Sunday, July 08, 2007

Ixodes ricinus and Lyme disease


This charming looking insect is Ixodes ricinus or the hard bodied tick. (The penny is 15mm in diameter.)

It preys on mammals by sucking their blood and storing it in its abdomen. It particularly likes rabbits, sheep, deer and sea kayakers. This year seems a bad season for them and it is worth examining yourself after walking through vegetation like bracken. They climb it in wait and anticipation of feasting upon their next victim.


Traditionally people have pulled then out with their nails or tweezers, burned them off with a cigarette or attempted to suffocate or stun them using Vaseline or alcohol. Unfortunately all these methods cause the little creature to dig further in and to puke its stomach contents into the victim's blood stream. This partially digested blood is a heady cocktail that contains another of God's creations, a spirochete bacterium called Borrelia burgdorferi sensu lato. This causes a condition called Lyme disease in humans. Believe me (and I am a doctor), Lyme disease is something you would much prefer not to have.

Public service announcement: if you get a red ring spreading out from a tick bite you should seek medical advice, mention you have been bitten by a tick and you are concerned about Lyme disease.

A much safer way to remove the injurious, illegitimate and far from insignificant insects is to use a little rotating hook such as the O'Tom, available from all good veterinary surgeries. You slide the tapered fork behind its bloated abdomen then slowly twist without pulling. The tick can resist a pull by digging in with its jaws and fore feet but it's helpless against gentle rotation. Some favour anticlockwise and others clockwise rotation. My own experience is that both are equally effective.

Are you curious what to do with the now pitifully struggling insect which you have untimely ripped from its natural element? Well, this might not be good for your Karma, but the following is my humble suggestion. I take some delight in burning the hapless former parasite.

If only it was so easy to get revenge on the Scottish midge.

10 comments:

  1. I think any dog owner can recognise this. They're nasty little beasts and they can get astonishingly huge.

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  2. Hi Rene, this one came off Rory the Border terrier.

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  3. Exactly the brand/type of tick remover I use on Clisham the cat when he brings in some unwanted 'friends' on himself after frolicking in the fields. Cheap and very, very effective!

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  4. David Winkworth19/07/2007, 08:45

    Guys, I think you're all off the track a bit with tick removal. Pulling the little nasties out upsets them and as a last great act of defiance they give you one last squirt of saliva. Who needs that!
    Here in Australia our St John Ambulance(and other health authorities) recommend killing them in situ with a little squirt of insect rellent and another 5 minutes later. The repellent acts as a narcotis and a toxicant...and the tick just falls out a few hours later. I've proved this treatment effective on many sea kayaking trips along out tick-infested coast. No more tick tweezers in my first aid kit!

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  5. Nasty looking critter, but not an insect - ticks belong to the class Arachnida (as do spiders and scorpions amongst others) - two too many legs to be an insect!

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  6. David thanks for your reply, I agree about pulling them with tweezers but the illustrated gizmo does not pull them out, a gentle twist is all that is required, the tick cannot resist the rotating movement.

    With regard to insect repellant it sounds a great idea but I would be worried that in its attempt to escape the noxious substance it would bury deeper and 5 minutes before it falls off is quite a long time in which it could disgorge its stomach contents.

    Colin thank you! The photo quite clearly shows 8 legs! I note that it does only have 6 legs in the larval stage, how on earth should it be classified?

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  7. Anyone with a fear of ticks shouldnt go to Little Colonsay, NW coast of Scotland, as they have a severe infestation! Ticks rule the roost over there

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  8. Greetings Anonymous, yes I know Little Colonsay, an island only exceeded in tick infestation by the isle of Scarba, recently visited by Tony and myself.

    At least little Colonsay now appears to be rid of the rat infestation, which drove out its last human inhabitants. Perhaps the ticks ate them!

    :o)

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  9. Hey Douglas. do you know much about Lymes? im looking for some advice as i think i may have caught it on a kayaking trip to Ardnish.

    J

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  10. Hi J You catch it from an infected tick bite. The sign of the infection is a spreading reddish ring that grows outwards with the bite in the centre. If you are feeling tired at the with flu like symptoms after a tick bite then definitely see your doctor and tell him/her you have been bitten.

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