Renal Therapies

Leptospirosis is a febrile (fever) disease that is caused by an infection with bacteria. Other names for the disease include mud fever, swamp fever, or sigar cane fever. The severe cases of leptospirosis are called Weil's syndrome. There are about 35-60 cases of the disease reported in the US each year, mostly in Hawaii and the south Atlantic states. Most occur between July and October.

The livestock industry can be severely affected by the instance of leptospirosis. Animals that are infected can pass the bacteria through their urine for months or even years. The bacteria can be transmitted through cuts or mucous membranes. Once inside the host, the bacteria enters the blood stream and spreads to the major tissues and organs. The inner lining of blood vessels can be damaged, as well as the liver, kidneys, heart, lungs, central nervous system, and eyes. The symptoms of leptospirosis are fever, headache, chills, vomiting, jaundice, anemia and sometimes rash.

In the kidneys, there is a decrease in urine production after 3-7 days of illness. Usually, the disease is treated with antibiotics like penicillin or erythromycin. However, the helpfulness of drugs in the latter stages of the disease is controversial. To remove waste products from the blood, hemodialysis may be performed.

No concrete records of kidney transplant exists currently for farm animal species.

Pacemakers

Manufacturers often donate pacemakers to veterinary hospitals after several months have passed their shelf-life expiration date. People have also willed their pacemakers to animals after passing away. Though the pacemakers have a shorter lifespan, it is less significant in animals due to their shorter lifespan.

Implantation is performed on a standing tranquilized horse with an incision in the neck. Atrial and ventricular leads are inserted through the cephalic vein and a pocket is made for the pacemaker between the lateral pectoral groove and the manubrium sterni. The guidance of the wires was accomplished with ultrasound technology rather than the typical fluoroscopy because of the size of the animals.

Xena, a seven year old pregnant mare, was suffering from a complete heart block where the natural method of stimulating the heart was no longer working. Her heart rate had dropped from 40 to 10 beats per minute. Adrian Boswood, a Cardiologist from the Royal Veterinary College 's Queen Mother's Hospital for Animals worked with Mike Archer, Equine Surgeon, to fit the pacemaker. The pacemaker saved the life of her and her foal, Viper.

Prosthetic Limbs

Dottie, a pregnant dairy cow who had cracked her bone while trying to pull it free from a rock, was fitted with a prosthetic limb by Marc Klemmt, founder of Klemmt Orthopedic Services. He fitted the cow with an 8 pound artificial leg made of epoxy resin impregnated into a fiberglass and carbon-graphite shell with a core of solid maple for extra strength. One condition of the leg was that it must withstand 600 pounds of pressure. At the base or the leg, a skid-proof rubber boot was used that normally protects a diseased hoof from infection. Though the leg was built at no charge to the clients, the cost would have amounted to over $1,000. The entire procedure was successful as Dottie was able to give birth and continue producing milk.

A man that raises fancy chickens faced a problem when his rooster got tangled up in bailing twine that cut off circulation from his foot for a long enough time that it had to be amputated. The partial foot amputation was two inches from the proximal joint and had an ideal bulbous distal end for a supracondylar-type suspension. To prepare the socket, a two-stage casting technique was used to capture the shape and size of the residual limb, and a socket with anterior opening was laminated.

The prosthetic foot in action.

The only problem now was finding a prosthetic chicken foot. The surgeon found his answer in the Halloween aisle of a store. The pumpkin carving set provided the perfect answer. The saw was used like a pipe and the orange handle fit into the inside of the galvanized pipe. The scooper was used for the foot and was shaped into the correct angle of a chicken's foot with a propane torch. A gel liner normally used for fingers and toes was placed on the residual limb as a comfortable interface.

The prosthetic limb made for the rooster.

Prosthetic Implants

There is new hope for horses with bone fractures in the leg. What used to lead to the need to euthanize a horse has now found an answer in new technology.When an animal has a limb that is no longer functioning, many veterinarians believe that it is better to amputate the limb rather than try and save it. The ideal outcome of the surgery is to create the best limb for prosthesis.

Companies such as Equine Prosthetics, Inc. saw the need for prosthetic limbs in horses when they first attempted to repair Thor's limb, a 16 hand Thoroughbred. The first attempt was to attach a support plate to a shoe, but the support was not adequate.

Initially fitted with this ‘peg leg', Thor is now outfitted with the same type of prosthesis that Paralympic athletes wear and has nearly the same mobility as uninjured horses.

