Age-related changes of the haematological profile in green iguana (Iguana iguana rhinolopha)

Abstract

Most haematological trials focusing on green iguanas have had the form of one-off blood sample-taking analysis. Our project therefore set out to perform a long-term ontogenetic trial on blood-related animals kept in identical conditions. The trial involved 11 green iguanas (Iguana iguana rhinolopha), 5 males and 6 females, from a single clutch. The reptiles were kept in experimental terraria with a specific light regime (12 h/12 h), at temperature ranging from 24 to 35°C and air humidity from 60 to 80%. The health status of the iguanas was monitored at regular intervals. At the age of 14 to 36 months, the iguanas were sampled for blood at intervals of at least 30 days. Total red blood cell and white blood cells counts were performed manually, using haemocytometer with the Natt and Herrick's solution; packed cell volume (PCV) was established using the microhaematocrit method; haemoglobin concentration was determined spectrophotometrically by using a standard cyanmethaemoglobin method. The leukocyte differential counts were evaluated and the mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were established. No seasonal changes of the haematological indices were observed. No significant differences in the haematological indices between male and female subpopulations were found. As to the number of erythrocytes, a statistically significant drop (p < 0.01) was observed comparing the data at 14 to 15 months of age (1.64 ± 0.58; 1.17 ± 0.18 1012/l) with those at 34 to 36 months (1.01 ± 0.14; 0.88 ± 0.12; 0.93 ± 0.08 1012/l). Apart from that, we recorded a statistically significant (p < 0.01) drop in packed cell volume (PCV) comparing the figures at 14 to 18 months (0.39 ± 0.04; 0.38 ± 0.03; 0.39 ± 0.04 l/l) with those obtained at 34 to 35 months of age of the animals (0.32 ± 0.03; 0.35 ± 0.02 l/l). On the other hand, our results confirmed a statistically significant (p < 0.01) rise in haemoglobin concentration comparing the data at 23 to 24 months (73.1 ± 7.2; 64.5 ± 8.8 g/l) with those at 35 to 36 months (92.5 ± 7.4; 94.0 ± 4.6 g/l). A similar statistically significant rise (p < 0.01) was confirmed for computed red cell indices (MCV, MCH, MCHC), too. The physiological basis underlying these changes remains to be examined in the future.