Watch out! This years severe tick season has depleted our national antivenom stockpile, and manufacturers are struggling to keep up with demand. The current weather pattern is doing more than just filling the dams; it’s nurturing a thriving a tick population, and paralysing our pets in unprecedented numbers. Is this a sign of climatic things to come?
Over the last decade of El Nino, tick numbers have been suppressed by long, hot, dry spells that kill baby ticks. In contrast, the current La Nina and Indian Ocean Dipole weather patterns have resulted in regular heavy rain over the entire Eastern sea board, and a booming tick population.
The Australian Veterinary Association today issued a warning regarding nationwide shortages of tick serum, the main weapon in the treatment armoury for animals struck down with tick paralysis. Manufacturers report this is partly due to extremely large numbers of cases currently occurring, particularly along the Eastern seaboard.
There are also reports that ticks this year have been unusually toxic with vets forced to use higher doses of antivenom. It’s likely that environmental conditions like the weather, would impact not only on tick numbers but also on their physiology. Just as the toxicity or nutritional value of plants can vary due to growing conditions, potency of insect venom may be similarly influenced by the environmental factors.
I can confirm that Byron Shire’s tick season has been unusually severe with more ‘tick immune’ animals going down, and unusually high frequency of life-threatening complications. We have seen more cases of secondary aspiration pnemonia and pulmonary oedema, with more animals ending up on oxygen support.
Protracted recovery, taking a week or more, and sudden and unexpected death, many days after almost full recovery, have also been observed. This is presumed to be cadiomyopathy – weakening of the heart muscle. Usually mortality rates are only about 3%, this year may be 5% or higher. If we run out of antivenom, death rates could surge to 30% or more.
Such complications result in longer hospitals stays and a greater financial and emotional cost for pet owners. It’s more taxing for vets aswell given the difficulties predicting which animals will respond well and which will succumb, despite treatment.
Some manufacturers are predicting that shortages may ease in January and February as tick populations decline through natural attrition. Until then It’s probably worthwhile upping your tick prevention strategies.