Paralysis ticks Ixodes holocyclus (also known as dog ticks, shell-backs or scrub ticks) are found on the east coast of Australia. They can be fatal to your pets – once attached they release a toxin from their salivary glands that affects the animals central nervous system and causes paralysis. The biggest risk involves vomiting whilst upper airway muscles are paralysed which can result in them inhaling their vomit and lead to pneumonia.