Electron microscopic studies of canine mammary tumors

Spontaneous mammary tumors in high cancer strain female mice have been shown to be of viral etiology. These tumors contain characteristic virus particles, which can be consistently detected on electron microscopic examination. However, with very few exceptions, virus particles could not be found in spontaneous mammary tumors developing in other species, including humans. Therefore, in the present study Electron microscopic studies were conducted to know the ultra structural changes in canine mammary tumor and tissues were examined for the presence of virus like particles as a causative in the development of tumors.