Viral and protozoal skin disease Flashcards
1
Q
Name large animal vesicular diseases?
A
- Foot and Mouth Disease*
- Vesicular Stomatitis*
- Swine Vesicular Disease*
- Blue Tongue*
- Rinderpest*
- Malignant Catarrhal Fever
- Mucosal Disease
- Infectious Bovine Rhinotracheitis
- Bovine Herpes Mammillitis
* notifiable
2
Q
What are the genera clincal signs of vesicular diseases?
A
- Vesicles (small fluid filled elevations less than 1cm) and when vesicle bursts you see erosions/ulcers
- Affect broadly non haired areas
- Muzzle
- Oral mucosa
- Tongue
- Udder, teats
- Coronary band
- Can shed hooves & horns
3
Q
Name 2 other notifiable diseases, clinically indistinguishable from FMD?
A
Vesicular stomatitis:
- Occurs in Cattle, pigs, horses
- Never seen in the UK
- Mortality moderate to low
- Spread by biting insects
- Zoonotic – influenza-like symptoms, occasionally mucocutaneous vesicles & erosions
Swine vesicular disease
- Pigs
- Eradicated from UK in 1982
- Endemic in Italy
- Mortality low, some loss of production
- Spread by direct contact, fomites, infected meat products
- Spreads more slowly than FMDV
4
Q
What are the clinical signs of blue tongue in sheep?
Spread by culicoides
A
- Oral ulcers
- Discharge of mucus and drooling from mouth and nose
- Swelling of the mouth, head and neck and coronary band
- Occasionally
- Purpura (non blanching rash)
- Fever
- Lameness
- Breathing problems
5
Q
How are Notifiable Viral Diseases controlled?
A
- Usually no treatment
- Slaughter & disposal of infected & in-contact animals
- –> Quarantine/Protection zone
- –> Movement restrictions
- –>Disinfection
- +/- Vaccination
- Eradication programmes
- Surveillance programmes – monitor spread
- Reporting of confirmed cases
6
Q
What is this?
A
Bovine Herpes Mammillitis (Ulcerative mammilitis)
7
Q
How many bovine papilloma viruses are there?
A
6 types in the cow - I, II, III, V & VI important in skin
8
Q
Describe bovine papilloma virus and it’s significance?
A
- Highly prevalent in the UK – 50% of cattle have lesions =‘Angleberries’, cutaneous warts
- Usually animals 6-24mo old
- May present as
- Large, cauliflower-like masses – head, neck, shoulders
- Flat wide-based warts
- Pedunculated masses
- Lesions on body rarely cause problems – unsightly, especially show animals
- May bleed & become secondarily infected
- Lesions on teats or genital areas problematic
9
Q
How should bovine papilloma virus (warts) be treated?
A
- Warts contain large amounts of infectious material
- Trauma from fence posts, halters, contaminated tagging equipment etc à transmission
- Treatment not usually required – spontaneous regression
- Surgical removal if pedunculated?
- Disinfect stalls, fence posts & other environmental reservoirs
- Autogenous vaccine
10
Q
Describe classical swine fever?
A
- Identical clinical signs to African Swine Fever (also notifiable, never seen in UK)
- Fever
- Constipation, diarrhoea
- Conjunctivitis
- Blotchy discolouration of the skin (not vesicles or ulcers)
- Abortion, stillbirth, weak litters
- Hindlimb weakness
- Nervous signs
- Recovered pigs excrete virus for long periods
- Can remain active for months
- CAN LOOK SIMILAR: d/d Post-weaning Multisystemic Wasting Disease (PMWD)/ Porcine Dermatitis Nephropathy Syndrome (PDNS)
11
Q
Discuss border disease?
A
- ‘Hairy shakers’ ‘Fuzzy Lamb disease’
- Border Disease Virus (Pestivirus)
- Congenital infection
- Small, weak lambs
- Abnormally hairy birth coat
- Tremor of skeletal muscles
- –> Death
- Abortion, stillbirth in ewes
- Some lambs survive – if infected in first half of gestation –> persistently infected (PI) sheep – source of infection for pregnant ewes
- Control
- Management - prevention of exposure of pregnant ewes to PI sheep. No vaccine.
