One of the major issues I address with producers is a way to quantify how sick a pen or individual calf is. A helpful system that we implemented is a clinical illness score (CIS) system. This numerical system allows a producer to quantify a calf at the chute and also gives us a means of retrospectively evaluating a pen of calves.
The system I use consists of a CIS scale of 1 to 4.
2: A calf that—while not obviously ill—is, in the pen rider’s mind, worth taking a trip to the chute to be evaluated further.
3: A calf that is obviously ill and needs treatment.
4: A calf that is moribound and needs to be removed from the pen immediately to go to a hospital or be humanely euthanized.
Treatment standards. To further evaluate these animals, a rectal temperature is taken. Although I am not a believer in temperature being the holy grail of diagnostics, I think it can have its place. Keep in mind that on a normal Midwest July day all the cattle will have temperatures above 104°F!
Within this system, I use temperature to help determine the status of my CIS 2 class of cattle. A CIS 2 has to have a temperature of 103.5°F to receive treatment. Work with your veterinarian to set this parameter, as it may change seasonally or in the face of an outbreak. To clarify, a CIS 2 with a temperature of 101°F would not be treated; a CIS 2 with 105°F would be. A CIS 3 is treated regardless of temperature. A variation of this would be to lower the class of antibiotic given to CIS 2 animals that are below the temperature cut off.
Although there is nothing magical about this system, it gives a more objective assessment for pen riders. Research reveals there is poor agreement between pen riders on what qualifies an animal’s need for treatment. About 60% of cattle called sick are agreed upon.
Of the cattle that are called sick, only about 60% are really ill, and, of those, only about 60% are identified. In short, we are not very good at determining if a calf is ill, and there is no gold standard to determine if you were right or wrong.
Think about this example: a calf is called sick and treated, and the next day looks normal. Was this a treatment success or a misdiagnosis because the calf was never ill? I encourage everyone to keep a treatment log and have a column for CIS. Use the systematic approach and see if it helps to more objectively treat sick cattle.