The evaluation of extracorporeal shockwave therapy in naturally occurring osteoarthritis of the stifle joint in dogs

Extracorporeal shockwave therapy (ESWT) has expanded from the original uses of human urinary calculi treatment to veterinary orthopaedic applications. This paper investigates the feasibility and efficacy of treating dogs with osteoarthritis of the stifle joint with ESWT. In this study, dogs with persistent stifle lameness despite previous surgical or medical treatment were either treated with ESWT or served as untreated controls. The more lame rear limb of each dog was determined by force platform analysis. The range of motion (ROM) of the stifle joints was assessed by goniometry. Force platform gait analysis and goniometry were performed on both groups for four visits at threeweek intervals and a final examination four weeks later. Shock wave therapy was performed three times on the treated dogs, once at each of the first three examinations. A placebo treatment consisting of clipping and wetting the hair was performed on the control dogs. The vertical forces were evaluated for objective analysis of treatment response. For peak vertical force (PVF), four of seven treated dogs improved, while only one of five of control dogs improved. The PVF for the within group analysis did not show any significant change for the treated group, however, the control group has a significant decrease (p=0.05) in PVF consistent with an increase in lameness. The range of motion (ROM) of the stifle joint improved in five of seven treated dogs and three of five controls. Dogs in the treated group had a trend toward increased ROM (p=0.07) and a ‘positive slope’ when compared to dogs in the control group which did not have a significant change (p=0.78) and had a negative slope indicating the dogs were developing a decrease in ROM. The subjective data provided by client questionnaire did not show significant difference between groups.

Initial experiences with extracorporeal shock wave therapy for treatment of bone spavin in horses – part II

Extracorporeal shock wave therapy (ESWT) has grown from the original use of treating urinary calculi into a mechanism to treat some specific orthopaedic diseases of humans and animals. This paper describes a group of horses with bone spavin treated with ESWT. Horses were treated with a high energy focused shock wave machine. Horses were examined for lameness pre-treatment and 12 weeks post-treatment. There was a decrease in the lameness of 80% (59/74) of the horses treated. ESWT provides a viable noninvasive mechanism of treating refractory bone spavin in the horse.

The evaluation of extracorporeal shock wave therapy on collagenase induced superficial digital flexor tendonitis

Extracorporeal shock wave therapy (ESWT) is being used to treat desmitis and tendonitis in horses. This paper compares the clinical, ultrasonographic and histological characteristics of ESWT treated collagenase induced superficial digital flexor tendon (SDFT) lesions, versus untreated controls. This blinded study utilizes six mature, healthy horses where bilateral forelimb SDFT lesions were induced. One forelimb was treated while the other served as an untreated control. Three shock wave treatments were administered at three week intervals. At weekly intervals, ultrasonograms were used to measure: 1) percentage lesion at the maximum injury zone (MIZ), 2) the grey scale of the SDFT at the MIZ, 3) the percentage disruption of the longitudinal fibres at the MIZ. The data were also summed from 8–20 cm distal to the accessory carpal bone. Measurements of the external width of the SDFT were obtained through the study period. Examinations were performed on four occasions to evaluate heat, response to palpation, presence/character of swelling over the SDFT, and lameness. At the completion of the study all tendons were evaluated histologicalally. The lesion size, grey scale, and longitudinal fibre disruption at the MIZ, and sum of each variable changed significantly over time, however, there was no difference between treated and control groups. Histopathology showed increased neovascularization in treated tendons (p = 0.001). When compared to untreated controls, ESWT did not change the ultrasonographic appearance of the tendons. However, it did increase neovascularization.

Extracorporeal shockwave therapy for treatment of superficial digital flexor tendonitis in racing Thoroughbreds: 8 clinical cases

Extracorporeal shock wave therapy (ESWT) was administered to 8 racing Thoroughbreds with superficial digital flexor (SDF) tendon injuries sustained during racing or race training. The tendons were assessed ultrasonographically. The ability of the horse to return to racing was monitored. Five of 8 horses raced successfully, 2 re-injured the tendon during retraining, and 1 horse was retired due to age and lesion severity.

