Screw fixation of accessory carpal bone fractures in racing Greyhounds: 12 cases (1981-1986)

Fractures of the accessory carpal bone in 12 racing Greyhounds were repaired by use of internal fixation with screws. All dogs had a sprain-avulsion fracture of the distal margin of the articular surface of the accessory carpal bone, where the accessorioulnar ligament inserts (type I). Two dogs had a second avulsion fracture at the proximal margin of the articular surface, where the palmar ulnocarpal ligament inserts (type II), and 2 dogs had a second fracture at the caudal end of the bone at the insertion of the accessoriometacarpal ligaments (type III). Fractures were exposed surgically, using a palmarolateral approach between the fourth and fifth accessoriometacarpal ligaments, and were repaired using 1.5-mm or 2-mm cortical screws. Eight dogs were evaluated radiographically to monitor fracture healing. Union of fractures, with bridging of the fracture gap, usually developed by 5 to 8 weeks after surgery. Follow-up evaluation after surgical repair was possible in 11 dogs; 10 (91%) returned to training or racing, and 5 (45%) of those won 1 or more races.     

Unusual muscle and tendon disorders of the forelimb in the dog

Five dogs with unusual muscle and tendon disorders of the forelimb are described. In one dog, mineralisation of the tendon of insertion of the supraspinatus muscle was treated surgically but lameness returned following the resumption of exercise. Of two cases of avulsion of the origin of the extensor carpi radialis muscle, one was successfully managed conservatively while the other needed surgical intervention to resolve the lameness. A single case of chronic avulsion/rupture of the tendon of insertion of the extensor carpi radialis muscle was successfully managed conservatively while a case of medial displacement of the biceps brachii tendon was surgically corrected by repair of the transverse humeral ligament. The aetiology, diagnosis and management of the above conditions is discussed.     

Effects of racing on hematologic and serum biochemical values in greyhounds

Blood samples were collected on nonracing days from 57 racing Greyhounds at 2 weeks, 8 weeks, 13 weeks, and 16 weeks after the beginning of the racing season. Hematologic and biochemical tests were performed to detect marked changes induced by stress of racing. In general, these Greyhounds were healthy. Rhabdomyolysis was detected in one dog. In several other dogs, possible subclinical muscle injury was identified by increased serum creatine kinase activities. Mean serum Ca concentrations tended to decrease during the racing season. None of the tests was a good predictor of racing performance. Mean values for several hematologic and biochemical tests were different from those of other breeds of dogs.     

Short incomplete sagittal fractures of the proximal phalanx in ten horses not used for racing

Objective— To describe short incomplete sagittal fractures of the proximal phalanx (type Ia P1 fractures) in horses not used for racing and report outcome.
Study Design— Retrospective study.
Animals— Horses (n=10) with type Ia P1 fractures.
Methods— Retrieved data of horses with type Ia P1 fractures were signalment, history and results of orthopedic examination. Radiographs were re-evaluated for position and length of the fracture line, presence of osteoarthritis or subchondral cystic lesions (SCL), periosteal new bone formation and subchondral sclerosis. Conservative treatment (n=4) included box confinement for 2 months followed by 1 month of hand walking. Surgical therapy (n=6) consisted of internal fixation by screws inserted in lag fashion in 5 horses. Concurrent SCL were debrided by curettage via a transcortical drilling approach. In 1 horse, only SCL curettage but not internal fixation was performed. Outcome was assessed on a clinical and radiographic follow-up examination in all horses.
Results— Mean follow-up time was 27 months (median, 13.5 months; range, 9 months to 9 years). All horses treated with internal fixation were sound at follow-up and had radiographic fracture healing. Of the 4 horses managed conservatively, 3 remained lame and only 1 horse had radiographic evidence of fracture healing. Catastrophic fracture propagation occurred in 2 horses not treated by internal fixation, 20 and 30 months after diagnosis, respectively.
Conclusions— Horses with a type Ia P1 fracture treated surgically had a better outcome than those managed conservatively and lack of fracture healing seemingly increases the risk of later catastrophic fracture.
Clinical Relevance— Surgical repair of type Ia P1 fractures should be considered to optimize healing and return to athletic use.     

