Equine wounds

Question 1

What type of necrosis do acids vs alkalis cause

Answer 1

Acids cause coagulation necrosis
Alkalis cause liquefaction necrosis

Question 2

what are the 3 stages of wound healing

Answer 2

Inflammatory phase; = immediate and for a few days
Proliferative phase; angiogenesis, granulation, epithelialisation and contractino
Maturation/remodelling; scar tissue formation

Question 3

How to prepare a wound

Answer 3

Before clipping hair must coat wound surface with KY jelly
Best to use isotonic saline to wash the wound; avoid using hibi/PI on the wound suface

Question 4

Why do we often get dying off of upwards V flap tissue and should we keep it

Answer 4

most blood supply comes from proximal to distal so this area will be poorly vascularised as most blood supply cut off
Will likely necrose
But good to keep as it can act as a biological dressing to cover the wound

Question 5

Why do we need to appose lesions on the coronary band in horses

Answer 5

To prevent hoof abnormalities forming

Question 6

What is delayed primary wound closure

Answer 6

Where a wound is left a few days to give time for removal of contamination before closing up

Question 7

When do we need to use second intention heling

Answer 7

Very contamined or large skin defects that can’t be closed primarily

Question 8

What is best for suturing equine skin

Answer 8

Monofilament materials e.g nylon, PDS, prolene

Question 9

What factors affect wound healing

Answer 9

Contamination
Tension
Vascularity
Dead space
Motion

Question 10

What are some issues with using drains

Answer 10

act as a foreign body
Can be a wick for infection

Question 11

How does wound infection delay healing and what factors predipose a wound to infection

Answer 11

Bacteria prolong inflammatory phase and produce collagenases which reduce wound strength

Predisposed to by: devitilised tissue, FBs, haematoma/seroma/dead space, movement, excessive oedema

Question 12

What is a good dressing type for open wounds

Answer 12

Hydrogens to give moist environment

Question 13

When might we use corticosteroids on wounds

Answer 13

Chronic wounds with exuberant granulation tissue

Question 14

What is proud flesh

Answer 14

Excessive granulation tissue which is higher than the skin margin therefore making it hard for epithelium to grow over it

Question 15

What would a mature granulation bed with a cleft or draining tract present make you suspicious of

Answer 15

Bony sequestra acting as a foreign body

Question 16

How can we deal with excessive granulation tissue

Answer 16

Topical corticosteroids if not infected
Surgical excision under sedation and local anaesthesia

Question 17

What type of graft thickness are normally done in horses and what does this mean

Answer 17

Usually full thickness i.e epidermis and whole dermis

Question 18

Difference in how fresh tissue/granulation tissue accepts skin grafts

Answer 18

Fresh tissue accepts best > new granulation tissue > mature granulation tissue
BUT can’t do pinch punch grafts onto fresh tissue

Question 19

Preparation of recipient wound bed for skin grafting

Answer 19

Culture and sensitivity
Topical antibiotics for 2-3 days pre-graft
Excise excess granulation tissue 2-3 days before grafting

Question 20

Pinch island graft

Answer 20

= small discs of skin harvested by hand using scalpel blade

Question 21

Punch island graft

Answer 21

= full thickness plugs of skin harvested using skin biopsy tool

Question 22

Expected survival of pinch/punch grafts

Answer 22

60-75%

Question 23

When might we do split vs full thickness grafts

Answer 23

Split thickness = epidermis and. just portion of dermis; needs specialist equipment

Full thickness = whole epidermis and dermis and done on yard; but not accepted as well

Question 24

When might we choose to do a tunnel graft

Answer 24

For large skin defects esp in mobile sites or if hard to bandage

Question 25

When might horses not present as too painful ddespite synovial sepsis

Answer 25

If the synovial structure is open and draining so there is no build up of pressure

Question 26

When do we se haematogenous spread of bacteria leading to synovial sepsis

Answer 26

Mainly in foals with failure of passive transfer

Question 27

How do we diagnose synovial sepsis

Answer 27

synoviocentesis

Question 28

Treatment of cellulitis

Answer 28

Broad spectrum antibiotics, NSAIDs, bandaging, forced walking, cold hose therapy, lancing of any micro-abscesses

Question 29

How do horses with synovial sepsis typically present

Answer 29

Afebrile Variable lameness

Question 30

Normal synovial fluid characteristics

Answer 30

Straw coloured Viscous Low white cell count; <10x10^9/L White cells are low proportion neutrophils <15% Low total protein <10g/L

Question 31

Synovial fluid characteristics in a septic joint

Answer 31

Red (sero-sanguinous), cloudy Watery High white cell count; >20x10^9/L White cells are high proportion neutrophils >90% High total protein >30g/L

Question 32

Treatment of synovial infections

Answer 32

Must be rapid and aggressive Gold standard is synovial lavage via arthroscopy + broad spectrum antibiotics; systemic and local Bandaging Stall rest

Question 33

Prognosis for synovial infections

Answer 33

90% survival with gold standard treatment 50-70% return to athletic functino With conservative treatment very poor prognosis

Question 34

What do we classify infection as in terms on amount of bacteria/g tissue

Answer 34

>10^5 bacteria/g tissue

Question 35

What pathogen is typically involved in iatrogenic synovial sepsis

Answer 35

Staphs

Question 36

What antibiotics to use to treat synvial sepsis systemically and locally

Answer 36

Systemicaly: penicillin + gentamycin Local: aminolycoside i.e gentamycin