DeBowes Rm

Surgical Management of Urolithiasis

A review of equine urolithiasis is presented. Special emphasis is placed on clinical diagnosis and management. Although somewhat uncommon, urolithiasis is a potentially serious condition with an apparent predilection for male horses. Although the entire urinary tract is at risk for urolith formation, the bladder and urethra are most commonly affected. The principal signs include stranguria, hematuria, and dysuria. Severe abdominal discomfort is often observed in patients suffering from distal urinary tract obstructions. If urolithiasis is promptly identified, a variety of surgical techniques may be applied to resolve and treat this condition.

Penetrating wounds, abscesses, gravel, and bruising of the equine foot.

Foot-associated lamenesses are common diagnostic challenges for the equine practitioner. This article reviews the commonly occurring penetrating and concussive solar injuries of the equine foot. Diagnostic and therapeutic approaches for the management of these conditions are suggested. With proper treatment, many of these serious injuries will show excellent results.

The effect of intra‐articular methylprednisolone acetate and exercise on equine carpal subchondral and cancellous bone microhardness

Dorsal carpal osteochondral injury is a major cause of lameness in horses undergoing high intensity training. Intra-articular corticosteroid treatment is used commonly to manage exercise-associated articular pain, but its use remains highly controversial in the equine athlete. This project, therefore, aimed to compare the mechanical properties of intra-articular MPA and diluent-treated middle carpal subchondral and cancellous bone in horses undergoing a short-term treadmill exercise programme. It was hypothesised that subchondral and cancellous bone mechanical properties are influenced by intra-articular administration of methylprednisolone acetate (MPA). Eight 2-year-old female horses had MPA or diluent administered into contralateral middle carpal joints at 14 day intervals, for a total of 4 treatments per horse. Horses underwent a standard treadmill exercise protocol until euthanasia (Day 70). Standard sites were located on the dorsal aspect of third, radial and intermediate carpal bones. Osteochondral samples from each test site were divided into subchondral bone and cancellous bone portions. These were dried, resin-embedded and gold-coated. Microhardness measurements were obtained at each test site. No significant effect of intra-articular treatment was detected. At each site, cancellous bone trabecular struts had an 18-19% higher microhardness value than the overlying subchondral bone. These findings indicate that intra-articular administration of MPA at this dose has no effect on subchondral or cancellous bone adaptation to short-term exercise and, therefore, on the propensity of carpal bones to injury. Further investigation into the calcified cartilage layer, effect of different corticosteroid preparations and diffusion of medication are required.

Improved osseointeraction of calcium phosphate-coated external fixation pins Studies in calves

We investigated osseointeraction of solution-precipitated calcium phosphate (SPCP)-coated transfixation pins used in external skeletal fixation of a calf stable fracture model. One group (SPCP) received centrally-threaded transfixation pins which had SPCP coating; the other group (control) received identical, but not coated, pins. Radiographs were obtained 1 and 40 days after surgery and examined for evidence of osteolysis. Bone phase 99mTc-MDP studies were performed 6 and 28 days after surgery. Calves were killed 40 days after surgery and mechanical tests performed. Dual-energy x-ray absorptiometry (DEXA) and histomorphometric analyses were done. A smaller proportion of SPCP pins (5/24) had evidence of discharge during the study compared with control pins (21/24). A smaller proportion of SPCP pins (4%) had radiographic evidence of osteolysis compared with control pins (42%). Uptake of 99mTc-MDP was similar for SPCP and control calves. Uptake was significantly greater in bone segments showing radiographic evidence of osteolysis than in bone segments not having osteolysis. Yield stress (MPa) for axial displacement was similar in the treatment groups. Bone mineral density was less in SPCP pins. Affinity index and interface histologic score were greater and osteoclastic index less in SPCP calves. Coating of transfixation pins with solution-precipitated calcium phosphate improved the osseointeraction of pin and bone during this 40-day study.

Standing rectal and tail surgery.

A variety of rectal, perirectal, and coccygeal surgeries can be performed in the standing equine patient if appropriate chemical and physical restraints are available and adequate regional anesthesia can be achieved. Some rectal tears and most rectal prolapses, mass lesions, perirectal abscesses, rectal biopsies, and selected injuries of the tail can be managed without prohibitive difficulty. Severe injuries that compromise the small colon cranial to the peritoneal reflection may require flank laparotomy, midline celiotomy, or humane euthanasia to manage the disease process effectively and appropriately. The foremost perioperative consideration beyond the use of effective restraint is the management of tenesmus in horses with rectal tears or prolapses. Medications to control bowel motility, epidural anesthesia, antiinflammatory analgesics, and topical compounds adequate to soothe and lubricate inflamed rectal tissues are an important adjunctive therapy in the aftercare of these surgical patients. Of nearly equal importance is the requirement that a loose fecal consistency be maintained with laxative diets, psyllium, and mineral oil. Failure to maintain a loose consistency of stool after treatment of these conditions may lead to rectal impaction or incisional dehiscence and surgical failure.

Wounds Associated with Osseous Sequestration and Penetrating Foreign Bodies

Nonhealing wounds can present a frustrating clinical challenge to the veterinary practitioner. In many cases, healing is delayed by the presence of a foreign body or sequestrum; a review of wounds complicated by the presence of osseous sequestration and penetrating foreign bodies is presented. The typical signs include delayed wound healing and the presence of serous to exudative drainage, which may vary from intermittent to continuous. The use of radiographic or sonographic imaging modalities is often of value in reaching a diagnosis. Removal of the sequestra or foreign body is generally curative.

Autosuture repair of a jejunoileal inguinal herniation in a horse

Summary An American Saddlebred stallion presented for an acute abdomen which was non-responsive to medical therapy. Physical and laboratory evaluation suggested a tentative diagnosis of small intestine incarceration within the inguinal ring. The use of the TA-90 and GIA-50 autosuture devices in performing a jejunocecostomy in the horse is described. These stapling devices greatly reduced the operative time required in performing intestinal resection and anastamosis compared to hand suture techniques.