Serum creatinine concentrations in retired racing Greyhounds

Background: Greyhounds frequently have laboratory values that are outside reference intervals established for dogs. Our recognition of increased serum creatinine concentrations in several Greyhounds posed a problem when evaluating a Greyhound with suspected renal disease.
Objective: The purpose of this study was to compare serum creatinine concentrations between Greyhound and non-Greyhound dogs.
Methods: Thirty retired racing Greyhounds and 30 age-and gender-matched control non-Greyhound dogs were evaluated. Serum creatinine concentrations in both groups were measured using a standard biochemical method and compared statistically using a Kruskal-Wallis test.
Results: Creatinine concentration was significantly higher in the Greyhounds ( P < .01) than in the control group.
Conclusion: Greyhounds have a higher serum creatinine concentration than do non-Greyhound dogs. This idiosyncrasy should be taken into account when evaluating healthy Greyhounds and those with suspected renal disease.     

Surgical and Conservative Management of Bilateral Dynamic Laryngeal Collapse Associated with Poll Flexion in Harness Race Horses

Objective— To test the hypothesis that in bilateral dynamic laryngeal collapse associated with poll flexion, vocal fold collapse (VFC) is the initial abnormal event that induces further laryngeal collapse, and that racing performance would therefore be substantially improved after bilateral ventriculocordectomy in affected individuals.
Study Design— Retrospective study.
Animals— Twenty-six horses.
Methods— Medical records (1998–2006) of harness racehorses admitted for high-speed treadmill videoendoscopy (HSTV) that had bilateral dynamic laryngeal collapse associated with poll flexion were reviewed. Race records, owner interviews, and follow-up HSTV were used to evaluate outcome after either surgical treatment including bilateral ventriculocordectomy or conservative management.
Results— Bilateral dynamic laryngeal collapse, defined as bilateral VFC with concurrent arytenoid cartilage collapse (ACC), was identified in 26 horses. Norwegian Coldblooded Trotters (NCT) were overrepresented. Sixteen horses had surgical treatment and 10 were treated conservatively. Return to racing and racing performance was not improved within or between groups after the treatment. On follow-up HSTV of 6 surgically treated horses, there was no residual soft tissue collapse in the ventral portion of the rima glottidis; however, ACC and other abnormalities were still evident.
Conclusion— Bilateral ventriculocordectomy resolved VFC, but failed to stabilize the arytenoid cartilages or to significantly improve racing performance.
Clinical Relevance— Bilateral dynamic laryngeal collapse associated with poll flexion is a serious performance-limiting upper respiratory tract disorder that is overrepresented in NCT racehorses. Our results suggest that VFC is not the initiating event in this complex obstructive airway disorder for which there is currently no consistently effective treatment.     

Femoral diaphysis fractures in cattle: 26 cases (1994–2005)

Objective   This retrospective study was conducted to evaluate the outcome for cattle with diaphyseal fractures of the femur, but not including capital physeal injuries.
Methods   Sources of information were medical records of cattle having a definitive diagnosis of diaphyseal femoral fractures and telephone survey of owners.
Results   Medical records for 26 cattle with femoral fracture were found; of the 20 aged less than 2 months, 15 were treated surgically, 4 conservatively (stall rest) and 1 was euthanased without treatment. The surgical treatment varied according to the configuration of the fracture and the surgeon's experience. Surgery for mid-diaphyseal fractures had a significantly better surgical outcome then distal diaphyseal fractures (P < 0.05), as there were significantly fewer postoperative complications. Of the 15 calves treated surgically, 10 were discharged from hospital and 5 were retained in the herd without noticeable lameness. Of the 4 calves treated conservatively, 3 were alive at follow-up, but 2 were still lame. Of the 6 older cattle, 3 were euthanased without treatment and 3 were treated conservatively, 2 of which were alive at follow-up but 1 was still lame.
Conclusion   Conservative treatment of femur fracture in cattle is possible but associated with complications during the convalescence. Continued research is needed to optimise distal diaphyseal fracture stabilisation in young cattle.     

