The difficult challenge of rabbit venipuncture can be due to either the patient or the phlebotomist. Not all rabbits are used to be handled which makes performing diagnostic tests difficult. On these patients consider either sedation with butorphanol or short term anesthesia with isoflurane. There is less chance of injury to the rabbit or the staff if a fractious rabbit is given a small amount of “happy” drugs. For those rabbits that do not require pharmaceutical assistance it is a good idea to wrap the patient in a towel to help prevent movement. Remember to let the patient out of the towel as soon as you are finished since they do have the tendency to overheat easily. As far as the phlebotomist goes, a cooperative patient, proper supplies, a good assistant and practice is the only way to go.
There are several sites that can be used for blood collection. Which is the best? Some say the jugular vein and others may say the central artery of the ear; what do we say? Which ever works for you and your patient is always the best option.
Depending on which vein you will be drawing blood from you may need to shave the area. Take great care when shaving. The fur is very thick which makes shaving difficult yet the skin itself is very thin and tears easily. Be sure your clippers are clean, free of fur and have a fresh blade.
Supplies needed include hair clippers with fresh blade, alcohol, 1cc syringe with 23-27 gauge needle, blood collection tubes, +/- heparin, dry gauze pad, a towel, +/- sedation/anesthetic drugs and an assistant.
The cephalic vein is accessible for a blood draw depending on the size of the rabbit. Due to the short antebrachial length and small vein size drawing blood from a cephalic vein is easier on larger breeds of rabbits. Restraining a rabbit for a cephalic blood draw is similar to a cat or dog. The difference would include lightly wrapping them in a towel and always gently restraining their heads.
The saphenous vein is located across the lateral aspect of the tibia and is accessible in most breeds. Restraining for a saphenous blood draw is similar to restraining a cat. The main difference is that you do not need to stretch them on their sides. Most rabbits will sit sternal and let you extend out one of their hind legs for the blood draw. It is a good idea to have a towel lightly draped over the patient.
The jugular vein is a nice vein to use as long as your patient can be sedated; it is also the vein of choice on small rabbits. Once sedated, shave the fur from the mid-cervical area on the ventrolateral aspect of the neck. Place the patient in dorsal recumbency with the head over the end of the table and the feet held in a caudal position. Be carful not to overextend the neck or you may cause respiratory difficulties.
Rabbits are unique in having very accessible options on their ears for blood collection. You can use either the central artery or the marginal vein for a blood draw. You can also get a more than ample sample from the ear on your larger breeds, which is not the case with small breeds or young patients. Restraining for an ear draw is usually quite simple. Your assistant should lightly place a towel over the patient and let them stay in a sternal position. Using two fingers you can hold off the vein proximal to the venipuncture site and obtain your sample. If the blood collection is slow consider using a heparinized syringe. Once you have obtained your sample and removed your needle hold pressure on the site for 3-5 minutes and monitor the ear for bleeding over the next 15-20 minutes. The ear vein and artery have a tendency to develop thrombi leading to vascular ischemia, which ultimately causes necrosis of the affected area. Possible ear trauma may occur any time an ear is used for a blood draw; consider this prior to drawing blood.
References:
Exotic Animal Care – Tully and Mitchell
Exotic Animal Medicine for the Veterinary Technician – Ballard and Cheek
