Radiographic findings in young llamas with forelimb valgus deformities: 28 cases (1980-1988)

Twenty-eight llamas with a mean age of 6.2 months had bilateral forelimb valgus deformities. The range of valgus deformity, as measured on a craniocaudal radiographic view, was 6 to 25 degrees, with a similar degree of deviation in each limb. Morphologic abnormalities in the distal portion of the radius and ulna were more prominent in the ulna and included metaphyseal and epiphyseal flaring, physeal ectasia, and metaphyseal sclerosis. Distal radial epiphyseal ectasia, and metaphyseal sclerosis. Distal radial epiphyseal wedging was believed to be secondary to the ulnar deformity. Radial bowing with lateral and caudal concavity and unequal cortical thickness was evident. Epiphyseal and metaphyseal flaring with physeal ectasia was noticed in the distal portion of the third and fourth metacarpal bones. Carpal bones were unaffected.     

Factors associated with outcome in foals with neonatal isoerythrolysis (72 cases, 1988-2003)

Background: Neonatal foals with isoerythrolysis (NI) often die, but the risk factors for death have not been identified.
Objectives: To identify factors associated with outcome in foals with NI and to identify factors associated with death from liver failure or kernicterus in the same population.
Animals: Seventy-two foals with NI examined at referral institutions.
Methods: Retrospective case series. Information on signalment, clinical examination findings, laboratory testing, treatment, complications, outcome, and necropsy results were obtained.
Results: The overall survival rate was 75% (54 of 72). Liver failure (n = 7), kernicterus (n = 6), and complications related to bacterial sepsis (n = 3) were the 3 most common reasons for death or euthanasia. The number of transfusions with blood products was the factor most strongly associated with nonsurvival in a multivariate logistic regression model. The odds of liver failure developing in foals receiving a total volume of blood products ≥ 4.0 L were 19.5 (95% confidence intervals [CI]: 2.13–178) times higher than that of foals receiving a lower volume ( P = .009). The odds of kernicterus developing in foals with a total bilirubin ≥ 27.0 mg/dL were 17.0 (95% CI: 1.77–165) times higher than that of foals with a lower total bilirubin ( P = .014).
Conclusions and Clinical Importance: Development of liver failure, kernicterus, and complications related to bacterial sepsis are the most common causes of death in foals with NI. Foals administered a large volume of blood products are at greater risk for developing liver failure.     

Endoscopic appearance of gastric lesions in foals: 94 cases (1987-1988)

Of 183 foals examined by use of gastroendoscopy during 1987 and 1988, 94 had gastric lesions. Sixty-eight of 120 foals in the 1- to 85-day-old age range had endoscopically confirmed gastric lesions, and 26 of 63 foals in the 90- to 310-day-old age range had gastric lesions. Lesions were observed most frequently in the stratified squamous mucosal epithelium, particularly adjacent to the margo plicatus. Lesions were observed in the gastric glandular mucosa in 26 of the 94 foals with gastric lesions, and with a greater frequency in foals with a clinical disorder than in foals with no disorder (27% vs 3%). In young foals, lesions were consistently observed in the stratified squamous mucosal epithelium adjacent to the margo plicatus along the greater curvature of the stomach at 2 specific sites. These lesions were frequently associated with desquamation of the stratified squamous mucosal epithelium, which was observed in 69 of the 82 foals less than or equal to 30 days old and in 13 of the 101 foals greater than 30 days old. Lesions in the stratified squamous mucosal epithelium adjacent to the margo plicatus were associated with concurrent clinical disorders in foals greater than 90 days old, but developed with identical frequency in foals less than 90 days old with or without a clinical disorder. Lesions in the stratified squamous mucosal epithelium along the lesser curvature of the stomach were observed only in foals with concurrent clinical disorder, and with a higher frequency in foals greater than 90 days old than in younger foals (24% vs 3%).     

