| Disease |
Aetiology & Epidemiology |
Foot Lesions |
Clinical signs & pathology |
Ovine interdigital dermatitis.
(Brandpoot) |
Early mild F.
necrophorum infection in wet hot
coastal regions. Predispose to footrot & footabscess. |
Mild erosion, erythema & interdigital dermatitis of one
or more feet. No smell, almost no under-running of horn. |
Mild lameness. Small % may develop exudative dermatitis &
sinus tracts. No other clinical signs |
Infectious footrot.
(Vrotpootjie) |
D. nodosus & F. necrophorum
Outbreaks in wet weather. High morbidity.
Few chronic lame sheep in dry seasons. |
Interdigital dermatitis, under-running of horn of medial
claw. Strong smell of necrotic horn. No pus. All 4 feet affected |
Separation of sensitive from outer hard horn. Very severe
lameness. Can hardly walk. Respond to penicillin antibiotic treatment |
Foot abscess. Bulbar necrosis.
(Sweerklou) |
F. necrophorum &
A. pyogenes
Adult sheep, usually less than 10%
affected. Correlate with tick infestations |
Usually only one digit affected with severe lameness.
White pus discharge above coronary band. Foot hot, swollen & painful |
Severe lameness. Necrotic abscess & permanent deformity
of digit develop Extend into joints & ligaments |
Toe abscess.
(Toonsweer) |
A. pyogenes &
F. necrophorum
Infection enter on sole wall at white line
through minute fissures |
Greyish pus & gas found on exposure. Sinus tracts
present. No swelling found but claw hot & painful |
Primary affects lamellae of hoof Only under horn of toe
above coronary line |
Dermatophilosis. Strawberry footrot.
(Klontwol) |
Dermatophilus congolensis
zoospores spreads rapidly in wet conditions or from infected dipping tanks
around the feet. Secondary to orf. |
Proliferative dermatitis (lumpy wool)with exudative
crusts and scabs. Heal in a few months. Coronet to knee or hock affected |
Mild lameness. Cytology & culture to demonstrate the
Dermatophilus organisms in the
crusts. Histopathology of skin with Gram staining. |
Post-dipping lameness.
Erysipelothrix rhusiopathiae |
Cutaneous infection from contaminated non-bactericidal
dips or footbaths. Wound infection. |
Fetlock and lower parts of the legs affected by crusting
dermatitis |
Purulent necrotic acute dermatitis. Oedema with
lymphadenitis and laminitis. Responds to antibiotics. |
Orf (Contagious ecthyma)
(Vuilbek) |
Lambs mostly or non-immune adults. Dry summer months,
contagious |
Raised proliferative crust lesions with tenacious scabs
on coronet skin |
Rarely lambs have septiceamia. Lameness mild. Lesions
around mouth almost always present. |
Blue-tongue
(Bloutong) |
Insect-borne disease of mid- or late summer. Variable
morbidity |
Coronitis, separation of horn. Lameness is late in the
syndrome. Laminitis visible |
High fever, salivation. Severe lameness and recumbency.
Erosions around mouth and tongue. Muscle necrosis & laminitis |
|
Arthritis (Bacterial or mycoplasma infections) |
Common in young lambs after naval infections or
septisaemia. Bacteremia. Localization in the joint – chronic arthritis |
No foot lesions. (Arthritis of joints in the foot or
elseware affected) |
Aspiration and culture for the specific organism.
Arthritis and septisaemic disease. Respond to antibiotic in early phase. |
|
Laminitis |
Sporadic. Lambs in feedlots which are introduced too
quickly to heavy grain ration |
Laminitis – acute hyperemia, heat, haemorrhage and pain
of the sensitive laminae |
Mild to severe rumenal asidosis poor response to
treatment. Control by diet management. |
White muscle disease. Vit E : Se deficiency
(Vlekspiersiekte) |
Diets deficient in Se/Vit E. High cobalt |
None |
Bilateral symmetrical necrosis and calcification of
muscles. Illthrift respond to Se./Vit E treatment. |
|
Photosensitivity coronitis |
Primary plants or secondary due to liver damage. (geeldikkop
and dikoor) |
Acute coronitis red and inflamed coronary band |
Skin lesions, and / or icterus with hepatic pathology |
|
Tick bite induced pododermatitis & paralysis |
Interdigital tick infestation.
Ixodes rubicundus
= Karoo paralysis Rhipicephalus
evertsi = Spring lam paralysis |
Ticks present in interdigital skin |
Tick bite lesions. Ticks present in interdigital space.
Paralysis neurotoxic pathogenesis. |
