Blood Collection from Poultry
This video describes taking blood samples from poultry to test for exposure to infectious diseases. Correct bird restraint and handling of the sample are also demonstrated.
- [Narrator] Learning to collect blood samples from poultry is an important skill for veterinarians, poultry technicians, and poultry caretakers.
The most common reasoning for collecting blood samples is to test for antibodies that birds produce as a result of exposure to certain infectious diseases.
To obtain a good sample, it's important to know how to collect, handle, and store it.
It's also important to practice safe methods of handling the bird to prevent unnecessary stress or possible injury to the animal.
In this video, we'll look at the supplies you'll need to take a blood sample, how to handle the bird when two people are performing the procedure and when one person is performing the procedure, how to draw the blood sample, and how to store and ship the sample for testing.
First let's look at supplies.
You'll need sterile three to five milliliter syringes to collect the sample.
Choosing the appropriate length and gauge needles is important.
For smaller birds such as young broilers or bantam poultry, a 23 gauge needle, one-half to one inch in length is suggested.
For larger birds such as layers, a 20 or 21 gauge one inch long needle is recommended.
You'll need a blood collection vial to store the blood after you collect it.
You could use red top glass clot tubes, which are available online through livestock or veterinary supply companies, or you could use sterile plastic snap cap microcetrifuge tubes which are available through laboratory supply companies.
There are two main components of blood: the red and white blood cells, and the clear yellow serum portion.
Most antibody tests will utilize the serum component of the blood sample, so you'll want to allow the blood to clot, which separates the cells in the blood from the liquid serum.
So don't use blood vials that contain an anticoagulant such as heparin.
Plastic bags can be used to store the blood vial tubes together.
Double bagging is recommended.
If you're shipping the samples, a sturdy box with shock-absorbing material such as bubble wrap or paper padding helps protect the samples.
Permanent markers can be used for labeling the vials or the bags.
An insulated cooler with freezer packs can be useful for storing and shipping samples in hot weather.
Next, let's take a look at the anatomy of a bird's wing and see where you'll draw the blood sample.
The brachial vein, frequently called the medial wing vein, is the most common site for collecting blood from birds.
This vein is located on the underside of the wing between the biceps and triceps muscle, running parallel with the humerus, the arm bone.
It is a large vein immediately visible under the skin.
As you can see, the skin is extremely thin and nearly transparent in this area, with few feathers covering the vein.
How much blood should you collect?
Normally you'll collect one to three milliliters of blood which is sufficient to run most tests.
The maximum amount of blood you can safely collect from a healthy bird is 1% of its body weight.
So in a hundred-gram bird, one milliliter is all you should collect.
However, in birds larger than this, three milliliters can be safely collected which is adequate to run several antibody tests.
Next, let's look at handling.
It's important to handle your bird safely to avoid injuring the bird and to get a good quality blood sample.
The method of holding the bird may vary based on the age or size of the bird and whether one or two people are involved in the process.
Here's how to collect a blood sample using two people.
If an assistant is available, collecting blood with two people may be easier.
One person can concentrate on bird restraint and hematoma prevention, while the other person collects and handles the blood sample.
We'll demonstrate the two person technique with a laying hen.
When using a table, one person will pick up the bird using one hand under the body and one hand gently restraining the wings to keep the bird from flapping.
Lay the bird on its side, keeping the legs restrained, then gently lift up the wing.
You may need to pluck a few feathers to get a clear view of the brachial vein.
Pluck the feathers at the base gently, quickly, and firmly, pulling in the direction of growth.
If you need to sanitize the area, you can use an alcohol wipe which also helps make the vein stand out.
As the assistant restrains the bird, the other person inserts the needle.
Withdraw the plunger slightly to break the seal and create a small vacuum inside the syringe.
To take the sample, insert the needle using a very shallow angle, nearly parallel to the skin with the bevel facing up, and avoid going through the feather follicles.
Slowly pull back the plunger, allowing it to fill with the proper amount of blood, but not too fast as this may create too much vacuum and cause the wall of the vein to collapse, stopping blood flow.
