TICKS

TICKS This past weekend my red healer started shaking his head and rubbing it against anything he could. So having a master degree in parasitology I immediately thought of ear tick or mite. I was right, looking into his ear with a flash light I found spinose ear ticks. These are the most common tick in NM in cattle and horses. This the first time I found them in a dog. It looks like this year may be a bad year for ticks, in livestock as well as companion animals. All stages of ticks are exclusively parasitic. Most ticks that attack domestic livestock are in the family Ixodidae, the group referred to as hard ticks. In the family Argasidae, soft ticks, there is one species that is damaging to cattle, the spinose ear tick. Historically the way to control ticks and their diseases was to use pesticides, acaricides, to kill the ticks and their infectious agents. Slowly many ticks are becoming resistant to the commonly used pesticides. Early removal of attached ticks is important in minimizing the risk of contracting tick-borne diseases. Acaricide choices are limited to diazinon, pyrethroids, carbaryl and avermectins. Dipping vats have been shown to be effective ways to treat cattle by making them walk through the acaricide baths but recent years have shown a decrease in this method except at the border for cattle fever tick populations. This is still a good option for dogs however. Applying the products with a high pressure sprayer or pour-ons are other options, as well as dusts. Ear tags were originally designed to be used against ticks and are still very effective in preventing infestations but the movement away from ear tags for horn fly control has lead to an increase in tick outbreaks on cattle. Vaccines have been shown to be effective in others countries against tick infestations but are not yet usable in the United States, hopefully one day they will be. Field management provides another way to control tick populations by eliminating stages of ticks not on the host by destroying or removing vegetation where ticks hide. Vegetation changes can be done by burning or clearing, ticks need cover to prevent desiccation from the heat. Eradication had been achieved before with the cattle fever tick, but not a possibility anymore due to the amount of time, money, personnel and resources needed to attack tick populations in the amount of force needed to completely rid the US of them. There are five major genus of ticks, but only four in Eddy County. Demacentor, include the American dog tick and is a three host tick, it must take three bloodmeals from three different hosts. American dog ticks are major pests of people and domestic animals. Adults will attack dogs, medium mammals, livestock and humans. Adults are most abundant in late spring and early summer. American dog ticks are a major vector (carrier) of Rocky Mountain spotted fever in the eastern US. The genus Rhipicephalus includes the brown dog tick and the brown ear tick. They are mainly found on mammals and sometimes on birds or reptiles. Brown dog tick prefers dogs and often infests houses, especially when dogs are kept inside. They cause considerable stress to owners and dogs that encounter thousands of them during summer months. The genus Amblyomma contain medium to large sized ticks that parasitize all terrestrial vertebrates. Important species include the Gulf Coast tick, the Lone Star tick, and the tropical bont tick. Not common to Eddy County but I have found a few. Rocky Mountain wood tick is an important pest attacking livestock and wildlife in western North America. They are the primary vector of Rocky Mountain spotted fever and Colorado tick fever virus. Lone star tick is one of the most notorious tick pest species in the US. All stages of the tick attack companion animals, livestock, wildlife, and humans. Deer are the primary hosts for the adults The spinose ear tick is in the genus Otobius, the adults do not feed but the young are found in the auditory canals (ears) of cattle, horses and most mammals including wildlife. Ticks have four stages of their lifecycle, egg, larvae, nymph and adult. All ticks feed on blood during some or all stages. Ticks have remarkably long lives with many surviving for one or more years without feeding. Hard tick females take one large bloodmeal after mating in which they swell and then drop from the host to lay hundreds to thousands of eggs. The female will then die after laying eggs. The male will feed repeatedly and mate several times before death. Soft tick females take repeated small bloodmeals and lay several batches of eggs after each feeding. They can go several months between feedings and typically mate off of the host, they are resistant to starvation. The spinose ear tick is very different in that the female does not feed, so they lay eggs without feeding. Feeding begins with the secretion of a cement-like substance during the first 2 days. The tick then gradually begins to feed and creates a new outer layer to accommodate the massive bloodmeal. Ticks transmit many microbial disease agents to livestock and companion animals. They also can be debilitating and sometimes fatal to the host. Heavily infested livestock and poultry may experience economic reductions that can be significant. Eddy County Extension Service, New Mexico State University is an equal opportunity/affirmative action employer and educator. All programs are available to everyone regardless of race, color, religion, sex, age, handicap, or national origin. New Mexico State University, U.S. Department of Agriculture, and the Eddy County Government Cooperating.