This study carried out in College of Veterinary Medicine /University of Basrah toevaluate the effect of different doses of pumpkin seed oil (PSO) on Thyroid functions inChlorpyrifos (CPF) treated male rats. Fifty adult male rats were used and randomly dividedinto five equal groups, 10 rats per each group: Group 1(control) administered orally cornoil(1ml /kg.bw) , whereas first treated group administered CPF 1/20th LD50 (6.7 mg/kg bw).Group 3, 4 and 5 were administered CPF (6.7mg /kg.bw) plus PSO(20, 40, and 80 ) mg/kg.bwrespectively. The treatments were given once daily by oral gavages for 8 weeks. At the end ofthe experiment, animals were sacrificed and blood samples were obtained for evaluation ofthyroid hormones (T4 and T3 ) and tissue samples from thyroid gland kept in 10% neutralformalin for histopathological examination.The results indicated that male rats treated with Chlorpyrifos demostreated a significantincrease (P<0.05) in thyroid stimulating hormone (TSH) and a significant decrease (P<0.05) inthyroxin(T4) and triiodothyronine (T3) hormones compared with control group.Histopathological examination of CPF treated males showed that thyroid gland revealeddestruction of thyroid follicles with infiltration of macrophages on the site of folliculardestruction. On other hand groups treated with 20,40 and 80 mg pumpkin seed oil inducedimprovement in above cited parameters and histological changes in dose dependent manner

Twenty-four male domestic shorthair cats were used to evaluate the acute and chronic effects of a single, toxic but sublethal, orally administered dose of chlorpyrifos. A dose of 10 mg/kg of body weight did not induce clinical signs of toxicosis, but a dosage of 40 mg/kg induced clinical signs of toxicosis, and 1 of 12 cats died. Chlorpyrifos given at a dosage of 0.1 mg/kg to 2 cats reduced whole blood and plasma cholinesterase (Che) activities to values obtained after cats were given doses that induced clinical signs of toxicosis. Regeneration time for whole blood and plasma Che activities ranged from 7 to 28 days. Brain Che activity was considerably decreased in 1 cat that died 4.5 hours after dosing, but was normal in all others at 28 days after dosing. Other than decreased Che activity, significant changes were not seen in hematologic or serum biochemical values. Toxin-related lesions were not seen during macroscopic or microscopic examination.