Initial experience with extracorporeal shock wave therapy in six dogs – part I

Extracorporeal shock wave therapy (ESWT) may be an effective treatment modality for delayed or chronic non-union fractures. ESWT is a non-invasive technique that avoids the potential morbidity and mortality associated with traditional surgical procedures, and its use does not preclude subsequent surgical treatment. This case series demonstrates the feasibility, versatility and safety of treating dogs with ESWT.

Biomarkers of bone metabolism in horses: Ante-mortem versus post-mortem correlation in serum and aqueous humour

The objective of this study was to determine the correlation between ante-mortem and 24-hour postmortem concentrations of four markers of bone metabolism in equine serum and aqueous humour. The markers evaluated were osteocalcin, bone alkaline phosphatase, carboxyterminal propeptide of type-1 procollagen and carboxyterminal cross-linked telopeptide of type-1 collagen (ICTP). The concentrations of these markers were poorly correlated (P > 0.05) between aqueous humour and serum. ICTP was the only serum marker significantly correlated (r = 0.93) between ante- and post-mortem samples. ICTP is, therefore, a potential marker for evaluating antemortem markers of bone metabolism in dead horses.

Potential femoral head osteonecrosis model induced by high-intensity focused ultrasound

Osteonecrosis of the femoral head is a common disease that can result in complex hip replacement. To evaluate potential treatments, a model that consistently creates osteonecrosis is needed. We studied and demonstrated the possibility of developing an osteonecrosis model using high-intensity focused ultrasound (HIFU) on canine femora in vitro. To achieve these goals, the temperature in the medullary cavity of the femoral head was measured. A phenomenological model was developed to fit the measured temperature variations with the HIFU parameters for similar HIFU experiments on femoral heads. The average temperature discrepancy between model and measured values was less than 0.83°C. Histology confirmed that the temperature in the medullary cavity can be elevated to a level at which an acute thermal injury is created. HIFU has the potential to be used in a non-invasive model of osteonecrosis.

The effect of variable waveform low-intensity pulsed ultrasound in a fourth metacarpal osteotomy gap model in horses

The objective of this study was to evaluate the effects of variable waveform low-intensity ultrasound on the healing of a fracture gap of the fourth metacarpal bone in horses. A randomized, blinded, controlled trial was conducted in eight healthy adult horses. In each horse, a 1-cm osteotomy of the fourth metacarpal bone was created. One randomly selected metacarpal gap was treated daily with a 40-min session of ultrasound and the opposite gap was managed similarly with an inactive transducer. The fourth metacarpal bones were radiographed weekly. Fluorescent markers were administered at 14, 28, 56 and 70 d. At the completion of the study at day 84, the bones were harvested and evaluated with peripheral quantitative computed tomography (pQCT) and histology. There were no significant differences between treated and control bones for any of the radiographic, pQCT or histologic parameters evaluated. These findings suggested that low-intensity ultrasound did not affect bone formation in a fracture gap model in the horse.

The evaluation of extracorporeal shock wave therapy on collagenase induced superficial digital flexor tendonitis

Extracorporeal shock wave therapy (ESWT) is being used to treat desmitis and tendonitis in horses. This paper compares the clinical, ultrasonographic and histological characteristics of ESWT treated collagenase induced superficial digital flexor tendon (SDFT) lesions, versus untreated controls. This blinded study utilizes six mature, healthy horses where bilateral forelimb SDFT lesions were induced. One forelimb was treated while the other served as an untreated control. Three shock wave treatments were administered at three week intervals. At weekly intervals, ultrasonograms were used to measure: 1) percentage lesion at the maximum injury zone (MIZ), 2) the grey scale of the SDFT at the MIZ, 3) the percentage disruption of the longitudinal fibres at the MIZ. The data were also summed from 8-20 cm distal to the accessory carpal bone. Measurements of the external width of the SDFT were obtained through the study period. Examinations were performed on four occasions to evaluate heat, response to palpation, presence/character of swelling over the SDFT, and lameness. At the completion of the study all tendons were evaluated histologicalally. The lesion size, grey scale, and longitudinal fibre disruption at the MIZ, and sum of each variable changed significantly over time, however, there was no difference between treated and control groups. Histopathology showed increased neovascularization in treated tendons (p = 0.001). When compared to untreated controls, ESWT did not change the ultrasonographic appearance of the tendons. However, it did increase neovascularization.

