Abstract
Background: Parasitic infection is one of the main problems in equidae, particularly donkeys.
Aim: This study evaluated the oxidative stress in donkeys infected with Strongylus spp. through determining the correlation between antioxidants levels; malondialdehyde (MDA) and total antioxidant capacity (TAC) and the severity of parasitic infection. It also compared the therapeutic efficacy of piperazine citrate as an oral anthelmintic drug and Doramectin as an injectable one.
Methods: The study was conducted on 40 donkeys naturally infected with Strongylus spp. These donkeys were divided into two groups (20 donkeys each) according to treatment; piperazine citrate treated group [PipTG] and doramectin treated group [DoraTG]. Thorough clinical examination, hematological, biochemical and parasitological assays were performed before (Day 0) and after treatment (Days 7, 14, 21 and 28). All data were statistically analyzed by independent-sample t-test or paired t-test.
Results: In both groups, mean values of MDA was significantly reduced while those of TAC was significantly elevated after treatment at days 7, 14, 21 and 28. These significant changes were reported after treatment between PipTG and DoraTG with favor of DoraTG. Serum concentrations of MDA were significantly reduced while those of TAC were significantly elevated at DoraTG when their values compared with those in PipTG either at days 7, 14, 21 or 28. Significant correlations were reported in PipTG and DoraTG. Negative significant correlations were reported between faecal egg count (FEC) and each of whole blood picture indices (RBCS, Hb and PCV), serum TAC and faecal egg count reduction percentage (FECR%). Positive correlation was seen between FEC and MDA. MDA exhibited a negative correlation with both of blood picture and TAC; hence, TAC was positively correlated with these blood picture indices in both PipTG and DoraTG. In PipTG, anthelmintic resistance was present (R) at days 7 and 14 while it was suspected (S) at day 21 then it was absent (N) at day 28. In DoraTG, anthelmintic resistance was suspected (S) at day 7 then it became absent (N) at days 14, 21 and 28 post therapy. Conclusion: the immunological status of the infected donkeys was greatly improved after treatment. The therapeutic efficacy of injectable doramectin was more efficient than that of oral piperazine citrate in Strongylus spp. infected donkeys.

Key words: Donkeys, Doramectin, Malondialdehyde, Piperazine citrate, Strongylosis, Total antioxidant capacity.