Age Susceptibility of Ducks to the Rous Sarcoma Virus and Variation of the Virus in Ducks

The study demonstrates that ducks, previously considered resistant, can be infected with the Rous sarcoma virus if injected shortly after birth with large amounts of the virus. Infected ducklings develop either a fatal hemorrhagic disease or sarcomata that appear weeks to months later. Once tumors are induced, the disease can be transmitted to other ducks regardless of age, leading to widespread tumors. Interestingly, the virus loses its ability to infect adult chickens after passing through ducks. This research highlights the age-dependent susceptibility and the virus's ability to adapt to different hosts, resulting in varied disease manifestations.