The evaluation of extracorporeal shockwave therapy in naturally occurring osteoarthritis of the stifle joint in dogs

Extracorporeal shockwave therapy (ESWT) has expanded from the original uses of human urinary calculi treatment to veterinary orthopaedic applications. This paper investigates the feasibility and efficacy of treating dogs with osteoarthritis of the stifle joint with ESWT. In this study, dogs with persistent stifle lameness despite previous surgical or medical treatment were either treated with ESWT or served as untreated controls. The more lame rear limb of each dog was determined by force platform analysis. The range of motion (ROM) of the stifle joints was assessed by goniometry. Force platform gait analysis and goniometry were performed on both groups for four visits at three-week intervals and a final examination four weeks later. Shock wave therapy was performed three times on the treated dogs, once at each of the first three examinations. A placebo treatment consisting of clipping and wetting the hair was performed on the control dogs. The vertical forces were evaluated for objective analysis of treatment response. For peak vertical force (PVF), four of seven treated dogs improved, while only one of five of control dogs improved. The PVF for the within group analysis did not show any significant change for the treated group, however, the control group has a significant decrease (p = 0.05) in PVF consistent with an increase in lameness. The range of motion (ROM) of the stifle joint improved in five of seven treated dogs and three of five controls. Dogs in the treated group had a trend toward increased ROM (p = 0.07) and a 'positive slope' when compared to dogs in the control group which did not have a significant change (p = 0.78) and had a negative slope indicating the dogs were developing a decrease in ROM. The subjective data provided by client questionnaire did not show significant difference between groups.

The effects of extracorporeal shock-wave therapy on the ultrasonographic and histologic appearance of collagenase-induced equine forelimb suspensory ligament desmitis

Extracorporeal shock-wave therapy (ESWT) may stimulate healing of desmitis in multiple species. The objective of this study was to evaluate the ultrasonographic and histologic appearance of collagenase-induced suspensory ligament (SUL) desmitis in untreated ligaments and ligaments treated with ESWT in horses. Four mature horses had SUL desmitis induced in both forelimbs. Beginning 3 weeks after induction of the lesions, one ligament per horse was treated 3 times at 3-week intervals with ESWT. The percent lesion, echogenicity and fiber alignment scores of the SULs were evaluated at 3-week intervals for a total of 15 weeks. At the completion of the study, the horses were euthanized and the SULs collected, fixed and processed for histopathologic evaluation. Ultrasonography showed treated SULs had a smaller percent lesion at the maximal injury zone (p = 0.001), and the total percent lesion (p = 0.01), total fiber alignment score (p = 0.0167) and total echogenicity (p = 0.0023) were all smaller in the treated ligaments. The fiber alignment score and echogenicity were not statistically different at the maximal injury zone. The treated SULs had a more concentrated area of metachromasia associated with healing than the untreated ligaments, where metachromasia appeared more diffuse throughout the ligament. ESWT improved the rate of healing as assessed ultrasonographically.

Evaluation of dual energy x-ray absorptiometry for in situ measurement of bone mineral density of equine metacarpi

OBJECTIVE

To determine the accuracy and precision of dual energy x-ray absorptiometry (DEXA) for measuring bone mineral density in horses in situ. Sample Population-12 randomly selected forelimbs from 12 horses.

PROCEDURE

Metacarpi were scanned in 2 planes and DEXA measurements obtained for 6 regions of interest (ROI). Each ROI was isolated and bone density measured by Archimedes' principle. Linear regression analysis was used to determine the correlation between the 2 measurements at each ROI. An additional metacarpus was measured 10 times to determine the coefficient of variation for both techniques.

RESULTS

Dual energy x-ray absorptiometry and bone density were significantly associated at multiple ROI. The addition of age, weight, and soft tissue or bone thickness improved these associations. Repeated measurements had a low coefficient of variation.

