OAKEY: A BLUE HEELER WITH A PARALYSIS TICK

Oakey is an old Blue Heeler that is very much loved by her Mum and Dad and as such is taken everywhere they go. During the festive season this year the family set off to visit relatives in Brisbane however on their return and unbeknown to them Oakey has picked up a Hitch-Hiker.
Not long after returning home Oakey started to vomit and then became weak in the hind legs so that within 24 hours she could no longer use her hind limbs. When presented we found she was depressed but generally in good condition except that she was unable to use her hind legs. During the examination we found a gun-metal grey coloured tick near one of her lips. The characteristics of this tick are:

• Small head
• All the legs are near the head
• Is a gun-metal grey colour
• Has a distinct anus
• And paralyses animals

This makes this tick a member of the Ixodes family which are the paralysis ticks.

The Ixodes tick is known by a number of different names in different areas of Australia. It may be referred to as the paralysis tick, bush tick and sometimes marsupial tick however the former probably best describes. This particular tick requires very specific environmental conditions to survive and reproduce and is therefore not found everywhere. In our local area of Bundaberg we do not have suitable condition and therefore do not see the tick. The only area they are found in this locality is along the Baffle Creek. Although no found locally we see the tick on a regular basis as it is found at the base of the Great Dividing Range from Kennelworth through to New South Wales as far as Casino; the tourist strip of South East Queensland.

Similar to all ticks the Ixodes has a life cycle that involves an egg, lava, nymph, adult life cycle. The tick is often found on native marsupials especially bandicoots and possums where is has little effect on the animal. Once the nymph has moulted and become an adult, then problems can arise. If the adult tick attaches to a non-native then it can cause illness or death. Once the adult tick has been one the animal and sucking blood for about 5 days it starts to release sufficient toxin to affect the nervous system. This is initially seen as staggering and classically a change in vocalisation. As more toxin is released the animals start to vomit and become ataxic and finally are paralysed in the hind legs. Death results if the respiratory muscles become paralysed or because of the effect on the larynx some animals die because they aspirate food or water and damage their lungs.

The tick affects dogs, cats, calves, foals and fawns.

The classic poisoning that we see is the dog that returned home about 5 to 10 days ago from a trip south and suddenly starts to vomit and shows weakness of the hind leg occasionally have an abnormal bark and we are able to find a tick. Occasionally we do not find the tick because it has already dropped off the dog however these ticks leave a characteristic ulcer behind which usually takes several days to heal.

To prevent poisoning there are some simple rules to follow.

1. Find out if you are going to be in a Ixodes area by asking your local vet before going on holidays, asking a vet who practices in the area you are holidaying, or ask the people where you are staying or their neighbours.
2. Each day search the dog for ticks and double check in hiding places such as the ears and between the toes.
3. Use a tickicide that is registered for paralysis ticks such as Frontline spot ons or spray, or Proban but remember to use your fingers and check each day.
4. Continue to check each day when you return home for at least 10 days.