Stress Fractures of the Acetabulum in 26 Racing Greyhounds

Acetabular fractures in 26 racing Greyhounds were reviewed. All fractures occurred during racing or training and were unrelated to any external trauma. All fractures had similar configurations, were minimally displaced, and involved only the acetabulum. Affected dogs were young (16-36 months). Fractures occurred unilaterally (22 dogs) and bilaterally (4 dogs). There was no sex predilection, and both right and left sides were equally represented. Bilateral fractures were associated with retraining between the occurrence of the first and second fractures. Radiographically, a fracture line was consistently visible in the caudal third of the acetabulum. Fractures in gross specimens resembled an inverted "Y." Results of histologic evaluation of two fractured acetabula showed changes characteristic of a nonunion fracture. Microfractures were evident in the grossly normal acetabulum opposite the fractured side. Evidence obtained from this study suggests a common pathogenesis of the fractures related to tremendous repetitive stresses produced during running. Greyhounds with unilateral acetabular fractures may provide a reproducible model for future studies of stress fractures in animals and humans because of the high incidence of bilateral fractures that develop during retraining. Surgical repair of the acetabular stress fracture was more successful than conservative management in returning the dogs to competitive racing.     

Fractures of the Calcaneus in Racing Greyhounds

Fifty-one calcaneus fractures associated with (41) or without (10) central tarsal bone (Tc) fractures in racing greyhounds were evaluated and categorized. All calcaneal fractures with no Tc fractures had a plantar proximal intertarsal subluxation. No subluxations were found in dogs with both calcaneal and central tarsal fractures. The calcaneal fractures were treated either with coaptation splints or surgical repair. Surgical techniques included a Steinmann pin with a figure eight tension band device or screw or plate fixation as primary techniques supplemented by Kirschner wires and cerclage wires. In all calcaneal fractures associated with plantar proximal intertarsal subluxation, an arthrodesis of the calcaneoquartal joint was performed. All 22 surgically repaired fractures in dogs available for physical and radiographic reexamination had healed within 1 to 6 months. Eight dogs with fractures of the calcaneus associated with fractures of Tc returned to a racing career. None of the dogs with plantar proximal intertarsal subluxation raced again. Based on the orientation of the fracture lines and on dissection of two tarsi with calcaneal fractures, a hypothesis on the pathogenesis of calcaneal fractures in racing greyhounds was formulated.     

Juvenile Pancreatic Atrophy in Greyhounds: 12 Cases (1995–2000)

Background: This study describes compound failure of the endocrine and exocrine pancreas in Greyhounds, a condition that has not been reported in the veterinary literature.
Objective: To describe the clinical and pathologic findings in 12 Greyhounds with juvenile pancreatic atrophy.
Animals: Ten Greyhounds presented for necropsy examination and 2 sibling Greyhounds presented for clinical evaluation before necropsy, all with a history of small-bowel diarrhea.
Procedures: Retrospective study of laboratory and pathologic findings in 12 Greyhounds, including serum trypsin-like immunoreactivity assays, oral glucose tolerance testing, and serum anti-insulin antibody concentrations.
Results: Gross pancreatic atrophy was found in all 12 dogs. Histopathologic lesions were found in both the endocrine and exocrine pancreas and included acinar cell apoptosis, zymogen granule loss, cytoplasmic clearing or vacuolar change, lobular atrophy, islet loss, and lymphocytic or lymphoplasmacytic pancreatitis. Antemortem test results on the 2 Greyhound puppies indicated concurrent exocrine pancreatic insufficiency (EPI) and insulin-dependent diabetes mellitus (IDDM).
Conclusions and Clinical Importance: Compound failure of the exocrine and endocrine pancreas is rarely reported in dogs and neither disease is well recognized in the Greyhound. This condition is of potential economic importance to the Greyhound racing industry.     

Central tarsal bone fractures in the racing Greyhound: a review of 114 cases

A total of 114 central tarsal bone (Tc) fractures, including associated secondary fractures, were identified in 114 racing Greyhounds. The fractures were classified according to a previously described scheme. The type IV Tc fracture, dorsal and medial slab fractures, was most common. A Tc fracture alone, or a Tc fracture with associated fractures of the 4th tarsal bone (T4), calcaneus, or T4 and lateral base of the 5th metatarsal bone were the most commonly observed. The prevalence of secondary fractures increased with the severity of the Tc fracture. Management of Tc fractures involved 3 methods: coaptation, single-screw fixation, and 2-screw fixation. Additional repair was performed as indicated by the presence of concurrent secondary fractures. A total of 71% of the dogs returned to competitive racing.     

