Hemolymph Cytology, Cell Count, and Electrolyte Reference Values in Cameroon Red Tarantula (Hysterocrates gigas)
Theraphosidae is a large family of tarantula spiders commonly kept as pets or display animals in zoological institutions. A variety of diseases and diagnoses have been reported in captive tarantulas.3 There has been a growing interest and demand over the last decade for arachnid medicine, but the range of currently available diagnostic tests is limited. Hemolymph analysis could be a fundamental tool for arachnid health assessment. The objective of this prospective study was to establish reference intervals for hemocyte counts, and acid-base and electrolyte parameters in Cameroon red tarantulas (Hysterocrates gigas). Ninety-nine mature Cameroon red tarantulas from the Toronto Zoo collection were anesthetized using isoflurane in an induction chamber for the collection of 0.35 ml of hemolymph from the dorsal opisthosoma. Electrolytes (sodium, chloride, potassium, ionized calcium, and bicarbonate) were measured using a radiometer (ABL800 FLEX, Radiometer America, Brea, CA, USA), and hemocyte counts were obtained using the Avian Leukopet™ system (Vetlab Supply, Palmetto Bay, FL, USA) and hemocytometer. Cytocentrifuge preparations of hemolymph were Wright’s stained, and a differential cell count was performed on all available cells. Due to rapid coagulation and degranulation of cells, preparations were made immediately after sampling. Reference intervals were calculated using a nonparametric approach with 90% confidence intervals of the reference limits.2 Hemocyte classification was based on the available literature.1,4,5 These results will help establish baseline reference intervals for use in tarantula medicine and will also allow for a more quantitative assessment and thus a better understanding of arachnid health.
This research was supported by an Ontario Veterinary College Pet Trust research fund.
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