Characterization of Clostridium difficile isolates from foals with diarrhea: 28 cases (1993-1997)

OBJECTIVE: To determine molecular characteristics of Clostridium difficile isolates from foals with diarrhea and identify clinical abnormalities in affected foals. DESIGN: Retrospective study. ANIMALS: 28 foals with C difficile-associated diarrhea. PROCEDURE: Toxigenicity, molecular fingerprinting, and antibiotic susceptibility patterns were determined. Information on signalment, clinical findings, results of clinicopathologic testing, whether antimicrobials had been administered prior to development of diarrhea, and outcome was obtained from the medical records. RESULTS: Twenty-three (82%) foals survived. Toxin A and B gene sequences were detected in isolates from 24 of 27 foals, whereas the toxin B gene alone was detected in the isolate from 1 foal. Results of an ELISA for toxin A were positive for fecal samples from only 8 of 20 (40%) foals. Ten of 23 (43%) isolates were resistant to metronidazole. Molecular fingerprinting revealed marked heterogeneity among isolates, except for the metronidazole-resistant isolates. Sixteen foals had tachypnea. Hematologic abnormalities were indicative of inflammation. Common serum biochemical abnormalities included metabolic acidosis, hyponatremia, hypocalcemia, azotemia, hypoproteinemia, hyperglycemia, and high enzyme activities. Passive transfer of maternal antibodies was adequate in all 12 foals evaluated. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a large percentage of C difficile isolates from foals with diarrhea will have the toxin A and B gene sequences. Because of the possibility that isolates will be resistant to metronidazole, susceptibility testing is warranted. Clostridium difficile isolates from foals may have a substantial amount of molecular heterogeneity. Clinical and hematologic findings in affected foals are similar to those for foals with diarrhea caused by other pathogens.     

Neonatal isoerythrolysis in horse foals and a mule foal: 18 cases (1988-2003)

OBJECTIVE: To assess data regarding clinical features, clinicopathologic and blood gas variables, and outcome from horse and mule foals with confirmed neonatal isoerythrolysis (NI). DESIGN: Retrospective case series. ANIMALS: 17 horse and 1 mule foals. PROCEDURE: Medical records of foals (< 14 days old) with NI were reviewed. Information collected included signalment; clinical examination findings; results of hematologic, serum and plasma biochemical, and venous blood gas analyses and urinalysis; treatments; and outcome. RESULTS: Data from 17 horse foals and 1 mule foal with NI (mean age, 71 hours) were evaluated. Many foals had high serum indirect and direct bilirubin concentrations and sorbitol dehydrogenase activity. Whole blood immunoglobulin concentrations were < 400 mg/dL in 4 of 15 foals. Fresh whole blood transfusions were administered to 10 of 18 foals. Among the blood factors implicated in 11 foals, one (Dg) had not previously been associated with NI. Of 10 foals that received blood transfusions, 7 had significant improvements in Hct and hemoglobin concentration and 2 had significant improvements in central venous oxygen tension. Fifteen foals survived to discharge. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that blood factor Dg may be associated with NI in foals. Liver disease may be concurrent with NI in foals, and NI can develop in foals with inadequate passive transfer of colostral antibodies. Whole blood transfusions were successful at increasing oxygen-carrying capacity and improving peripheral tissue oxygenation in NI-affected foals. With appropriate treatment, the prognosis for foals with NI is good.     

Smoke exposure in dogs: 27 cases (1988-1997).

OBJECTIVE: To evaluate clinical findings, prognostic variables, and clinical course of dogs exposed to smoke. DESIGN: Retrospective study. ANIMALS: 27 dogs exposed to smoke in residential fires. PROCEDURE: Medical records were reviewed for 1988-1997. Time of year, signalment, interval from fire to arrival at veterinary hospital, duration of smoke exposure, clinical signs at the fire scene, physical examination findings, changes in respiratory tract signs, radiographic findings, hematologic and arterial blood gas analyses, initial treatment, clinical course, and outcome were recorded. RESULTS: 27 dogs (16 uncomplicated and 11 complicated cases) were identified. In the complicated group, 4 dogs died, 4 were euthanatized, and 3 had a complicated clinical course. Stupor or coma (8 of 17 dogs), coughing or gagging (6), and respiratory difficulty (6) were commonly observed at the fire scene. Substantial improvement was evident within 5 to 30 minutes after dogs were given supplemental oxygen at the fire scene. More severely affected dogs had a higher median PCV (58%) than less severely affected dogs (50%). Most common thoracic radiographic findings were an alveolar (10 dogs) or an interstitial (3) pattern. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs exposed to smoke can develop respiratory or neurologic complications. Monitoring progression of respiratory problems on the day after the fire may provide clinicians with clues about the severity of each dog's condition.     

