Originally published in the November 2015 issue of Veterinary Practice News. Enjoyed this article? Then subscribe today!
Here’s the advice many veterinary specialists offer in dealing with animals’ wounds: Look deeper.
While a wound itself may call for immediate attention, beneath the damaged tissue may lurk a deeper injury, or a rampant infection lying in wait in an area critical to a pet’s future mobility.
Early and thorough exploration of wounds allow them to be cleaned before tissue becomes more infected or necrotic, and more importantly, before the bacteria spread system-wide, said Marije Risselada, DVM, Ph.D., Dipl. ECVS, Dipl. ACVS.
“Exploring the wound — looking for trauma to underlying structures — is key in bite wounds, as the act of the fight and the motion of the dog that is biting and the one that is bitten oftentimes tear the underlying muscles, tendons, tissues, while the overlying skin is more mobile and only shows some small puncture wounds,” Dr. Risselada said.
She is an assistant professor in small animal soft tissue and oncologic surgery at the North Carolina State University College of Veterinary Medicine.
Chad Schmiedt, DVM, Dipl. ACVS, an associate professor of soft tissue surgery at the University of Georgia College of Veterinary Medicine, puts such exploration atop his list of the basics of wound care.
Dr. Schmiedt’s basics include biopsying and culturing problem wounds, being mindful of tension, and identifying the underlying problem in patients with wounds that won’t heal.
“When dealing with hard-to-handle wounds, I think veterinarians should revert to the basics of wound healing,” Schmiedt said, urging practitioners to keep in mind that there is “always a biological reason” a wound won’t heal.
If a wound is stuck in the inflammatory and debridement stage, a treating veterinarian should consider that something prevents it from moving on to the repair phase, he said.
“Usually this is dead or necrotic tissue that needs to be removed, infection, or inappropriate wound care — some magic treatment one keeps slathering on,” Schmiedt said. “If a wound is stuck in the repair phase with a granulation bed that will not contract and epithelialize, this is usually because the tension is too great for the myofibroblasts, there is infection, or inappropriate wound care.”
Another of Schmiedt’s priorities is identifying a biological problem and correcting it.
He believes one of the biggest obstacles in wound healing is a wound that forms because of an underlying problem, such as pressure sores or decubital ulcers. Without doing something to address the underlying problem, these wounds will not heal, he said.
Schmiedt isn’t the only expert who preaches a basics-first approach to wound care.
The application of wound management basics is “fundamental to successful outcomes,” said Susan W. Volk, VMD, Ph.D., Dipl. ACVS, an assistant professor of small animal surgery at the University of Pennsylvania School of Veterinary Medicine.
Dr. Volk’s tenets of wound management include proper cleansing, debridement and lavage of the wound, provision of adequate wound drainage, adherence to surgical principles, and selection of appropriate method and timing of wound closure.
“Preoperative patient assessment and client counseling are also key, particularly in cases with extensive wounds or comorbidities, to successful outcome and ensuring long-term commitment and investment throughout the duration of the post-operative period,” Volk said.
She sees no single solution in wound management.
“To optimize the healing potential of any wound, it is critical to have a thorough understanding of the normal wound-healing process for each species, the factors that can derail these events and compromise healing, and the treatment options that are available,” she said. “With these in mind, clinicians should reassess wounds throughout the healing process to promote an ideal wound-healing environment, minimize complications and intervene should healing not progress as anticipated.”
Wound Care Techniques
Veterinary medicine has no shortage of wound care products and devices. They include a large and growing variety of dressings and topical agents and devices, as well as biological and regenerative therapies, Volk said.
“The key to their successful application is in understanding the advantages and limitations to each and when to apply them to individual wounds,” she said.
A newer technique to tackle tough wounds, in the view of North Carolina State’s Risselada, is negative-pressure wound therapy, in which a porous bandage is kept at a constant negative pressure.
“This allows less frequent bandage changes, which we oftentimes would have to do under sedation or anesthesia to keep our patients comfortable and minimize pain and trauma,” Risselada said. “More classically used bandages would have to be changed every 12 to 24 hours, while the [negative-pressure wound therapy] would have to be reapplied every three days.”
Georgia’s Schmiedt also is big on negative pressure.
