Dogs are at special risk after they have visited a tick-infested area, since the engorging ticks are rarely found until the dog is showing signs of intoxication. From the time of attachment of ticks to dogs, the earliest signs vary from 6 to 14 days with most dogs showing signs on the seventh day. Sometimes paralysis may occur 1-2 days after the removal of the engorged tick.
Paralysis tick antivenom, given intravenously, is the prime treatment, together with removal of all ticks. Generally, puppies require a smaller dose while old dogs and greyhounds need a higher dose.
Recommended supportive therapy includes atropine sulphate, antiemetics, antibiotics, fluid replacement therapy, respiratory stimulants and oxygen. Phenylbutazone helps mobilise larger dogs.
Death may be caused by cardiopulmonary compromise as well as paralysis of the respiratory muscles suggesting that consideration should be given to drugs and therapies to support the cardiorespiratory systems.
A recent survey found that only 5% of dogs taken to the vet died from tick paralysis and younger dogs were more likely to survive. It has been observed that tick virulence varies with geographic location and may vary as the season progresses with ticks being more virulent at the onset of the tick season and their ability to induce disease waning with time. Also, dogs may be more immunologically naive earlier in the season having had no tick exposure since the preceding season.
Dog owners need to be educated about the need for daily or twice daily searches for ticks and the correct use of preventative products.
(Reference: Atwell et al. 2001 Aust. Vet. J. 79: 412-418)
Contributed by R. Brooks. Last updated: January 2008
