Viral Diseases of Skin Flashcards
describe papilloma virus, include transmission, clinical disease, treatment, and prevention
virus: naked, double stranded DNA virus that is very stable in the environment
transmission: direct contact
clinical disease: warts, sometimes can lead to malignant cancers
treatment: generally self-limiting, depending on case and severity can surgically remove or freeze
prevention: no vaccine for canine papilloma virus
-keep away from infected dogs and wash toys
describe strains of canine papillomavirus
CPV1: MOST common
-oral exophytic papillomas
-endophytic papilloma
-invasive SCC
CPV2:
-endocytic papillomas
-SCC in situ (local)
CPV3, 4, 5:
-pigmented plaques
-occasional SCC
CPV6: endophytic papillomas
CPV7: exophytic papillomas
-SCC in situ (local)
may be FYI
describe the disease course of canine papilloma virus
- virus infects BASAL layer of the stratified squamous epithelium
- basal cells increase in their mitotic activity and develop wart like structures
- infectious particles are synthesized as basal cells and then differentiate into CORNEAL layers
-often causes hyperkeratosis!! - lesions generally spontaneously regress as the cell-mediated immunity causes destruction of infected cells
describe clinical disease of canine papilloma virus
- can appear as solitary or multiple papillomas
- can be pigmented, rounded, have frilled edges, or other
- can be oral, genital, on the eyelid or conjunctiva, on the footpads, or form fibropapillomas (muscle)
- papillomas growing inward (endophytosis) can cause pain, esp on feet
- generally benign but
-can become inflamed, ulcerate, or be in areas/be so numerous that they inhibit normal activity - can undergo malignant transformation and become cancerous
describe bovine papilloma virus
- warts on the skin and in the alimentary tract
-13 types: BPV 1-13 - groups:
-deltapapillomavirus (fibropapillomaviruses): infect only keratinocytes, cause proliferation of keratinocytes and fibroblasts; multiple lesions in animals <2 years and often spontaneously regress within 1 year
–BPV1: infects paragenital areas, including penis, teats, and udders
–BPV2: infects skin, GIT, bladder
–can interfere with breeding and calving
-xipapillomavirus: infects keratinocytes, papillomas only involve epithelium
–BPV 3 (skin), 4 (upper GIT), 6 (teats and udders)
-epsilonpapillomavirus: BPV5 both papillomas and fibropapillomas
- highly prevalent worldwide:
-cutaneous warts most common in younger animals (<2 years)
-not all animals carrying virus will have warts (carriers possible) - transmission:
-contaminated halters, tattooing ear tagging tools, or any skin cut
-warts on the teats of lactating cows transmit to calves via abrasions
describe disease course of bovine papillomavirus
- warts will appear 1-6 months after inoculation
- warts spread from the ear to other sites on the head and neck
- duration is very variable: 1month to >1 year
- spontaneously regress due to animal’s immune response
- recurrence is possible
describe equine papillomavrius
- warts on: face, distal limbs, ears, genitals
- young horses (<3 years)
-generally resolve on own or use
–cryotherapy (cosmetic)
–chemical cautery - infection with bovine papillomavirus (esp types 1 and 2) can cause sarcoids
-locally aggressive, non-metastatic fibroplastic skin tumors
-infection alone is not enough to cause sarcoid though, need some other trauma, immunosuppression, etc.
