted when it’s this rapid.
“The critical level is score 4.5 because by then the head is low and the animal is breathing from the flank and may stop drooling because it’s so dehydrated. At this point, risk of death is high. When they start going into heat stroke, they are very dehydrated and everything is shutting down,” Spiers said. If you’ve been paying attention to cattle as you move them, you will stop and let them rest well before they get to this point.
If a person uses dogs, they must be well-trained and only working cattle when asked — not chasing any cattle unnecessarily. Dogs on a roundup or cattle drive can be very counterproductive if they move the cattle faster than they need to go, or get the cattle upset and stressed.
When using dogs, it’s also important to make sure the dogs don’t get overheated on a hot day. “I went to New Zealand a couple years ago when my wife was judging a horse show there, and I went to a big sheep ranch. We moved about five bunches of sheep that day after they got done shearing. The sheepman had some really good dogs, but also had enough water tanks that the dogs could cool off. Those dogs got hot, but they knew where every tank was and they’d go jump in and cool down,” he said.
“If you use dogs, you need some water sources along the way, or it will be really hard on dogs — and sometimes that’s the end of them. They get dehydrated very quickly and get too hot,” Randall said.
“Their respiration rate gets very high because they can’t sweat much; they have to pant faster to try to cool themselves. If their body temperature gets too high they go into convulsions and may die quickly. If you have dogs that are hyper, trying to do too much, leave them home if it’s going to be a hot day.” That’s when you need dependable, experienced dogs that won’t try to do anything extra without your command; they just follow your horse unless you send them out after cattle.
“Some people pack water along for themselves, and try to give the dogs some water now and then if there are no water tanks. But a lot of guys never carry any water. When I was a kid, no one ever carried any water when we were riding; you just waited until you found a tank or a windmill. In southeastern Montana there aren’t very many streams, and it was not recommended to drink out of the Powder River!”
Horses are also susceptible to heat stress if you overwork them on a hot day. “If they are in good shape, and fit, they can stand a lot of work. But a soft horse on a hot day climbing hills and sweating a lot may get dehydrated and overheat.” If it’s hot and humid, it’s even worse because sweat doesn’t evaporate as readily and the horse doesn’t cool down, and just sweats more to try to cool himself — and becomes more dehydrated.
“If the horse gets severely stressed (heat stroke) and collapses, and you are far from help, that horse may not survive, so it’s wise to be in tune with your horse and know the early warning signs. If the horse has been sweating, and has stopped sweating, that’s a clue that he’s too dehydrated to sweat. If you quit working him at that point, and get him cooled down, he might be OK, but if you keep asking him to keep going — and he’s been a long time without water — you may end up losing that horse,” Randall said.
Riders should be aware of subtle signs of stress when working a horse in hot weather. Many horses have a tremendous amount of heart and will keep going, but start to show signs of stress. The overheated horse is listless, tired, and walks with a stumbling or stiff gait (no bounce). Where normally his ears would be pricked forward and he has enthusiasm for the job, he may become lop-eared and droopy. These are things a rider should pay attention to. Don’t keep pressing the horse or he may keep going until he collapses. You can do a “pinch test” to check for dehydration. Skin becomes less elastic due to fluid loss from underlying tissues. A pinch of skin pulled out from the neck or point of the shoulder does not spring right back into place but stays tented for a few seconds. If it takes 2 or 3 seconds for the skin to sink back into place, the horse is moderately dehydrated. If the skin stays elevated for 6 seconds or longer, he is severely dehydrated.
Some people don’t let their horses drink when they are hot and sweaty, for fear of colic or founder, but horses need to drink or they will become dehydrated. “We were taught to not water a hot horse, but water should not be withheld,” Randall said. A lot of cold water all at once can cause the gut to cramp, but warm water is usually safe.
“Most of the water you come across in summer — in a water tank, especially — has sat in the sun awhile and won’t be very cold. A mountain stream would be colder. If the water is very cold, you can limit the horse to about a gallon and then give him a little time, and then give him another drink. A person can learn to count swallows as the horse drinks, and limit the horse to about 12 to 15 swallows. Then after awhile you can let him have another dozen or so swallows — and keep spacing out his drinks,” Randall said.
“Endurance horses can get really dehydrated in hot weather. In the Middle East, when those horses come into a check point the rider’s crew cools the horse with ice-water. On a hot cattle drive, when you get to a water source you could pour water over your horse to help him cool down. Get your saddle off and get water over his neck, back and croup, and the inside of the legs,” he said. “This will help cool the horse by evaporation. Blood vessels near the skin surface, bringing overheated blood from the core regions, can get rid of some of that heat if you keep putting water over the horse.”
“A fit horse won’t get in trouble as quickly as the ‘weekend warrior’ horse that’s only ridden sporadically. On some cattle drives, people bring their friends along, and some of them may have soft horses — and the people aren’t in shape either. Sometimes a person needs to get off and walk, to help the horse, but if the rider weighs an extra 50-100 pounds, has bad knees and bad hips and smokes two packs a day, that rider might not be able to do that very readily.” ❖
— Smith Thomas is a cattle rancher, horseman, freelance writer and book author, ranching with her husband near Salmon, Idaho. She can be reached at email@example.com.