A message from Dr. Roger Thomas, Thomas & England Veterinary Service –
This is a blood infection spread by ticks. The organism attaches to the red blood cells. The immune system cannot remove the organism from the red blood cells so instead it attacks the entire red blood cell destroying it. Symptoms are weakness, weight loss, abortion, labored breathing, jaundiced (yellow) tissues (inside of mouth, whites of eyes), etc. In areas that the cattle are more naive to this organism (and this area is considered more naive because there is not as much of a constant exposure to the organism), many animals will show illness only 1-2 days before death and it is too late to treat by the time symptoms show. The organism has already been in the body for 30-100 days by the time the animal appears ill. All animals can have the organism in their body however usually cattle that are 5 years old or older are the ones that show clinical disease. Treatment consists of a broad spectrum antibiotic, however when the animal is showing clinical disease, mortality rates are near 100 percent even with treatment.
Prevention is the key. A mineral containing 4000 grams/ton of CTC (Chloratetracycline) should be fed throughout the vector (tick) season. Minerals can be found commercially available that contain this level or above. An alternative method is adding 2 lbs. of CTC 50 per every 50lb bag of mineral. Getting the mineral out early in the vector season is crucial however getting it out now is better than not at all.
Remember, unfortunately with this disease by the time you notice them sick it is almost always too late to effectively treat and save the animal. Older cows that are under stress (pregnant or lactating – which is almost every cow) are the ones at greater risk. This level of CTC in mineral should be fed throughout each summer. It will also aid in the prevention of pinkeye and foot rot.