Lymphoproliferative Disease, a disease of turkeys and chickens, is caused by a retrovirus (LPDV).
Known to occur in domestic turkeys in Europe and Israel, LPDV was first recognized in wild North American turkeys in 2009. Sporadic cases have been identified every year since then, though its significance for wild turkey populations is unknown. LPDV seems to be a disease that has spilled over from domestic to wild birds.
LPDV affects domestic chickens and wild turkeys. To date, the disease has only affected turkeys in the wild. Rare cases of a similar disease have been seen in other wild birds in North America, however these cases were not caused by LPDV, but rather a similar, related virus.
Domestic fowl are affected by LPDV in the UK, Austria, the Netherlands and Israel. Wild turkeys have been diagnosed with the disease, in Arkansas, Georgia, New Jersey, New York, New Hampshire, Maine, North Carolina, Pennsylvania, and West Virginia. Others have been found positive for the virus, but without diagnostic lesions.
It is believed that the disease is transmitted horizontally between birds that have had direct contact.
Disorientation, weakness, lethargy are common signs in those birds that are still alive, though the disease is rapidly fatal and birds are often found dead. Scabby nodules on the skin of the legs and head are also often seen.
Multiple tan nodules in the organs, enlarged spleen and liver, and skin nodules are suggestive of LPDV infection. Turkeys with this disease may also have concurrent infection with Avian Pox virus, though the relationship between these viruses is currently unclear. Laboratory tests can detect the viruses that are present. Please refer to the Avian Pox disease description for more information on clinical signs and diagnosis of that disease.
No treatment is available.
Because turkeys are flocking birds, proximity is an important risk factor. Practices that bring birds together such as feeding will lead to the spread of the disease if the virus is present.