& Management / Disease
Investigation & Management / Techniques:
Before performing any clinical technique, the associated legal
and ethical considerations should be consulted, knowledge of the
potential complications/ limitations/ risk
should be gained, and the level of expertise
and qualification required must be ascertained.
When blood sampling a hedgehog wildlife casualty, it is important that
general considerations applicable to blood sampling of all wildlife
casualties be considered. (See: Blood sampling - Wildlife Casualty Assessment)
A detailed description of intravenous access is available (See: Intravenous Access (Venepuncture) of Hedgehogs) and should be consulted in combination with this page.
The following information relates directly to considerations for blood
sampling of the hedgehog.
- Blood sampling in the hedgehog has not been a frequently practised
technique to date. However it is now receiving increased attention as a
tool to assist with health screening and pre-release assessment of
- Blood sampling in the hedgehog requires general anaesthesia in the
vast majority of cases. Access may be possible if the animal is
unconscious or seriously injured, however in these hedgehogs the
peripheral perfusion is likely to be poor and the veins collapsed.
- Intravenous access for blood sampling may be from a
number of veins, although the superficial veins of the hind limbs appear
to be most commonly used.
- The medial saphenous vein has been recommended as the vein of choice
for blood sampling in the hedgehog. The hedgehog should be positioned
laying on its back (dorsal recumbency) with the hind limb in extension
for the sampling procedure.(J3.151.w2)
- Intravenous access is possible via the saphenous vein running
approximately in the midline along the back of the hind limb. The
hedgehog can be positioned laying on its belly (ventral recumbency)
with its hind limb extended.(V.w26)
- The lateral or medial saphenous vein can be used for blood sampling (B284.6.w6);
superficial veins of the hind limbs can be used.(B151)
- The lateral saphenous, a superficial vein, can be used for intravenous
- The vein can be visualised running across the lateral aspect of
the hind limb as it passes over the stifle. (B150.w1)
- Alternate veins which can be accessed include the cephalic, jugular (B291.12.w12),
or cranial vena cava. (B150.w1,
- Cardiac puncture and retro-orbital sinus
bleeding are techniques described in the literature which are
considered by many to be ethically unacceptable. (J3.151.w2,
- Clipping a nail short has been described as a method for collecting
small blood samples from hedgehogs.(B150.w1,
However this amputation technique is likely to be painful and is
considered by many to be ethically unacceptable. (J3.151.w2,
- In addition, the blood samples obtained have a high risk of
contamination with urine, faeces or other material. (V.w26)
- Ensure that all equipment is available prior to starting the
- Ensure adequate restraint of the patient; usually requires general
anaesthesia for the hedgehog. (See: General Anaesthesia of
- Carefully clip and clean the injection site and
disinfect with surgical spirit.
- An appropriate needle size (gauge and length) and
syringe size should be chosen, according to the preference of the
- A 27 gauge, 1/2 inch needle swaged on to a one
millilitre syringe has been described for blood sampling in the
- A 24 gauge, five-eighths inch hypodermic
needle on a one millilitre syringe may be used for intravenous
access in the hedgehog. (V.w26,
- 'Raise' the vein by applying pressure,
occluding venous return, therefore making the vein fill with blood.
- Insert needle into the vein slowly and at a
very acute angle, almost parallel
to the vein.
- Slowly fill the syringe with blood by withdrawing the
- Too great a pressure on the syringe plunger when taking blood may cause the vein
to collapse, stopping the blood flow and may damage blood cells (particularly when using a
small gauge needle).
- Release the pressure and stop raising the vein when the
sample has been taken.
- Remove needle from the vein slowly and with care.
- Apply pressure over the
venepuncture site until clotting has occurred.
- Clean any excess blood from the area after clotting has
|Appropriate Use (?)
- Analysis of a blood sample has been recommended as part of the
pre-release veterinary check for casualty hedgehogs (B151,
and should be considered wherever possible.
- Increased focus of attention is now being placed on the importance
of blood sampling
in the hedgehog as a method to aid in health checks and pre-release
- Blood sampling and testing has not been widely practised to date
because of the lack of established blood sampling techniques in the
- Interpretation of blood analysis data to date has been limited by
the lack of large sample size, species-specific, reference range
information available. (J3.151.w2)
- Variation of reference range data in the literature exists due to
small sample sizes in some studies and variables including
environmental conditions, sex and age. (J3.151.w2)
- Further research is required to establish reference range data for
hedgehogs with investigation of the importance and effect of a number
of variables (e.g. ambient and body temperature, diet etc.) (J3.151.w2)
- The minimum amount of blood required should be taken.
- No more than 1% of the body weight of the
individual should be taken at one time. (B36.6.w6)
- A more conservative ceiling of 0.5% of the body
weight of the individual at any one time is often used.
- Blood samples of 0.5 ml have been reported to be
taken from hedgehogs of over 500 g body weight. (J3.151.w2)
|Complications/ Limitations / Risk
- Venepuncture for blood sampling can be difficult in the hedgehog (J15.21.w1,
particularly with small individuals.(V.w26)
- Intravenous access can be very difficult in
hedgehogs, particularly if veins are very small or collapsed.
- The short neck and local fat deposits in the hedgehog make the jugular
vein of the hedgehog less accessible when compared with other species
for blood sampling.(B284.6.w6)
- Risk of haematoma formation - associated blood loss can be
significant for animals of small body weight.
- Veins are fragile, and will accept a relatively few number of punctures.
- Complications (haematoma, phlebitis, bruising) can be
reduced through optimal venepuncture technique and vein management.
- General anaesthesia is generally required for
intravenous access in the hedgehog.
- Requirement for physical and chemical restraint, and the stress
which this may involve.
- Care should be taken to ensure that only a safe volume of blood is
taken, depending on the body weight of the hedgehog and allowing for
disease or debility.
|Equipment / Chemicals required and Suppliers
- Appropriate-sized needle and syringe.
- Appropriate anticoagulant sample tubes.
|Expertise level / Ease of Use
- Procedure should only be
undertaken by an individual with appropriate clinical training and practical experience;
this would usually be a veterinarian or someone with advanced veterinary technician
- Cost of disposables including needle, syringe,
- Cost of external laboratory work.
- Cost of reagents and equipment for in house testing.
|Legal and Ethical Considerations
||In some countries there may be
legislation restricting the use of this type of technique to licensed veterinarians. For
example in the UK: "The Veterinary Surgeons Act 1966 (Section 19) provides,
subject to a number of exceptions, that only registered members of the Royal College of
Veterinary Surgeons may practice veterinary surgery." (See: LCofC1
- RCVS Guide to Professional Conduct 2000 - Treatment of
Animals by Non-Veterinary Surgeons)
Blood cannot be taken except to benefit the health and
welfare of the individual animal.
If blood is to be taken for research purposes appropriate
project and personal licences are required under the Animals
(Scientific Procedures) Act 1986. See: Wildlife
||Becki Lawson (V.w26)
||Debra Bourne (V.w5),
Suzanne I. Boardman (V.w6),
Tiffany Blackett (V.w44)