What Vet Techs Need to Know About Wound Care

It’s summertime... and that means many families are spending more time outdoors with their pets. Unfortunately, this seemingly positive change can mean that you might be seeing more trauma cases than usual! Outdoor activities and travel expose pets to different risks than those they encounter during the lazy months of winter.

Whether it’s a cat presenting for a spider bite, a dog presenting after a fight at the dog park, or something completely different, clients often seek veterinary care for their pets’ wounds and vet techs play a fundamental role in that care.

Initial Wound Treatment 

The first step in wound care is clipping hair away from the wound. A water-soluble lubricant is typically applied to the wound, to reduce the amount of hair that gets into the wound. Next, a #40 blade is used to clip the hair surrounding the wound. After clipping the hair, sterile saline can be used to flush the lube and contaminating hair from the wound.

Next, the skin around the wound should be scrubbed with chlorhexidine. Avoid scrubbing the wound itself, as this can delay healing. The wound should be flushed with large amounts of sterile saline. Using a 20 ml syringe of sterile saline with an 18-gauge needle will allow you to apply adequate pressure to flush out bacteria and contaminants without damaging the tissues.⁽¹⁾

Once the wound has been clipped and cleaned, it may be more thoroughly evaluated.

Wound Classification

Wounds are classified by their degree of contamination. There are three major classes of wounds:

Class 1 or clean: a wound with minimal contamination, that has been present for less than six hours.  

Class 2 or clean-contaminated: a wound with expected contamination but no visible signs of infection and/or a wound that has been present for 6-12 hours.

Class 3 or contaminated: a wound with visible contamination and/or a wound that has been open for over 12 hours.⁽²⁾ 

Wound classifications are valuable, because they help the veterinary team determine the most appropriate method of wound healing. 

Wound Healing Methods

Wounds may be treated in a number of different ways, depending on the degree of contamination and the size and shape of the wound. 

There are three basic healing methods that can be employed in the care of veterinary wounds:

• First intention healing: suturing or stapling the wound. Also referred to as primary closure, this method is most appropriate for Class 1 wounds in well-vascularized areas. 

• Second intention healing: leaving the wound open to heal by epithelialization and contraction. This process is often used for Class 2 or Class 3 wounds. 

• Third intention healing (also known as delayed primary closure): the wound is left open for several days until the infection is controlled, then the wound is closed surgically. This process may be used for Class 2 or Class 3 wounds.⁽¹⁾

Bandaging Wounds 

Various types of bandages may be used in veterinary patients, depending on the specifics of the wound and its location on the pet. Bandages are often used to cover wounds that are undergoing second intention or third intention healing, although they may also occasionally be placed over wounds that have been sutured or stapled closed. 

The most common bandages are modified Robert-Jones bandages and tie-over bandages.⁽¹⁾ Modified Robert-Jones bandages can be used to wrap a limb or the body, while tie-over bandages utilize stay sutures to apply a bandage to a part of the body that cannot be easily wrapped. 

Bandages typically have three layers: the primary layer, the secondary layer, and the tertiary layer. 

Primary (contact) layer

This is the layer that is closest to the wound. There are three unique types of primary layers that may be used in wound management, depending on the desired effect.

• Adherent: These bandages debride the wound, using sterile gauze pads as a primary layer. Wet-to-dry bandages are used for wounds with thick discharge; gauze squares are soaked with sterile electrolyte solution before applying them to the wound. Dry-to-dry bandages are used for wounds with thin, watery discharge; dry gauze is applied directly to the wound.

• Nonadherent: These bandages use a Telfa^® pad or other non-stick dressing against the wound. They offer protection of the wound, with no other benefits. 

• Semi-occlusive: These bandages utilize gel-impregnated gauze, hydrocolloids, or hydrogels. They protect the wound while also keeping the wound moist.⁽¹⁾

In some cases, wound dressings may be applied before placing the primary layer. Many veterinarians use honey or granulated sugar as a wound dressing for infected wounds that are in need of superficial debridement. Sugar and honey both exert antimicrobial effects by creating a high-osmolarity environment; this same feature draws swelling and edema out of the wound. They also remove devitalized tissues while drawing increased numbers of inflammatory cells into the wound and promoting healing.(3) 

Secondary layer

This is the thickest layer of a typical bandage. This layer, which is often made of cast padding or roll cotton, absorbs drainage from the wound. Additionally, the secondary layer provides pressure that aids in the control of swelling and edema.

Tertiary layer

This external layer secures and protects the bandage. The tertiary layer is often made of Vetrap® or Elastikon®. 

Bandage Care 

Proactive bandage care is essential. A moist or contaminated bandage can lead to many problems, so it’s important to ensure that owners understand and are willing to maintain a bandage. Without proper care, a bandage can do more harm than good.

All bandages should be closely monitored for signs of swelling (proximal or distal to the bandage) and slipping. If either of these occur, the bandage should be replaced. Many veterinarians recommend leaving the tips of the toes exposed when bandaging a limb, so that the owner can more easily monitor for swelling.

Bandages must be kept clean and dry. Any bandage that becomes wet, whether due to environmental moisture or strike-through, must be changed promptly. Honey and sugar bandages often need to be changed every 12-24 hours, due to the large volume of fluid that they draw out via osmolality; owners should be advised of this need before placing this type of bandage.

While the specifics of wound care vary depending on the situation, the basic principles are the same for all wounds. Understanding these fundamentals will allow you to work with a veterinarian to address a variety of wounds, modifying treatments based upon wound characteristics, patient characteristics, and the client’s willingness to comply with instructions.

Resources 

1. Bosco J. 2012, January/February. Today’s Technician: Principles of Wound Care & Bandaging Techniques. Today’s Veterinary Practice. Retrieved from https://todaysveterinarynurse.com/articles/todays-technician-principles-of-wound-care-bandaging-techniques/
2. Slatter D. 2002. Wound management of superficial skin wounds. Textbook of Small Animal Surgery, 3rd ed. Philadelphia: Saunders Elsevier. p 269.
3. Wardlaw J. 2011. Unique Therapies for Difficult Wounds. Today’s Veterinary Practice. Retrieved from https://todaysveterinarypractice.com/wp-content/uploads/sites/4/2016/04/T1107F01.pdf