Jon Geller, DVM, offers his farm animal health experience in caring for cows, calves, horses and sheep. This issue covers the art of wound management for farm animals and details on how to treat common injuries.
Liters of blood ran down my arms, soaking my coveralls and congealing like cherry pudding in puddles around my boots. "All bleeding eventually stops," I said over and over to myself as the blood from a gelding's shoulder wound began to ease. Soon the horse would weaken and collapse and the bleeding would, in fact, stop.
Critters on the farm manage to get hurt in many ways, and while Mother Nature does a pretty good job with healing wounds, domestic animals do not possess the genetic fortitude of their wild relatives so wound management for farm animals is a must. Untreated wounds can get infected, abscess, putrefy, necrotize and slough, leading to amputation, or, in the case of a large animal, euthanasia. For the cat with the bite-wound abscess, the foal with the wirecutter, the dairy cow with the lacerated teat, or the dog whose foot was crushed by a coyote trap, timely and correct treatment is essential. By following a few consistent steps, any informed person can administer some early treatments to ensure complete wound-healing.
Farm Animals: Open Wounds
If you have to stop the bleeding on a bad cut, there are few treatments better than applying direct pressure. It is by far the most effective way to stop bleeding. Ice packs can also help to constrict blood vessels.
After the bleeding stops, the most important step in open wound treatment is irrigation. Thoroughly flush the wound with dilute disinfectant, saline solution or even water. The fluid flushes out contamination and bacteria, and provides gentle pressure on the macerated tissues to stimulate the healing process. Eventually, circulating proteins in the bloodstream attract a new layer of epithelial cells to form a matrix of healing tissue over the wound. Using this scaffolding of new cells, the body will, over time, rebuild its normal tissues.
In the case of the injured gelding, I hung a liter of fluids with an extension line from the ceiling joist, letting the fluids gravitate down into the wound. I returned a week later to determine what muscles, tendons, ligaments and skin were still viable and then trim away any dead tissue (a process called debridement).
Until then, Carrie, the horse's owner, had to flush the wound twice a day. I showed Carrie how to do hydrotherapy — a fancy name for applying a steady stream of water onto the wound using a garden hose for ten or 15 minutes — instead of the careful saline irrigation I had done initially. Surprisingly, most horses will tolerate hydrotherapy once they get used to it. Since all of the tissues of the wound on Carrie's horse were laid open, the wound's edges could not be sutured back together. Even so, several months of hydrotherapy and two weeks of antibiotics would heal the shoulder.
I gave the gelding a hefty injection of penicillin in the side of the neck, and after explaining the procedure I gave Carrie the rest of the bottle to use for twice-daily injections for the next two weeks (see "Giving and Administering Penicillin Injections").
Farm Animals and Farm Pets: Abscesses
An abscess is a pocket of infection that usually occurs when bacteria is injected through the skin by a contaminated object like a tooth, claw or piece of wire. The body walls off this pocket with a sphere of scar-like tissue, and eventually the pocket usually breaks through the skin to the outside. Even so, infection can spread into surrounding tissues and the bloodstream, making the animal quite sick.
Max the cat loved to fight, and on my most recent visit his temperature was 105 degrees Fahrenheit and he was not eating, indications that infection was starting to take hold. Typically, an abscess may not appear until three to seven days after the initial injury. At the first sign of swelling, cat owners should carefully inspect the area for evidence of a small wound (it might be necessary to clip some fur from the site first).
Once the entry wound is discovered, a vigorous scrubbing with a moist cloth will open up the initial entry wound so the pus drains out. Apply pressure to drain the wound, but be gentle or the pus could be forced out of the abscess and back into the bloodstream. If scrubbing does not open the abscess, it should be lanced by your veterinarian. Also, oral or injected antibiotics should be used as soon as the abscess is detected. Your veterinarian will have to prescribe these for you — an amoxacillin suspension typically works well. Don't use any expired antibiotics you might have lying around — they quickly lose potency.
After the initial draining, apply a hot pack to the wound two to three times a day to encourage continuous drainage. Your veterinarian may also be able to supply you with a curved-tip flushing syringe, which can be used to infuse dilute antibacterial disinfectant like chlorihexidene (Hibiclens) or iodine (Betadine) into the abscess. In any wound, it is important that the solution be generously diluted, otherwise the wound may become irritated and will be slow to heal. Do not use alcohol or hydrogen peroxide for wound flushing — they are painful, irritating and ineffective. Don't use antibacterial ointments, either, because they interfere with drainage.