“We commonly use V.A.C. Therapy on wounds in the repair stage or after skin grafting,” he said.
Additionally, he has been using a more topical edetate disodium, or silver-based products like Tricide, Silvalon or Silvaklenz, from Molecular Therapeutics, in the inflammatory and debridement stage, or if an infection is present.
Go Beyond the Surface of Equine Wounds
Veterinarians who specialize in equine medicine echoed a sentiment that small animal practitioners offer on the topic of wound healing.
“The most important thing is to figure out what is underneath the wound,” said Anthony Blikslager, DVM, Ph.D., Dipl. ACVS, a professor of equine surgery and gastroenterology at the North Carolina State University College of Veterinary Medicine.
“Is there a joint there, tendon or a tendon sheath, anything like that, which makes it much more complicated than dealing with just the wound tissue?”
Dr. Blikslager advocates referrals for wounds that may be beyond superficial and when the possibility exists that some areas critical to mobility may be affected.
A general practitioner may take radiographs and ultrasound, and clean up a wound to see it better. But upon discovering that a wound or infection went into a joint, a tendon or a tendon sheath, “It would be best to refer it right away,” Blikslager said.
He suggests a referral to an orthopedic surgeon in such cases because a horse may have to be anesthetized and arthroscopy performed for a closer examination, along with a “big flush” to remove foreign material or dead tissue.
To help determine whether a wound has affected a joint, veterinarians can distend the joint from a site away from the wound and inject saline into one site in the joint to see if comes out the other.
Blikslager cited as an example the hock joint, which has four pouches, with a wound over one of those areas. A practitioner may go into one of the other pouches and prep it and distend it with saline to see if it leaks out.
These areas are a great place for infections to hide out and proliferate, he said.
Giving antibiotics intravenously or by mouth are the standard treatment for infections, but vigorously flushing out these impacted areas is crucial to get rid of an infection that can get trapped in and begin to eat away at cartilage, a tendon or tendon sheath, Blikslager added.
This may sound overly thorough, but missing or ignoring an infection or injury that can affect a crucial area can cause a delay in proper treatment.
It’s after such delays —most often five to seven days from the occurrence of the wound—that horses typically are taken to Blikslager.
Too often, that’s too late.
“If it’s five, seven days from the wound, it just becomes very difficult them to get them turned around,” Blikslager said.
For a joint infection that is treated immediately, the prognosis is fair to get the horse returned to soundness, Blikslager said.
But the outlook is guarded at five days of occurrence of the wound and poor at a week or longer. At the latter point, lifelong residual lameness becomes likely in a horse, Blikslager said.
Erin Denney-Jones, DVM, owner of Florida Equine Veterinary Services Inc. in Clermont, Fla., offered several best-practice tips for practitioners dealing with a wound.
“Best practice for wound care is keeping it clean and covered if possible—especially lower limb leg wounds,” Dr. Denney-Jones said. “Using an antibacterial solution when cleaning is highly recommended.”
She likes tried-and-true techniques.
“The antibiotic-infused mesh bandages as well as serum or amnion dressings are all still being used with good success,” Denney-Jones said. “With that said, the basic clean-the-wound, apply-antibiotic-dressing and cover is still an excellent way to aid healing.”
Like Blikslager, her take-home message is that if a wound is not healing as well as expected—and the client is in compliance with the doctor’s orders—a further investigation is called for.
In such a case, Denney-Jones suggests considering a foreign body, such as a splinter, bone sequestrum or summer sore (habronemiasis).
This all requires solid diagnostics, and boning up on one’s diagnostic skills is a must for practitioners who want to better determine the depth of wounds and what is causing them, Blikslager said.
”If you get good at ultrasound, that would be a way to get better at tracing the wound,” he said.
Ultrasound equipment is providing increasingly sharper resolution, and that has paved the way for a new, inexpensive technology that Blikslager recommends every practitioner consider purchasing.
The new relative bargain for veterinary diagnostics is a smartphone. The quality of cell phone cameras combined with the increased resolution of ultrasound equipment—not to mention the speedy and efficient means of transmissions that modern cellphones provide—makes referrals quick and easy, he said.
“In something like 30 seconds we can be talking about that wound,” Blikslager said. “People take an iPhone and shoot right off the screen and it’s good enough.”