CONCLUSIONS AND CLINICAL RELEVANCE

Dual energy x-ray absorptiometry can be used to accurately and precisely measure the bone density in the equine metacarpus. Dual energy x-ray absorptiometry appears suitable for serial in vivo measurement of bone density of the equine metacarpus. Dual energy x-ray absorptiometry may be used for studies to evaluate the effects of diet or drugs on bone density or density changes from bone remodeling that develop prior to stress fractures.

In vitro comparison of the use of two large-animal, centrally threaded, positive-profile transfixation pin designs in the equine third metacarpal bone

OBJECTIVE

To compare the in vitro holding power and associated microstructural damage of 2 large-animal centrally threaded positive-profile transfixation pins in the diaphysis of the equine third metacarpal bone.

SAMPLE POPULATION

25 pairs of adult equine cadaver metacarpal bones.

PROCEDURE

Centrally threaded positive-profile transfixation pins of 2 different designs (ie, self-drilling, self-tapping [SDST] vs nonself-drilling, nonself-tapping [NDNT] transfixation pins) were inserted into the middiaphysis of adult equine metacarpal bones. Temperature of the hardware was measured during each step of insertion with a surface thermocouple. Bone and cortical width, transfixation pin placement, and cortical damage were assessed radiographically. Resistance to axial extraction before and after cyclic loading was measured using a material testing system. Microstructural damage caused by transfixation pin insertion was evaluated by scanning electron microscopy.

RESULTS

The temperature following pin insertion was significantly higher for SDST transfixation pins. Periosteal surface cortical fractures were found in 50% of the bones with SDST transfixation pins and in none with NDNT transfixation pins. The NDNT transfixation pins were significantly more resistant to axial extraction than SDST transfixation pins. Grossly and microscopically, NDNT transfixation pins created less damage to the bone and a more consistent thread pattern.

CONCLUSIONS AND CLINICAL RELEVANCE

In vitro analysis revealed that insertion of NDNT transfixation pins cause less macroscopic and microscopic damage to the bone than SDST transfixation pins. The NDNT transfixation pins have a greater pull out strength, reflecting better initial bone transfixation pin stability.

In vitro comparison of metaphyseal and diaphyseal placement of centrally threaded, positive-profile transfixation pins in the equine third metacarpal bone

OBJECTIVE

To evaluate in vitro holding power and associated microstructural and thermal damage from placement of positive-profile transfixation pins in the diaphysis and metaphysis of the equine third metacarpal bone.

SAMPLE POPULATION

Third metacarpal bones from 30 pairs of adult equine cadavers.

PROCEDURE

Centrally threaded positive-profile transfixation pins were placed in the diaphysis of 1 metacarpal bone and the metaphysis of the opposite metacarpal bone of 15 pairs of bones. Tensile force at failure for axial extraction was measured with a materials testing system. An additional 15 pairs of metacarpal bones were tested similarly following cyclic loading. Microstructural damage was evaluated via scanning electron microscopy in another 6 pairs of metacarpal bones, 2 pairs in each of the following 3 groups: metacarpal bones with tapped holes and without transfixation pin placement, metacarpal bones following transfixation pin placement, and metacarpal bones following transfixation pin placement and cyclic loading. Temperature of the hardware was measured with a surface thermocouple in 12 additional metacarpal bones warmed to 38 C.

RESULTS

The diaphysis provided significantly greater resistance to axial extraction than the metaphysis. There were no significant temperature differences between diaphyseal and metaphyseal placement. Microstructural damage was limited to occasional microfractures seen only in cortical bone of diaphyseal and metaphyseal locations. Microfractures originated during drilling and tapping but did not worsen following transfixation pin placement or cyclic loading.

CONCLUSIONS AND CLINICAL RELEVANCE

Centrally threaded, positive-profile transfixation pins have greater resistance to axial extraction in the diaphysis than in the metaphysis of equine third metacarpal bone in vitro. This information may be used to create more stable external skeletal fixation in horses with fractures.