describe vesicular stomatitis virus
virus: rhabdovirus; enveloped, negative-sense RNA virus
transmission: SW US
-spread by black fly vector
-plus direct contact with lesions
-can spread to humans and cause flu-like symptoms
clinical disease:
-horses, cattle, swine, sheep, camelids: crusting scabs or lesions on mouth, tongue, nostrils, ears, coronary bands, hooves, teats, ventral abdomen
treatment: treat lesions to prevent secondary infections
prevention: insect control
REPORTABLE DISEASE: resembles much more serious pathogens so gotta make sure it’s just this
–the ONLY vesicular virus of horses though
describe foot and mouth disease virus
virus: picornavirus; naked, positive-sense RNA virus
transmission:
-contact with saliva, nasal secretions, or feces from infected animals or contaminated objects
clinical disease:
-cloven-hoofed animals (cattle, swine, sheep, goats): causes fever and blisters on mouth, tongue, nostrils, and hooves
–loss of appetite and lameness
treatment: supportive, treat lesions to prevent secondary infections
prevention: avoid contact with infected animals
-wash and disinfect and vaccinate (no vx in US rn because it’s not here now)
REPORTABLE DISEASE: currently NOT in the US and strict import rules in place to keep it from coming it
the MOST IMPORTANT economic disease of livestock in the world
describe the different hosts and general clinical signs of foot and mouth disease
cows: indicators; come down first
swine: amplifiers; once they get it, virus goes crazy and replicates
sheep and goats: maintenance; may not notice they have it, more subclinical or VERY SUBTLE
in general:
1. animals don’t eat, nurse, or move around
2. tremendous loss in body weight
3. recover 3 weeks later but now gaunt condition (economic loss)
how is foot and mouth disease virus handled/controlled (4)
- prevent entry into country
- depopulation and disinfection of farm
- ring vaccination of farms around infected farm
- vaccination when endemic
what viruses all cause vesicular disease of swine?
- foot and mouth
- vesicular stomatitis virus
- vesicular exanthema of swine
- senecavirus A
importance: all signs indistinguishable from FMDV, have commercial/exportation restrictions when present
ALL reportable except senecavirus A; contact state vet IMMEDIATELY
generally describe vesicular stomatitis virus (VSV), swine vesicular disease virus (SVDV), vesicular exanthema of swine virus (VESV), and senecavirus A (SVA)
VSV: rhabdoviridae
-hosts: equids, ruminants, swine, humans
-transmission: insect vectors (flies) and direct contact
-source of virus: vesicle fluid
SVDV: picornaviridae/enterovirus
-host: swine
-USA is free
-transmission: DC, fomites
-source of virus: oral secretions, feces, urine, semen
VESV: caliciviridae
-host: swines, seals, cetaceans
-eradicated in swine globally, circulates in marine mammals
-transmission: DC
-source of virus: vesicle fluid, oral and nasal secretions
senecavirus A: picornaviridae/senecavirus
-host: swine, cattle, wild mice
-transmission: oral-nasal, DC, fomites
-source of virus: oral and nasal secretions, feces
describe diagnosis and control of vesicular disease of swine
diagnosis:
-antibody response: serum, oral fluid
-RT-PCR, ELISA, virus isolation: CFT
vesicular fluid, scrapings, swab (erosions, nasal, oral), feces
control:
-screening and quarantine
-surveillance
-control of importations: animals, animal products, semen, embryos
-heat treatment of waste food fed to pigs
-outbreaks: quarantine, movement restriction, cull positive and in-contact, clean and disinfect
-vx used in countries where FMD has not been eradicated
describe orf disease virus
virus: parapoxivirus; enveloped dsDNA virus
transmission:
-contact with saliva
-nasal secretions
-bites from infected animals
-contaminated objects
-can spread to humans and cause painful blisters (ZOONOTIC, proliferative)
-even though enveloped, can survive for 12 years in the environment in crusts!!!
clinical disease:
-sheep and goats: blisters or lesions on mouth, lips, muzzle, tongue, nostrils, teats, or crusting lesions on ears and feet
treatment: supportive, treat lesions to prevent secondary infections
vaccination: live vaccines
-best used in animals <1 month old
-brush vaccine over scarified areas of skin; inside thigh or behind elbow
-segregate vaccinated animals from unprotected stock until scabs fall off
describe bluetongue virus
virus: reovirus, naked dsRNA virus
transmission:
-spread by biting midges in cullicodes species
host range: sheep, goats, cattle, wild ruminants (deer, elk, etc.)