Type I immune-mediated polyarthritis in dogs: 39 cases (1997-2002)

OBJECTIVE: To determine clinical signs, laboratory findings, relationship to vaccination, and response to treatment for type I immune-mediated polyarthritis (IMPA) in dogs. DESIGN: Retrospective study. ANIMALS: 39 dogs PROCEDURE: Clinical records and radiographic reports from 3 university referral hospitals were reviewed. Clinical signs, laboratory and investigative findings, relationship to vaccination, and response to treatment were evaluated. RESULTS: Clinical signs and initial laboratory and clinical investigative findings were frequently abnormal but were nonspecific and not associated with likelihood of recovery. Time of vaccination was not associated with onset of disease. Chemotherapeutic immunosuppression resulted in complete cure in 56% of dogs. Continuous medication was required in 18% (7/39) of dogs, relapses were treated successfully in 13% (5/39) of dogs, and 15% (6/39) of dogs died or were euthanatized as a result of disease. CONCLUSIONS AND CLINICAL RELEVANCE: The possible involvement of vaccination in type I IMPA was not made clear from this study because of the small population size. Signalment, clinical signs, and results of diagnostic tests other than multiple synovial fluid analyses were generally nonspecific. Most dogs with type I IMPA responded to initial immunosuppressive treatment, but 31% (12/39) of dogs relapsed, required further treatment, or both.     

Factors associated with prognosis for survival and athletic use in foals with septic arthritis: 93 cases (1987-1994).

OBJECTIVE: To identify factors affecting the prognosis for survival and athletic use in foals with septic arthritis. DESIGN: Retrospective study. ANIMALS: 93 foals with septic arthritis. PROCEDURE: Medical records were reviewed to obtain clinical findings, laboratory test results, radiographic findings, treatment method, and outcome. Race records for Thoroughbreds and Standardbreds were evaluated to determine whether foals subsequently raced and whether they raced successfully. RESULTS: 43 foals had 1 affected joint, 44 foals had multiple affected joints, and number of affected joints was not recorded for 6 foals. The femoropatellar and tarsocrural joints were most commonly affected. Osteomyelitis or degenerative joint disease were detected in 59% (46/78) of foals. Failure of passive transfer, pneumonia, and enteritis were common. Foals were treated with lavage, lavage and intra-articular administration of antibiotics, lavage and arthroscopic debridement with or without partial synovectomy, or lavage and arthrotomy to debride infected bone and systemic administration of antibiotics. Seventy-three foals survived to be discharged from hospital, and approximately a third raced. Isolation of Salmonella spp from synovial fluid was associated with an unfavorable prognosis for survival and multisystem disease was associated with an unfavorable prognosis for survival and ability to race; other variables were not significantly associated with survival and ability to race. CONCLUSIONS AND CLINICAL RELEVANCE: With treatment, the prognosis for survival of foals with septic arthritis was favorable, whereas prognosis for ability to race was unfavorable. Multisystem disease, isolation of Salmonella spp from synovial fluid, involvement of multiple joints, and synovial fluid neutrophil count > or = 95% at admission may be of prognostic value.     

Treatment and outcome of dogs with leptospirosis: 36 cases (1990-1998)

OBJECTIVE: To characterize serologic and clinical features and outcome of dogs with leptospirosis that were treated conservatively (i.e., medical management alone) or with hemodialysis. DESIGN: Retrospective study. ANIMALS: 36 dogs with leptospirosis. PROCEDURE: History; results of physical examinations, ultrasonography, and serologic, hematologic, and serum biochemical analyses; time to resolution of azotemia; and outcome were obtained from medical records. Dogs were treated conservatively (n = 22) or with hemodialysis (14). RESULTS: Between 1990 and 1998, amount of rainfall was positively correlated with number of cases of leptospirosis identified per year. Serum antibodies against 6 Leptospira serovars were measured, and titers were highest to Leptospira pomona in 16 (44%) dogs, L bratislava in 9 (25%) dogs, and L hardjo in 1 (3%) dog. Eight (22%) dogs had equally high titers to L pomona and L bratislava, 1 (3%) had equally high titers to L grippotyphosa and L canicola, and 1 (3%) had high titers to L grippotyphosa, L pomona, L canicola, and L bratislava. During initial evaluation, all dogs were azotemic. Thirty (83%) dogs survived, including 12 of 14 (86%) dogs treated with hemodialysis and 18 of 22 (82%) treated conservatively. Serum creatinine concentration was similar in both groups after resolution of clinical signs. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with L pomona and L bratislava was recognized as a cause of leptospirosis in dogs, and resulted in development of acute renal failure with various degrees of azotemia. Prognosis for dogs with mild to moderate azotemia was good with conservative treatment, whereas treatment with hemodialysis appeared to improve prognosis for dogs with severe azotemia.     