Prevalence of gastric ulcers in show horses

OBJECTIVE

To determine prevalence and risk factors for gastric ulcers in show horses.

DESIGN

Field survey.

ANIMALS

50 horses in active training that had been transported to at least 1 event in the 30 days prior to endoscopy.

PROCEDURE

Interview of owner, physical examination, serum biochemical analysis, CBC, and gastric endoscopy were performed.

RESULTS

Gastric ulceration was detected in 58% of the horses. Horses with a nervous disposition were more likely to have ulceration than quiet or behaviorally normal horses. Horses with gastric ulceration had significantly lower RBC counts and hemoglobin concentrations than those without ulceration.

CONCLUSIONS AND CLINICAL RELEVANCE

Show horses have a high prevalence of gastric ulceration. Lower RBC counts and hemoglobin concentrations may be the result of chronic gastric ulceration.

Effect of hypothyroidism on blood lipid concentrations in horses

OBJECTIVE

To measure and compare concentrations of selected blood lipids before and after thyroidectomy in horses.

ANIMALS

5 healthy adult mares.

PROCEDURE

Mares were confirmed to be euthyroid. Thyroidectomy was performed, and hypothyroidism was confirmed. Selected blood lipid variables were measured before hypothyroidism was induced and weekly for 4 weeks after induction. Plasma concentrations of very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), serum triglyceride (TG), total cholesterol (TC), and nonesterified fatty acid (NEFA) were measured. The composition of VLDL and LDL also was examined.

RESULTS

Mean plasma concentrations of VLDL and LDL increased significantly after thyroidectomy. By 4 weeks after thyroidectomy, a ninefold increase in mean plasma concentration of VLDL and a threefold increase in LDL, compared with baseline values, were detected. After thyroidectomy, mean percentage of TG in VLDL increased significantly, whereas free cholesterol and cholesterol ester content decreased. Mean percentage of TG in LDL also increased by 3 to 4 weeks after thyroidectomy. Serum concentrations of TG and TC increased, whereas serum NEFA concentration decreased.

CONCLUSIONS

Hypothyroidism significantly alters blood lipid concentrations of horses. After thyroidectomy, markedly high VLDL concentration, appearance of TG-rich VLDL, increased serum concentrations of TG and TC, and decreased blood concentration of NEFA were evident.

CLINICAL RELEVANCE

Examination of blood lipid concentrations of horses may be useful for detecting naturally acquired hypothyroidism.

Effects of omeprazole paste on healing of spontaneous gastric ulcers in horses and foals: a field trial

A multicentre, blinded, randomised complete-block, field trial was conducted with 140 horses and foals age 4 weeks-28 years to determine if omeprazole paste is effective and safe in promoting healing of spontaneous gastric ulcers under a variety of field conditions and in different breeds and ages of horses. Horses in the study had gastric ulceration as determined by gastroscopy and were divided into replicates of 4 or 5 animals. One horse in each replicate was assigned randomly to receive an empty omeprazole syringe (sham-dosed control) and the remaining horses received omeprazole paste once daily for 28 days. Gastroscopy was repeated at the end of the study. Horses treated with omeprazole had significantly (P < 0.01) more improvement in ulcer scores at the end of the study compared with controls. Ulcers were improved in 32.4 and 99.0% of the control and omeprazole groups, respectively. Ulcers were completely healed in 8.9 and 86.7% of the control and omeprazole groups, respectively. Under typical field conditions, omeprazole was effective at enhancing healing of spontaneous gastric ulcers in horses of a variety of ages and breeds.

Complete fractures of the third metacarpal or metatarsal bone in horses: 25 cases (1980-1996)

OBJECTIVES

To compare treatments of complete fractures of the third metacarpal (MC) or metatarsal (MT) bone in horses and to identify factors that could impact prognosis.

DESIGN

Retrospective case series.

ANIMALS

25 horses with fractures of the third MC or MT bone that were treated by use of internal fixation, external coaptation, or both.

