antibiotics | Horse Racing Free Tips

Pros And Cons Of Antibiotic Injections In Equine Joints

Because of the finesse with which equine veterinarians inject medications into joints, the procedure can appear uncomplicated. While injecting joints with antibiotics can help clear infections, the procedure is not without risks. Veterinarians must therefore consider a number of important factors before moving forward with intra-articular antibiotic therapies.

Managing Osteoarthritis

Medicating joints with corticosteroids, polysulfated glycosaminoglycans, or hyaluronic acid is commonplace in equine sports medicine. Intra-articular injection is often used in conjunction with other modalities, including oral joint health supplements. Oral products decrease inflammation and improve mobility, boosting the overall health of joints. Examples of appropriate products include high-quality supplements that contain proprietary combinations of glucosamine hydrochloride, chondroitin sulfate, MSM, and hyaluronic acid.

According to a recent review of intra-articular antibiotic use, 78 percent of veterinarians use intra-articular antibiotics in combination with other medications.^* By adding an antibiotic, often amikacin, to corticosteroid or polysulfated glycosaminoglycan, veterinarians hope to sidestep the development of a septic joint.

Considering the low risk of infection following joint injections, the question then becomes whether or not veterinarians should use prophylactic antibiotics. Moreover, because intra-articular antibiotics are used “off-label,” no researched guidelines for appropriate intra-articular use exist.

Prophylactic intra-articular antibiotic use therefore has two major ramifications:

Veterinarians may administer an excessively high dose. “According to some evidence, antibiotics like amikacin have toxic effects on cartilage cells and other joint tissues,” said Peter Huntington, B.V.Sc., M.A.C.V.Sc., director of nutrition at Kentucky Equine Research.
Unnecessary use of antibiotics contributes to antibiotic resistance. “With few new antibiotics in development and growing multidrug resistance to currently available medication, revisiting the practice of prophylactic antibiotic use in horses may be warranted,” Huntington added.

These concerns associated with intra-articular antibiotic administration supports alternative strategies for maintaining joint health.

Managing Septic Joints

Intra-articular antibiotics are indispensable in the face of a septic joint because direct administration into the joint can achieve high local drug concentrations. If, on the other hand, antibiotics are offered orally, high dosages would be needed for longer durations to achieve the same result as an intra-articular injection.

[Story Continues Below]

“Systemic antibiotics, however, may be associated with important and potentially life-threatening side effects such as gastrointestinal disturbances that disrupt the microbiome. In the face of microbiome disarray, pathogenic bacteria may proliferate, altering immunity and increasing the risk of diarrhea or laminitis,” Huntington explained. When systemic antibiotics must be administered, gastrointestinal support in the form of research-proven supplements should be considered.

Local antibiotic delivery directly into a joint may also:

Improve owner compliance as injections do not rely on the owner administering the entire course of oral antibiotics;
Make treatment more affordable, as a systemic antibiotic maybe be cost prohibitive for an owner;
Shorten the course of treatment and improve outcomes; and
Result in high concentrations at the site of infection that may be particularly useful for fighting “floating biofilm,” which is an accumulation of microbes embedded within a self-produced extracellular matrix that helps protect the bacteria from antibiotics.

^*Pezzanite, L.M., D.A. Hendrickson, S. Dow, L. Chow, D. Krause, and L. Goodrich. 2021. Intra-articular administration of antibiotics in horses: Justifications, risks, reconsideration of use and outcomes. Equine Veterinary Journal:13502.

Study: Massive Doses Of Antibiotics Many Not Be Needed Post-Surgery

Horses who undergo colic surgery are often given a five-day round of antibiotics to fight off possible infection after the surgery is complete. A new study has shown that a single antibiotic injection could provide the same amount of protection.

Dr. Sabita Diana Stöckle notes that many human and veterinary surgeries conclude with a round of short-term (24-hour) antibiotic treatment to reduce the risk of disease. For colic surgery, however, it's common for antibiotics to be administered for well over 24 hours.

Stöckle and her colleagues used 67 horses that had undergone colic surgery to compare the standard five-day course of antibiotics to a single-shot dose. Thirty of the horses received a single shot of penicillin and gentamicin once before the surgery. Some horses also received an additional shot during surgery if needed. The other 37 horses received the standard, five-day antibiotic protocol.

The study team found no significant differences in post-operative adverse issues between the two groups; there was minimal difference in the amount of colitis, hemolytic anemia or surgical site infections. They suggest that the single antibiotic dose may be an effective alternative to the common, five-day protocol, if proper hygiene and close patient monitoring also occurs.

Read the article here.

Study Finds Amniotic Extract Unhelpful To Speed Eye Healing In Horses

Equine eye injuries can be difficult to address and harder to heal – and they can be very painful for the horse. Any therapy that can be used to speed healing and decrease down time is welcomed by those who have had to administer eye meds to a horse.

A new experiment has shown that adding commercially available amniotic membrane to traditionally used antibiotics, antifungals, and pupil-dilating agents did not speed healing when compared with traditional medical treatments alone.

Drs. Victoria Lyons, Wendy Townsend, George Moore and Siqi Liang induced superficial corneal ulcers in both eyes of 10 healthy horses. One eye was treated with amniotic extract and the other eye was treated with the extract only to serve as the control. Both eyes were treated with topical therapies that included antifungal, antibiotics and drugs to dilate the pupil.

The ulcers were stained and photographed every 12 hours until they completely healed. Eyes treated with the amniotic fluid healed between 68.2 to 162.7 hours; eyes that used the control healed in 87.4 to 167.6 hours. No matter which therapy was used, the eyes healed in two distinct phases: a rapid initial phase and a slower second phase with a visible duration.

