Some vacutainers have a line to mark how much to add to the tube or will say on the tube label how much to add. However, if you are using a vacutainer system, the vacutainer should fill relatively accurately. If using a needle and syringe/ butterfly catheter, then the amounts to add can vary. Also if you are using a needle and syringe and transferring to a vacutainer, remove the top of the tube and take your needle off before transferring the blood to the tube. If you stick the needle through the top, you can hemolyze your sample. And with this combo, if the blood is flowing slowly, you can form microclots or macroscopic clots in your sample if they aren't transferred quickly enough to your anticoagulated vacutainer and inverted around 8 times (this can affect some lab results). Forming clots is not really a huge problem if drawing from the jugular because of how quickly the blood flows. For the tubes that I have seen, the lavender (EDTA) tubes take a little over 1 mL of blood and plain reds have no additives so you can put in whatever amount without ruining the sample. Around 2 mL should usually be good for most labs. The heparin (green) and plain (red) microtainers we use take 1.3 mL of blood. The tiger top/ red and yellow top (serum separator) tubes we use take a little over 2 mL. Again these amounts can vary though so take a look at your vacutainer tubes and investigate a little more.
These are not meant to be "how to" videos. We are trying to show the general public what happens to their pets when they get taken "into the back" for procedures that they may not understand. If you are learning medical procedures such IV catheters, the ideal place is in a hospital where you can watch and learn in real life. Good luck!
I insist on vet techs doing blood draws in my presence as opposed to taking my dog back into the lab where I can't see them. My dog was diagnosed with epilepsy at 3 months of age and a known trigger is "painful/unpleasant vet visits. I watched a vet tech repeatedy stab a needle into my dogs leg trying to extract blood. After about 5 stabs I told them to stop and find someone with better capabilities. I was labeled a difficult owner now at 2 vets. The latest vet tech just goes for the jugular. What's the disadvantage/advantage of doing the jugular vs leg?
The jugular is the largest vein and the easiest to use, especially if you need more then 2cc of blood. It also requires the least amount of restraint on the Animal. The back legs are most difficult and the front leg is reserved for catheters. Any vet clinic should want most blood draws to be from the jug. It is the most low stress way to do it. The only exception being if there are any clotting factors.
If your pet has a condition where they may need to be hospitalized, techs and vets will try to reserve the vein in the front legs for catheters (front leg is the most common place for an intravenous catheter) so that fluid or drug support can be easily administered. The jugular requires less restraint and allows you to collect large volumes of blood quickly which can make it less stressful for pets. However, pets vary; some do better with front or hind leg venipuncture, and others are more calm for a jug. As for taking the pet to the lab or treatment area, some pets are more anxious, excitable, or aggressive around owners. As for the multiple pokes, that doesn't mean that the tech or vet is incapable. There are a variety of factors that can make the vein hard to hit, such as if your dog is dehydrated or older, or simple differences in anatomy from dog to dog. It is important to remember also that your vet and techs are only human and sometimes they miss or have an off day. Even the best vets and techs miss a vein sometimes, and nobody is perfect.
What may seem unprofessional to you is what most settings in an animal hospital look like. Everyone takes utmost care in having a hygienic work environment.
