Beef producers deal with infectious conditions throughout the year. Challenges such as respiratory disease, scours, footrot and pinkeye keep you hopping with preventive tactics. When that fails, it's time to pull the sick ones and treat them.
If you have calves hitting the ground this spring, scours will be the next big health challenge. The people responsible for finding and treating sick cattle at your place probably have varying skill and experience levels. But, regardless of the disease or the caretaker's experience, the keys to successful treatment are the same.
- Identify sick cattle early in the disease process.
- Correctly identify the disease and causative agent.
- Administer appropriate therapy.
- Monitor sick cattle to continue therapy in a timely manner if needed.
We can all probably agree on these important steps. But how do we tell if they're getting done?
Identifying Sick Cattle If you evaluate cattle for illness, you're either consciously or subconsciously picking out signs of disease. These signs make up your "case definition."
Writing down a case definition for a disease is a way of teaching others with less experience. If the definition accurately represents your criteria for selecting sick cattle, then it's also valuable for "adjusting your dial" if the results suggest you're treating too many cattle or getting to them too late.
For respiratory disease, a definition might include depression, increased respiratory effort, persistent cough and fever, plus other signs such as discharge from the eyes or nose and sunken flanks. A definition for scours would include visible diarrhea, depression and dehydration as indicated by skin elasticity and sunken appearance of the eyes.
We need to guard against case definitions that are so broad they select many "false positives" - cattle that are treated but aren't actually sick. This amounts to wasted time and money. And, if antibiotics are used in treatment, you heighten the risk of future resistance to the drug.
Yet, telling the difference between false positives and sick cattle in the early stages of disease can be tough. Until we have a reliable test for this, it's better to err on the side of a few false positives rather than wait until the animal is in an advanced disease state before being pulled for treatment.
By waiting too long to treat, the therapy may be inappropriate or the calf's immune system may be weakened. In these cases, cattle will respond poorly to therapy, and many deaths may occur, as well as chronic non-responders. Your veterinarian should be a vital partner in sorting out the cause of this type of response.
If you suspect your case definition is not identifying sick cattle until the disease is more advanced, keep track of cattle that you wondered about but didn't treat at the time. If a large proportion of these cattle require treatment in the next few days and you are experiencing treatment response problems, then a change in case definition may be needed rather than a change in treatment. There is no silver bullet for treating too late.
You're probably very good at finding scouring calves, but can you differentiate between E. coli, Salmonella, Rota virus, Corona virus and Cryptosporidium by observing the calf? Similarly, in respiratory disease we may find varying responses to drug therapy for the different bacterial and viral pathogens involved. We often need to go beyond just classifying the general disease to guiding treatment choices.
Providing additional treatment in a timely manner has two requirements: a case definition for cattle that have failed to respond to the initial treatment and a designated time to make this evaluation. The timing of this evaluation is as important as the method of evaluation.
We have seen too many cases where the loss of an animal may have been prevented if additional treatment had been given in time. Records are required to make sure you evaluate cattle for success or failure at the appropriate time.
For example, scours therapy with oral fluids and electrolytes may be appropriate if the calf is getting up and nursing. However, if the calf is unable to rise, your protocol may call for intravenous therapy. Some scours cases may benefit from antibiotics, but not always.
As with treating too late, no magic potion compensates for delayed follow-up therapy.
If We Lost Some... Before blaming treatment response for a high death loss, determine if the problem was one of morbidity (number getting sick) or case fatality (percent of those treated that died). If 100 cattle are involved, a 3% death loss may be reached by losing three head out of 75 treated (75% morbidity, 4% case fatality) or by losing three out of 12 treated (12% morbidity, 25% case fatality).
In the first example, the problem was that a large percentage became ill. No change in treatment would likely improve the death loss in any future cases. In the second example, an unacceptable case fatality rate is combined with a lower morbidity. An appropriate response would be to consider your case definition, if the cause is appropriately identified and if the treatment is appropriate for the disease and the cause, which isn't necessarily infectious.
Making It Work None of the above will work without a commitment to a written plan shared with all involved and a resolve to write down what was done and what happened. We encourage you to routinely take a hard, honest look at your treatment practices.