Incomplete Oblique Sagittal Fractures of the Dorsal Cortex of the Third Metacarpal Bone in Six Horses

Objective —To describe incomplete oblique sagittal dorsal cortical fractures of the equine third metacarpal bone, their surgical repair, and subsequent performance of the horses.
Study Design —Retrospective examination of medical records and racing performance.
Animal Population —Six Thoroughbred race horses, 2 to 4 years of age.
Methods —Radiographic confirmation of all fractures preceded general anesthesia and surgical correction. Three fractures were treated by intracortical compression using screws placed in lag fashion, and five fractures were treated by osteostixis. Race records were reviewed for each horse to determine performance after surgery.
Results —Fractures were best observed on palmarodorsal radiographic projections. Three horses treated by intracortical compression returned to racing, but fracture recurred in one horse and was treated by osteostixis. This horse and the other three horses treated by osteostixis raced after surgery.
Conclusions —Horses with incomplete oblique sagittal fractures of the dorsal cortex of the third metacarpal bone can race after surgical management of the fracture by screws placed in lag fashion or osteostixis. The authors' preferred surgical procedure for managing this fracture is osteostixis.
Clinical Relevance —Palmarodorsal radiographic projections of the third metacarpal bone are recommended in young Thoroughbred race horses suspected of having dorsal metacarpal stress fractures.     

Effects of racing and training on serum thyroid hormone concentrations in racing Greyhounds.

OBJECTIVES: To determine the effects of racing and training on serum thyroxine (T4), triiodothyronine (T3), and thyroid stimulating hormone (TSH) concentrations in Greyhounds. ANIMALS: 9 adult racing Greyhounds. PROCEDURE: Serum thyroid hormone concentrations were measured before and 5 minutes after a race in dogs trained to race 500 m twice weekly for 6 months. Resting concentrations were measured again when these dogs had been neutered and had not raced for 3 months. Postrace concentrations were adjusted relative to albumin concentration to allow for effects of hemoconcentration. Thyroid hormone concentrations were then compared with those of clinically normal dogs of non-Greyhound breeds. RESULTS: When adjusted for hemoconcentration, total T4 concentrations increased significantly after racing and TSH concentrations decreased; however, there was no evidence of a change in free T4 or total or free T3 concentrations. Resting total T4 concentrations increased significantly when dogs had been neutered and were not in training. There was no evidence that training and neutering affected resting TSH, total or free T3, or free T4 concentrations. Resting concentrations of T3, TSH, and autoantibodies against T4, T3, and thyroglobulin were similar to those found in other breeds; however, resting free and total T4 concentrations were lower than those found in other breeds. CONCLUSIONS AND CLINICAL RELEVANCE: Except for total T4, thyroid hormone concentrations in Greyhounds are affected little by sprint racing and training. Greyhounds with low resting total and free T4 concentrations may not be hypothyroid.     

Results of a web-based health survey of retired racing Greyhounds

BACKGROUND: Adoption of retired racing Greyhounds has become increasingly popular during the past decade. To date, research has focused on the physiologic and clinicopathologic peculiarities of Greyhounds but there is little published information on disease prevalence in the breed. OBJECTIVE: The objective of this study is to determine the prevalence of disease in retired racing Greyhounds. ANIMALS: In this study, 747 Greyhounds were used. METHODS: A standardized survey method was used, and survey responses were collected by an Internet survey. Owners could answer a survey for every Greyhound that they had owned since January 1, 2005. RESULTS: Of the 692 eligible participants, 441 (63.7% response rate) completed surveys for 747 Greyhounds. The mortality rate for Greyhounds within the 2-year period was 15% (113 of 747 died). The most common cause of death reported was cancer (66 dogs, 58%), and the most common type of cancer listed as the cause of death was osteosarcoma (28 dogs, 25%). The most commonly reported groups of diseases or disorders were skeletal (232 dogs, 33%), skin (197 dogs, 28%), digestive (132 dogs, 18%), cancer (94 dogs, 13%), and endocrine (85 dogs, 11.9%). Forty-five percent of Greyhounds diagnosed with cancer and 6% of the overall population had osteosarcoma. CONCLUSIONS AND CLINICAL IMPORTANCE: The results of this study can be used by veterinary researchers to continue to investigate the most common diseases in this population. As more retired racing Greyhounds enter the pet population, the results of this study will help educate veterinarians and owners about the most prevalent diseases in the breed.     

