Green ticks are dangerous, yes. The tick commonly called a “green tick” in Australia is the paralysis tick (Ixodes holocyclus), named for the greenish-grey color of its body when engorged with blood. It produces a potent neurotoxin that can cause ascending paralysis in humans and pets, and in rare cases, death. It is one of the most medically significant tick species in the world.
The paralysis tick is found along Australia’s eastern seaboard, from Cooktown in Queensland down to Victoria. This range overlaps heavily with where most Australians live, making encounters common, especially in bushland, coastal scrub, and even suburban backyards near these areas.
How the Paralysis Tick Causes Harm
Female paralysis ticks produce a family of neurotoxins called holocyclotoxins. These toxins interfere with nerve signaling at the point where nerves connect to muscles. Specifically, they block calcium from entering nerve terminals, which prevents the release of the chemical signals muscles need to contract. The result is a progressive, creeping paralysis that starts in the legs and moves upward through the body.
The toxin is injected through the tick’s saliva while it feeds. The longer a tick stays attached, the more toxin it delivers. This is why safe removal (and speed of removal) matters so much.
Symptoms and How They Progress
Symptoms typically appear 3 to 7 days after a tick attaches. The first signs are easy to dismiss: fatigue, mild flu-like muscle aches, and general weakness. Some people notice tingling or unusual sensations in the limbs. There is no fever, rash, or headache, which can make it tricky to connect these early symptoms to a tick bite.
Within hours to days, the weakness becomes more obvious. It starts in the legs, causing unsteadiness when walking, and then moves upward to affect the arms. Deep reflexes disappear. In severe cases, the paralysis reaches muscles involved in speaking, swallowing, and breathing. Respiratory failure is the most serious complication and can be fatal without intervention. How severely someone is affected depends on the number of ticks attached and how long they’ve been feeding.
Children Are at Higher Risk
Children are more vulnerable to tick paralysis than adults, largely because their smaller body mass means the same amount of toxin has a proportionally greater effect. In children, the typical pattern is an unsteady gait that develops over a day or two, followed by noticeable weakness in the legs that gradually climbs to involve the arms. A child who suddenly becomes wobbly or weak should be examined for an attached tick, particularly behind the ears, along the hairline, and at the back of the neck, where ticks are easily hidden.
Meat Allergy From Tick Bites
Beyond paralysis, tick bites can trigger alpha-gal syndrome, a serious and potentially life-threatening allergy to red meat and other mammal-derived products. When a tick bites, it can transfer a sugar molecule called alpha-gal from its saliva into your bloodstream. Your immune system may then flag this molecule as a threat. The next time you eat beef, lamb, pork, or other mammalian meat, your body mounts an allergic reaction that can range from hives and stomach pain to full anaphylaxis.
In the United States, the lone star tick is the primary species linked to alpha-gal syndrome, but in Australia, the paralysis tick has been associated with the condition. Not everyone who is bitten develops the allergy, and researchers still don’t fully understand why some people are affected and others are not. The allergy can persist for months or years after a bite, and repeated tick bites appear to increase the risk.
Other Infections Ticks Can Carry
The paralysis tick has been shown to harbor several potential human pathogens, including bacteria in the Rickettsia family. However, the actual risk of infection for a person bitten by this tick is still not well established. Research on ticks collected from the central coast of New South Wales confirmed the presence of these microorganisms, but how frequently they cause illness in humans remains an open question. The paralysis and allergic risks are currently considered more significant than the infectious disease risk for this species.
How to Safely Remove a Tick
The single most important rule: do not squeeze, twist, or agitate an attached tick. Disturbing a tick causes it to inject more saliva, and more saliva means more toxin and a greater chance of allergic reaction. The official Australian guidance is straightforward: freeze it, don’t squeeze it.
For adult ticks you can see, use an ether-containing freeze spray (available at pharmacies) to kill the tick in place on the skin. Spray the tick, let it die, and allow it to drop off naturally. Do not attempt to pick it out with household tweezers, fingernails, or tick-removal gadgets. Even levering the tick out with fine-tipped tweezers without killing it first is not considered safe, because this method does not prevent allergic reactions or anaphylaxis.
If you don’t have a freeze spray available, leave the tick undisturbed and get to a doctor or emergency department as quickly as possible for safe removal.
Danger to Dogs and Cats
Pets, particularly dogs, are highly susceptible to tick paralysis from the Australian paralysis tick. Signs usually appear 5 to 9 days after a tick attaches. You’ll notice weakness in the hind legs first, progressing to the front legs and eventually all four limbs. Australian cases tend to be more severe and faster-moving than tick paralysis in other parts of the world, with full paralysis of all legs developing within hours in some animals.
Other warning signs in pets include drooling, difficulty swallowing, regurgitation, changes in bark or meow, and jaw weakness. In severe cases, the muscles that control breathing can become paralyzed. Sudden deaths have also been reported in the weeks following apparent recovery, which is why veterinarians typically recommend a strict two-week rest period after treatment. If your dog or cat shows hind-leg wobbliness during tick season, a thorough tick search and prompt veterinary care are critical.