may vary depending on the species of tick. Unlike Lyme disease, ehrlichiosis, and babesiosis, which are caused by the systemic proliferation and expansion of parasites in their hosts long after the offending tick is gone, tick paralysis is chemically induced by the tick and therefore usually only continues in its presence. Once the tick is removed, symptoms usually diminish rapidly. However, in some cases, profound paralysis can develop and even become fatal before anyone becomes aware of a tick's presence. Diagnosis Diagnosis is based on symptoms and upon finding an embedded tick, usually on the scalp. In the absence of a tick, the differential diagnosis includes Guillain–Barré syndrome. Early signs of tick poisoning could be a change of an animals' ‘voice’, weakness in the back legs or vomiting. Prevention No human vaccine is currently available for any tick-borne disease, except for tick-borne encephalitis. Individuals should therefore take precautions when entering tick-infested areas, particularly in the spring and summer months. Preventive measures include avoiding trails that are overgrown with bushy vegetation, wearing light-coloured clothes that allow one to see the ticks more easily, and wearing long pants and closed-toe shoes. Tick repellents containing DEET (N,N, diethyl-m-toluamide) are only marginally effective and can be applied to skin or clothing. Rarely, severe reactions can occur in some people who use DEET-containing products. Young children may be especially vulnerable to these adverse effects. Permethrin, which can only be applied to clothing, is much more effective in preventing tick bites. Permethrin is not a repellent but rather an insecticide; it causes ticks to curl up and fall off the protected clothing. Treatment Removal of the offending tick usually results in resolution of symptoms within several hours to days. If the tick is not removed, the toxin can be fatal. A 1969 study of children reported mortality rates of 10 – 12 percent, mostly due to respiratory paralysis. The tick is best removed by grasping it as close to the skin as possible and pulling in a firm steady manner. Because the toxin lies in the tick's salivary glands, care must be taken to remove the entire tick (including the head), or symptoms may persist. It is important to note that, unlike the toxin of other tick species, the toxin of Ixodes holocyclus (Australian paralysis tick) may still be fatal even if the tick is removed. For affected animals, food and water intake can worsen the