clinical disease:
-fever, face and tongue swelling, excessive salivation, cyanosis of tongue (blue hue)
-foot lesions and lameness, can cause constant changing position of the feet (dancing disease)
-can cause death!!!
treatment: supportive
prevention: avoid contact with infected animals, wash and disinfect, vaccinate (canNOT use vaccine when vector is present bc is a live virus and can reassort with the strains in the vectors)
describe pathogenesis of bluetongue virus
- affects large and small ruminants: sheep are most severely affected of domestics, goats, cattle, deer
- additional effects of vascular injury:
-thrombosis and infarction of tissues: tissue ulceration, cyanosis of lips and tongue, cyanosis and necrosis of coronary band
describe clinical signs of bluetongue virus
- most common in sheep after a 4-6d incubation period
-fever >105F
-listless and reluctant to move
-edema: lips, nose, submandibular region, ears, tingue
-ulcers in nose and mouth
-difficulty walking - in young lambs:
-signs more severe with higher mortality risk (>30%)
-pulmonary edema and asphyxiation - in mature animals:
-signs often more mild
-death results from bacterial complications and wasting/exhaustion - sudden death can occur at any time
describe control of bluetongue virus
- vaccination in endemic regions
-monovalent MLV vx avail
-do NOT use during vector season
-AVOID use in pregnant animals - killed and MLV vaccine for cattle (in europe only)
3, in europe can control with insecticide (not here tho)
describe canine distemper virus
virus: morbilivirus, enveloped negative-sense RNA virus
transmission: respiratory pathogen, close contact
host range: carnivores, ferrets, otters, seals, skunks
clinical disease:
-diphasic fever, depression, anorexia, interstitial pneumonia in severe cases (many more systemic)
-if survive acute phase, may develop nasal and digital keratosis, enamel hypoplasia, etc.
treatment: supportive
prevention: vaccinate, avoid contact with infected animals, wash and disinfect
describe feline herpesvirus
virus: herpesvirus, enveloped dsDNA virus
-feline viral rhinotracheitis
transmission: fomites and respiratory spread
clinical disease:
-fever, tearing, rhinitis, salivation, depression, anorexia
-ocular: conjunctivitis, keratitis, corneal ulcers
treatment:
-antiviral: oral or topical
-if secondary bacterial infection also present, abx
-supportive
prevention:
-FVRCP vaccination
-low stress environment
-avoid contact with infected animals
-wash and disinfect
describe canine herpesvirus
virus: herpesvirus, enveloped dsDNA virus
transmission:
-mother-pup tranmission during birth
-older animals: direct contact with virus containing fluids (nose, mouth, vaginal)
clinical disease:
-young (<3 wks): extremely dangerous and causes death within 48hr of symptoms (diarrhea, anorexia, hypothermia, poor febrile response, unchecked replication and systemic spread, fatal generalized necrotizing and hemorrhagic disease
-puppies >3 weeks: can develop lung infection and pneumonia, serious
-adults: mild; eye discharge, coughing, nasal discharge, genital sores, abortion, stillbirth
treatment:
-puppies: moving litter to nurse from mother with antibodies, keep them warm
prevention: avoid contact with ifnected animals, wash and disinfect
describe canine herpesvirus in older puppies and adults
- limited to respiratory, ocular, or genital tract
-NO systemic spread - generally subclinical or mild and self limiting
- short replication periods
- latency established in nervous tissue and lymphoid tissue
-reactivation with immunosuppression and stress!!
-generally see conjunctivitis, increased nasal secretions, genital lesions
-can see kennel cough (CIRDC!)
describe canine herpesvirus latency and reactivation
- after recovery (7-14d) virus will establish latency
-nervous tissue: sensory nerves and ganglia
-lymphoid tissue: tonsils, thymus, and LNs - reactivation occurs due to stress, pregnancy, immunocompromise, immunosuppressive therapy