If the blood does stop flowing, gently turn the syringe or slightly withdraw the needle.
Be sure to minimize any sideways movement of the needle.
When complete, withdraw the needle and apply pressure to the puncture site for several seconds until clotting occurs.
Continue to apply pressure for several seconds.
Despite the best of care, sometimes a small hematoma may still occur.
This will not harm the animal but may be a short-term cosmetic problem, especially if the bird is going to a show.
The hematoma will harmlessly resolve in one to two weeks.
If you're not using a table, the assistant holds the bird still against their body, restraining the feet at the hocks with one hand and lifting the outside wing with the other hand.
Again, the angle of the needle insertion should be nearly parallel to the brachial vein.
When complete, transfer the blood sample into the collection vial, then close it and lie it flat to allow the blood to spread out and clot.
Next, let's look at how one person can perform the procedure on their own.
Here we're using a broiler chicken that is about four weeks old.
To initially pick up the bird, grasp it gently with two hands, one hand underneath the body restraining its legs between your fingers and supporting its breast with that hand.
The other hand comes over the top of the bird with a finger going under each wing to restrain and support the wing.
It may struggle, so hold it closely to your body for several moments until it calms down.
You should never grab a bird by one wing or one leg.
Try to minimize excessive wing flapping, which can result in injury if the wing hits a solid object.
Don't apply excessive pressure on the neck or keel as this can be very stressful for the animal.
To take the sample, first withdraw the plunger slightly to break the seal.
This creates a small vacuum inside the syringe.
Hold the needle along the brachial vein pointing towards the top of the wing.
The angle of the needle should be almost parallel to the skin.
Since avian veins tend to have very little connective tissue support, they can slip around easily beneath the skin.
Plan to insert the needle either directly over the vein or slightly to the side, with the bevel of the needle facing up.
Try not to insert the needle right on top of a feather follicle, as they are very sensitive.
Insert the needle slowly into the vein.
Because of the slight vacuum previously created, a small amount of blood should enter the syringe on its own.
When done, withdraw the needle while simultaneously applying pressure to the puncture site.
Next, let's talk about what to do with the blood sample.
Its important to transfer the blood from the syringe into the desired container, ideally before the blood is clotted.
If using a red top clot tube with a vacuum, simply insert the needle into the tube and allow the vacuum to draw the blood inside.
If the blood is already clotted, remove the needle from the syringe then compress the syringe to express the blood.
Fill the container one-half to three-quarters of the way full, don't fill it completely.
Then lie it flat or at a slight angle to allow the blood to spread out on the bottom.
This allows better separation between the clot and the serum, and will result in higher serum yield.
Keep the sample at room temperature for at least 30 minutes.
Don't refrigerate the sample until the serum has separated from the clot.
It is important to minimize hemolysis of the sample since rupture of the red blood cells in the sample may adversely affect some test results.
Hemolysis can be minimized by not forcing the blood through the syringe needle when the sample has already clotted.
Hemolysis can also be reduced by pouring off serum from the clot when they have adequately separated.
Don't leave blood samples in the direct sun or expose them to high heat, such as inside a hot vehicle.
It is important to package the sample so it will arrive safely.
If you plan on shipping your samples for testing, first fill out the necessary paperwork for the samples.
The paperwork should be enclosed in a plastic bag to keep it dry.
Place the blood tubes in plastic bags and then double-bag them.
Line the bottom of the cooler with soft packing materials then place the bagged blood samples and the bagged paperwork inside, followed by a freezer pack on top to keep the samples cold.
Be sure there is enough packing material to prevent the tubes from moving around inside the box.
Samples should be shipped via an overnight courier to the testing laboratory.
It is not recommended to ship samples on a Friday as many laboratories are closed over the weekend.
It is always a good idea to call the day before to alert the laboratory that samples will be sent.
Separated serum samples may be refrigerated for a day or two if necessary.
Do not freeze the samples unless you have discussed this with the testing laboratory.
Some tests are adversely affected by freezing.
Now you should know everything you need to safely draw blood samples from poultry.