Levels of polychlorinated biphenyls and organochlorine pesticides in donkey milk: Correlation with the infection level by intestinal strongyles

AIM

The study aimed at evaluating the concentration levels of organochlorine pollutants in donkey milk and their modulation on the intestinal strongyle infection. Risk evaluation for consumer health was also investigated.

METHODS

We analyzed milk of grazing donkeys living in areas of Southern of Italy affected by organochlorine compounds environmental pollution and parasite infection. The presence of pollutants was assessed through summary statistics; regression analysis of intestinal strongyle on pollutant concentration was performed to investigate the relationship between the two variables.

RESULTS

PCB concentrations (mainly non-dioxin-like (ndl)-PCBs) were higher than OCP ones. Mean values of ndl-PCBs across areas ranged from 93.13 to 263.64 ng g^-1. In all sample units we detected the six indicator PCBs with the prevalence of the PCB 153, followed by the PCB 28 and the PCB 101. Among the dioxin-like (dl)-PCBs, non-ortho PCB 169, 77 and 126 were assessed in some milk samples; in all areas we detected the mono-ortho PCB 118 and PCB 105. Positive correlation between infection level and six indicator PCBs as well as between the former and HCB, on WW and LW, were observed (at least statistically significant at 5 percent). In some cases, Dl-PCB concentrations emerged as dangerous given the EU maximum residue limit for PCDD/Fs and dl-PCBs.

CONCLUSION

Evidence supports the hypothesis of an immunosuppressive role of organochlorine pollutants; risk evaluation reveals the potential health impact of dl-PCB intake, particularly for major donkey milk consumers such as infants, children with cow milk and multiple food intolerance, and elders.

Preliminary Observations of the Effect of Garlic on Egg Shedding in Horses Naturally Infected by Intestinal Strongyles

Intestinal strongyles are the most common endoparasites of horses, and anthelmintic treatments are the main strategy to control these nematodes. However, the development of anthelmintic resistance has led to a decreased efficacy of synthetic drugs, and for this reason, there is a growing interest in alternative control strategies as the use of medicinal plants. The aim of the present study was to determine the in vivo efficacy of garlic (Allium sativum) in horses naturally infected by intestinal strongyles. The field trial was conducted in a horse trotter farm in Southern Italy. Fifteen mares were selected based on fecal egg count >200 eggs per gram and allocated into three groups of five animals: fresh garlic group (FG group), animals received 40 g of fresh crushed garlic once daily for 15 days; dry garlic group (DG group), animals received 40 g of commercial dry garlic flakes food supplement once daily for 15 days; and control group (C group), not treated. Two weeks after the first administration of garlic, fecal egg count reduction test showed failure of garlic to reduce intestinal strongyles egg shedding (-11.7% and -19.4% for FG and DG groups, respectively). Red blood cell count values were in the normal ranges over the entire period of garlic administration. In our study model, the oral administration of garlic formulations has no effect on reducing the egg shedding of intestinal strongyles, and the garlic supplementation over a short period of time is not responsible for hematological changes in horses.

Anthelmintics efficacy against intestinal strongyles in horses of Sardinia, Italy

Intestinal strongyles (IS) are the most important parasites of equids, due to their high prevalence worldwide, pathogenicity and the spread of drug-resistant populations. Despite the large number of horses bred in Sardinia Island, Italy, no data are available on the efficacy of anthelmintic compounds in the control of horse strongylosis. Therefore the aim of the present study was to evaluate the efficacy of five commercial anthelmintic formulations containing fenbendazole (FBZ), pyrantel (PYR), moxidectin (MOX) and two ivermectin formulations (IVM1 and IVM2) against IS in Sardinia by performing a fecal egg count reduction test (FECRT) and investigating the egg reappearance period (ERP) after treatment. In total, 74 horses from 7 farms were examined. Coprocultures performed for individual fecal samples collected at the day of the treatment revealed that cyathostomins were the predominant parasitic species (98.6%). The FECR for all horses belonging to the treatment groups after two weeks was ≥ 95% with a 95% C.I. > 90%. The expected ERP did not decrease in any of the treatment group as FECR values < 90% were found at D60 for FBZ, at D90 for PYR and IVM1, at D150 for IVM2. All horses treated with MOX showed FECRT > 90% for the entire duration of the trial until D150. The results of the present survey indicate that drug-resistant cyathostomin populations are not present in the examined horse population, contrariwise to what observed in other Italian and European regions. The reasons and implications of these results are discussed.