Slaughterhouse Study on the Prevalence and Pathological Lesions Caused by Dictyocaulus Viviparus Infection in Cattle and Water Buffaloes

Background:  Dictyocaulus viviparus nematode is the cause of severe bronchitis in dairy animals which lead to significant economic losses in the industry of this type of livestock. The present study aimed to determine the incidence of D. viviparous, a highly endemic parasite in cattle and water buffaloes in Guilan province, Iran. Materials & Methods:   Stool samples from 212 cows and 189 buffaloes were tested using the Baermann technique. After slaughtering the animals, the lungs of all cows and buffaloes were isolated, sampled and carefully studied to determine D. viviparus in the lungs. Results:   In general, there was a significant difference in the prevalence of D. viviparus in the fecal samples of cows (22.64%) and buffaloes (26.32%). Macroscopic study revealed symptoms of severe pneumonia, nodular lesions, and hyperemia in lung tissues of 5 cows and 5 buffaloes. Microscopic (histopathological) studies showed lymphocytic bronchiolitis and multifocal eosinophilic with wide interalveolar walls in lungs infected with D. viviparus. Conclusion:   The prevalence of this parasite among cattle and buffaloes were 22.64% and 26.32%, respectively; but the difference between these two animal species was not significant. Overall, the prevalence of D. viviparus was higher among young animals in both species.