If you live anywhere in the Northern Rivers, chances are you’ve been bitten by a tick.
There’s also a good chance that you’ve found them on your pets and have even had to race one to a vet on occasion for treatment.
Ixodes holocyclus, commonly known as the Australian paralysis tick, is one of about 75 species of Australian tick fauna and is considered the most medically important.
It can cause paralysis by injecting neurotoxic venom into its host. It is usually, but not always, found in a 20-kilometre-wide band following the eastern coastline of Australia. This area also contains the majority of Australia’s most densely populated regions – doesn’t that give you the ticks?
The natural hosts for the paralysis tick include koalas, bandicoots, possums, and kangaroos, but other earthlings have to deal with this tiny little succubus – within this range Ixodes holocyclus is the tick most frequently encountered by humans and their pets.
Prevention is best for pets
According to Dr Russell Grigg, senior veterinarian at MyVet Byron Bay, as a rough guide, July to February is the main ‘season’ that we see tick paralysis patients. ‘However, I have seen cases of tick paralysis outside of these months every year for the past 20 years,’ says Dr Grigg.
But more than any other important information is that prevention is much better and cheaper, than the cure.
Dr Grigg says paralysis tick control was hit and miss until the last couple of years.
‘Now we have effective control methods. For dogs there are now two easy-to-administer products that are very effective at tick control – they are flavoured oral tablets; one is a once-a-month chewable tablet and the other is once-every-three-months chewable tablet. I recommend that every dog be on either one of these products.’
Dr Grigg says that for cats there is a once-every-three-month on the back-of-the neck liquid.
Dr Lauren Archer from North Coast Veterinary Services agrees that paralysis ticks typically start becoming more prevalent as the winter weather winds up. ‘This late winter period is also when we see young livestock being affected by paralysis ticks.’
Dr Archer says her prevention preference is for an oral product. ‘Many dogs swim in this area and collars or top spots can wash off with frequent swimming. We also have much easier-to-use preventatives for cats now – previously preventing tick paralysis in cats was very labour and chemical intensive; with new generation products the frequency of chemical usage is decreased and more cats can be protected.
And the cure?
Why is prevention better than the cure? Apart from the obvious reason being the stress caused to your pet, the cost of tick treatment is a bomb.
Dr Archer says that tick paralysis necessitates the use of an anti-venom specifically made for ticks. ‘This can be an expensive part of the process of treatment. The other expensive part is the intensive supportive care and monitoring some patients require. With tick paralysis cases most people would be looking at $1,000–1,500 minimum; however, severely affected patients can require 24-hour care and even a ventilator to keep breathing. These patients have been known to cost $5,000–10,000 or more at the emergency veterinary clinics to pull them through.
Dr Grigg says tick-paralysis treatment costs can vary widely as the disease is complex and life threatening and usually involves varied time in hospital on intravenous fluids and at times nasal oxygen supply. ‘The cost can vary from up to $1,000 for treatment without complications to anywhere up to $30,000. This has happened at the Gold Coast emergency clinics on a few occasions with dogs in intensive care on life support for extended periods.
‘Even with tick-paralysis treatment animals are often in a critical condition and can die during treatment. I tell my clients that the best thing to do is give the preventive chewy tablets and often advocate all-year-round management.’
Both Lauren and Russell say that cats and dogs are the most common patients they see affected by tick paralysis, but Lauren has treated a peacock, goats, sheep, a calf, and several miniature horses as well. ‘Native wildlife are much more resistant to the tick toxin because they co-evolved, but even these guys occasionally get overwhelmed by paralysis ticks.’
Russell says that he sees a handful of animals a year that are in quite advanced stages of tick paralysis by the time their carers bring them to the clinic for help. ‘Their body life-support systems are in very serious trouble. Saving these animals’ lives is very difficult and mortality rates are often high. These animals are always not on any prevention medication or have just lapsed with the treatments.
‘Since the introduction of the preventive tablets we are seeing probably 80 per cent less the usual annual number of dogs with tick paralysis symptoms needing medical treatment. So, in numbers we saw about 30 cases last tick season as compared to 150 cases in previous years.
No prevention for humans
Animals aren’t the only earthlings who can be affected by old mate ixodes.
While the jury is still out on the occurrence of Lyme disease in Australia, there are certainly instances of tick typhus in humans during the warmer months.
Allergy is yet another huge problem when it comes to ticks and Associate Professor Sheryl van Nunen from the Australasian Society of Clinical Immunology and Allergy (ASCIA) says that humans can suffer life-threatening allergies from tick bites.
‘Tick-induced allergies comprise large local reactions at the site of the tick bite; mammalian meat allergy after tick bite (MMA); tick anaphylaxis; mammalian meat allergy limited to gut symptoms; and FCIES (food carbohydrate-induced enterocolitis syndrome).
Van Nunen says that tick anaphylaxis only occurs when you are bitten by an adult tick. Nymph bites alone, however, can cause MMA.
Van Nunen says 35 per cent of people living in tick hyperendemic regions develop alpha-gal (galactose-alpha-1,3-galactose) specific-IgE. Of those, a little over eight per cent will have MMA. ‘Prevalence highest in the world is in Sydney basin (113/100,000).’
Tick anaphylaxis is 1/100,000 prevalence. Worldwide there was only one case some years ago reported in USA, one Frenchman, two Spanish goatherds, and 12 individuals in Japan with one presumed fatality in Japan.
‘I’ve seen more than 300 tick anaphylaxis sufferers,’ says van Nunen. ‘Gut symptoms are common, especially in children, but FCIES rare with 1/300 mammalian meat reactors.’
Van Nunen says that there were four fatalities from tick anaphylaxis reported from 1997 till 2013. There have been two deaths from mammalian products which are used in medicine. Both fatalities were caused by an anaphylactic response to murine, a (mouse)-derived cancer medicine in Australia. Alpha-gal is the precise allergen in the mammalian meat people react to in MMA.
‘For MMA you don’t develop this allergy without being bitten by a tick,’ says van Nunen. ‘Not everyone develops the allergy when bitten by a tick. If you do develop MMA after tick bite and you are bitten again by a tick your allergy levels can more than double (our research published last year) and if you don’t have another tick bite you can see a great reduction in your allergy levels over 18 months to 2 years and some can lose their MMA after 3–4 years.
The tick mantra
Van Nunen, whose role is diagnosis and patient education, says she is still seeing many people with these allergies, as are her colleagues.
‘Tick-induced allergies are the allergies you don’t have to have,’ she says. ‘Because, unlike with any other allergy, we know what causes them.
‘The mantra are: If you live, work, or play in tick-hyperendemic areas then:
- don’t scratch anything you can’t see (because it could be a tick)
- don’t disturb a tick (because she will squirt allergen into you)
- treat your backyard
- dress for the occasion
- kill the tick where it is
- dab it, don’t grab it for nymph and larval ticks (permethrin cream)
- freeze it, don’t squeeze it for adult ticks
Remember household tweezers are tick squeezers!’
(I have removed ticks myself with household tweezers. It’s tricky, but in an emergency, it can be done!)