Is it sheep Scab?

C S Parker BVM&S DBR MRCVS

Sheep scab

<1992 < 100 outbreaks per year Deregulation 1992 Everywhere except Australia/ N Zealand 100% morbidity

Sheep scab

Intense pruritis Rub shoulders or flanks

along ground Clawing/biting 1-5mm sores Serous exudation

exudate

Large areas develop 5 – 40 cm Shoulders + dorsum

Chronic Lesions

Skin becomes thickened

Flake like scabs Thick walled abscesses Can have seizures

Side effects

Seromas Fluid filled swellings Myositis Aural haematomas

Age & species

More severe in lambs & yearlings.

Different strains mites Long heavy fleeces Chronic carrier states

Treatments

Ivomec Dectomax Cydectin

Sheep scab

Chorioptic Mange

Chorioptic Mange

Chorioptic Mange

Thought to be eliminated before 2001

Slow build up Not seen in lambs

Chorioptic Mange

Itchy feet fetlocks Scrotal lesions

Forage mites

Late summer Quite itchy Grass or infected forage

Fly strike

Fly strike

Headflies

Feed on wounds Base of polls of young

sheep Active June to

September

Keds

Wingless flies 5 -7mm long Live on host Build up in Autumn &

Winter Scottish Islands

Lice

Increased as dipping decreased.

25% flocks infected Populations fall in Hot

or wet weather Eggs on fleece Itchy feet

Lice

Non Parasitic Diseases!

Photosensitisation

Plocteach! Movement poor to lush

pasture Excess dietary

Chlorophyll Skin active poisons- St

Johns Wort!

Photosensitisation

2ndry to liver disease Inherited condition in

Southdown & Corriedale

10% effected in some Scottish flocks

Bog Ashphodel

Photosensitisation – clinical signs

Wool free areas + midline of spine?

Anorexic, mildly itchy Lambs loose condition Oedema of face Seepage of fluid with

yellow crusts

Wool Slip

Large symmetrical areas wool loss

Common in winter shorn housed sheep

Stress induced No skin signs

Trauma !!

Chemical burns – phenolic dips

Scab sheep more susceptible

Orf

Needs contact with scabs +break in skin

Young lambs teeth errupting

Lasts 4 – 6 weeks Can have PI animals No colostral immunity

Orf – clinical signs

Reddening + swelling Scabs shed at 3 weeks Cycles of proliferation &

repair Muzzles lips teeth in

lambs or weaned lambs

Orf atypical lesions

Base of teats Ears Coronary band +

fetlocks Around genitals

Dermatophilus

Lumpy wool Outbreaks follow

prolonged wet weather Ears + nose most

common Chronic form scaly

areas on back Low grade pruritis

Pyodermas

Infected ulcers Face + eye area Tagging & troughs

Necrotic Dermatitis

Pseudomonas Prolonged soaking of

fleece Usually within 6 weeks

shearing Large ulcers under wool Foul green pus Internal abscesses fatal

Actinobacillosis

Skin thickening Multiple 5mm nodules in

skin of face, thick white pus

Kings Evil!

Caseous lymphadenitis

Lymph nodes

Ringworm

Crusty lesions on neck & ears

Combined lesions