Equine foot 1 Flashcards
Properties - hoof capsule under laod
- elastic and flexible (this is known as the hoof mechanism)
- protective (stones, trauma)
What does the hoof allow? 2
- internal swelling
- drainage
What is the weak point of the hoof?
white line
What is the hoof mechanism important for?
foot perfusion
What are the parts of the white line? 5
- sole
- white zone
- stratum lamellum
- stratum internum
- stratum medium hoof wall
How can you examine the hoof?
- hoof testers/ palpation
- percussion
- response to local analgesia
- Imaging (radiographs, advanced)
What is the most common site of lameness?
hoof/foot
What parts of the hoof can you palpate?
- dorsal DIP joint capsule
- DIP joint collatral ligaements
- collateral cartilages
- (distal recess DFTS and DDFT)
What can you look for when palpating the hoof?
- local heat
- digital pulses
- DIP joint effusion
- pastern oedema
Name 2 farriery related problems of the hood
- Nail prick (nail driven through sensitive laminae)
- Nail bind (nail driven too close to sensitive laminae)
How well does the hoof wall heal?
well if the coronary band is not damaged
T - septic pedal osteitis
- curettage
- wound care
What are hoof cracks?
- disruption of hood wall parallel to horn tubules and lamellae
- can extend into sensitive laminae (lame)
- multifactorial aetiology (poor horn quality, thin hoof wall, abnormal hoof angles)
What 2 aspects of foot balance should be assessed?
hoof from side and lateromedial foot balance
What are hoof wall avulsions?
- damage to coronary band –> permanently disturbed growth
What is a keratoma of the hoof capsule?
- columnar thickening of hoof horn extending towards inside of hoof
- mostly dorsal wall
- aetiology (mechanical irritation, hoof abscess)
- increased local pressure (typical lysis distal to phalanx)
What is a characteristic sign of hoof capsule keratima?
- clear lucency in solar aspect of pedal bone d/t local pressure keratoma –> bone resorption in this area
Name 2 infectious problems of hoof capsule
- thrush
- canker
Describe hoof capsule thrush
- infection leading to necrotic processes in frog area
- usually limited to lateral and medial sulci of frog (solar area)
- v smelly
Describe canker of hoof capsule
- mixed bacterial infection in depper tissue layers of entire frog and heels leads ot disintegration of intertubular honr
- warm, humid
- cheesy white pus
- pungent odour
- tendency to bleed
Tx - hoof capsule thrush and canker
- same for both
- area resected to expose lamellar area underneath
What is white line disease of horse hoof capsule?
- deterioration of white line of hoof capsule –> loss of bond b/w hoof wall and sole
- poor quality horn gets colonised by different bacteria and fungi
- warm, humid
Tx - hoof capsule disease
- management/ prevention (meticulous daily hoof care, stall hygiene)
- debride all necrotic and diseases horn
- disinfect area
- protective bandages for sensitive laminae
- sulci –> hardening solutions (formalin, alternatives)
CS - hoof abscesses
- various
- shod and unshod horses
- infection on area of sensitive lamina after bacterial penetration
What is the commonest cause of TL lameness?
hoof abscess
Name 2 types of solar soft tissue
- chronic foot abscess
- quittor
What is a chronic foot abscess?
- burst out of coronary band
- aka ‘gravel’ amongst owners
What is quittor?
- infection of collateral cartilage
- seen on palmar/plantar aspect, above coronary band (Vs. chronic foot abscess which bursts out at the coronary band)
Tx- navicular fractures
- single screw
What are bipartite navicular bones?
- congentital anomaly
- important ddx to fx (usually lamer)
- can result in chronic lameness and DIP joint OA (athletic horses)
- usually both TL affected
- relatively rare
- classic xray appearance
How are navicular disease and syndrome different?
- disease = 1 cause
- syndrome = variety of CS, aka ‘ palmar heel pain’
Dx - navicular syndrome
- ID multiple structures involved in heel pain syndrome:
- navicular bone
- navicular bursa
- DDFT
- DIPJ
- collateral ligaments of DIPJ
What is navicular bursoscopy?
- sx to address DDFT tear
- method: enter DDFT sheath, separate ligament that attaches to navicular bursa (T-ligament)
- 60-70% success rate
Signalment - navicular syndrome
- 1/3 chronic TL lameness
- 6-12 yo horses (i.e. middle aged)
- taller, lighter breeds (some evidence of hereditary)
Presentation - navicular syndrome
- usually bilateral
- insidious onset
- occasionally ‘toe first’ gait
- toe elevation may increase lameness (on ramp)
- hoof testers (usually negative)
- positive response to PDNB
- radiography (advanced changes to detect)
- advanced imaging
How sensitive are radiographs for diagnosis a lameness?
not very - 70% yield no diagnosis
Outline use of ultrasound for diagnosing foot problem
- limited use for feet
- user dependent
Outlien use of nuclear scintigraphy for diagnosing foot problem
- high sensitivity
- low specificity
Outline use of CT for diagnosing foot problem
- little information on soft tissue
Outline use of MRI for diagnosing a foot problem
- diagnosis in 90% cases
- limited area examined
Define DFTS
digital flexor tendon sheath
What does the PDNB do?
- non-specific block
- if positive, do further smaller blocks to localise lesion (e.g. navicular bursa)
- blocks DFTS, navicular bursa, coffin joint/ DIPJ
Where should you aim when blocking the DIPJ?
- 1cm below coronary band
- 50% b/w dorsal and palmar aspects of hoof
Where might you get indications for navicular bursoscopy? 2
- diagnostic analgesia
- advanced imaging
What are osseous cyst-like lesions?
- midline
- P3 near collateral ligmaent
- verigy significance (blocks)
- also in navicular bone, P2
Tx - osseous-like cysts
VARIABLE:
- arthroscopy
- drilling (forage)
- medication of DIPJ
- etc.
CS - P3 fractures
- acute onset severe lameness
- d/t exercise, kicking
- 6 point classification (numerical and descritive)
Outline the classification of P3 fractures
- ) wing, non-articular
- ) wing, articular
- ) sagittal
- ) extensor process
- ) comminuted
- ) solar margin
Dx - type 1 and 2 P3 wing fractures
- may be hard to see on routine radiographs
- take appropriate oblique projections
- CT/ MRI if necessary
Describe type 3 P3 fractures-
narrow well-defined lines of acute fracture
Describe type 4 P3 fracture
- involves DIPJ
- displacement by CDET
- matched fracture bed and fragment
- remember extensor process has variable shape, determine if secondary ossification centre versus chip fracture (based on CS, verify need for sx)
Tx - fracture of P3
varies according to which type (1-6) of fracture
Differentiate a hoof cast and a foot cast
- hoof cast only covers hoof
- foot cast covers hoof and rest of foot
CS - DIPJ osteoarthritis
- CS can be v subtle
- look for osteophyte on dorsal aspect and palmar aspect of navicular bone
- remember 4-5 variations of extensor process
Tx - DIPJ osteoarthritis
- intra-articular medication (sodium hyaluronate, corticosteroids, polysulphated GAGs = PSGAGs, IL-1 receptor antagonist protein = irap)
- prolonged use of NSAIDs
- corrective farriery
What is pedal osteitis?
Repetitive concussion leads to chronic inflammation of laminae –> bone resorption (appears as fuzzy edge on radiograph versus sharply define pressure resoprtion seen with hoof capsule keratoma)
