In-vivo and in-vitro effectiveness of three insecticides types for eradication of the tick Rhipicephalus sanguineus in dogs

Abstract

Background: External parasites contribute to extensive harmful impacts on their hosts which is why control and eradication of external parasites have been included in all biosecurity plans of dog houses.
Aim: To evaluate the in-vitro and in-vivo effectiveness of chemicals like Doramectin injectable and Fipronil 50 mg/ml drops and herbal mixes eco-friendly insecticides like phenylpyrazole–garlic–camphor mix spray for combating the external parasitism in dogs and their influence on the hematological, biochemical, and cortisol (CORT) profiles.
Method: The in-vitro effectiveness of the insecticides was conducted by using a total of 216 developmental stage Rhipicephalus sanguineus (72 adults, 72 larvae, and 72 eggs) designed into three replicates of petri dishes (3 plates × 8 units × 3 stages/replicate); each replicate was exposed to 1 ml insecticide. The number of surviving ticks was recorded after 0, 2, 4, 8, 16, and 24 hours. Sixteen Rottweiler male dogs aged 1 year and 45.5 kg were divided into four groups. Three groups (G1, G2, and G3) were experimentally infested with R. sanguineus ticks 3–4 weeks post-dog arrival and kept under observation from zero-time of experimental infestation for 1–2 weeks. The three experimentally infested dog groups were treated with Doramectin injectable, Fipronil 50 mg/ml drops, and phenylpyrazole–garlic–camphor mix spray, respectively, and the fourth group was designed as a negative control.  A total of 144 samples, including 48 ethylenediaminetetraacetic acid blood, 48 whole blood, and 48 sera samples, were collected.
Results: The in-vitro efficacy revealed highly significant (p < 0.01) 100% killing efficacy that was achieved after 8 hours in Doramectin and Fipronil 50 mg/ml and 24 hours in phenylpyrazole–garlic–camphor mix. The in-vivo trials revealed highly significant (p < 0.01) improvements of red blood cells, hematocrit, mean corpuscular hemoglobin concentrations, platelets, total and differential leukocytic counts, erythrocyte sedimentation rates in the second hour, total protein, creatinine, alanine aminotransferase, urea, glucose, triglycerides, total cholesterol, and CORT levels in the 2-week (P₁) and 4-week posttreatment (P₂) samples in Dormectin, Fipronil 50 mg/ml, and phenylpyrazole–garlic–camphor mix-treated dogs with more pronounced recovery in phenylpyrazole–garlic–camphor mix spray-treated dogs.
Conclusion: The insecticides were able to provide a high level of protection against experimental infestation with concern to the different modes of application. Phenylpyrazole–garlic–camphor mix spray (eco-friendly) achieved higher insecticidal action compared to the chemicals.