Ticks in Colorado

Ticks like to attach to warm places, like the arm pit.

Ticks are blood-feeding parasites and attach themselves to animals and occasionally people. They can be found throughout Colorado and are common at higher elevations. A few varieties affect humans. These ticks have a life cycle of four stages: egg, six-legged larva or seed tick, nymph and adult. Avoid dense foliage when camping or hiking and always do a tick check.

Definition

Colorado has about 30 species of ticks. Hard-shelled ticks from the Ixodidae family are very common. This kind of tick attaches itself to a host, feeds for several days, becomes bloated and drops off. Soft ticks from the Argasidae family are not as common. They can be found in the nests built by their animal hosts. Most of these ticks feed sporadically, for a few hours at a time.

Types of Ticks

Common ticks found in Colorado are the winter tick, which attaches itself to deer, elk and large domestic animals; the Rocky Mountain wood tick, found on small rodents, porcupines, deer, large domestic animals and humans; D. parumapertus, on jack rabbits; the American dog tick, found on rodents, dogs, raccoons, small animals and sometimes people; the rabbit tick, which feeds on rabbits; Ixodes cookei, found on rodents, carnivores and occasionally people; I. kingi, on prairie dogs and the like; I. sculptus, which attaches to burrowing rodents and their predators; I. spinipalpis, which go for rabbits, wood rats and peromyscus mice; I. texanus, found on weasels and martens; ornithodoros hermsi, on chipmunks, rock squirrels and small rodents; and the brown dog tick, which feed on dogs, people and can reproduce in the home.

Diseases and Repellent

Colorado tick fever is the most common disease transmitted by tick. About 100 cases are reported a year in Larimer, Boulder, Jefferson and Gunnison counties. April, May and June are the peak months of the year for the fever.

Rocky Mountain spotted fever, even though it's named for the area, isn't common in Colorado. Ticks can also transmit tularemia and relapsing fever. Tick paralysis is a rare condition from tick parasites that occurs when a tick is attached for a long time and causes an ascending paralysis. Symptoms include difficulty walking, limb numbness and difficulty breathing. The condition is reversed when the tick is removed.

How to Avoid and Remove a Tick

Ticks are active in spring and early summer. Brush and grassy areas along fields and trees should be avoided. Wear long sleeves, long pants and pull socks over pant legs.

Apply an insect repellent with DEET to the skin and clothing. Don't use high concentrations on children. Another tick product is permethrin. Apply it to clothing, but not to skin.

Do tick checks after an outdoor excursion. Ticks take up to 24 hours to begin feeding. Grasp the tick with tweezers or plastic-covered fingers, pull the tick straight away from the skin without smashing it. Disinfect the area.

References

• Colorado State University Extension; Colorado Ticks and Tick-Borne Diseases; W.S. Cranshaw and F.B. Peairs; May 2010
• Colorado State University; Ticks in Colorado; Joe Julian