Ticks

Like fleas, ticks are ectoparasites. They live on the skin surface of a ‘host’ and feed on their blood. The tick species in Australia that usually attack dogs and cats include the paralysis tick (Ixodes holocyclus), brown dog tick (Rhipicephalus sanguineus) and bush tick (Haemaphysalis longicornis). Paralysis ticks are deadly because they inject a paralysing toxin as they feed. This affects a dog’s muscles, including those that allow them to breathe. As many as 100,000 domestic animals annually are affected by the paralysis tick, with up to 10,000 receiving veterinary clinic treatment. Tick paralysis can also affect humans, especially children.

Ticks don’t jump or fly, so physical contact is the only method of transportation. They tend to lurk at the top of tall grass and shrubs waiting to attach or drop on to to a passing host. Once a paralysis tick has attached to your pet, it might be several days before symptoms show, but include: weakness of the legs (usually hind first) and loss of balance; vomiting or dry retching; unusual or laboured breathing; unusual bark – a different sound to normal. If your dog is showing any of these symptoms, see your vet immediately.

It depends how bad symptoms are. A dog will usually need to be hospitalised for administration of tick antiserum and monitoring, and in severe cases where there are breathing problems, oxygen and artificial respiration might be required. Symptoms often continue to worsen for a day or two after the tick is removed, before they start to improve. But not treated promptly, tick paralysis can be fatal.

There are several tick preventative products available. But even if you use them, it's still important to regularly check for ticks all over your dog’s body. Tick problems are more common in the warmer months, so if you live in a tick area, examine your dog every day.

The ticks above are 3-host ticks. This means that at each stage of life it feeds and then drops off the host and develops to the next stage. So that over a whole lifecycle (about a year) the tick will have three different hosts.

Stage 1 – eggs laid:
A female adult tick feeds on its host and becomes engorged. It falls off its host into the environment and lays thousands of eggs.

Stage 2 – larvae:
Eggs hatch to larvae, which look like very tiny versions of adult ticks, but only have 6 legs instead of the adult 8. They feed on a host, and then drop off into the environment.

Stage 3 – nymph:
Larva develops into a nymph - larger than the larva, but smaller than the adult tick (now has 8 legs). Nymph feeds, then drops into the environment.

Stage 4 – adult tick:
Nymph develops into an adult tick, attaches to a host and feeds.