Paralysis tick (Ixodes holocyclus)
An Australian tick whose toxin causes progressive paralysis in pets. Without rapid vet treatment, often fatal. Preventable.
Ixodes holocyclus, the Australian paralysis tick, lives along the east coast from north Queensland to eastern Victoria. The female tick injects a neurotoxin in her saliva that causes ascending paralysis — weakness starting in the back legs and moving forward, eventually paralysing the respiratory muscles.
Signs typically appear 3–7 days after attachment: change in bark or meow, weakness on the hind legs, vomiting, regurgitation, difficulty swallowing, laboured breathing, eventually collapse. Time from first signs to respiratory failure can be hours.
Treatment: emergency vet visit, tick search and removal, anti-tick serum (an antibody therapy), supportive care that may include sedation, IV fluids, oxygen, and sometimes mechanical ventilation. Even with treatment, mortality is around 5%. Without treatment, mortality is much higher.
Prevention is non-negotiable for east-coast Australian pets: monthly chewables (Bravecto, NexGard, Simparica), spot-on products, or some long-acting collars. Daily tick searches after walks — particularly head, ears, face, neck, between toes. The tick is small (sesame-seed size) and easy to miss.