CALF_News_October_November_2019

16 CALF News • October | November 2019 • www.calfnews.net CALF ANIMAL HEALTH Chuteside Manner EXPLORING THE FRONTIER OF ANIMAL HEALTH Tetanus An Ancient Disease in Modern Times By Patti Wilson Contributing Editor S ome of the most persistent and brutal diseases on earth seem to be those that have been with us since the begin- ning of recorded history. Rabies and malaria are examples of stubborn pes- tilence that refuse to go away. Another malady we continue to battle is tetanus. Nearly every mammal is susceptible, and every livestock producer needs to manage for it. I am betting that our readership first learned the word tetanus from our moth- ers.“Don’t step on a nail,” they warned as we headed out the door, barefoot, on a hot summer day.“You’ll get tetanus!” Because of improved health care in the United States, vaccinations have become routine. Thankfully, they are effective. So much so that many of us now take this deadly disease for granted. Our livestock are not always as well served. LEFT: Housing young cattle in clean pasture conditions reduces the risk of tetanus infection after spring brandings. Above all, vaccinate faithfully. A brief history According to the National Vaccine Information Center, the first clinical description of tetanus dates back to records from the fifth century BC. It was 1884, however, before legitimate scien- tific experiments were able to isolate the disease and study it. Initially, important discoveries about tetanus were made in Italy and Ger- many. In 1889, a Japanese bacteriologist determined that it could grow only in anaerobic (no oxygen) conditions and confirmed its ability to affect various species of mammals. By 1900, pharma- ceutical companies began developing antitoxins against tetanus. They were largely produced in horses, who were bled to harvest their blood serum. A fortunate circumstance grew from the timing of these discoveries; the anti- toxin serum was widely used on injured soldiers in World War I. Ground troops suffered wet, unsanitary conditions in trench warfare. Shrapnel wounds were a common injury and conducive to the tetanus bacteria. Military physicians began to use the antitoxins freely, even experimenting with its use in varying strengths and number of doses to help prevent and overcome tetanus in the battlefield. As a result, many soldiers suffered from serum sickness and allergic reactions from the antiserums. An effec- tive vaccine, tetanus toxoid (TT), was not available until 1938. Tetanus vaccination programs in the United States have reduced reported tetanus cases from 601 in 1948 to just 20 in 2018. Across the species There are several items to note in the characteristics of tetanus. The most sus- ceptible individuals to contract the pain- ful disease are humans, horses and lambs. Cattle follow closely behind, with higher incidences in warmer climates. Our cats and dogs do better, they are somewhat immune, while birds are not affected. The bacterial spores Clostridium tetani prefer living in cultivated soil and intes- tinal tracts, and are closely related to the clostridial bacteria causing blackleg. Tetanus spores are highly resistant to heat and disinfectants, making them impossible to eradicate. Puncture wounds are a perfect route for the spores to take hold, especially when a small particle of soil or foreign matter is left. Sheep and cattle suffer additional risk through banding, docking and castration. Likewise, calving cows run risks when giving birth in dirty lots or when unclean equipment is used to pull calves. The Mayo Clinic website states that gunshot wounds are a risk factor in con- tracting tetanus. It seems, however, if one is shot, that individual has better things to worry about than tetanus bacteria. What does it look like? Incubation for tetanus varies from three days to several months, but usually