Equine Foot (Bolt) Flashcards
How can examination of the hoof wall be caried out?
- hoof testers
- palpation
- percussion
- response to local analgesia
Which structures can be palpated around the hoof?
- DOrsal DIP joint capsule
- DIP joint collateral ligaments
- Collateral cartilages
- distal recess DFTS + DDFT
Can you relate specific structures to pain in the hoof?
- no, not by direct visualisation palpaton or manipulation
- intrasynovial and perpheral nerve blocks not very specific
What should you look for when exmining the foot?
- digital pulses
- local heat
- DIP joint effusion
- pastern oedema
How can integrity of synovial structure be assessed?
- contrast bursography/radiography
- MRI (soft tissue info too)
What is nail prick and nail bind?
> nail prick - nail driven through sensitive laminae > nail bind - nail driven too close to sensitive laminae -> abscess
Tx septic pedal osteitis
- curettage
- wound care
Aetiology of hoof cracks?
- poor hoof quality
- thin hoof full
- abnormal hoof angles
Which direction are hoof cracks most commonly seen in?
- parallel to horn tubules and lamellae
- can extend into sensitive laminae
Tx hoof cracks
- shoe with bar shoe
- sutures/clamps/plates over cracks
- debridement and stabilisiation
> as long as don’t reach the coronary band will be ok
Which aspects are foot imlanace looked at?
- lat-med (pedal bones should be in line - eg. club foot)
- dorsopalmar (mroe difficult to correct)
How are hoof wall avulsions formed?
- damage to coronary band -> permenantly disturbed growth
What is a keratoma? Common?
== “malignant tumour” -> columnar thickening of hoof horn extending towards inside of hoof
> aetiology: mechanical irritation/chronic infection (hoof abscess)
- ^ local pressure -> typical lysis distal phalanx with clear margins (not fuzzy like pedal osteitis)
- not common
Radiographic findings of keratoma?
- local pressure -> lysis and resorption of pedal bone tip
Tx keratoma
- remove (cut window, or go to sole but this will -> splay)
What 2 infectious causes of hoof pathology are most common?
> thrush - looks like pus in the foot - necrosis of the frog - smelly - usually limited to lateral and medial sulci of frog > Canker - cream cheesey - deep layers of frog - mixed bacterial infectioin of the entire frog and heel -> disintegration of intertubular horn - warm humid enviroent - oungent and tendency to bleed
Tx canker/thrush
resection and debridement
- not often painful, will heal
Pathogenesis of white lien dz?
- deterioration of white line of hoof capsule -> loss of bond between oof wall and sole
- poor quality horn colonised by bacteria and funghu
- warm humid environment
Tx white line dz
> management
- dialy hoof care
- stall hygeine
debridement of necrotic and diseased horn
- disinfect are
- sensitive laminae (protective bandage)
- sulci hardening solutions (formalin or others)
What is a hoof abscess? Ddx?
> Ddx pedal bone fx
- shod and unshod horses afefcted
- infection of area of sensitive laminae after bacterial penetration (can be aftr shoeing)
What is “gravel”? Ddx?
> gravel - chronic foot abscess - bursts out at coronary band > Ddx: "Quittor" infection of lateral cartilages - above the coronary band - palmar/plantar
Best rads for navicualr bone fx?
- Dorsopalmar
- Skyline navicular bursa
- Echo other views
Tx navicular fx?
- fix with single lag screw
> no rotational stability but can minimise DJD In coffin and damage to DDFT
Ddx navicular fx?
> Bipartite navicular bone
- separate ossification centres
- congenital
- will be less lame than Fx!!
- can result in chronic lameness and DIP joint OA
- Rad other foot to r/o
- rare condition
What is navicular syndrome?
> most common forelimb lameness
palmar heel pain
no one cause, distinct pathophysiology or cure
Which stuctures are involved in navicular syndorme?
- navicular bone
- navicular bursa
- DDFT
- DIP
- collateral ligaments DIP joint
How es a DDFT tear appear on MRI?
Intense signal cf. surrounding DDFT
How may a DDFT tear present clinically?
3/10 lame
- blocked coffin and navicular bursa partial improvement
Tx DDFT Tear?
- navicular bursoscopy
Clinical scenario for navicular syndrome?
- 6-12 yo horses
- taller, lighter breeds (some evidence hereditary trait)
- usually bilateral
- insidious onset
- occassionaly “toe first” gait
Hx and PE associated with navicular syndrome?