By the way, your cat may try to kill you when you do all this. If your cute little kitty turns into a hissing ball of fur, call your veterinarian so your feline can be adequately sedated.
Farm Animals: Sold Abscesses
Hoofed animals like horses and cattle commonly get abscesses on the soles of their feet when they step on sharp objects that penetrate vital tissues. Sole material should be pared away until the abscess is exposed, and the foot should then be soaked in a dilute disinfecting foot bath twice a day for four or five days. If you have access to antibiotics, those can be helpful as well. In the case of a serious penetrating wound to the foot involving a nail or long object, call your veterinarian immediately. Infections deep in the foot's tissues can cause permanent lameness if not treated aggressively.
Large animals will commonly get abscesses under their skin after being poked by a piece of wire or a nail. Treat these as you would a normal abscess, with repeated flushings for three to five days and hot-packing. If antibiotics are available, they can be used to stave off any systemic infection.
Farm Pets: Degloving Injuries
If you keep leg traps on your property, there is always a chance that a cat or dog will get caught. A degloving injury occurs when the skin is stripped — or degloved — from a limb or part of the torso.
if the vital structures underneath the stripped skin are still functioning, the potential for complete healing exists. By pinching toes to check for pain sensation and stimulating bleeding to assess blood flow, one can check the viability of vessels and nerves before doing extensive treatment on a limb that might have to be amputated. Fortunately, hounds get around quite well on three legs.
In dogs and cats, open wounds heal faster using a bandage, changed daily, for ten to 14 days. Moisten the bandage before application so that its removal pulls off dead tissue. Pulling off the bandage also stimulates minor bleeding and attracts the growth factors that stimulate formation of a healthy bed of healing cells. Irrigate the wound with sterile fluid before applying a new bandage to keep infection under control. You should either feed or inject antibiotics, depending on the species and temperament of the patient (check with your doctor first).
Dairy Cows: Teat Lacerations
Teat lacerations in dairy cows can have serious consequences - namely the permanent loss of the udder for milking — if not treated promptly and correctly. Usually, an abnormal drainage route for milk (called a fistula) will form, and normal teat sphincter function will cease. Mastitis or inflammation of the udder will occur, leading to irreversible scarring.
Superficial cuts can be cleaned and treated with topical antibiotic ointments and a bandage. Deeper cuts must be carefully sutured back together, matching all three layers of the mammary tissue meticulously.
The pressure of hand-milking an injured teat will usually disrupt a suture line and prevent healing. In addition to a teat tube, milking machines can be used immediately to drain the teat without affecting the suture line. In any case, antibiotics should be infused daily into the teat, along with twice daily penicillin injections to prevent mastitis. After milking, the milk should be checked for mastitis with the aid of a California mastitis test.
Farm Animals: Barbed Wire Cuts
Barbed wire seems to have an affinity for the equine limb, and infection can set in quickly. Wire cuts should be treated within several hours to allow cosmetic closure of the wound. After that time primary healing of sutured wound edges is unlikely. Also, horses are extremely sensitive to tetanus and should receive a tetanus vaccine booster with any wound, regardless of how superficial it may seem.
It I can get to the scene early enough; I sedate the wounded beast, clip the hair around the wound, clean the cut and sew the edges back together. I also apply a padded bandage to reduce swelling and change the bandage in three days. Even if your vet cannot close the wound for more than five hours, you should treat the cut similarly with a bandage and a vaccination.
Daily scrubbing with dilute disinfectant such as Betadine or Hibiclens is a must. Sometimes excessive granulation tissue, known as proud flesh, can develop over the exposed wound, causing unsightly, irregular mounding of the flesh. In such cases, the granulation tissue, which does not contain nerves, should be trimmed back before the final layer of skin cells grows back.
Because the risk of complications is high, I do not recommend that horse owners living in remote areas sew up wirecuts. However, if there are no other options, I recommend that you ask your veterinarian for a training session along with some instruments and supplies for treating a simple wire cut using local anesthetic instead of sedation. If the horse is rank, forget it; your vet will have to sedate the beast.
There are as many varieties of wounds as there are critters, but by applying the same principles of wound management to each one — with an emphasis on irrigation — the odds of eventual success are good.