Changes

The sites for obtaining blood samples in snakes include the ventral tail vein, the palatine vein and cardiocentesis.  Restraint is by gentle, careful handling or by chemical means. Asepsis is extremely important during blood collection and the site of collection should be prepared as if for surgery. Prior to collection it is important to have all materials and equipment ready: cotton wool, antiseptic (chlorhexidine or a povidone-iodine detergent), needle and syringe of suitable sizes, and the blood handling materials.

The sites for obtaining blood samples in snakes include the ventral tail vein, the palatine vein and cardiocentesis.  Restraint is by gentle, careful handling or by chemical means. Asepsis is extremely important during blood collection and the site of collection should be prepared as if for surgery. Prior to collection it is important to have all materials and equipment ready: cotton wool, antiseptic (chlorhexidine or a povidone-iodine detergent), needle and syringe of suitable sizes, and the blood handling materials.

==Ventral tail vein==

==Ventral tail vein==

*The palatine veins can be visible when the mouth is open.

*The palatine veins can be visible when the mouth is open.

*Care is necessary in restraint and haemorrhage must be considered. This can be controlled by applying pressure with a cotton-tipped applicator that has been adrenalinised.

*Care is necessary in restraint and haemorrhage must be considered. This can be controlled by applying pressure with a cotton-tipped applicator that has been adrenalinised.

[[Image:Take_blood.jpg|350px|thumb|right|(Copyright © RVC)]]

[[Image:Take_blood.jpg|350px|thumb|right|Cardiocentesis (Copyright © RVC)]]

==Cardiocentesis==

==Cardiocentesis==

==Protocol for blood handling==

==Protocol for blood handling==

The following protocol is for reptiles that weigh over 300 g. For reptiles under this weight less plasma will be available for biochemistry. It may be necessary to prioritise your tests.

The following protocol is for reptiles that weigh over 300 g. For reptiles under this weight, less plasma will be available for biochemistry. It may be necessary to prioritise your tests.

*Essential materials and equipment - 0.5 ml heparin tube (orange), 1.0 ml heparin and gel tube (green), 4 coverslips (or 3 microscope slides).

*Essential materials and equipment: 0.5 ml heparin tube (orange), 1.0 ml heparin and gel tube (green), 4 coverslips (or 3 microscope slides).

*Advisable - microhaematocrit tube, centrifuge and refractometer.

*Advisable: microhaematocrit tube, centrifuge and refractometer.

*Take blood aseptically. 1.0 ml of blood is put in the heparin/gel tube for biochemistry and 0.5 ml into the heparin tube for haematology.

*Take blood aseptically. 1.0 ml of blood is put in the heparin/gel tube for biochemistry and 0.5 ml into the heparin tube for haematology.

*Two blood films are made immediately the needle is withdrawn from the vein. Slide smears are adequate but coverslip smears are superior.

*Two blood films are made immediately the needle is withdrawn from the vein. Slide smears are adequate but coverslip smears are superior.

*A haematocrit-capillary tube is filled for centrifuging for PCV then total protein by refractometer. This step is not essential but will give immediate results. A buffy coat smear can also be obtained.

*A haematocrit-capillary tube is filled for centrifuging for PCV then total protein by refractometer. This step is not essential but will give immediate results. A buffy coat smear can also be obtained.

*The sample for biochemistry is centrifuged immediately to separate the plasma. A delay may cause artificial changes to the biochemical parameters (e.g. potassium concentration declines due a shift of ions from the plasma into the red blood cells).

*The sample for biochemistry is centrifuged immediately to separate the plasma. A delay may cause artificial changes to the biochemical parameters (e.g. potassium concentration declines due a shift of ions from the plasma into the red blood cells).

==Use of anticoagulants==

==Use of anticoagulants==

EDTA may be suitable for some species but, as a general rule, use lithium heparin for haematology since EDTA lyses erythrocytes of some species of reptiles.  Blood films are best made with fresh blood without an anticoagulant immediately following collection and then air-dried. Heparin creates a blue tinge to blood films and causes clumping of the thrombocytes and leukocytes whereas those made from blood without anticoagulant give superior cellular morphology.

EDTA may be suitable for some species but, as a general rule it is recommended to use lithium heparin for haematology since EDTA lyses erythrocytes of some species of reptiles.  Blood films are best made with fresh blood without an anticoagulant, immediately following collection, and then air-dried. Heparin creates a blue tinge to blood films and causes clumping of the thrombocytes and leukocytes whereas those made from blood without anticoagulant give superior cellular morphology.

[[Category:Snake Specimen Collection]]

 

 

 

 

[[Category:Snake Diagnostics|B]]