63. Infectious hoof diseases in cattle Flashcards
Digital dermatitis risk factors
Digital dermatitis (DD), mortellaro disease
• Risk factors
o Hygiene
o Nutrition
o Mycotoxins
o Endotoxins
o Low BCS
o Immunosuppressive agents (IBR,BVD….)
o Etc.
Aetiology of digital dermatitis?
Aetiology
o Spirochaetes (treponema spp., sometimes borrelia spp)
o Fusobacterium, Bacteroides, mycoplasma spp)
Occurence and Cause of digital dermatitis?
Occurrence
o Frequently on the back of the digital cushion on the skin in between the toes
o Rarely – dorsally on the coronary bands, under the dewclaws
• CS
o Walking on toe tips
o Red, uneven erosions lined by long hairs
o Purulent smelly excretion
o It can reach the hoof wall – more serious
Therapy of digital dermatitis?
Therapy
o Investigating and eliminating risk factors – hygiene, nutrition, epidemiology
o Individual local – spray containing AB (tetracycline)
o Herd level: foot bath (copper-sulphate, zinc-sulphate,(formaldehyde)) – regular checks for results,
treatment continued until the sores dry
Risk factors of interdigital dermatitis?
Interdigital dermatitis (ID)
• Risk factors:
o Hygiene
o Wet, humid environment, bedding contaminated with urine and faeces
Aetiology of interdigital dermatitis?
Aetiology
o Numerous bacteria play a role
o Most important – dichelobacter nodosus – proteolysis
Epidemiology of interdigital dermatitis?
Epidemiology
o Spread from animal to animal (D. nodosus able to survive in the environment for > days but far
longer in the dirt accumulated on the hooves)
Occurence of interdigital dermatitis?
Occurrence
o Tie stalls: more frequent on the HL, free stalls: equally
o More frequent in winter
Pathogenesis of interdigital dermatitis?
Pathogenesis
o Bacteria colonise the epidermis layer of the skin on the interdigital space
o Slow lysis of the skin at the edge of the hoof wall – erosion, ulcer – like lesions
Cause of interdigital dermatitis?
CS
o Initially exudative dermatitis at the border of the skin and horn – can be visible on the dorsal surface
o Fissures on the digital cushion – ulceration – lameness
o Animal stands from one foot to the other
o If ulcer is present on the hind claws – walking on toe tip abnormal horn growth
o Chronic skin irritation – interdigital fibroma
Therapy and prevention of interdigital dermatitis?
Therapy
o In serious cases the area should be cleaned, dried and treated with local bacteriostatic agents, hoof
trimming occasionally foot baths for 1 hour BID
• Prevention
o Clean, dry bedding
o Regular hoof trimming
o Regular foot baths from fall to late winter
Foot rot predisposing factors occurence and aetiology?
Foot rot (interdigital phlegmon)
• Predisposing factors
o Wet environment, soft feet
o Objects able to cause hood injuries – nails, sharp rocks, potholes
• Occurrence
o Usually only one foot is affected – front and HL equally
o No preference for age or season
• Aetiology
o Fusobacterium, Bacteroides, dichelobacter
Cause of footrot?
CS
o Sudden onset of serve lameness
o The claws are swollen, interdigital skin is red and hard, later the sweeling can reach the upper parts
of the leg
o The toes separate, the swelling is usually symmetrical
o Fever, anorexia, lethargy, decreased milk yield
o The affected area slowly necrotises- characteristic smell
o Sometimes hematogenous spread – worsens despite treatment
o Secondary infection – severe necrosis – distal interphalangeal (DIP) joint infection
Therapy of foot rot?
Therapy
o Systemic
§ AB treatment immediately – penicillin IM increased dosage, sulphonamides IM/IV,
cephalosporins
§ Early diagnosis – OTC LA 1 treatment
o Local
§ Clean the area, but! Do not excise necrotised tissues extensively – joint is very close
§ Bacteriostatic treatment but! No long-term bandaging (enclosed space – maceration)
§ Rarely: AB treatment with the technique used for the intravenous anaesthesia of the distal
limb (IVRA)
Prevention of foot rot?
Prevention
o Hygiene – feeding and watering troughs, roads
o Isolation of affected animals
o Regular foot baths (copper sulphate, zinc sulphate)
