Digital dermatitis (Mortellaro's disease) is a painful, infectious condition of the claw skin. It causes lameness and, in many herds, considerable economic loss. This article gives an overview of aetiology, clinical presentation and herd management.
Clinical signs
Typical findings are circumscribed, reddened, often strawberry-like and painful skin lesions, usually on the skin at the interdigital cleft and heel of the hind limbs. Lesions may be moist, bleed on contact and be surrounded by necrotic tissue. Lameness is common.
The literature usually classifies the appearance into stages (M0 to M4).
Aetiology and predisposing factors
The disease is multifactorial. Several bacteria are involved, in particular Treponema spp., along with Dichelobacter nodosus, Porphyromonas levii and Fusobacterium necrophorum, among others. Wet, soiled walking surfaces and poor claw hygiene favour onset and spread within a herd. Buying in infected animals is a further risk.
Diagnosis
Diagnosis is usually clinical, made on the lifted, cleaned claw. Key points are differentiation from other claw disorders such as interdigital phlegmon or claw ulcers, and assessment of the coronary band.
Herd management
Management is the responsibility of the veterinarian. Measures include:
- early detection through regular claw inspection and trimming
- dry, clean bedding areas and walkways, with good manure management
- precautions when introducing new animals
- topical or systemic medicines only at the veterinarian's decision and in line with applicable medicines law
- follow-up of affected animals