Survival rates for horses undergoing stapled small intestinal anastomosis: 84 cases (1988-1997)

OBJECTIVE: To determine whether location and type of small intestinal anastomosis and other variables were associated with short- and long-term survival rates in horses undergoing stapled small intestinal anastomosis. DESIGN: Retrospective study. ANIMALS: 84 horses that underwent small intestinal anastomosis. PROCEDURE: Medical records from 1988 to 1997 were examined for horses that underwent stapled small intestinal anastomosis. Horses were allotted into 4 groups: jejunojejunostomy (n = 27), jejunoileostomy (11), jejunoileocecostomy with small intestinal resection (20), and jejunoileocecostomy without small intestinal resection (26). Survival rates and other variables were determined. RESULTS: Horses that underwent jejunoileocecostomy without resection had a significantly higher survival rate at all intervals than did horses in the other 3 groups. At 180 and 365 days after surgery, horses that underwent jejunojejunostomy had a significantly lower survival rate than those that underwent jejunoileocecostomy with intestinal resection. Horses that underwent jejunoileocecostomy with intestinal resection had a significantly higher survival rate at 1 year, compared with the combined jejunojejunostomy and jejunoileostomy groups. Preoperative heart rate was inversely associated with survival rate. Overall survival rates at discharge and 1 year were 81 and 56%, respectively. For horses that underwent small intestinal resection, survival rates at discharge and 1 year were 65 and 47%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Horses that underwent anastomosis of the small intestine to the cecum without resection had the highest survival rate, compared with horses that required intestinal resection. In some instances, resection and anastomosis involving the cecum had better prognosis than resections involving 2 segments of the small intestine.     

Variables associated with outcome in dogs undergoing extrahepatic biliary surgery: 60 cases (1988-2002)

OBJECTIVE: To report clinical findings and define clinical variables associated with outcome in dogs undergoing extrahepatic biliary surgery. STUDY DESIGN: Retrospective study. ANIMALS: Sixty dogs that had extrahepatic biliary tract surgery. RESULTS: Primary diagnoses included necrotizing cholecystitis (36 dogs, 60%), pancreatitis (12 dogs, 20%), neoplasia (5 dogs, 8%), trauma (4 dogs, 7%), and gallbladder rupture from cholelithiasis without necrotizing cholecystitis (3 dogs, 5%). Bile peritonitis occurred in 19 (53%) dogs with necrotizing cholecystitis, 4 dogs with trauma, and 3 dogs with cholelithiasis without evidence of necrotizing cholecystitis. Cholecystectomy (37 dogs, 62%) and cholecystoduodenostomy (14 dogs, 23%) were the 2 most commonly performed procedures. Median hospitalization for survivors was 5 days (range, 1-15 days). There were 43 surviving dogs (72%) and 17 nonsurvivors (28%, 4 died, 13 euthanatized). Presence of septic bile peritonitis (P=.038), elevation in serum creatinine concentration (P=.003), prolonged partial thromboplastin times (PTTs; P=.003), and lower postoperative mean arterial pressures (P=.0001) were significantly associated with mortality. CONCLUSIONS: Extrahepatic biliary surgery is associated with high mortality and a relatively long hospitalization time for survivors. Cholecystectomy and cholecystoduodenostomy were the most common surgical procedures to treat the 4 major biliary problems (necrotizing cholecystitis, pancreatitis, neoplasia, and trauma) observed in this cohort of dogs. The relatively high mortality rate likely reflects the underlying diseases and their effects on the animal (septic bile peritonitis, higher serum creatinine, prolonged PTT, and lower postoperative mean arterial pressure) rather than complications of surgery. CLINICAL RELEVANCE: Septic bile peritonitis, preoperative elevated creatinine concentration, and immediate postoperative hypotension in dogs undergoing extrahepatic biliary tract surgery are associated with a poor clinical outcome. Adequate supportive care and monitoring in the perioperative period is critical to improve survival of dogs with extrahepatic biliary disease.     

