9. Diagnostics, therapy and prevention of locomotor diseases Flashcards
(9 cards)
Describe digital dermatitis
Multifactorial
* Treponema spp.
* Cocci
* Campylobacter
* Fusobacterium
* Prolonged exposure to slurry.
Most commonly affecting hindlimbs - above interdigital cleft on plantar aspect of pastern.
CS: Lesions - erect hairs, exudate, hypertrophy of dermis/epidermis -> hairy warts.
Dx:
* Mortellaro scoring system (5 stages)
* CS, characteristic lesions
Tx:
* Scraping/excision of lesions
* Chlortetracycline
* Disinfection spray
* Bandage
* Always treat M1 and M2, not M3-M4 as they are healing or chronic dermatitis
* Footbaths (5% copper sulphate and 3-5% formalin)
Describe Dermatitis interdigitalis “Foot rot”
3 forms:
1) Dermatitis interdigitalis/heel horn erosion:
- Caused by: Dichelobacter nodosus
- CS: Erosions/ulcerated lesions with exudate and hypertrophy of skin in inderdigital skin
- Tx: Trimming, clean lesions, topical disinfection, oxytetracycline spray. Footbath with formalin
2) Mild form of foot rot:
- Caused by Fusobacterium necrophorum + Dichlobacter nodusus
- In sheep/goat
- CS: Pink-white moist skin, sensitive to touch –> lameness
- Can progress to foot rot (phlegmona interdigitalis) if not treated.
3) Contagios/phlegmonar interdigitalis:
- Caused by Fusobacterium necrophorum + Dichlobacter nodusus + Corynebacterium pyogenes.
- Mainly sheep (+goat)
- CS: Necrosis, sole separation, swelling, apathy, foul odor.
- Dx: CS, lesions, cultivation.
- Tx: Foot trimming, remove necrotic tissue, foot bathing (10% zinc sulphate, copper sulphate), disinfection (hydrogen peroxide), ATB
** Vaccination - Footvax for sheep.
Describe sole ulcers
= Pododermatitis solearis circumscripta purulenta et necroticans
Causes: Claw overgrowth, bad trimming, subclinical laminitis, lipomobilization, or standing too long on concrete.
Location: Flexor process of P3 — mostly lateral claw of hind limbs or medial claw of front limbs –> closed (hemorrhagic) or open (necrotic).
CS: Sudden lameness, ↓ milk yield, ↓ body condition score
Dx: CS and visualization of lesion.
Tx:
* If open ulcer = claw trimming, removal of necrotis tissue (nice bleeding), ATB, disinfectant (copper, iodine)
* Deep infection = Amputation, recovery takes about 2m.
Px: Correct and regular hoof trimming.
Briefly about toe and heel ulcers
= Pododermatitis circumscripta/diffusa septica
Similar to sole ulcer but less common.
Toe ulcers are thought to result from pressure from cranial margin of pedal bone.
Describe Downer cow syndrome
pressure-induced ischemic necrosis from prolonged recumbency (≥12–24h), due to trauma, infection, degeneration, or toxins.
Common in dairy cows, especially around calving and early lactation.
Two types:
1) Alert: Normal appetite, sternal position, no systemic signs.
2) Non-alert: Depressed, systemic illness, possible CNS signs.
Dx: CS, ↑ CK, LDH, AST, and myoglobinuria (dark urine).
Treatment:
* Address underlying cause,
* Give analgesia, IV fluids (Ca, K, P, Mg),
Provide supportive care — soft bedding, regular rolling, and lifting.
Describe White Muscle Disease
Selenium and vitamin E deficiency, mostly in young animals.
Risk factors: Low selenium in feed, high PUFA, copper or vitamin A (↓ vit E availability).
Two forms:
1) Congenital (cardiac form): Affects heart muscle and Purkinje fibers → respiratory distress, arrhythmias, stillbirth, or death in 2–3 days. PM: white chalky plaques in left ventricle.
2) Delayed form:
* Skeletal muscle: Stiffness, arched back, painful firm muscles, recumbency.
* Cardiac: Sudden death.
* Respiratory muscles: resp. distress
* Tongue muscles: dysphagia.
Dx: History, feed test, CS, PM (muscle mineralization), biochem, liver biopsy (↓ selenium).
Tx: Selenium injection (2.5 mg/45 kg) + oral vitamin E → improvement in 3–5 days.
Px: Balanced diet, selenium supplementation before calving and in young animals.
Describe osteomyelitis
Inflammation to bones
* Caused by - S. dublin, Trueperella pyogenes, Fusobacterium necrophorum
CS: lameness, painful swelling of hock and fetlock joints. Cervical pain and resistance in movement of neck/head if affecting cervical vertebrae.
Dx: CS, x-ray, bone biopsy, culture
Tx: Longterm ATB
Actinomycosis
= Lumpy jaw
Caused by - Actinomycosis bovis.
Part of normal oral flora but becomes pathogenic when entering wounds in oral cavity -> spreads to bone.
CS: Form chronic, local, pyogranulomatous abscesses in mandible, maxilla and facial bones.
Can see facial distortion, loose deeth, dysphagia.
Dx: CS, culture, biopsy, x-ray
Tx: Sodium iodine, ATB (penicillin or oxytetracyclines)
Septic arthritis
A joint infection caused by various agents —Mycoplasma, Chlamydia, CAE virus, Actinobacillus, Treponema, Streptococcus, etc.
Routes of infection:
1) Hematogenous (e.g. navel, GIT, lungs)
2) Trauma (wounds)
3) Iatrogenic (e.g. joint injections or surgery)
CS: Severe lameness, joint swelling (often one or more joints).
Dx:
* Synovial fluid: Cloudy, ↑ neutrophils
* X-ray & USG
Tx:
* ATB
* Joint flushing
* NSAIDs (flunixin meglumine)