Dual-energy X-ray absorptiometry measurement of bone-mineral density in the distal aspect of the limbs in racing Greyhounds

OBJECTIVE: To determine those bones in the distal aspect of the limbs of Greyhounds with fatigue fractures that have the greatest left-to-right differences in bone-mineral density (BMD). SAMPLE POPULATION: Limbs obtained from 20 Greyhounds. PROCEDURE: Dual-energy x-ray absorptiometry (DXA) of the distal aspect of each limb and isolated bones from 10 dogs with a fracture of the central tarsal bone (CTB) of the right pelvic limb was performed. High-resolution scanning was performed on excised bones, and BMD measurements of CTB also were obtained from limbs of dogs without a CTB fracture. RESULTS: The BMD of the accessory carpal bone and calcaneus was not significantly different from the BMD of those bones in the contralateral limb. Although BMD of the CTB of the entire right pelvic limb and isolated bones from dogs with a CTB fracture was lower, compared with values for the entire left pelvic limb, values for isolated CTB from dogs without a CTB fracture were not significantly different. Metacarpal or metatarsal and thoracic or pelvic limb significantly affected BMD for measurements of the entire limb and isolated bones. Left-to-right differences in BMD were greatest for metacarpal 5. CONCLUSIONS AND CLINICAL RELEVANCE: Asymmetric adaptive remodeling of metacarpal 5 can be detected by DXA. The potentially confounding effects of CTB fracture and unknown racing history made it difficult to interpret BMD changes in the CTB of these specimens. Densitometry could be developed as an in vivo assessment for risk of fractures in racing Greyhounds.     

Iatrogenic sciatic nerve injury in eighteen dogs and nine cats (1997-2006)

Objective— To report clinical features associated with iatrogenic peripheral nerve injury in dogs and cats admitted (1997–2006) to a referral teaching hospital.
Study Design— Retrospective study.
Animals— Dogs (n=18), 9 cats.
Methods— Patients had acute signs of monoparesis attributable to sciatic nerve dysfunction that developed after treatment. Neurologic examination and electrodiagnostic testing were performed. Surgical therapy was used for nerve entrapment and delayed reconstructive surgery used in other cases.
Results— Of 27 nerve injuries, 25 resulted from surgery (18 with treatment of pelvic injuries). Iliosacral luxation repair resulted in tibial (4 cats) and peroneal (3 dogs) nerve dysfunction. Other causes were intramedullary pinning of femoral fractures (3), other orthopedic surgery (cemented hip prosthesis [2] and tibial plateau-leveling osteotomy [1]), and perineal herniorrhaphy [1]. Nerve injury occurred after intramuscular injection (1 cat, 1 dog). Immediate surgical treatment was removal of intramedullary nails, extruded cement, or entrapping suture. Delayed nerve transplantation was performed in 2 dogs. Within 1 year, 13 patients recovered completely, clinical improvement occurred in 7, and there was no improvement in 7. Five of the 7 dogs that did not recover had acetabular or ilium fracture.
Conclusion— Iatrogenic sciatic nerve injury occurred most commonly during treatment of pelvic orthopedic diseases and had a poor prognosis. Clinical variation in sciatic nerve dysfunction in dogs and cats can be explained by species anatomic differences.
Clinical Relevance— Iatrogenic sciatic nerve injury leads to severely debilitating locomotor dysfunction with an uncertain prognosis for full-functional recovery.     

Sacral osteochondrosis in two German Shepherd Dogs

Two young adult male castrated German Shepherd Dogs were referred for evaluation of intermittent episodes of hindlimb pain. Physical examination suggested lumbosacral stenosis, and plain radiographs and computed tomography revealed lesions consistent with sacral osteochondrosis. One dog had osteochondral fragments removed surgically; the other was managed conservatively. The surgically treated dog had complete resolution of clinical signs whereas the dog managed conservatively had repeated episodes of mild pain and received one short course of non-steroidal anti-inflammatory medication in 18 months. Sacral osteochondrosis has not been previously reported in Australia.     