Mechanical ventilation in foals with botulism: 9 cases (1989-2002)

"Shaker foal" disease, toxicoinfectious botulism of foals, was 1st described as a clinical entity in 1967. The reported mortality rate was 90%, with death occurring within 24-72 hours of the onset of the characteristic clinical signs. The mortality rate decreased when equine-origin botulism antitoxin became available; however, a certain percentage of foals continued to die of respiratory failure. Mechanical ventilation is an important part of the treatment of infant botulism and is essential to the survival of many affected infants. We report a retrospective study of 9 foals with toxicoinfectious botulism where early mechanical ventilation was employed as part of the treatment. Foals receiving mechanical ventilation were progressively acidemic and had increased PaCO2 tensions before mechanical ventilation. These arterial blood gas abnormalities were ameliorated with mechanical ventilation. One foal was euthanized for economic reasons; survival in treated foals was 87.5%. Mechanical ventilation of foals with botulism and respiratory failure appears to be an effective therapy.     

Clinical signs, underlying cause, and outcome in cats with seizures: 17 cases (1997-2002)

OBJECTIVE: To determine clinical signs, results of diagnostic testing, underlying cause, and outcome in cats with seizures. DESIGN: Retrospective study. ANIMALS: 17 cats with seizures. PROCEDURE: Only those cats in which an underlying metabolic abnormality causing the seizures had been identified, diagnostic imaging of the brain and CSF analysis had been done, or a necropsy had been performed were included. Seizures were classified as being a result of metabolic disease, symptomatic epilepsy (ie, epilepsy resulting from a structural lesion of the brain), or probably symptomatic epilepsy (ie, epilepsy without any extracranial or identifiable intracranial disease that is not suspected to be genetic in origin). RESULTS: 3 cats had seizures associated with an underlying metabolic disease (hepatic encephalopathy), 7 had symptomatic epilepsy (3 with neoplasia and 4 with meningoencephalitis), and 7 had probably symptomatic epilepsy. Six of the 7 cats with symptomatic epilepsy died or were euthanatized within 3 months after the diagnosis was made, whereas 6 of the 7 cats with probably symptomatic epilepsy survived for at least 12 months after the diagnosis was made. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cats with probably symptomatic epilepsy may have a good long-term prognosis.     

Treatment of slipped capital femoral epiphysis in cattle: 11 cases (1974-1988)

A mixed population of 11 cattle (7 dairy, 4 beef; 9 male, 2 female) were examined because of acute onset of non-weightbearing hind limb lameness. Radiography revealed slipped capital femoral epiphyseal fracture in all cattle, with the exception of one large bull. Ten of the 11 cattle were treated with open reduction and internal fixation, using intramedullary pins. Cattle affected with slipped capital femoral epiphyseal fracture in previous reports typically have been calves that required forced extraction during dystocia. Cattle in this report were in the following 2 age groups in which trauma was the likely cause: 3 to 5 months and 1.5 to 2.3 years. Follow-up information was provided for 7 of the 10 cattle. Four of the 7 were functional and had no clinical signs of arthritis, abnormal gait, atrophy, scarring, contralateral compensation, breakdown, or other difficulty 6 months after surgical correction. If early diagnosis is achieved, it appears that reduction with intramedullary pinning can provide a good long-term prognosis in cattle when function as breeding animals is important to their future value.     

