Farm dermatology

Question 1

Common problems

Answer 1

Infectious
Neoplasia
Nutritional
Toxic
Physical
Congenital

Question 2

Ectoparasites

Answer 2

Indoor- lice and mites
Outdoors- flies, ticks

Question 3

Pediculosis

Answer 3

Lice on back and neck
Pruritis
Lice and eggs visible macroscopically
Microscopic speciation
Sucking- lignonathus vituli, haematopinus
Chewing- bovicola bovis

Question 4

Mites

Answer 4

Acariasis / mange
Psoroptes bovis
Chorioptes bovis
Sarcoptes scabei
Pruritus, rubbing hair loss in housed cattle
Dx- skin scrape, liquid parrafin smear microscopy
Neck and face- sarcoptes
Elsewhere- the other 2

Question 5

Ectoparasite Tx

Answer 5

Pediculosis and mange
Management and mange
Mild infestations Tx may not be needed
Self limiting
ML, SP (lice resistance reported)

Question 6

Trichophyton verrucosum

Answer 6

Ringworm
Youngstock
Circular raised crusted plaques
Dx- culture and microscopy from peripheral lesion hair pluck
Tx- clean and disinfect housing
-Turn out (UV sensitive)
-Topical enilconazole
- Vax lowers severity (prophylaxis)

Question 7

Pustular impetigo

Answer 7

Staph
Wounds, udders, perineum
Poorly applied ear tags

Question 8

Abscess and cellulitis

Answer 8

Actinobacilli (T pyogens)
Lower jaw and popliteal LN
Can be associated with Sys Dz
Open drain and Ab

Question 9

Bacterial Dz

Answer 9

Draining fistulas
Lumpy jaw - actinomyces bovis
Wooden tongue - actinobacillus ligniersii
Rain scald - Dermatophilosis congolensis
-wet weather, skin microtrauma
-topical disinfectant, penicillin

Question 10

Viral Dz

Answer 10

Papillomatosis - warts
- common and self limiting (can remove Sx)
Stomatitis/vesicular Dz
-self limiting
-papular stomatitis - muzzle
-herpes mammilitis - udders
-may indicate systemic Dz

Question 11

Nutritional

Answer 11

Deficiencies
Poor coat
Responds to multivitamin injections
Cu def/ Mb tox
-poor growth, brown tinged coat w/ glasses

Question 12

Toxic

Answer 12

Photosensitisation
Unpigmented skin affected
Photodynamic agents ingested
2° hepatogenous damage
House out of sun
Tx CS

Question 13

Sheep

Answer 13

Rubbing- pruritus
Wool break- nutritional, systemic Dz
Trapping
Dog attacks

Question 14

Psoroptes ovis

Answer 14

Sheep scab
Allergic reaction to mites and faeces
Concentric wool loss with scaling and crusting
Dermatitis 2° Dz
Slow Dz
Dx- skin scrape
Tx- OP dip
Mandatory Tx in England
Whole flock recommended

Question 15

Bovicola ovis

Answer 15

Pediculosis
Often incidental finding
Pruritis
Dx- macroscopic in fleece, skin scrape
Underlying cause
Shear flock
Topical SP

Question 16

Orf

Answer 16

Viral zoonosis
Mouth, feet, teats (lambs and mastitis ewes)
Self limiting (<1m)
Biosecurity important
Ab for 2° Dz
Vax (not in naive flocks)