Monday, June 29, 2009

So you want to sample a village dog's blood....

Actually, likely you really, really don't. But I do, and so I'm going to explain how you actually do it here. It's one of those grunt work type parts of science (that is, it's data collection) but relatively pleasant and interesting, since it's often pretty challenging. Plus, the perks (international travel to places way, way off the beaten track) are excellent.

So, here's how we actually do it.

First, we put all of the following into a large duffel bag, and throw that into the back of a 4x4:
  • butterfly needles (needles with wing shaped handles and tubing attached)
  • Vacuum sealed test tubes
  • Tube holders and needles (plastic holders and needles to puncture vacuum sealed tubes)
  • alcohol swabs
  • measuring tape
  • data sheets
  • sharpies
  • pens
  • leads (the kind you slip over a dog's neck)
  • muzzles (in about eight sizes)
  • camera
  • a cooler with ice
  • fish scale (suspensory scale)
  • goat sling (a mesh sling for holding dogs from the scale)
Step 1: Find willing helpers. People looking for coauthorships and recommendations tend to be particularly good people to work with, as they're cheap and enthusiastic.

Step 2: Find dogs. If people keep them as pets or guards, this means driving around the countryside with translators (sometimes more than one) to explain your pressing need for blood from rural dogs. After many strange looks, most people are willing to help if only out of curiosity. I've often thought that it's probably particularly helpful that I'm female, as I get some especially strange looks diving onto riled up dogs with thick bite proof gloves. Novelty gets you a lot of interest.

If people don't keep dogs, we usually rely on shelters. Shelters are awesome because they usually have very calm, well-socialized dogs and enthusiastic staff. Also, it's great to be able to compensate people by donating to a dog shelter and helping the animals too.

We've also tried driving around looking for dogs, but this usually doesn't work as well.

Step 3: Restrain the dog. Get the owner or any other foolishly helpful soul (ie, me or Ryan or our collaborators) to put a lead on the dog. If it freaks out, let it do so until it runs low on energy. Then cautiously put a muzzle on the dog from behind:

If the dog is chill, that last bit is less necessary, which saves loads of time.

Step 4: Measure the dog. For breed dogs there are more than 30 of these measurments. We take six: body length, height, chest girth, chest width, face width, and snout length. Usually I call out these measurements to Ryan, who writes them down along with a number of other types of physical descriptions and takes pictures.

Step 5: Get the blood! Get someone strong and confident to hold the dog still and hold a forelimb so that the cephalic vein is obvious after an alcohol swab. Insert butterfly needle attached to tube holder and needle. When there's blood in the butterfly needle's tube, attach the vacuum tube. Wait, trying desperately to instill patience in a figity dog, for the tube to fill with five cc's of blood. Fiddle gently with the needle and pump the dogs paw to increase the speed of the flow.

Step 6: Weigh the dog (if it's under 50 lbs) using a fish scale and goat sling. Ignore the local people's laughter as the dog slips out of the sling for the third time before you can suspend the sling from the scale.

Step 7: Carefully release the dog, making sure no one lets go of the lead or muzzle before everyone's clear and they've really been removed from the dog. Losing one of four leads to a dog running away is not fun in the middle of a busy sampling day.

Apparently, with loads of helpers, tons of chill dogs, and an efficient system, you can take blood using this method (ie, steps 3-7) at a rate of about one dog every three minutes or so. At least, that's what we did today--seventy dogs in less than four hours.

Step 8: Mail blood home. Talk to people repeatedly about the lack of danger from healthy domestic dog blood and attach loads of letters making it clear that there is no value nor any troubling regulations on shipping this stuff.

And then we move onto the next country! That's how I'm spending my summer, and while it's exhausting and not fabulously intellectual, we're having a blast.

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