By James Wright
Promedmail.org reports that the Texas Animal Health Commission (TAHC) confirmed the presence of cattle fever ticks in Live Oak County in November. Cattle fever ticks are a significant threat to the United States cattle industry because they are capable of carrying microscopic parasites that attack and destroy the red blood cells of affected cattle, causing acute anemia, high fever, and enlargement of the spleen and liver, ultimately resulting in death for up to 90 percent of susceptible naive cattle.
Texas cattle fever has a rich history and caused a great deal of conflict during the period in the late 1800s when Texas longhorn cattle were being moved north to railheads in the Midwest. Some Missouri farmers, fearing for the safety of their cattle, instituted what came to be known as the “shotgun quarantine” to prevent the Southern cattle from moving across their land. That pushed the cattle drives west to frontier towns like Dodge City.
Dr. Daniel Salmon, a veterinary surgeon of the period, studied the disease and determined that transmission could not be explained by any known mechanism at that time. In 1885, Salmon established the Bureau of Animal Industry’s (BAI) veterinary experiment station, and he hired Fred Kilborne, an agricultural scientist, to head it. BAI was a pre-cursor of the U.S. Department of Agriculture.
Kilborne believed that the distribution of Texas cattle fever coincided with that of cattle ticks. Kilborne, Dr. Theobald Smith (a pathologist and epidemiologist) and Dr. Cooper Curtis (a veterinarian) investigated the disease in a well-designed experimental study carried out on the BAI’s research farm. They proved that Texas fever was transmitted from cow to cow by ticks, and this was the first demonstration of a vector-borne disease.
Texas cattle fever is considered to be a foreign animal disease in the United States today. Keeping this disease out of the country by constant monitoring for the tick responsible for transmission requires continued vigilance on the part of producers, private practice veterinarians, and state and federal veterinarians.
There is a permanent Texas cattle tick quarantine zone, where ticks still are well established, between Texas and Mexico. This 500-mile-long zone ranges from 200 yards to 10 miles wide along the Rio Grande River from Devils River to the Gulf of Mexico. Unfortunately, it appears that this zone will have to be expanded. The infested premises in Live Oak County is located approximately 110 miles outside of the Permanent Fever Tick Quarantine Zone.
With the addition of Live Oak County, there are now four Control Purpose Quarantine Areas (CPQAs) outside of the Permanent Fever Tick Quarantine Zone, located in Jim Wells, Kleberg and Willacy counties. At present, there are approximately 450 000 acres under various types of fever tick quarantine outside of the Permanent Quarantine Zone, including a Temporary Preventative Quarantine Zone in Cameron County. Read more HERE or HERE.