Tumours.
Leukaemia.
Multicentric lymphosarcoma: B or T cell tumours. All lymph nodes become enlarged without a corticomedullary junction and they may be palpable, especially the mesenteric lymph nodes.
Thymic lymphosarcoma: T cell tumours. Only the thymus becomes enlarged and eventually fills most of the thoracic cavity. This results in dyspnoea and diagnosis can be confirmed by radiography.
Alimentary lymphosarcoma: B cell. Tumours of the Peyer's patches.
FeLV-associated diseases:
Immunodepression. Infected cats may die from chronic gastrointestinal and respiratory diseases.
Reproductive failure: FeLV crosses the placenta of viraemic cats. This results in viraemic kittens with thymic aplasia or the placentitis can result in foetal resorption.