PROCEDURE

Medical records from the Veterinary Medical Data Base of horses treated for fractures of third MC or MT bone at Texas A&M University from 1980 to 1994 and Purdue University from 1980 to 1996 were reviewed. Information on signalment, results of physical and radiographic examinations, treatment, and outcome were obtained. For horses that had radiographic evidence of healing, long-term follow-up information was obtained by telephone contact with owners or referring veterinarians.

RESULTS

Age, sex, weight, and limb affected were not related to outcome; however, affected horses were younger than the general hospital populations. Seventeen horses had open fractures at referral. Infection was the most common complication after surgery, with open fractures more likely to become infected. Nonunion in an infected fracture was the most common reason for postoperative failure (7 horses). Long-term follow-up was available for 16 horses; 11 of these had no complications related to surgical repair.

CLINICAL IMPLICATIONS

Fractures of the MC or MT bone are not always associated with a poor prognosis in horses. Proper case selection, rigid fracture stabilization, and efforts to prevent or treat infection will improve success rate.

Cobalt 60 radiotherapy for treatment of squamous cell carcinoma of the nasal cavity and paranasal sinuses in three horses

Three adult horses underwent aggressive treatment of squamous cell carcinoma of the nasal cavity and paranasal sinuses, using course-fractionated cobalt 60 radiotherapy. Squamous cell carcinoma of the nasal cavity and paranasal sinuses is not commonly diagnosed in horses. Historically, horses with this type of neoplasm have not been treated or have undergone some form of surgery. The prognosis for long-term survival or cure has been poor. Long-term results of cobalt 60 radiotherapy were good to excellent and exceeded those usually reported for horses treated surgically. On the basis of these results, use of radiotherapy for these neoplasms is recommended.

In vivo evaluation of intramedullary interlocking nail fixation of transverse femoral osteotomies in foals

OBJECTIVE

To evaluate an intramedullary interlocking nail for stabilization of transverse femoral osteotomies in foals.

STUDY DESIGN

A transverse osteotomy and restabilization with an intramedullary interlocking nail was performed on the right femur in three foals and the left femur in three foals.

ANIMALS

Six foals weighing 149 to 207 kg.

METHODS

The femur was destabilized with a transverse middiaphyseal osteotomy and repaired with a 0.5-in (12.7 mm) interlocking nail. The implanted femurs were radiographed monthly until completion of the study 6 months after surgery. At the completion of the study, all foals were observed for evidence of lameness, gluteal thickness was determined by ultrasonographic measurement, and a necropsy was performed.

RESULTS

Healing was satisfactory in all foals. Five of the six had osseous bridging of the osteotomy apparent radiographically by 3 to 4 months. The sixth foal had postoperative infection but was healed radiographically in 5 months. There was a mean decrease in gluteal muscle thickness of 6.6 mm (P = .04) in the operated limb of the five foals that healed without complication. Two foals were lame at the completion of the project; one foal with varus deformities of the contralateral limb was mechanically lame, and another was grade 2/5 lame on the operated limb. On necropsy, there was circumferential enlargement of the diaphysis of all operated limbs with the majority of the callus at the cranial and medial aspects of the cortex. All nails were solid within the medullary cavity.

CONCLUSIONS

The intramedullary interlocking nail provided adequate stabilization for repair of the transverse osteotomy.

CLINICAL RELEVANCE

Further investigation is warranted before use for stabilization of spontaneously occurring fracture configurations.

In vitro evaluation of four methods of attaching transfixation pins into a fiberglass cast for use in horses

OBJECTIVE

To compare the axial stability provided by 4 methods of attaching transfixation pins into a fiberglass cast.

DESIGN

Axial stability of 4 methods of transfixation pin attachment to a fiberglass cast cylinder was determined in vitro. Methods of attachment included simple incorporation of the pins into the cast, placement of a washer and nut on the pin and incorporation into the cast, extension of pins beyond the cast and attachment to a steel halo, and washers within the cast and attachment to a steel halo.

POPULATION

A model was designed to simulate a transfixation cast applied to the equine metacarpus. 8 identical constructs were present in each of the 4 groups. 6 fiberglass cylinders were also tested to identify the contribution of the cast cylinder to the overall stability of the transfixation cast.

