Association of Zoo Veterinary Technicians

Just as the other Bibliographies are just developing we are adding this resource to the web page. Below is a post from the AZVT forum which will be the begining of what we hope to be a valuable resource.

Alleman et al. Morphologic and cytochemical characteristics of blood cells from the desert tortoise (Gopherus agassizii). Am J Vet Res. 53 (9) p1645-1651. 1992.

Bounous et al. Cytolchemical staining and ultrastructural characteristics of peripheral blood leucocytes from the yellow rat snake (Elaphe obsoleta quadrivitatta). Comp Haematol Int 6 p86-91. 1996.

Bratthauer et al. Use of 25% EDTA as an improved anticoagulant for some avian species. AZVT 15th Annual Proceedings 1995. Feldman et al. Schalm's Veterinary Hematology. 5th edition. 2000.

Lippincott Williams & Wilkins, USA. ISBN 0 683 30692 8. Hajkova et al. Morphology of blood cells from Russian tortoises (Agrionemys horsfieldi). Proceedings European Association of Zoo and Wildlife Veterinarians (EAZWV) p261-267. 2000, Paris, France.

Hawkey and Dennet. A colour atlas of Comparative Veterinary Haematology. 1989. Wolfe Publishing Limited. London, GB. ISBN 0 7234 0930 7.

Skeba and Wright. Hematology and plasma chemistries of captive prehensile-tailed skinks. AZVT 15th Annual Proceedings 1995.

Wood and Ebanks. Blood cytology and hematology of the green sea turtle (Chelonia mydas). Herpatology. 40 (3) p 331-336. 1984.

Work et al. Morphologic and cytochemical characteristics of blood cells from Hawaiian green turtles. Am J Vet Res 59 (10) p 1252-1257. 1998.

And of course some comments from our own esteemed resident Guru and great guy

Joel Pond joelpond@hotmail.com Date: 10/23/00 Time: 8:52:10 AM

Gwen - As Mark said, many of us use or have used N&H solution for birds, reptiles, and fish wbc counting. But I would have to say probably as many of us use the eosinophil pipette method (EP). There are advantages and disadvantages to both methods. You need to decide which is best for you. NH advantages: Low reagent cost, is a direct counting method, allows tech to do both a red cell and white cell count from the same sample, does not require a differential to obtain counts, dilutions can be made from and using Unopettes for RBC's or made by yourself if you have accurate enough pipettes to measure 20uL and 1.98 mL, can count cells of any of the above species (with practice), stains all wbc's (but also may cause staining of thrombocytes) Advantages of eosinophil pipette: no reagent preparation (commercially available), depending on counts and species and your abilities this method may be less time consuming, is an indirect method (requires a differential which you will likely be doing anyway. Disadvantages of NH: requires extra dilution (pipetting) steps for preparation of reagent and sample, requires measuring and mixing chemicals for reagent (a one time project as the solution - once made - lasts a long time and gets better with age), may take longer to perform test depending on abilities of tech and the animal's condition, requires a little more tech experience to prevent counting large thrombocytes, if using Thoma glass diluting pipettes for sample prep (instead of Unopettes)- tech time is increased for cleaning them properly, may stain thrombocytes which will artifactually raise wbc count, more experience required to be comfortable using (my opinion) . Disadvantages of EP: will not work well for some species or skinks, fish, or elasmobranchs (cartilagenous fishes), is an indirect method requiring a differential (the EP gives an absolute count of the sum of heterophils and eosinophils in the sample), cannot perform an RBC count from the same prepared sample, stains only eosinophils and heterophils. I probably left something out, perhaps someone else will venture an opinion. Another variation of the NH method is using Toluidine blue in saline as the cell counting method - it is easier to make up than NH and the technique is the same. I have experience in using all three techniques. Personally, I use the EP method the most. For those species with neutrophils or non-staining pink granuled wbc's I use the Toluidine blue method. Several years ago a comparative study was performed and found no STATISTICAL difference between them (NH and EP). But then there was no agreement of the counts obtained, either. So it comes down to choosing a method you are comfortable with and using it. Joel