Ticks: Have mouth parts, will travel

Are white-tailed deer and migrating birds conspiring to ruin your life? It's possible. You can thank them both for doing their part in the spread of ticks to new areas.  

There are, of course, a few other reasons domestic animals and people are encountering ticks and the diseases they carry more often, such as reforestation, wildlife restocking efforts, Environmental Protection Agency regulations on environmental pesticides, and people's desire to live in places we haven't before, says Michael Dryden, DVM, MS, PhD. But the biggest cause, as he sees it, is the dramatic increase in the white-tailed deer populations in the United States.

Let's take a central state, Kansas, as an example. From the years 1905 through 1937, the white-tailed deer population is recorded as zero. According to Dr. Dryden, there are more white-tailed deer in the state of Kansas alone than there was in all of North America 100 years ago! 

Deer distribute the ticks by land, and the migrating birds deliver them by air mail. Cattle egrets, meadowlarks and more drop their tick bombs all along their way. The only thing that determines whether a tick population takes hold is whether the ticks can survive in the new environment. Humidity, low winter temperatures and the state of forestation are a few of the factors that can determine whether hitchhiker ticks can set up shop in a new place.

We know territories are expanding for several tick species and, as a consequence, the diseases they carry. The Companion Animal Parasite Council (CAPC) has resources to show you those territories-here's a link to more resources and information. So let's take a brief look at what these tick populations can leave in their wake, in addition to the heebie-jeebie factor.  

Amblyomma americanum (the lone star tick)

Quick tick fact!

Did you know that even though Ixodes scapularis is known commonly as the deer tick, Amblyomma americanum also depends on the white-tailed deer for its survival? Dr. Dryden even says that if you remove white-tailed deer from an area, the lone star tick can become extinct in that area within four to five years.

These assertive ticks actually hunt down their hosts-while most lone star ticks quest, that is, waiting on low shrubs, bushes and blades of grass, some will run toward their host instead of passively waiting for an opportunity. Scary stuff! Lone star ticks can transmit:

> Ehrlichiosis

> Rickettsiosis

> Tularemia

> Cytauxzoonosis

> Coxiellosis (Q fever)

> Heartland virus

> Bourbon virus

> Southern tick-associated rash illness (STARI) 

Lone star ticks can also, in rare cases, cause people to become allergic to red meat. Yikes!

Amblyomma maculatum (the Gulf Coast tick)

These ticks are the super-villains of the common tick world! They are large, ornate, aggressive and tough to kill. They are mostly a problem for cattle (causing gotch ear), but if a dog eats one, it can contract hepatozoonosis-an incurable, debilitating disease. They also can transmit rickettsiosis to people and tick paralysis to dogs and people.

Dermacentor variabilis (the American dog tick)

This tick may have “dog” in its name, but that doesn't matter much when it's looking for a blood meal. The American dog tick regularly infests urban wildlife, such as raccoons and squirrels-which means these ticks are probably in your backyard. What it can transmit:

> Rocky Mountain spotted fever

> Tularemia

> Cytauxzoonosis

> Tick paralysis 

Ixodes scapularis (the deer tick or blacklegged tick)

These sneaky, underhanded ticks may seem harmless, but actually carry some of the nastiest tick-transmitted diseases. The deer tick can transmit:

> Lyme disease

> Anaplasmosis

> Babesiosis (in people)

> And at least 2 newly recognized Borrelia species that are distinct from Borrelia burgdorferi (Lyme disease)

Quick tick fact!

The nymph stage of Ixodes scapularis is active in late May, June and early July, and the adults are more active in the fall and spring. It is the nymph that is responsible for most Lyme disease in people, while the adult ticks are primarily responsible for the disease in dogs. So you see a seasonal transmission pattern.

Did you know that Lyme disease is a Centers for Disease Control and Prevention (CDC) notifiable infectious disease in people? However, the Centers for Disease Control and Prevention postulates that only about 10 percent of cases are being reported to them. They do have 30,000 to 35,000 human cases of Lyme disease reported to them every year but think that about 300,000 people get Lyme disease every year! 

Rhipicephalus sanguineus (the brown dog tick)

First of all, let's get this straight-no, the common name does not mean that it only feeds on dogs that are brown! Second, this is the only tick that prefers to feed off of dogs during all of its life stages. Third, it can survive at much lower humidities than other ticks. It is the only tick species in North America that can infest buildings, including our homes. Brown dog ticks can transmit:

> Ehrlichiosis

> Babesiosis

> Rocky Mountain spotted fever

> Anaplasmosis (in Hawaii and the Caribbean)