Papillomaviridae

Question 1

Describe the general characteristics of Papillomaviridae.

Answer 1

-transform cultured cells
-produce papillomas (warts) on skin & MM
>warts are benign neoplasms = hyperplastic epi outgrowth that regress spontaneously
>may progress to malignancy - part of property of specific virus strains
—EX: HPV -> cervical carcinoma in women
-species & site specific
-serologic cross reactivity not detected
-replication = growth & differentiation of cells in strat squamous epi of skin & MM

Question 2

Describe oncogenic papillomaviruses.

Answer 2

1. Benign wart = papillomavirus DNA is episomal
   >not integrated into host cell DNA & persist as auto rep episome
2. Papillomavirus induced malignant cancer = viral DNA integrated into host

Question 3

Describe bovine papillomatosis.

Answer 3

1. Host = cattle (warts common)
   -natural bovine papillomavirus inf of horses occur after exposure of horse to cattle
2. Transmission
   -contam fomites (milking equipment, halter, nose lead, grooming, earmarking equipment etc)
   -sex (venereal warts)

Question 4

Describe the different types of bovine papillomatosis.

Answer 4

1. Fibropapilloma
2. Cutaneous papilloma
3. Bracken fern

Question 5

Describe fibropapillomas in bovine.

Answer 5

-caused by bovine papillomavirus type 1,2,5
-fibrous core covered w strat squamous epi
>outer layer is hyperkeratinized
-lesions are small firm nodules to lg cauliflower like growth
-grayish to black & rough/spiny
-common on udder & teats, head, neck, shoulders
>also: omasum, vag, vulva, penis, anus

Question 6

Describe cutaneous papillomas in bovine.

Answer 6

Bovine papillomavirus type 3
-lesion lack fibrous core
-flat w broad base

Question 7

Describe bracken fern in bovine papillomaviruses.

Answer 7

Bovine papillomavirus 4
-transient papilloma in alimentary tract
-ingest bracken fern = transition to invasive carcinoma of alimentary tract
-bracken fern has carcinogens, mutagens, immunosuppressive chemicals
-papillomavirus type 1 & 2 may also contribute to the syndrome of ‘enzootic hematuria’ -> urinary bladder cancer

Question 8

Describe the treatment of bovine papillomatosis.

Answer 8

Treatment:
-surgical excision, or cryosurgery w liquid nitrogen
-topical agents, podophyllin & undiluted medical grade DMSO (DiMethylSulfOxide)
-bovine interferon-a
-wart vaccine = killed

Question 9

Describe canine oral papillomatosis.

Answer 9

-contagious, self limiting dz affecting oral cavity of dogs
-warts benign on lips & spread to buccal mucosa, tongue, palate, pharynx -> roughened & cauliflower like
>dont extend below epiglottis or into esophagus
-lesions regress spontaneously
-progression to squamous cell carcinoma (rare)

Question 10

Describe the clinical signs and treatment.

Answer 10

1. CS
   -halitosis (bad breath), hemorrhage, ptyalism (hypersalivation), discomfort
   -warts interfere w mastication & deglutition
   -warts regress or secondary bacterial inf & ulceration
   -ocular warts = conjunctiva, cornea, eyelid
   -recovered dogs are refractory to reinf
2. Treatment
   -surgical excision, cryosurgery, electrosurgery
   -autogenous vaccine

Question 11

Describe equine sarcoids general characteristics, transmission, lesions, & treatment.

Answer 11

GC:
-horse, donkey, mule (1-6yr) most common neoplasm in horses
-locally invasive benign fibroblastic skin tumors
-associated w bovine papillomaviruses 1 or 2
-dont metastasize
-persist for life
-locally invasive
-recur after surgical removal
Transmission:
-not confirmed
-flies act as vectors
-fomites, transmitted via stable management practices
Lesions:
-occur in traumatized areas
-single or multiple
-growths reach size of man fist, bulge under skin
-become ulcerated
Treatment:
-cryotherapy, surgical or laser excision, local immune modulation, local radiotherapy