Sites of Blood Collection…
As shown in the figure, the major sites of blood collection in your pet is jugular vein, cephalic vein and saphenous vein. Depending on certain cases like, if you need large quantity of samples, then collection from jugular vein is preferred, as it’s a big vein and carries large quantity of blood from the body. Cephalic vein is the vein of choice of veterinarians for collecting samples in routine practice for moderate quantity of the blood. Somehow, if cephalic vein gets collapsed during collection procedure then samples can be collected from the saphenous vein also.
For collecting the blood from pet, we need to puncture these veins using suitable syringe and needle. A vein may get collapsed if sample is taken very quickly hence it should be drawn at appropriate speed. It is always recommended that the collection procedure should be undertaken by a veterinarian or a professionally trained technician only to avoid the phlebitis (inflammatory condition of vein) and related conditions post blood collections.
1. Jugular Vein:
This is a very prominent vein located at front site of the neck. Jugular vein is present at each side of the trachea in dogs, cats, horses, cows, and many of other animals. Jugular vein can be seen clearly if you clip the hair around the neck region and then by pressing at the bottom of the groove beside the trachea. Clipping of hair will help for visualization and proper location of the vein before inserting the needle with soft hand. You can see the jugular vein as illustrated below:
2. Cephalic Vein:
The cephalic vein is located at the dorsal surface of the front leg. This vein actually travels beneath the skin between the wrist joint and the elbow as shown in figure no 5 below-
Blood collection from cephalic vein is bit easier as compare to others as restraint of the pet is convenient and this vein locates easily. To view the vein,extended the elbow of the pet and put the index finger on the front of the leg above elbow joint and thumb at below from back side of the leg. Apply the firm and gentle pressure to lock the blood flow at elbow joint. This position willhelp to raise the vein for required interventions.
3. Saphenous Vein:
Most of the professionals use saphenous vein as an emergency vein for blood collection procedures as this is very small in diameter and fragile in nature. There are also likely of more chances of damage of the vein forming hematoma at the site. This vein runs at the lateral surface just above an ankle. To locate this vein, keep your pet in lateral resting position. Hold the hind leg just below the knee joint and apply the finger pressure from lateral surface (fig no. 7) which results into the protrusion of the veins for collection of the blood.
Basic equipment’s required for the successful collection of the blood samples from pets are mentioned below-
1. Needles & Syringes:
various sizes of the needles are available in the market and selection of the needle size is depends on the size of the vein, quantity of the blood required and animal type i. e. small or large size of pet. 20-22 gauge needles are preferred by most of the practicing vet for collecting the blood in their daily practice. Gauge is the measure of the width of the needle. Selection of the gauge of the needle is depends up on the size and amount of blood supposed to be collected from the pet.
Apart from the gauge size; the length of the needle also plays an important role in the smoother blood collection procedures. 3/4-inch length of the needle is good for most of the venipuncture. Short length of the needle has a better control and less chances of vein collapse, hematoma, or puncturing the vein on both sides occurs.
Syringe capacity used for collection of blood is depends on the quantity of the blood for withdrawal. If more quantity needs to withdraw the big syringe of 10 or 20 ml capacity is used. If medium amount required then 5 ml syringe is preferred. In routing practice if less quantity of the blood needs to draw then 1-2 ml syringes are mostly used.
2. Collection Tubes:
The collected blood must be transfer quickly in the suitable tubes for its preservation. The selection of the collection tubes varies with reference to the test requirement. The various collection tubes are available with different color code as shown in fig 8. For example, blood collected for the routine complete blood count (CBC) needs to transfer in the purple/lavender cap vial which contains EDTA. The EDTA acts as an anticoagulant and keeps the blood safe for estimatiation till analysis in laboratory.
Likewise, if you want to do liver or kidney function tests then blood must be transferred into the red color cap which is a plain vial and did not contain any anticoagulant which helps for clot formation to separate out the serum from blood sample collected. Tube with yellow color cap is also available for clot activation to get the more quantity of serum sample for tests. If you plan the coagulation studies then blood must be collect in a light blue vials containing sodium citrate. Heparin vials of green color caps are preferred for the estimations of electrolyte like sodium, potassium etc. from the collected blood samples.
If you are suspecting your pet is suffering from diabetes and wants to know the blood glucose level then blood should be collected in a sodium fluoride vials of gray color cap.
The holdings of blood samples at desired/recommended tubes which are well demarcated by different cap colors are very important for their proper preservation to derive accurate reports from testing laboratory.
Sending the samples in laboratory…
Samples once collected at clinics must be sent immediately at testing laboratory for analytical work. If you keep hold the samples for long period they may detoriate and gets spoiled and such samples may not give you the proper test results. Usually in laboratories, the samples must be processed within 4-6 hours after its collection hence needs to be sent there on early basis.
While dispatching the samples, they should have properly labeled with all the details like name of owner, name of pet, age, sex, breed, brief medical history and clinical signs with the name of referring veterinarian. Most of the testing laboratories give their test requisition form which must be filled in completely for better handling of the samples during analysis/lab work.
Once the test done the report must be received from the laboratory at earliest and consult the veterinarian for his/her opine on the health of our pet for better care and corrective plan of actions.
Blood collection procedure requires a practice and professional experience. Pet owners must have a basic knowledge of the procedure, locations of the veins and equipment’s requirements for the same. The critical steps like selection of collection tubes, post collection complications etc. must be viewed seriously. All emphasis must be given for collecting the requisite quantity of the blood following recommended and painless methods.