PROCEDURE

Load-sufficient curves were recorded, and a stiffness modulus was calculated for each treatment group and for a simple fiberglass cylinder without transfixation pins.

RESULT AND CONCLUSION

There was no significant difference among the 4 methods of attachment. The fiberglass cast material appears to be the major determinant of axial stability.

Surgical repair of traumatically induced collapsing trachea in an ostrich

A region of tracheal collapse was identified by endoscopy after surgical repair of a traumatic injury to the neck in an ostrich. During periods of excitation, the ostrich would become dyspneic and collapse. A tracheal split-ring prosthesis was placed surgically to support the collapsing trachea. This technique, which is frequently used in dogs, is applicable for use in birds with collapsing trachea.

Permanent tracheostomy in standing horses: technique and results

Permanent tracheal stomas were created in seven sedated, standing horses with severe upper airway obstruction. After local anesthesia, a 3-cm by 6-cm rectangle of skin was removed from the ventral surface of the neck, 3 cm distal to the cricoid cartilage. The sternothyrohyoideus muscles were clamped proximally and distally, then transected to expose the tracheal rings. The ventral third of four tracheal rings was dissected from the tracheal mucosa that was then incised in a double "Y." Two layers of suture were used to achieve mucocutaneous closure. Stomas healed without serious complications; two mares subsequently foaled, and three horses were used for riding.

Treatment of olecranon bursitis in horses: 10 cases (1986-1993)

Medical records of 10 horses with olecranon bursitis were reviewed to examine treatments, evaluate a technique for en bloc resection of the bursa in standing horses, and determine outcome of the horses after treatment. Before admission, 6 horses had been treated by needle aspiration of fluid from the mass, followed by injection of corticosteroids. Subsequent treatment for 2 of these 6 horses included open drainage and packing of the cavity with gauze soaked in 7% iodine solution. None resolved after these treatments. After admission to the hospital, 5 horses were treated medically and 5 were treated by en bloc resection of the bursa. One horse that had received intralesional injection of a radionuclide was lost to follow-up evaluation. One horse treated conservatively by open drainage and packing and 1 treated by injection of a radionuclide had resolution of the olecranon bursitis. Only 1 of these 2 horses had a cosmetic result. The acquired bursae decreased in size in 2 horses (1 treated with a corticosteroid and 1 with orgotein), but were still visible 7 and 46 months after treatment, respectively. The surgery site of 4 horses that were treated by en bloc resection healed by primary intention, and the owners of these horses were pleased with the cosmetic results. The suture line of 1 horse dehisced 5 days after surgery. Proliferative granulation tissue was removed on 2 occasions, and the site healed by second intention after 2 months. A small knot and some white hair remained at the surgery site.

Use of a full-thickness autograft on the tarsus of an ostrich

Full-thickness, cutaneous autografting was successfully performed on an adult female ostrich to heal a granulomatous wound on the right tarsus. With surgical techniques used in domestic species such as dogs and horses, skin grafting is an alternative in avian species when conventional wound closure is not appropriate.

In vitro comparison of the standard short limb cast and three configurations of short limb transfixation casts in equine forelimbs

Axial stability of equine oblique proximal phalangeal osteotomies with application of the standard short limb cast or 1 of 3 configurations of transfixation casts was determined in vitro. Transfixation cast methods included use of parallel pins, divergent pins, or parallel pins incorporating a metal walking bar. Displacement at the osteotomy was recorded for each limb at 4,448 N. Standard short limb casts provided significantly (P = 0.0002) less axial stability than did any form of transfixation cast. Significant differences were not found between the 3 transfixation casts.

In vitro comparison of the effect of parallel and divergent transfixation pins on breaking strength of equine third metacarpal bones

Breaking strength (torque at failure) of equine third metacarpal bones, with transfixation pins placed parallel in the frontal plane and 30 degrees divergent from the frontal plane, was determined in vitro. Two transfixation pins were placed through the distal metaphysis, using a jig designed to drill the holes in the assigned configuration. Paired metacarpal bones II through IV from 12 horses were tested in torsion. The torsional moment of the force applied through the transfixation pins at failure was compared for each limb. Metacarpal bones with divergent pins were significantly (P = 0.030) stronger, compared with those with parallel pins. Metacarpal bones with parallel pins failed with longitudinal oblique fractures through a proximal bone-pin interface, whereas those with divergent pins failed with more comminuted fractures through multiple bone-pin interfaces.

