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This article was published in 1942
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.

AN UNUSUAL TYPE OF TICK FOUND ON SHEEP

(Amblyomma triguttatum).

H. YEOMAN. Stock Inspector, Moree.

Unusual seasons, such as droughts, bring along new diseases and parasites, and a new type of sheep tick came under my notice during the height of the recent drought and at midsummer time.

In this case the sheep, mainly ewes—1,700 in all—came over from Queensland some months prior to the ticks being seen and, when seen, the parasites were in fairly large numbers on affected sheep and a big number of sheep had them on.

To me the tick was as near as possible to what I know the Scrub or Coastal Tick is, and, when engorged, just as found on cow's udders or on dogs, it was the same shape and same colour as this type of tick. When specimens were sent to Glenfield no surprise was expressed about this new parasite and they had a name for him at once.

The tick appears to make its abode on the sheep, round about the top portion of the face, around the ears and inside and outside of the ears. They evidently fall off the sheep when engorged and leave a small pin hole; in some cases around this site is found a hard pea-like swelling.

From what I can gather the above sheep had been closely examined some three months prior to the tick being found and no parasites were seen at that time, and when I saw the sheep the ticks were mostly engorged and had dropped off. Prior to me seeing the infected sheep, the owner stated that the sheep were greatly worried and he claimed that at least 30 had died from the tick worry. I am not of the opinion that any sheep died of the tick bite, but from other causes.

All sheep, when I inspected them, were fat, and on examining the heads of any animal that may have had the tick on, the small pin holes or the pea sized swollen area could be seen or felt. The owner of the sheep, when he saw his sheep with the tick about the head as described, immediately came to the conclusion they were the Queensland cattle tick (Boophilus Australia) and such a conclusion caused a good deal of worry as to what would have to be done to both sheep and the property.

At least six months later there is no further sign of the above parasite on sheep on the property, it does not appear to have re-infested the sheep; the number may not have been sufficient to breed enough for this purpose or the climatic or other conditions would not allow them to carry on their life cycle off the host.

On enquiring further about this type of parasite, I find that during the drought period of 1912 a large sheep owner of this district had a similar experience with this type of parasite on his sheep. No losses from the tick were known; the sheep were that bad, he states, that he put one mob through a race and picked the ticks off and crushed them underfoot.

Glenfield recommends dipping the affected sheep in arsenical dip, at cattle dip strength, to rid the sheep of this type of tick.

 


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