Primrose is a burro who, at five months old, had a severely infected hind leg after being attacked by dogs. The infection, similar to a staphylococcus infection in humans, had reached the bone in both legs. It had so weakened the right rear limb that the bone cracked. Dr. Gayle Trotter, who had never amputated a burro or horse limb before, removed the leg below the hock a t Colorado State 's Veterinary Teaching Hospital. “ We used a recommended technique in amputations, salvaging soft tissues such as ligaments and tendons and wrapping them around the stump after rounding off the end of the bone,” Dr. Trotter said, for “it provides better cushioning for the limb if soft tissue is available.” Prosthetic technician Theresa Conrath fitted Primrose with a prosthetic leg.

Large Animal Prosthesis

The problem with animals as large as Primrose and Thor is that these are animals that are neither accustomed to nor built to walk on three legs. If they are unable to immediately use the prosthetic limb correctly, they may compensate on other legs which could result in injury to the healthy leg.

Immediately after the surgery to remove the damaged portion of the leg, the residual limb is placed in a snug fitting cast with a temporary prosthesis. This is done for a few reasons: to keep the wound clean and free of debris, to keep edema from settling into the surgical site, and to retain mobility. By keeping excess fluid from settling in the wound site, maximum circulation is retained which will promote healing. Retaining mobility will also help keep maximum circulation and also help build and maintain musculature. After the initial limb is fitted, it will have to be changed over time to compensate for the changing form of the leg that is bound to take place. Each final prosthetic device is custom-made from carbon fiber, acrylic resin, and stainless steel, which leads to prices from $6,000 to $10,000. Care and cost does not stop there. After surgery, the leg must be cared for every day to clean and inspect for infection and sores.

The problem with bone fractures in horses is not correcting the fracture, but healing the fracture after surgery. Without crutches to support them, horses must be able to support up to 3,000 pounds of force when rising from anesthesia. Because of technologies such as the Anderson sling that transports a horse after surgery and supports it during recovery, doctors and veterinarians have been able to continue to develop new and improved implants for mending the fracture itself.

Intermedullary Interlocking nail

UC Davis' equine orthopedic surgery program has developed an implant that has been successful in human surgery for a long time. The intermedullary interlocking nail gives hope to horses with long leg bone fractures. The nails are positioned within the medullary cavity and can be secured to the proximal and distal fracture segments using transcortical screws which penetrate both cortices of the bone, as well as pass through holes in the nail. Thus, unlike Steinmann pins, which can only counteract bending forces, interlocking nails can also counteract axial and rotational forces. The nail is placed centrally in the axis of the bone unlike bone plates that only give exterior support. With bone plates, there has always been a challenge of attaining correct alignment along the fracture and contouring the plates to the bone. The interlocking screws that penetrate the central nail in combination with traction applied to the proximal and distal fracture segments bring the fractured pieces into correct position. This new technology has limited interference with the soft tissue and cuts down on surgery time.

Carbon Fiber Implants

In an attempt to aid horses with bowed tendons, research has been done using carbon fiber implants that consist of about 40,000 fibers in total each of which is 8 microns in diameter. These fibers induce tissue growth and result in a structure of carbon and tissue about 8 mm in diameter. The implant was inserted using a specially designed trocar and cannula that penetrated the center of the tendon up to the carpometecarpal joint. The trocar was removed and the implant was inserted through the cannula, which was then removed. Shown in the table below, many of the horses were able to return to work and compete in races.

Blood Transfusion

Blood transfusion in larger domestic animals follows the same format as those for cats and dogs, yet the amount of donors depends on the species. Cattle and sheep have many potential donors in large herds, but horses might not have as many options. Most blood given in transfusions is from a direct relative of the animal, usually the mother. Because livestock rarely hold personal value to farmers, putting the animal down is probably more common than spending money and effort trying to maintain one individual in a herd of hundreds or thousands.

Many equine performance shows state the rule that a horse a horse only needs “the appearance of two eyes,” not necessarily two functional eyes, to compete. Therefore, for many horses that suffer eye injuries or infections, a prosthetic eye is beneficial even if it is for appearance alone. The most common infection is equine recurrent uveitis where the immune system excessively responds to bacterial infection and instead of ridding the eye of the infection begins to damage the eye, causing deposits of thick fibrin in the ocular fluid. This leads to a constant inflammation which damages the eye and in many cases results in blindness with constant bouts of pain.

For many horses with this problem, the eye must be removed in order to eliminate the pain associated with it and a ceramic ocular prosthesis is implanted in the closed socket. If the eye does not need to be removed, a veterinary ophthalmologist can insert a prosthetic ball inside the eye before the eye shrinks. Through an incision in the sclera, the eye fluid, lens, iris and retina are removed and a darkly colored prosthetic ball is inserted. The eye retains fairly normal appearance since the sclera is intact and the dark prosthetic is showing through the cornea. The eyelids, conjunctiva, glands, and eye muscles remain intact leaving the horse the ability to move its eye normally.

The procedure, including the prosthesis, can cost between $2,500 and $3,500.