Mobile ad hoc network, is nowadays becoming extremely famous in research vicinity. A range of protocols and methodology is coming into account to resolve an assortment of issues associated with a mobile ad hoc network. The nodes in mobile ad hoc network are present in ad hoc fashion i.e.; they are connecting to each other without using wires. In addition, they do not necessitate any central authority for performing their tasks. This thing creates mobile ad hoc network active and disseminated in character. In this paper, we implemented improved Watchdog protocol called as I-Watchdog protocol with Destination-Sequenced Distance-Vector Routing (DSDV) routing protocol that provides efficient and secure routing with prevention of denial of service attack as well as detection of congestion in the network background. In this paper, proposed I-Watchdog procedure does proficient recognition of the presence of malicious nodes in a mobile ad hoc network as well as it finds the genuine reason of the happening of loss of packets. Additionally, we will analysis the improved performance of mobile ad hoc network in the presence of DSDV with I-Watchdog protocol in provisions of packet drop ratio (PDR), throughput along with end-to-end delay.