12
Q
What is Parapoxviruses more commonly known as?
A
- Contagious pustular dermatitis (orf)
- Pseudocowpox
- Bovine papular stomatitis
13
Q
Name Small Animal Viral Skin Diseases?
A
- Canine Papillomas
- Feline Papillomas
- FeLV/FIV
- Feline Calicivirus
- Feline Herpesvirus
- Canine Distemper Virus
- Cowpox
- Myxomatosis
14
Q
What is this?
A
Canine papillomas (warts)
- Contagious via direct/indirect contact
- Usually allow to resolve spontaneously, though new ones may develop
- Treatment
- Surgery if causing problems
- Topical keratolytic/softening preparations (water & petroleum jelly)? Decreases discomfort but does not alter the course of the infection
- Imiquimod cream? Interferon? Azithromycin? Anecdotal reports not well validated.
15
Q
What might this be?
A
Canine papillomas (warts)
- Pigmented viral plaques (little black spots in these breeds could well be viral plaques)
- Especially French bulldogs, pugs
- May not spontaneously resolve
- Care re concurrent use of immunosuppressive drugs…
17
Q
What is this?
A
Feline Calicivirus/Herpesvirus
- Oral ulceration
- Mild sneezing & conjunctivitis
- +/- Lameness, polyarthritis
- +/- small ulcers/crusts – look like cat bites
- +/- severe facial dermatitis/ulceration (a d/d for head and neck pruritus)
- Rare virulent form with marked crusting, oedema, systemic disease àdeath
- See Cardiorespiratory teaching for management
18
Q
What might this be?
A
Cowpox
- Important because it looks very like other feline skin diseases. Often seen in cats that hunt a lot.
- Orthopoxvirus
- Uncommon
- Cattle rarely implicated as a source of infection for cats. Natural reservoir is small wild animals – voles, woodmouse - cats infected while hunting
- –> infected bite wound head, neck, forelimb –> small nodule –> Viraemia (+/-mild pyrexia, inappetance, depression) –> 10-14 days – multiple secondary lesions over body – papules/nodules, plaques/crusts
- Rarely pruritic
- Usually seen July to November
- Occasional generalised systemic infection
- D/d Cat bite abscess, eosinophilic granuloma (these are often treated which large dose of steroids which is the worst thing you could do if it has orthopoxvirus), dermatophytosis, superficial pyoderma, mycobacterial infection (feline leprosy)
- Spontaneous resolution over 6-8 weeks
- Broad spectrum antibiotics if secondary infection
- DO NOT GIVE CORTICOSTEROIDS!
- Zoonotic! Can kill immunosuppressed people
19
Q
Which protozoal disease is of concern in the UK now and why?
A
Leishmaniasis
- Worldwide distribution – Mediterranean & Portugal, now reported in northwest Europe
- UK? Not yet? Only dogs travelled abroad
- Zoonotic!
- Transmitted by bloodsucking sandflies
- Reservoir – domestic & wild dogs, rodents, other wild mammals
- Incubation – weeks to years, mainly dogs < 5 years - dogs imported from endemic areas may develop disease months or years later!
- Infection
- –> Th1 response –> cell-mediated immunity –> resistance
….or…..
- Th2 response –> humoral response –> persistent infection/ clinical signs
- 2 pathogenic mechanisms if they become infected:
- Non-suppurative granulomas (à skin, hepatic, enteric, osseous disease)
- Circulating immune complexes (à renal, joint, ocular lesions)
- Slowly-progressive, multi-systemic disease…
- Complex disease with several manifestation
22
Q
How is leishmaniasis diagnosed?
A
- Demonstration of organism in macrophages in lymph node or bone marrow aspirates
- Serology or PCR (many animals imported from spain etc.. Will show antibodies means they have come across disease but not actively infected)
- Skin biopsies supportive
