Keep an Eye out for Fever Ticks

by Brodie Miller, DVM

In veterinary school we learned about reportable diseases and what our duties were related to these diseases as accredited veterinarians. It seemed that most of the focus, or at least what I retained, concerned the well-known disease programs such as brucellosis, tuberculosis, and equine infectious anemia. I, also, recall the emphasis placed on identifying signs of potential foreign animal diseases, such as foot-and-mouth disease, and on reporting suspicious cases to regulatory.

The importance of the Cattle Fever Tick Eradication Program was a subject I did not fully appreciate or understand when I started practicing veterinary medicine. While practicing, it was not uncommon to observe ticks on cattle, but the thought never occurred to me that those ticks could be cattle fever ticks. Perhaps this was a natural function of practicing in North Central Texas, where cattle fever ticks had not been an issue for generations.

Fast-forward ten years, after taking a position with Texas Animal Health Commission in south Texas and being thrust onto the front lines, I now have a much greater appreciation for the battle being waged by ranchers and regulatory agencies against this dreaded pest. Since May of 2014, cattle fever tick infestations have been discovered in several counties located well outside the permanent quarantine zone, which is located along the Texas-Mexico border from Val Verde County to Cameron County. The reasons for these infestations are multifactorial and include weather patterns, livestock and wildlife hosts bringing fever ticks into the state from Mexico and then contributing to their spread, and the fact that livestock and wildlife are regularly transported long distances on trailers across Texas.

The most recent fever tick Control Purpose Quarantine Area (CPQA) was established in Live Oak County after an authorized veterinarian observed an uncommonly heavy tick infestation on cattle he was evaluating. Fortunately, the veterinarian had the awareness and foresight to collect a number of these ticks and contact Texas Animal Health Commission (TAHC) to determine if they were cattle fever ticks. The TAHC laboratory confirmed the ticks as cattle fever ticks on Nov. 30, 2016. The resulting quarantine and inspections of nearby livestock herds revealed seven additional infested premises in Live Oak County, leading to the establishment of a CPQA consisting of more than 61,000 acres and impacting 270 landowners.

Fever tick infestations and resulting quarantines have a significant economic impact on the affected producers. Given the life cycle of the cattle fever tick, infested quarantines generally last a minimum of 15 to 18 months. Quarantines involve periodic inspections of livestock and wildlife, as well as treatment for ticks prior to moving from the area. While quarantines are a temporary, yet substantial, hardship for affected landowners and producers, the potential ramifications of not identifying and addressing cattle fever tick infestations quickly could be devastating to Texas cattle industry, especially if interstate movement restrictions, such as dipping, were imposed.

Texas veterinarians are the first line of defense the state has in protecting the heath and marketability of its livestock. TAHC asks all Texas veterinarians to be vigilant in checking cattle, equine and deer for cattle fever ticks. With authorized veterinarians being on the lookout for this tick in the course of their daily duties, they become a force multiplier for USDA and TAHC, better enabling us to address infestations earlier and thereby reducing the impact on Texas ranchers and the livestock industry. To help in this endeavor and to raise awareness, the TAHC is offering a cattle fever tick continuing education program. For more information regarding this CE, visit the TAHC Veterinary Authorized Personnel webpage at http://www.tahc.texas.gov/vets/authorized/.