WOUND MANAGEMENT Estelle E Felarise, DVM Greene, Lewis and Associates

The Skin  Is the largest organ of the body  Its’ main functions are to protect against the environment, bacterial invasion and to aid in thermal regulation and prevention of water loss.  One of the most common emergencies we see in equine practice today involves the skin.

Wound Management: Goal  To restore function and to optimize the cosmetic appearance as expediently as possible.

How do wounds heal?  All cutaneous or skin wounds heal by two independent processes: contraction and epithelialization.  Epithelialization is the process of skin cells proliferating and migrating to cover the surface of cutaneous defect.  Wounds heal by producing a bed of granulation tissue and contracting from the edges eventually covering the surface of the wound.  In order for this to occur a good blood supply and an adequate inflammatory response are necessary.

Wound Healing:  Wounds on the trunk of the body heal differently than the wounds on the lower limbs.  Clinical observation suggest that the rate of wound healing on the equine limb is approximately half that of body wounds.

Granulation tissue:  Is produced in 3-4 days after the wound has occurred.  Is pink to red in color, firm, has a roughened appearance and is found within an open wound.  Is necessary for wound healing until it becomes excessive or “proud” meaning that it starts to protrude above the level of the wound edges.

Granulation tissue cont….  When the granulation tissue protrudes, the wound edges cannot contract and therefore the healing process is stalled.  Bandaging and confinement can help decrease or prevent excessive granulation tissue formation.  The least amount of movement a wound undergoes the faster it will heal.

“ Proud Flesh” or Excessive Granulation Tissue  The reason for this excessive proliferation is unknown.  When compared with other species the equine species is the only one that produces “proud flesh”.

Promotion of Granulation Tissue:  The use of hydrotherapy daily helps promote the growth of granulation tissue on wounds above the hocks and knees  Other products such as Granulex® or Nitrofurasin also help to promote the growth of granulation tissue.

First Aid for Traumatic Wounds  Preventing further injury  Stop or decrease blood loss  Minimizing contamination

Initial assessment by the owner:  Call the veterinarian  How long ago did the wound occur?  Location?  How deep is the wound?  Is there flesh hanging?  Is the horse bleeding? If so how much?  Is the horse lame?  When was the last tetanus booster?

Veterinary Initial Assessment  Is the horse in pain?  What is the location of the wound?  Can the wound be sutured or not and does it need debridement?  Can the wound be bandaged or left open?

What comes next?  Restraint and provide analgesia to the horse  The veterinarian will decide whether or not to:  Block the area around the wound and suture it closed  Put the horse under general anesthesia to suture the wound closed depending on horses attitude and wound location  If there is nothing to suture then he will clean and debride the wound.

To suture or not to suture:  How long ago did the injury occur?  Location of the wound  Is there enough skin to suture the wound closed with minimal resistance?  Is the skin salvageable?

If sutured:  The “golden period” for wound closure is 6- 8 hours.  If it’s within this time period and there are decent skin flaps that have good blood supply the veterinarian may elect to suture the wound closed.

Before suturing:  The wound is clipped and disinfected.  Then the area is block with local anesthetic.  If any debridement needs to be done it is done now. Debridement is the removal of dead and devitalized tissue and reduces the level of bacteria in the wound.

Bandaging:  Wounds that are sutured are usually bandaged if possible.  Bandages are usually changed every 5-10 days.  The bandage should be kept dry

What to do with the horse?  The horse should be kept confined with the least amount of movement possible.  Any amount of movement can put unwarranted stress on the laceration and increase the incidence of dehiscence.  The horse should be put on antibiotics for 5-7 days with or without anti-inflammatories.  The sutures are removed in days.

The wound fell apart:  If a wound is under tremendous tension or damaged tissue is sutured together there is a good chance it will fall apart or dehiss which usually occurs within 5-7 days after it was sutured.

