Dermatology Flashcards
what factors can contribute to rub marks on cows?
cubicle design/bedding
feed barriers
cleanliness - management, SARA…
welfare/bullying
what is pediculosis?
lice infestation
what are the main clinical signs of lice infestations in cattle?
usually pruritic
patterned hair loss - head, neck, flanks, shoulders
what are the two types of lice?
sucking and chewing
what sucking lice are found in cattle?
Linognathus vital
Haematopinus eurysternus
what chewing lice are found in cattle?
Bovicola bovis
what can heavy sucking lice infestations have on calves?
anaemia
what possible mite infestations can effect cows?
Chorioptes bovis
Sarcoptes scabei
Psoroptes bovis
Demodex bovis
(most to least rare)
what are the clinical signs of mite infestations in cattle?
pruritis, rubbing and hair loss
what is the distribution of Chorioptes and Psoroptes?
legs, feet, tail base, caudal udder
what is the distribution of Sarcoptes?
neck and face
how can mites be diagnosed?
skin scrapes around the edge of lesions (deep needs capillary ooze)
which mite of cattle is zoonotic?
Sarcoptes scabei
what shaped pedicles does Chorioptes bovis?
cup shaped
what shaped pedicles does Sarcoptes scabei have?
trumpet
what is done to treat pediculosis and mites in cattle?
check underlying health, management and husbandry
mild infections are self limiting
synthetic pyrethroids or macrocyclic lactones (determine if chewing/sucking mite)
what is the most common cause of ringworm in cattle?
Trichophytan verrucosum
how would ringworm lesions be described?
circumscribed crusted plaques that can form large coalescing lesions
how is ringworm treated/controlled?
clean/disinfect housing
turn out animals
vaccine can reduce severity
topical enilconazole
what causes pustular impetigo in cattle?
Staphylococcal infections
where is pustular impetigo localised to?
wounds, udder, perineum, ear tags
what are some common areas for abscess formation?
lower jaw
lymph nodes
infected/chronic haematomas
penetrating injuries
what causes lumpy jaw?
Actinomyces bovis
what causes wooden tongue?
Actinobacillus ligniersii
what causes rain scald?
Dermatophilus congolesis
why is curing lumpy jaw (Actinomyces bovis) often difficult?
usually underlying osteomyelitis is present
what conditions cause rain scald (streptothricosis)?
wet weather and skin microtrauma
what is done to treat rain scald?
topical disinfectant
oxytetracycline/penicilin
move to dry environment (house)
what is used to treat bovine viral papillomatosis?
generally self-limiting (surgical removal indicated if penile/teat)
what systemic diseases could cause ulceration of the mouth?
mucosal disease
malignant catharral fever
IBR
foot and mouth
what are the clinical signs of foot and mouth?
pyrexia (>40 degrees), depression, lameness
vesicles on muzzle, tongue, nostrils, feet
what deficiency causes a poor growth rate and brown tinged coat with spectacles?
copper deficiency (molybdenum toxicity)
what are some causes of photosensitisation?
st johns wort
ragwort
liver damage (phylloerythrin accumulation)
what causes sheep scab?
Psoroptes ovis
what is sheep scab?
allergic skin reaction to Psoroptes Otis mites and faeces
what are the clinical signs of sheep scab?
wool loss, scaling, crusting
dermatitis/secondary infection
disrupted feeding and condition loss
intense pruritis and discomfort
how is sheep scab diagnosed?
skin scrape from edge of the lesion
serum antibody ELISA
is sheep scab notifiable?
it is in Scotland
not in England - requires mandatory treatment
how is sheep scab treated?
organophosphate dip - diazinon
what lice infects sheep?
Bovicola ovis
what are the clinical signs of Bovicola ovis?
(generally incidental finding unless heavy infestation)
pruritis - fleece loss and damage
what could heavy lice infestations in sheep indicate?
underlying health/nutrition risk
heavy stocking density
where are orf lesions found?
mouth, feet and teats
what is used to treat/contol orf?
self-limiting
antibiotics for secondary infection
scabivax (only in infection confirmed)
good biosecurity
how long does it take for orf to heal?
1-4 weeks (self limiting)
wha causes caseous lymphadenitis?
Corynebacterium pseudotuberculosis
what are some diseases flies/ticks are vectors for?
bluetongue
schmallenberg
new forest disease
BVD
summer mastitis
tick borne disease (babesiosis, Q-fever)
