Farm animal dermatology

Question 1

What is the main cause of skin disease in cattle

Answer 1

ectoparasites

Question 2

What is the most important ectoparasite in cattle

Answer 2

lice (4 species- 1 biting, 3 sucking)

Question 3

What is the most common ectoparasite of sheep

Answer 3

psoropties ovis - sheep scab mite

Question 4

Describe the lifecycle of lice

Answer 4

live on skin surface
life cycle is direct and simple
whole life cycle happens on the host

Question 5

Describe the epidemiology of lice in cattle

Answer 5

very common
more common in winter
don’t survive well off the host

Question 6

describe the impact of lice in cattle

Answer 6

decreased BCS/ daily live weight gain
damaged skin
usually poor doers- often animals will have concurrent disease

Question 7

List the 3 species of lice seen in cattle

Answer 7

Bovicola bovis
Linognathus vituli
Haematopinus eurysternus

Question 8

what is the most common species of lice in cattle

Answer 8

Bovicola bovis

Question 9

where is bovicola bovis generally seen in cows

Answer 9

on the head
is a chewing/ biting louse

Question 10

Describe how you diagnose lice in cattle

Answer 10

they are big so visable with naked eye

Question 11

List 3 methods of treatment for lice in cattle

Answer 11

Pour-on synthetic pyrethroid - kills everything
pour-on group 3-ML anthelmintics - kills everything
injectable group 3- ML anthelminitics - remove all sucking lice and >98% of biting lice - so not used as much

All cattle in direct contact must be treated

Question 12

What is pink eye

Answer 12

Infectious bovine keratoconjunctivitis (IBK)
caused by the bacterium Moraxella bovis

Question 13

how does infectious bovine keratoconjunctivitis get transmitted

Answer 13

face fly

Question 14

what are the signs of infectious bovine keratoconjunctivitis

Answer 14

corneal ulcers
oedema
lacrimation
opacity
epiphora

Question 15

what is the treatment for pink eye

Answer 15

antibiotics - IM
NSAIDs

Question 16

describe how to prevent pink eye

Answer 16

fly control e.g. permethrin
biological control- parasitic wasps

Question 17

Describe onchocerca

Answer 17

thin white worms found in the eye of cattle
transmitted by blackfly or culicoides

Question 18

Describe the impact of the warble fly

Answer 18

gadding behaviour
ectopic migration and paralysis
downgrade of the hide
reduced reproduction

notifiable in Scotland

Question 19

Describe how to treat warble flies

Answer 19

organophosphates
98% effective in autumn and less efficient in spring

Question 20

What is the most common mite seen in catte

Answer 20

surface mite- chorioptes

Question 21

Describe the clinical signs of chorioptic mange

Answer 21

tail mange
leg mange
scrotal mange

Question 22

describe how you diagnose chorioptic mange

Answer 22

deep skin scrapes - from the edge of the lesion

Question 23

what is the treatment for chorioptic mange

Answer 23

Permethrin (synthetic pyrethroid)
OR
pour on Macrocyclic lactones (injectable less effective)

Question 24

What is the most common tick seen in cattle

Answer 24

Ixodes ricinus

Question 25

List 5 consequences of ticks in cattle

Answer 25

poor body condition intense irritation weight loos and reduced milk yeilds hide/fleece damage vehicles for disease-causing agents

Question 26

Name a viral disease that ticks can cause in cattle

Answer 26

Tick-borne encephalitis

Question 27

List some bacterial diseases that ticks can cause in cattle

Answer 27

lyme borreliosis Q-fever tick-borne relapsing fever

Question 28

what parasite can ticks transmit in cattle

Answer 28

babesiosis

Question 29

Describe the clinical signs comonly seen with Babesia

Answer 29

pyrexia severe haemolytic anaemia haemoglobinuria- red urine death

Question 30

Describe how you diagnose babesia

Answer 30

previous history - have the animals come onto marginal grazing recently examination of skin often confirms presence of ticks

Question 31

Describe the aetiology of photosenstisation

Answer 31

direct- due to defect (congential or acquired through ingestion) in animals metabolism of RBC secondary- occurs in animals with liver damage local- from reaction to the sap of some plants

Question 32

What plant can cause photosensitisation in csttle

Answer 32

St Johns wort

Question 33

Describe the clinical signs of photosensitisation

Answer 33

non-pigmentated skin affected hair-loss reddening , peeling ulceration of skin

Question 34

Describe how you diagnose photosensitisation

Answer 34

on clinical signs

Question 35

describe how you treat photosensitisation of cattle

Answer 35

removal to cool shaded housing supportive therapy treatment for liver failure identify and remove possible plant sources of the photosensitising chemicals