Background: the potential protective and therapeutic effects of Aloe vera juice against malathion induced haematological changes in young rabbits (Oryctolagus cuniculus) were evaluated in this study.
Material and methods: Rabbits were allocated into two sets of experiments short (7 days) and long (21 days) periods. Animals of each set were divided into eight groups; four treated groups and each treated group had its own control. The animals of the first group were orally dosed with Aloe vera juice (0.84 ml/kg b. wt.). Rabbits of the second group were orally dosed with malathion (5 mg/kg b. wt.).  In the third group (the protective group) animals were dosed orally with malathion concomitant with Aloe vera juice. Animals of the fourth group (the therapeutic group) were dosed orally with malathion; for 7 days followed by Aloe vera juice for the same period. All the animals were sacrificed, blood samples were collected and used to determine the levels of hematological indices: red blood cells (RBCs), white blood cells (WBCs), haemoglobin (Hb), haematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC).
 Results: rabbits treated with Aloe vera juice (group 1) showed insignificant change in WBCs count, MCH and MCHC after treatment for both periods. On the other hand, other parameters exhibited significant (RBCs count) and highly significant (Hb and Hct values) change in rabbits treated for the short period. The rabbits of the second group (treated with malathion) exhibited a marked increase in WBCs count, MCV and MCH values, while, the values of RBCs, Haemoglobin and Hct were decreased.
The protective group (Group3) showed that the values of all the tested haematological parameters (except MCHC, in both periods of treatment, and WBCs count in the short period of treatment) recorded a significant change in rabbits  treated for short (7 days) or long (21 days) periods. A marked recovery in RBCs count and MCH value was observed in rabbits treated for 21 days. Regarding to group 4 (the therapeutic group), it was found that in both terms the rabbits exhibited insignificant changes in the values of all the tested haematological parameters compared to their corresponding controls, except three parameters in which they recorded significant (WBCs count, MCHC) and highly significant (Hct) increase compared to their control values after the long period only. These observations indicated the ability of Aloe vera juice to improve the deleterious effects caused by malathion administration.