Keeping calves healthy: How to treat the sick ones
When weaned calves hit the feedlot their new normal requires some adjustment. A certain percentage will always get sick, but good feedlot health managers can keep those numbers as morbidities, not mortalities.
Chris Thomsen of Belle Fourche, S.D., is a technical services veterinarian for Merck Animal Health. He says the top four feedlot calf health concerns are led by respiratory problems – also known as bovine respiratory disease, and followed by gastrointestinal disorders, muscular-skeletal ailments, and neurologic problems.
BRD is a disease complex – meaning it is caused by a wide range of factors, singly or in combination with each other. Environmental factors such as weaning, transportation, and new settings join with viruses and bacteria to impact respiratory function. According to animal health manufacturer Zoetis, BRD is the cause of 75 percent of illnesses and up to 70 percent of cattle deaths in feedlots.
BRD is treated with antibiotics, including both steroidal and non-steroidal. Some feedlot operations institute metaphylactic antibiotic treatment – or treating an entire pen of cattle with a standard dose – upon arrival. “If you have a high risk group of cattle it might warrant this, but most of the time with healthy, ranch-raised Northern cattle it’s not necessary,” says Thomsen.
The most common symptoms of BRD are being off feed, droopy ears, nasal discharge, increased respiratory rate, decreased activity, and isolation from the herd.
Common feedlot gastrointestinal illnesses include gassy bloat, where the animal is unable to expel gas from the rumen and the pressure causes distress. Typical therapies include tubing the rumen, or in extreme cases, sticking a trochar and cannula into the rumen wall to expel the gas. “Typically in a feedyard we’re dealing with gassy bloats,” says Thomsen. “We tend to see more frothy bloats on cattle grazing wheat or rye pasture or alfalfa.”
Muscular skeletal ailments can be a mechanical injury from going through a chute, getting caught in a fence, or a result of getting ridden by a bulling animal, or they can be infectious-type problems, such as joint infections from mycoplasma or an infection from foot rot.
Neurological diseases impact an animals ability to control body movements, and can produce staggering, tremors or seizures, and unusual aggression or depression. Several neurological diseases in feedlot cattle include listeria, coccidiosis, tetanus and polio.
The natural survival instincts of cattle cause them to hide sickness or injury, which flag them as easy prey to potential predators. Getting an animal away from the herd is important to accurately evaluate them and take a rectal temperature.
Thomsen advice to pen riders is, if an animal warrants a second look it’s worth the pull. “If something looks a little off, pull it from the pen and get it to an area where you can evaluate it individually and get a temp.”
Normal temperature of a calf is 102.5, but Thomsen says most feedlots won’t start treating until a calf is at 103.5 or 104. “A lot depends on what is going on, and what the day is like,” he says. “If it’s been normal fall temperatures and then suddenly you have a 100 degree day, it’s going to raise the body temperature even in a healthy calf.”
Thomsen says in his experience feedlot health protocols vary. Some have a set number of times they will treat an animal, such as three, before they discontinue treatment. Some will treat up to a certain dollar amount. Others will continue treatment as long as they are seeing a positive reaction.
No matter the system, he says it is critical to work with a consulting veterinarian to establish post-treatment intervals between treatments. Every drug is different in the amount of time it takes to go into effect, and length of efficacy, which impacts re-pulls. Retreating with a second dose before the first has had time to go to work is not only inefficient and costly, but adds stress to an already sick animal.
Record keeping can run the gamut from writing down a tag number, date and treatment in a pocketbook, to sophisticated digital systems that scan an EID tag and treat with electronic syringes which record the injection directly to a computer program. Most feedlots have a system of visual identification as well, such as a series of notches on an ear tag or a different colored paint stick for each day of the week to more easily identify animals that have been treated and aid pen riders in not pulling again too soon.
Professional advice differs on whether to return treated animals to their home pen – which has the advantages of a familiar setting, established social hierarchy and consistent ration, or put them in a sick pen –where they can have less competition for feed and often access to more careful evaluation. Often, rehoming depends on the symptoms and treatments.
“Every operation is different, but a consulting veterinarian will help establish protocols based on science,” says Thomsen. “Ultimately, the goal is the same – to do everything we can to get animals better and back on feed.”
When treatments fail and a calf dies, conducting a post-mortem analysis, or “posting” an animal, can provide valuable information on cause of death as well as risk of herd infection.
“Anytime an animal dies unexpectedly it’s a good idea to open it up and see what is going on,” says Thomsen. “It might be a problem that could spread through the pen that can be identified in an acute early dead.” He recommends that for an animal that most likely died of known causes, such as a calf that has been treated for BRD multiple times, a necropsy isn’t as critical compared to a sudden or unusual death.
Thomsen also recommends that to get a true picture of what is going on, along with posting deads and getting diagnostics, feedlot managers should take deep nasal swabs on a sampling of pen mates. “Nasal swabs from live animals can show if there is a virus circulating among the herd – most viruses won’t kill an animal on their own, but they can set up host to bacteria that can get down deep in the lungs.”
Thomsen says the most important thing to remember with feedlot health is that nutrition must come first. “The immune system requires calories to operate,” he says. “Animals that aren’t eating are not going to be able to fight off disease or infection, despite the health protocol. Those that are on a high plane of nutrition are going to have stronger immunity, higher rate of gain, and overall better livelihood.”
To that end, a robust feedlot operation should encompass a team of professionals and resources including a veterinarian, nutritionist, animal pharmaceutical technical consultants and Extension personnel, as well as a network of other feedlot operators. “There are a lot of resources out there and the big thing to remember is, if things aren’t going the way you expect them to, don’t be afraid to ask for help,” says Thomsen.
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