Getting started with goat scanning
The following article is a short introduction to getting started with goat scanning using the Scan Pad ultrasound machine. This machine has been reviewed against other systems in our goat ultrasound road trip article.
We have produced a free downloadable quick start guide for the Scan Pad, which covers setting up your system and adding your name to the top left, saving images and videos, adjusting basic controls, and a final section on more advanced controls once you become more confident in your scanning. You can claim yours here.
Probe placement worked best for me under the back leg, pointing back towards the midline of the doe and towards bladder. Either right or left hind legs worked.
As with all animal scanning, the first hurdle is achieving good contact between the transducer and the skin. With particularly hairy goats, try watering down your ultrasound gel to get to the skin. If there are large black areas vertically down your image (usually at the sides), this means you are not making proper contact with the skin. The entire sector – the pie-shaped imaging area on your monitor – should be used. This can be more difficult with large convex probes than microconvex.
Once you’ve achieved good contact, with goats, it’s pretty difficult to miss a pregnancy altogether. It is, however, a little trickier confirming viability.
The first thing you’re likely to notice in a pregnant goat are the cotyledons. They’re everywhere! So much so that getting past them to find the kid can be a challenge at first.
Here’s a video of some of these placentomes:
You can see that they completely surround and partially obscure the developing foetus. Very slight movements are required to bring the kid into view. Practice keeping the head of the transducer in more or less the same spot and angling your probe back and forth using your wrist, as opposed to moving your whole arm around. Be patient. This is a brand new skill.
Once you’ve seen something of interest, focus on three key controls to start with.
- Gain: The ‘brightness’ of your image. On the Scan Pad, this is adjusted by twisting the big knob at the front of your machine.
- Depth: In effect, this makes the area you are looking at on your monitor appear bigger or smaller. Reduce your depth as much as you need to in order to get the pregnancy to occupy most of the imaging area. Try to start doing this from day one, or you will get into the habit of always scanning at the same depth and will end up missing a lot of detail! On the Scan Pad, press the same knob you used for gain, and then turn it. After a couple of seconds, this knob will return back to being the gain control, so if you need to adjust your depth again, you will need to press it again.
- Frequency: For pygmy goats, Gen or Res are good defaults. For larger goats, Gen or Pen will likely yield the best results. Remember that ‘Res’ stands for resolution, and ‘Pen’ stands for penetration. These are at opposite ends of the spectrum, such that better penetration means lower resolution (lower image quality). This is due to the physics of ultrasound, which you can learn more about on one of our online courses.
Tip: There is no value your gain, depth or frequency should be at. It depends entirely upon the image on your screen. Don’t be afraid to adjust your controls and see what happens (you can always restart your machine and start back at square one). This is the best way to learn what the controls do, and what works best for you and your animals at their current stage of pregnancy. If you feel stuck or want some feedback, please join us on social media on the Animal Ultrasound Association Facebook page.
February 19, 2021
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