"Tick season" is a useful phrase for parts of Australia. It's not a useful phrase for Brisbane.
Research comparing tick paralysis case data across the eastern states found that Victoria genuinely has two distinct seasons, separated by a proper winter gap. Queensland and New South Wales don't work that way. Temperature and moisture vary less across the year here than they do further south, and the tick population reflects that. There isn't a season with a quiet period built in. There's just a threat that doesn't fully switch off.
What the life cycle data actually shows
The paralysis tick, Ixodes holocyclus, moves through three life stages: larva, nymph, and adult. Studies describe the species as active throughout the year, with the peak activity of each life stage overlapping the others. Different stages rise and fall at different times, but because those windows overlap, there's no month in South East Queensland where the population simply disappears.
Case numbers still move up and down. An analysis of emergency hospital data from South East Queensland and Sydney's Northern Beaches, covering 2009 to 2023, found that weather conditions are what largely explain how heavy a given year's tick paralysis load turns out to be, not a fixed calendar pattern. Some years are quieter than others. None of them are tick free.
Why this matters here more than most places
Distribution modelling out of the University of Queensland's Department of Parasitology has mapped where I. holocyclus can establish, based on climate suitability, and confirmed its range runs the length of the eastern coastal strip, from northern Queensland to Victoria, with humidity and rainfall as the deciding factors rather than temperature alone. Brisbane sits well within that range.
The same research group has modelled how that range is likely to shift as the climate changes. Their projections don't point to the risk easing off. If anything, the conditions the tick needs to survive look set to persist, or spread further, across parts of its current range through to 2090. That's a reasonable basis for treating prevention as a permanent part of pet care here, not a seasonal top-up.
What this means in practice
If there’s no reliable quiet period, there’s no reliable time to ease off protection. In practice, that looks like:
- Tick prevention on a strict, ongoing schedule, all twelve months, not just spring through summer
- A physical check as a year-round habit, not something that starts when the weather warms up
- Treating a missed or late dose as a genuine gap in cover, whatever month it happens to be
The bottom line
Queensland doesn't get a break from paralysis ticks. The case data, the life cycle studies and the distribution modelling all point the same way. If prevention has been something you start in spring and wind back over winter, it's worth adjusting that habit. Year-round cover isn't overcautious. It's simply what the evidence supports.
Frequently Asked Questions
Is there a tick season in Brisbane?
Not in the way southern states have one. Queensland and New South Wales run one continuous period of tick activity, unlike Victoria, which has a genuine two-season split with a real gap in between. In Brisbane and South East Queensland, there’s no reliable quiet period.
When are paralysis ticks active in Australia?
Year round in South East Queensland. The tick’s three life stages have overlapping peak activity windows across the calendar, so some stage of the population is active in every month.
Do dogs and cats need tick prevention all year in Queensland?
Yes. Because there’s no consistent gap in activity, prevention needs to run on a strict, ongoing schedule for all twelve months. A missed dose in winter carries the same risk as a missed dose in January.
What makes some years worse for tick paralysis than others?
Weather. Case data from South East Queensland and Sydney’s Northern Beaches, spanning 2009 to 2023, shows weather conditions largely explain how heavy a given year’s case load is, rather than a fixed calendar pattern.
Where in Australia do paralysis ticks live?
Along the eastern coastal strip, from northern Queensland to Victoria. Humidity and rainfall are the limiting factors, not temperature alone, which is part of why Brisbane’s climate suits the species so well.
Will paralysis tick risk change with the climate?
Climate suitability modelling out of the University of Queensland projects that the conditions the tick needs are likely to persist, or expand, across parts of its current range through to 2090.
References
- Barker, D. & Barker, S.C. Climatic suitability of the eastern paralysis tick, Ixodes holocyclus, and its likely geographic distribution in the year 2050. Scientific Reports (Nature), 2021.
- Barker, S.C. et al. Two seasons of tick paralysis in Victoria yet one season in Queensland and New South Wales, Australia. International Journal for Parasitology, 2022.
- Barker, S.C. et al. The weather determined how “hot” the tick paralysis season was in eastern Australia: 2018–2024. Veterinary Parasitology, 2024.
- Barker, S.C., Department of Parasitology, School of Chemistry & Molecular Biosciences, The University of Queensland. Climatic requirements of the eastern paralysis tick, Ixodes holocyclus, with a consideration of its possible geographic range up to 2090. International Journal for Parasitology, 2021.
