Papillomaviridae Flashcards
Family: papillomaviridae
Can transform cultured cells
Produce papillomas (warts) on the skin and mucous membranes of most animal species
These warts are benign neoplasms are hyperplastic epithelial outgrowths that generally regress spontaneously
Usually species and site specific
Serologic cross reactivity has not been detected among papillomaviruses of different species
Occasionally may progress to malignancy, which in part is a property of specific virus strains
Family: papillomaviridae- replication
Linked intimately to the growth and differentiation of cells in stratified squamous epithelium of the skin and some mucous membranes
The story of oncogenic papillomaviruses
In benign warts, the virus DNA is episomal (not integrated with host DNA) and persists as an autonomously replicating episome
In papillomavirus-induced malignant cancers the viral DNA is integrated into that of the host. Thus integration probably is necessary for malignant transformation
Bovine Papillomatosis: host
Cattle
Warts are more commonly seen in cattle than in any other domestic animal
May occur in horses after exposure to cattle
Bovine Papillomatosis: Transmission
VIrus is transmitted between animals by contaminated fomites, such as milking equipment, halters, nose leads, grooming and earmarking equipment, etc
Sexual transmission of venereal warts in cattle
Fibropapilloma
Mostly caused by Bovine Papillomavirus 1, 2, 5
Papillomas have a fibrous core covered to a variable depth with stratified squamous epithelium, outer layers of which are hyperkeratinized
Lesions vary from small firm nodules to large coliflower-like growths
Grayish to black in color and rough and spiny to touch
Fibropapillomas are common on the udder and teats and on the head, neck and shoulders
They may also occur in the omasum, vagina, vulva, penis, anus
Cutaneous papillomas
Bovine Papillomaviruses type 3
lesions lack a fibrous core
Are usually flat with broad base, unlike the more usual fibropapillomas that protrude and are often pedunculated
Braken fern and Bovine Papillomatosis:
Bovine Papillomavirus 4 can cause transient papillomas in the alimentary tract
Ingestion of breaken fern can result in transition to invasive carcinoma of the alimentary tract
In cattle that eat braken fern, papillomavirus 1 and 2 may also contribute to the syndrome of enzootic hematuria that is characterized by hematuria and or urinary bladder cancer
Bovine Papillomatosis: Treatment
Surgical excision or cryosurgery with liquid nitrogen
Topical agents, podophyllin and undiluted medical grade DMSO
Bovine interferon-a
Bovine Papillomatosis: vaccine
Wart vaccine
Canine Oral Papillomatosis:
Contagious self limiting disease affecting oral cavity of dogs
The warts usually begin on the lips, and can spread to the buccal mucosa, tongue, palat, and pharynx. Later may become roughened and cauliflower-like. Do not extend below epiglottis or into esophagus
Lesions typically regress spontaneously
Progression to squamous cell carcinoma occurs rarely
Canine Oral Papillomatosis: Clinical signs
Halitosis (bad breath), hemorrhage, ptyalism (hypersalivation), discomfort
Numerous warts may interfere with mastication and deglutition
Warts may regress, or secondary bacterial infection and ulceration may occur
Ocular warts: conjunctiva, cornea, eyelid margins
Recovered dogs are refractory to reinfection
Canine Oral Papillomatosis: Treatment
Surgical excision, cryosurgery, electrosurgery
Autogenous vaccines
Equin Sarcoids
Commonly occur in horses, donkeys, and mules between 1-6 yrs. Most common neoplasm in Horses
They are locally invasive benign fibroblastic skin tumors
Associated with bovine papillomaviruses 1 or 2
Sarcoids do not metastasize. They may persist for life. Locally invasive. Recur after surgical removal
Equin Sarcoids: transmission
The mode of transmission has not been confirmed
Flies act as vectors?
Fomites, transmitted via stable management practives