Why suture if it will fall apart?  Skin provides a good biological bandage so even if the wound falls apart the skin has acted as a “band-aid” for a few days and helped speed up the healing process.  Also if the incision falls apart usually the wound you are left with is much smaller than the original wound.  Suturing also decreases the tendency of proud flesh to grow.

Areas under tension:  Carpus (knee)  Shoulders  Hocks  Fetlocks (ankles)

If the wound is not suturable:  Then the veterinarian will sedate the horse and proceeded to  Disinfect and debride the area  If it is on the lower limbs then the wound may be bandaged  The bandage should be changed every 5-10 days depending on the wound healing.

If the wound is left open…  If the wound is left open there are number of different ointments that can be used. Picking the right one will be up to your veterinarian and the type of wound you are dealing with.  Nitrofuracin ointment  Triple antibiotic ointment  Nolvasan ointment  Silver Sulfadiazine  Corticosteroids

Location of wounds:  Head:  Wounds on the head tend to heal very well due to the increased blood supply.  Lower limbs:  We try to close these by suturing first and then bandaging.  If they dehiss (fall apart) we then treat them as an open wound and control the granulation tissue to aid in healing.

Location of wounds:  Trunk:  These wounds tend to heal very well  But they heal more times than not by secondary intention, which means they heal by laying down a bed granulation tissue allowing the wound edges to contract as opposed to primary closure (suturing the wound closed)  Sutures do not hold well on some areas of the trunk of the body because they are under constant movement.

Complications of wounds  Sequestrum is a dead piece of bone that was damaged during the laceration or impact. It can take weeks to identify a sequestrum on radiographs.  Deep head wounds do have an increased likely hood of forming a sequestrum due to the fact that there is not much muscle to protect the bone.  The area over the cannon bone is also prone to sequestrums due to the lack of muscle under the skin.

Sequestrum

Topical vs Systemic Antibiotics:  Topical antibiotics do not penetrate tissues well, they do however help decrease the number of surface bacteria.  Topical antibiotics can be used to supplement systemic antibiotics (oral, IV or IM) in the treatment of heavily contaminated wounds.

To give or not to give?  Should I give Bute® or Banamine®?  At therapeutic doses NSAIDs appear to have no harmful effects on wound healing  This is usually up to the veterinarian  Making this decision depends on a variety of factors: Where the laceration is located How important is keeping the horse quiet in relation to wound healing. Whether or not synovial structures (joints, tendons, etc) are involved. How painful is the horse?

“Seadragon”  3 year old Thoroughbred gelding  Leg caught on electric fence wire  May 2007

“Seadragon”….. May 11, 2007

“Seadragon”…. May 31, 2007

“Seadragon”…. September 25, 2007

“Seadragon”…. July 6, 2008

“Seadragon”… September 19, 2008

“Albi”  18 month old Warmblood cross gelding  Leg caught on electric fence wire  January 2008

“Albi”…. Jan 2008

“Albi”… April 2008

“Albi”….October 2008

“Mini-me”  Yearling quarter horse filly  Both hinds legs caught in a hay rack  April 2008

“Mini-me”…. April 15, 2008

“Mini-me”…. May 20, 2008

“Mini-me”…. July 1, 2006

“Mini-me”… August 19, 2008

“Mini-me”….November 2008

“Marlo”  Weanling Thoroughbred mare  Injured her leg on her stall door.  December 9, 2008

“Marlo” ….. December 9, 2008

“Marlo”…. December 31, 2008

“Marlo”…. January 14, 2009

“Ruby”  Aged quarter horse mare  Injured her leg after running through a wooden fence  February 2006

“Ruby”…. February 18, 2006

“Ruby”…. February 22, 2006

“Ruby”…. March 06, 2006

“Ruby”…. March28, 2006

“Zack”…. January 1, 2009  12 year old Quarter Horse mare  Cut head on barn roof  January 2009

“Zack”… January 1, 2009

“Zack”… January 14, 2009