Transnasal incision of restrictive nasopharyngeal cicatrix in three horses

Three horses were found to have an extensive nasopharyngeal cicatrix that was responsible for respiratory impairment. The cicatrization was diagnosed by use of endoscopy during evaluations of the horses for inspiratory stridor. All 3 horses were treated by endoscope-guided transnasal incision of the cicatrix and were able to resume their previous activities.

Technique for long-term ileal cannulation in ponies

A T-cannula was fitted permanently into the ileum of ten mature ponies to quantify the role of the prececal and postileal segments of the digestive tract in equine nutrition studies. The ponies were anesthetized, positioned in left lateral recumbency, and the distal small intestine was exteriorized through a right paralumbar incision. A silastic T-cannula was inserted through a 2-cm longitudinal incision into the lumen of the ileum, on the antimesenteric surface, and sutured to the ileum. The stem of the cannula was exteriorized through a 2-cm circular skin incision, 6 cm caudal to the 16th rib. Nine ponies were alive with functional cannulas after six months. Primary complications associated with cannulation of the ileum were clinical signs of depression and dehydration produced by leakage of intestinal contents around the stem of the cannula. These complications were resolved with fluid and electrolyte therapy.

Intermittent antimicrobial infusion for management of a septic distal interphalangeal joint in a horse

A 13-month-old Quarter Horse colt sustained a puncture wound to the frog region of the foot, which penetrated the navicular bursa and distal interphalangeal joint, 7 days prior to examination. A street-nail procedure was performed to debride the tract and provide drainage of the navicular bursa and distal interphalangeal joint. An indwelling lavage system was placed through the dorsal aspect of the joint and antimicrobials were infused intermittently to supply a high local concentration of drug and to frequently lavage the distal interphalangeal joint and navicular bursa.

Small intestinal incarceration through the lateral ligament of the urinary bladder in a horse

Small intestinal incarceration through the lateral ligament of the urinary bladder was diagnosed in a 14-year-old, 569-kg, castrated Quarter Horse. The incarceration was corrected by ventral midline celiotomy. Approximately 70 cm of the middle portion of the jejunum was resected and end-to-end, single-layer anastomosis was performed. After surgery, the horse developed signs of adynamic ileus and lameness in the right forelimb. The horse developed laminitis in all 4 feet within 24 hours of surgery. The horse was euthanatized because of poor prognosis for survival. At necropsy, a 4.5-cm rent was found in the left lateral ligament of the urinary bladder. The cause of the rent in the ligament of this horse was not determined.

Use of an implant for intraosseous infusion as supportive therapy for a Vietnamese pot-bellied pig with urethral obstruction caused by a polyp

A Vietnamese pot-bellied pig with a urethral polyp was supported by total parenteral nutrition given through an intraosseous implant. Peripheral vascular access was difficult to establish and maintain in this anorectic pig, so a pediatric intraosseous implant was placed in the left tibia. Surgical repair of the urethra was not considered possible, and alternative techniques of a functional bypass were unacceptable to the owners, so euthanasia was elected. Histologic examination of the urethra revealed a polypoid structure believed to be similar to benign congenital polyps described in young boys.

Nonpharmacologic management of stereotypic self-mutilative behavior in a stallion

Self-mutilative behavior, a form of stereotypic behavior, can be a serious problem in stallion management. An 11-year-old Quarter Horse stallion was referred for evaluation of repeated episodes of self-mutilation and aggressive behavior. Historically, this behavior worsened when the horse was isolated from other animals and confined to a stall for long periods. Observations of the stallion revealed episodes of self-mutilation and other forms of stereotypic behavior precipitated by stressful situations. Modification of this behavior was achieved by environmental and nutritional management and provision of adequate exercise. Nonpharmacologic intervention can be a simple and inexpensive way to correct self-mutilative behavior.