Acute phase protein concentrations in retired racing Greyhounds

Background: Retired racing Greyhounds are popular as pets. Greyhounds have several differences in physiological values compared with other breeds, including lower serum α‐ and β‐globulin concentrations. We hypothesized that lower acute phase protein (APP) concentrations could contribute to lower α‐ and β‐globulin concentrations in this breed. Objectives: The purpose of this study was to compare serum concentrations of several APPs in Greyhounds with those of other dog breeds. Methods: We measured the serum concentrations of C‐reactive protein (CRP), haptoglobin (Hp), acid‐soluble glycoprotein (ASG), ceruloplasmin (CP), and serum amyloid A (SAA) in 15 clinically healthy retired racing Greyhounds and 11 age‐ and gender‐matched healthy nonGreyhound controls using previously validated methods. Results were compared by Student's t‐tests. Results: The concentration of Hp by both colorimetric and immunoturbidimetric methods was significantly lower in Greyhounds than in nonGreyhound dogs (P=.0009 and .019, respectively). The concentration of ASG was also significantly (P=.007) lower in Greyhounds, but CRP and CP concentrations were not significantly different between groups. SAA concentration was below the detection limit of the method in all dogs. Conclusions: The low serum concentrations of Hp and ASG should be taken into consideration when interpreting APP results in Greyhounds. Because both Hp and some ASG migrate in the α‐globulin fraction, these results may explain the low α‐globulin concentrations in Greyhounds.     

Vertebral stabilization using positively threaded profile pins and polymethylmethacrylate, with or without laminectomy, for spinal canal stenosis and vertebral instability caused by congenital thoracic vertebral anomalies

Objective— To describe diagnostic findings, surgical technique, and outcome in dogs with thoracic spinal canal stenosis and vertebral instability secondary to congenital vertebral anomalies.
Study Design— Retrospective clinical study.
Animals— Dogs (n=9) with thoracic spinal canal stenosis.
Methods— Medical records (1995–1996; 2000–2006) of 9 dogs with a myelographic diagnosis of spinal canal stenosis and/or vertebral instability secondary to congenital vertebral anomaly that were surgically managed by vertebral stabilization with or without laminectomy were reviewed. Data on pre- and postoperative neurologic status, diagnostic findings, surgical techniques, and outcomes were retrieved. Follow-up evaluations were performed at 1, 2, and 6 months. Long-term outcome was assessed by means of clinical examination or owner telephone interviews.
Results— Spinal cord compression was confirmed by myelography, and in 2 dogs, dynamic compression by stress myelography. Eight dogs regained the ability to ambulate postoperatively. One dog with a partial recovery regained voluntary movement but did not become ambulatory.
Conclusions— Spinal cord injury secondary to congenital vertebral anomaly may have a good outcome when treated by vertebral stabilization with or without laminectomy. Adequate stabilization of the vertebrae and improved neurologic outcome were achieved in most dogs.
Clinical Relevance— Vertebral stabilization using positively threaded profile pins and polymethylmethacrylate with or without laminectomy is an effective treatment for spinal canal stenosis and vertebral instability secondary to congenital thoracic vertebral anomalies.     

Use of the Kishigami Atlantoaxial Tension Band in Eight Toy Breed Dogs with Atlantoaxial Subluxation

Objective— To determine the applicability, complications, and long-term functional outcome of the Kishigami Atlantoaxial Tension Band (Kishigami AATB) for management of congenital and traumatic atlantoaxial (AA) instability in toy breed dogs.
Study Design— Case series.
Animals— Toy breed dogs (n=8) with congenital or traumatic AA instability.
Methods— The AA joint of each dog was surgically stabilized through a dorsal approach using the original or a modified version of the Kishigami AATB. Pre- and postoperative neurologic status, radiographs, and complications were reviewed. Follow-up examination was performed at 1 and 12 months.
Results— Functional improvement occurred in 5 dogs; 1 dog did not improve or worsen and 2 dogs were euthanatized at owner request. Adequate reduction and stabilization was achieved in 7 dogs based on immediate postoperative radiographs; failure of reduction was evident in 1 dog. No relevant complications occurred.
Conclusions— Kishigami AATB may be acceptable as an alternative method for dorsal stabilization of AA subluxation in toy breed dogs in which use of ventral screws or pins is challenging. Experience with this technique in a larger population is necessary to compare our results to those reported by ventral approach.
Clinical Relevance— The surgical technique described is effective, safe, and simple in the surgical treatment of AA subluxation in toy breed dogs.