- bilateral lamess
- toe elevation ^ lameness
- hoof testers usually negatvie
- response to PDNB
- navicular and DIP
Further diagnostics for navicular syndrome?
- Radiography
- MRI [gold standard]
- CT
- Not really scintigraphy
- Ultrasoound (very user dependent)
Structures taken ou by palmar digital?
- DFTS
- Coffin joint
- Navicular bursa and bone
- Collateral ligaments
- hoof wall
- pedal bone
- T ligament
- Impar ligament
DIP joint blocking process
- go dorsal midline (through extensor tendon)
- can go palmar/plantar but risk of navicular bursa
Outline navicular bursa block
- midline - navicular position horizontal approach
- midline- navicualr position 30* oblique approach
- lateral palmar/plantar approach
Function and physiology of the hoof capsule?
> elastic and flexible under load - "hoof mechanism" > protective function - stones and blunt trauma > no possibility for swelling/draining *weak point = WHITE LINE*
If navicular region is implicated in foot pain with diagnostic analgesia what further Dxx can be used?
Navicular bursoscopy
Current approach to tx of navicular syndrome?
Corrective farriery (roll toel use bar eg. Egg/heart bar) controlled exercise and pain relief
Where are osseus cyst like lesions commonly found?
Distal phalanx
- P3 near collateral ligament
Also in navicular bone and middle phalanx
Are osseus cyst like lesions always significant if found on imaging?
No! Verify with diagnostic analgesia
Tx available for distal phalanx DJP
- arthroscopy
- drilling (forage)
- medicating DIP
Why does the entire cyst need to be removed ?
Cyst lining secretes inflam mediators (PG2, IL1) disrupts inter stridulate cartilage
Typical presentation of distal phalanx (peda bone) fractures
- acute onset severe lamenss
- associated with excercise or kicking out
How can pedal bone fx be classified?
- numericl or descriptive
1: wing, non-articular
2: wing, articular
3: saggital
4: extensor process
5: comminuted
6: solar margin
7: foal
Are type 1 and 2 pedal bone fx seen easily on rads?
No not routine rads
- take appropriate obliques
- CT/MRI if necessary
How can fx be sen on mRI?
surrounded by decreased signal
WHen can type 3 fx be most eaily seen on imaging?
> 7d (bone resorption seen)
- before this hoof capsule will keep most fx. held together and not visable
What other structure is involved in a IV extenory process fx? Cause? Other things to r/o?
DIP joint
- displacement by common digital extensory tendon (Long in HL)
- matched fx bed and fragment can be seen
- NB: exensor yprcoess can be variable in shape, 2* ossification centres may appear similar to chip fx (dependant on clinical signs- verify need for sx)
Tx of wing fx? Poss complications?
- bar shoe
- foot cast/hoof cast
- lag screw?
> 6 months box rest
Complications - OA DIP (type 2)
- fibrous union
Tx midsagittal fx? Poss complications?
- Lag screw + 3-6mo box rest
- Bar shoe + 6-12mo box rest
> complications - OA DIP
Tx small extensor process fx? Large? Poss complications?
Small - removal via arthroscopy or arthrotomy \+ 3-4mo box rest > no complicatinos Large - removal arthrotomy -lag screw \+ 4-6mo box rest > OA DIP joint
Tx cominuted fx? Poss complications?
- transfixation cast
- euthanasia
+ 4-6mo box rest
> OA DIP or laminitis
Tx solar margin fx? Poss complications?
- bar shoe?
> 6 months box rest - no complications
How do bar shoes work?
Eliminate “hoof mechanism” doesnt let capsule flex
Are foo cast advocated?
Not really necessary
Where are osteophytes commonly seen in DIP joint OA?
- @ po int of reflexion of joint capsule
Tx DIP joint OA?
> intra-articular medication - sodium hyaluronate - corticosteroids - polysulphated GAGs (PSGAG) - Il-1 R antagonist protein (irap) > prolonged NSAIDs > corrective farriery (=navicular syndrome, ^ heel to facilitate breakover)
What is pedal osteitis? What is its aetiology similar to?
= keratoma aetiology
- repetitive concussion -> chronic inflammation of the laminae -> bone resorption
- on rads lysis/resorption of bone not associated with hoof wall deformity and with FUZZY edges = pedal osteitis
- cf. keratoma with well defined clear margins
