In this episode of Bovine Science, Dr. Bob Larson and Dr. Brad White discuss the risk factors associated with BRD in preweaned calves. They discuss past research over the subject and options to mitigate the risk.
Articles Discussed:
BRD in preweaned calves: What’s new in risk factors?
Strategies for Bovine Respiratory Disease (BRD) Diagnosis and Prognosis: A Comprehensive Overview
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| Bob Larson, DVM, PhD Reproductive physiologist and Epidemiologist Beef Cattle Institute Kansas State University RLarson@vet.k-state.edu |
Pneumonia in young calves is an important contributor to death loss before weaning. Many veterinarians and cattle producers think of post-weaning respiratory disease (also known as Bovine Respiratory Disease or BRD) when they think about pneumonia in cattle; but calves can get pneumonia while they are still suckling their dams. Because the risk factors associated with pre-weaning respiratory disease differ from BRD in stocker and feedlot cattle (which is usually associated with commingling and transportation), our understanding of how to prevent and control BRD in post-weaned calves is not sufficient to address pneumonia in suckling calves.
Several studies investigating calf pneumonia have reported that an average of 3% to 11% of calves are expected to suffer from the disease each year. In addition, nearly 1.5% of calves will die from pneumonia before they reach the age of weaning; which makes it the second leading cause of pre-weaning death with only scours causing more losses. The most likely age for calves to be diagnosed with pneumonia is between 70 and 150 days of age.
Herds that have more cases of calf scours as well as herds that bring in nursing calves from outside herds to graft onto cows that lost their calves, and herds that creep-feed calves or synchronize cows appear to be more likely to have cases of pneumonia. Calves born after a difficult birth and calves that failed to consume enough colostrum have been shown to be at higher risk of getting sick and dying before reaching weaning age. Veterinarians indicated in a survey that weather, calving in confinement, failing to adequately vaccinate the herd, and nutritional deficiencies were also suspected for contributing to the risk of calf pneumonia.
Many times, the first sign that a herd has a problem is when a calf is found dead. Because death in young calves can also be caused by other diseases such as blackleg, digestive tract disease, or trauma, a veterinarian will probably need to examine the dead calf and may need to submit samples to a diagnostic laboratory to identify the cause of death. Calves that show signs of pneumonia such as rapid breathing, laying down and being reluctant to rise, and having a high temperature should be treated with an appropriate antibiotic after consulting with your veterinarian.
Vaccinating calves against viruses such as bovine viral diarrhea (BVD), infectious bovine rhinotracheitis (IBR), bovine respiratory syncytial virus (BRSV), and bacteria such as Mannheimia haemolytica and Pasteurella multocida may help prevent outbreaks of calf pneumonia or reduce the severity of disease, but we know that a young calf’s immune system is not able to respond as well to vaccinations as an older calf’s. Because even a calf with a good immune response can be overwhelmed by a large exposure to germs, a successful plan to prevent disease in young calves need to involve more than just vaccinations.
Herds that have the best calf health have a short calving season and few heifers and cows experiencing calving difficulty. In addition, they keep young calves away from mud and other calves as much as possible. Cows that calve in good body condition and that are on a good plane of nutrition are more likely to have healthy calves. The best disease-control strategy is to focus on having good overall health of the cows and calves by meeting the herd’s nutritional needs, providing a good environment, and timely use of vaccinations in the cows and calves. If calves are affected with pneumonia while suckling their dams on summer range, you should be prepared to recognize and treat cases as early as possible with appropriate antibiotics in order to minimize death losses.
Dr. Brad White and Dr. Bob Larson are back to discuss a case where a producer had 20% of heifers open. They explore potential causes behind this reproductive issue, from bull problems to nutritional and health-related factors. They also share practical strategies and management tips producers can implement to improve reproductive success and set the herd up for a better breeding season.
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| Bob Larson, DVM, PhD Reproductive physiologist and Epidemiologist Beef Cattle Institute Kansas State University RLarson@vet.k-state.edu |
Although most of the time when we administer a treatment, vaccine, or other product to cattle we expect a positive outcome; occasionally cattle will have an adverse drug reaction. Adverse reactions can occur following the use of injectable antibiotics, dewormers, vaccines, insecticides, vitamin preparations, anti-inflammatory preparations, as well as skin ointments and other classes of drugs.
Adverse drug reactions are defined as any unintended and undesirable response to a drug and can be somewhat grouped as to being “human error” or “random”. Human error is often suspected if a high percentage of a group of cattle have an adverse drug reaction. The error can be due to an improper dose, route of administration, or combination of drugs. Improper dose can occur when a dose that is safe for another species results in an unsafe dose for cattle. Also, certain diseases such as liver or kidney disease or old age can cause a normally safe dose to cause problems in some individuals.
The label of any veterinary product will include instruction on the route of administration. The route can be: by mouth, applied to the skin, or injected into a muscle (intramuscularly/IM), under the skin (subcutaneously/SQ), or into a blood vessel (intravenously/IV). If a drug or product is labeled for one route of administration but given by another route, dangerously high doses of the active ingredient or other components of the product can result. It is important to understand that a veterinary product contains more than the active ingredient – it will also contain ingredients to keep the product stable over time and over a range of temperatures and other factors; and some non-active ingredients can be toxic at high doses.
Drug interactions can occur when one or more drugs antagonize another drug making it either ineffective or even dangerous. This can occur when drugs that were not intended to be mixed are mixed together in a bottle or syringe. The active drugs or the additives may cause the antagonism. Drug interactions can also occur even if antagonistic drugs are not mixed before injection, but are injected into the same animal and interact within the animal to cause adverse reactions.
You can reduce the risk of human error causing adverse drug reactions by only using drugs that you are very familiar with and that you have been trained to use by your veterinarian. Also, never mix drugs together in a bottle or syringe unless directed by the label. And, avoid giving multiple drugs at the same time unless your veterinarian advises you that it is safe.
Adverse drug reactions can also be caused by random, unknown factors. These types of reactions usually only affect one or a few members of a herd or group, but can cause a cluster of affected animals due to similar genetic factors in related animals. These types of reactions are unrelated to the dose or normal effects of the drug; and they are probably impossible to prevent. The active ingredient or carriers and other additives may cause random effects such as allergic reactions.
Allergic drug reactions in cattle most commonly occur following an injection and result in fluid build up in the lungs. The animals have sudden and severe respiratory problems making it difficult for them to breath. This type of reaction is called an anaphylactic response and often results in death. Rapid treatment with epinephrine and supportive care may help some affected cattle to survive.
Because the risk of adverse drug reactions is always small but present. Cattle should be observed after being treated with any veterinary product and not allowed to immediately leave the sight and care of the producer or veterinarian. Careful and appropriate use of veterinary products and attention following treatment are necessary to minimize the risk and cost of adverse drug reactions.
What causes 30-40% of pregnancies to not have a live calf? Dr. Bob Larson brings a research report article which summarizes a lot of information on pregnancy in beef cattle. Dr. Brad White and Dr. Larson will discuss new information that could be applicable when dealing with pregnancy loss in a herd.
Link to Article: Highlighting factors contributing to pregnancy loss in beef cattle
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