The researchers determined that adding a commercially available amniotic membrane extract to other topical medications did not significantly increase the rate of healing.

Read the article here.

University Of Florida Vets Use Placenta-Derived Treatment For Animals With Severe Bone Loss

A human placenta-derived compound developed by a University of Florida faculty member in the Herbert Wertheim College of Engineering is being used with promising results by veterinarians at UF's College of Veterinary Medicine to treat animals with severe bone loss.

Without the compound, the animals — which included a giraffe at the Jacksonville Zoo and Gardens and two pet dogs — would have almost certainly faced amputation of the affected areas, the veterinarians said.

The product's developer, Peter McFetridge, Ph.D., the Integra Lifesciences Term Professor in the J. Crayton Pruitt Family Department of Biomedical Engineering, studies the engineering of viable “living” tissues and organs for the repair and regeneration of diseased tissues. Stan Kim, BVSc., an associate professor of small-animal surgery at UF, learned of McFetridge's work and was intrigued about the placental compound he had been testing in rodent models with some success.

McFetridge and Kim began discussing possibilities for the product's additional use in small animals. Kim treated the dogs with the new compound at UF's Small Animal Hospital earlier this year.

“Both dogs had very bad fractures that did not heal and had lost a lot of bone,” Kim said. “Typical treatments usually fail in these types of cases.”

The dogs were completely healed after the placental treatment, he said, and are doing very well.

“The most exciting thing about the placental compound is that it seems to regenerate bone in a remarkable manner,” Kim said. “Although our main excitement is with regenerating bone, we have also had very positive results with wounds.”

Meanwhile, Kim's colleague, Adam Biedrzycki, BVSc., Ph.D., an assistant professor of equine surgery at UF, had been contacted in January by the Jacksonville Zoo and Gardens about the possibility of helping with the treatment of a 2-year-old reticulated giraffe named JoJo, who had become severely lame in October. Despite various treatments provided at the zoo, JoJo's foot problems had worsened.

“They asked if I or a colleague had any interest in consulting or participating in the case,” Biedrzycki said.

JoJo had a severe case of septic arthritis in the medial claw of her right front foot, he said. The zoo had been treating the giraffe with analgesics, antibiotics and stall rest, and had even applied a custom-made boot from a farrier who works with exotic hoof stock. However, radiographs appeared to show bone abnormalities and deterioration, contributing to lesions and fluid drainage.

“I told them that giraffes are certainly not my area of expertise, but in a bovine or horse with this condition we would do massive bone grafts, place antibiotic beads, administer antibiotics directly into the limb and spend lots of time and money trying to save the digit. In a cow, we would drill out and remove the dead or damaged tissue surrounding the foot bone. Then we would cast it followed by regular bandage changes on the limb and leave it to heal.”

That was essentially what was done with the giraffe, he said — but with the addition of the placental compound.

Biedrzycki spoke with Kim, who had used the placental compound successfully in a few cases. Kim put Biedrzycki in touch with McFetridge to further discuss the product and its potential for treating infections and stimulating bone growth.

Biedrzycki then brainstormed with Jacksonville Zoo veterinarian Yousef Jafarey, D.V.M., and his team to develop a plan: They would cut out the diseased bone, clean out the area and put in bone allografts, antibiotic beads and the placental product “to try to speed things up.”

The giraffe wore a cast on her foot, and three cast changes were performed six weeks apart. The second time, the area was cleaned out a bit more and additional placental compound was applied, Biedrzycki said.

“It was a very big deal,” he said. “I was really impressed with the whole team effort.”

That effort involved the zoo's keepers, its animal health team, an anesthesia crew and many more people performing various duties along the way, Biedrzycki said.

“You also had an army of people massaging the giraffe's neck, another team putting antibiotics in the vein, and the surgery team working on the foot, along with a farrier to help trim the foot,” he said. “There were probably about 30 people altogether working on this giraffe. I think they have the whole procedure down to an art now.”

He said the collaborative effort and range of expertise at the zoo was likely why JoJo did so well with the procedure and continues to improve.

“So far, the outcome is excellent,” he said. “The infection is gone and there is new bone growth at the site showing fusion between the bones, which is really unheard of. She still has some limb swelling, which will take a while to go down. But JoJo seems pretty happy at this stage.”

Jafarey said the zoo was astounded at JoJo's progress since working with Biedrzycki and the UF team.

“The introduction of this new compound has been integral in her recovery and we are excited that our organization participated in this groundbreaking research,” he said.

The material the UF veterinarians have been using started out being used to drive the regeneration of large vessels for heart bypass, McFetridge said.

“I never thought it could be used clinically, as it contains a lot of human maternal tissues, from the placenta, as well as the fetal side of the placenta,” he said. “But after several animal studies, we discovered that there was no negative immune response at all, and that it had a potent healing effect across a range of different tissues.”

Unlike typical biologic treatments that have one response, the placenta-derived material seems to promote healing in several vastly different tissues including bone, blood vessels and skin, McFetridge added.

McFetridge and two of his biomedical engineering department colleagues, Jon Dobson, Ph.D., the J. Crayton Pruitt Family Professor, and Blanka Sharma, Ph.D., an associate professor and the J. Crayton Pruitt Family Term Fellow, have co-founded a company in Gainesville, 42Bio, to commercialize the product for veterinary applications. They recently got private funding to move forward with research facilities at The Hub, UF's business incubator.

“So we're hoping to be able to provide this amazing material more widely, especially as we find out, almost daily, how well it helps heal critical injuries. The healing responses we've seen in the giraffe and the dogs are almost jaw-dropping.”