Total blood volume / maximum sample:

Rodents

Guinea pig, chinchilla: 0.5–0.7 ml/100 g

Gerbil: 0.3 ml

Hamster: 0.65 ml

Mouse: 0.14 ml

Rat: 1.3 ml

Rabbits total blood volume: 55–70 ml/kg

Ferret

Female of 750 g: 40 ml

Male of 1 kg: 60 ml

Max. 10% of total volume

Reptiles

Total blood volume: 70–110 ml/kg = 7–11% of body weight

Exception: tortoises, with a maximum volume of 5% of live weight (shell)

Plasma approx. 60–75 ml/kg

Maximum sample in snakes and lizards: 10%

Birds

Total blood volume: 7–10% of body weight

Take 10% of this volume = 1% of body weight, and 0.5% for a weakened bird

Purpose of the blood sample:

Full blood count, haematocrit, smear, differential

Sometimes a biochemistry panel: specific values (liver, possibly kidneys, and so on) or glucose

Equipment:

Rodents and rabbits

Jugular vein: 22–25 G needle, 2.5 ml syringe. Superficial and high; clip the fur; anaesthesia if needed

Retrobulbar venous sinus: heparinised microcapillaries. Anaesthesia, then compression

Ear vein: 25-27D needle, let it flow. Risk of thrombosis

Otherwise: 1 ml syringe + 25 G needle. Lateral saphenous vein: small in the guinea pig and chinchilla

Ferret

Haematocrit 44–61%, varying with coat colour (polecat/albino)

Jugular vein: 22–25 G needle + 2.5 ml syringe.

Lateral cephalic vein / saphenous vein: 1 ml syringe + 27–28 G needle (prevent collapse). Small quantity

Tail vein: 20–21 G needle, 3–5 ml, then compression. Warm the ferret up beforehand

Reptiles

Lizards

Ventral caudal vein: animal on its back, needle vertical on the midline of the tail, at a 45° angle in the caudo-ventral direction. At one quarter of the total tail length. Insert the needle gently between the vertebral bodies. If necessary, position the animal belly-down

Snakes

Cardiocentesis: at one fifth of the total length; feel the heartbeat with your thumb or spot it by eye, and steady the ventricle with your thumb

The ventral caudal vein runs along the tips of the vertebral processes, well away from the cloaca (hemipenal pockets)

The palatine veins, reserved for IV injection, collapse and carry a risk of stomatitis

Chelonians (tortoises and turtles)

Dorsal caudal vein. No dorsal vertebral processes; the vein is superficial and subcutaneous; hold the tail stretched downwards, at one third of its length; advance the needle towards the vertebral body, then withdraw it

Jugular vein: right side! Neck stretched forwards, at the lower third of the neck’s height, behind the tympanic membrane, with a tangential puncture

Post-occipital venous sinus: beneath the nuchal ligament

Birds

Toenail (claw); haemostasis is difficult

Wing vein: orange needle, on the inner face of the wing held clear of restraint; a single puncture, then compression!

Jugular vein D ! Head towards the tail, brief (flash) anaesthesia, part the feathers with alcohol

AuFuret Veterinary Practice, Perrin Frei Danielle