Parenteral nutrition in neonatal foals: clinical description, complications and outcome in 53 foals (1995-2005)

This retrospective study describes the use of and complications associated with parenteral nutrition (PN) administration to 53 equine neonates at the University of California Veterinary Medical Teaching Hospital. Medical records were examined and information obtained on signalment, physical examination, clinical diagnosis, outcome, total hospitalization time, insulin administration, microbiology culture results, other complications (i.e. thrombophlebitis) and necropsy findings. Complete blood count and serum biochemistry analytes, venous blood gas, serum electrolyte and glucose concentrations, and blood lactate concentration results were compared before and during PN administration in all foals. Seventeen foals (32%) developed hypertriglyceridemia (>200mg/dL). Triglyceride concentrations >200mg/dL were significantly (P=0.049) associated with non-survival. Forty-seven foals (89%) developed hyperglycemia (blood glucose >120mg/dL) and eight (15%) developed catheter-related complications (thrombosis or local sepsis). Packed cell volume, total protein, creatinine, blood urea nitrogen, and sorbitol dehydrogenase concentrations decreased while foals were on PN, while serum chloride concentration increased. This study highlighted that hypertriglyceridemia during the acute phase of neonatal illness may be detrimental to outcome, and that the safety of lipid-containing solutions in foals warrants further study.     

Mesothelioma in cattle: eight cases (1970-1988)

Over an 8-year period, 8 beef cattle with mesothelioma were admitted to the Auburn University College of Veterinary Medicine and the Louisiana State School of Veterinary Medicine. Diagnosis was confirmed by histologic examination of affected tissues. Five bulls, 1 steer, and 2 cows were affected. Four of the bulls had scrotal swelling; 2 cows and 1 bull had ventral abdominal swelling. The peritoneal cavity was involved in 5 cases, the pleural cavity was affected in 2 cases, and in 2 cases, disease was apparently confined to the vaginal cavity. Of the 8 cattle, 6 died or were euthanatized; only cattle with tumor apparently confined to the vaginal cavity survived.     

Deep digital flexor tenotomy as a treatment for chronic laminitis in horses: 35 cases (1988-1997)

OBJECTIVE: To determine long-term prognosis for horses with laminitis treated by deep digital flexor (DDF) tenotomy and to identify factors affecting success of the surgical procedure. DESIGN: Retrospective study. ANIMALS: 35 horses with laminitis treated by DDF tenotomy between 1988 and 1997. PROCEDURE: Information was obtained from individual medical records and follow-up telephone interviews with owners and referring veterinarians. Cumulative proportions of horses that survived 6 months and 2 years after tenotomy were determined. Effect of Obel grade of lameness on 6-month and 2-year survival and effect of distal phalangeal rotation on survival and future performance were evaluated by chi 2 analysis. Body weights of horses that survived > or = 2 years were compared with those of horses that survived < 2 years by ANOVA. RESULTS: 27 of the 35 (77%) horses survived > or = 6 months, and 19 of 32 (59%) survived > 2 years. Obel grade of lameness and body weight at time of surgery had no effect on 6-month or 2-year survival. Degree of distal phalangeal rotation had no effect on 2-year survival or the ability of horses to be used for light riding. Twenty-two of the 30 (73%) owners interviewed indicated they would have the procedure repeated on their horses given similar circumstances. CLINICAL IMPLICATIONS: DDF tenotomy is a viable alternative for horses with laminitis refractory to conventional medical treatment. In some instances, the procedure may be effective in returning horses to light athletic use.     

Pneumothorax in horses: 40 cases (1980-1997)

OBJECTIVE: To characterize pneumothorax in horses and to describe clinical signs, diagnostic testing, and clinical outcome of horses with pneumothorax. DESIGN: Retrospective study. ANIMALS: 40 horses. PROCEDURE: Medical records of horses with pneumothorax were reviewed to obtain information on signalment, history, clinical signs, diagnostic testing, treatment, and clinical outcome. RESULTS: Horses developed pneumothorax secondary to pleuropneumonia (17 horses), open wounds of the thorax (9), closed trauma to the thorax (7), surgery on the upper portion of the respiratory tract (3), and surgery involving the thoracic cavity (1); 3 horses had pneumothorax of unknown cause. Clinical signs included tachypnea, dyspnea, cyanosis, lack of lung sounds on auscultation of the dorsal aspect of the thorax, fever, tachycardia, signs of depression or anxiousness, and cough. Radiography and ultrasonography were useful to definitively diagnose pneumothorax. Pneumothorax was bilateral in 47.5% (19/40) and unilateral in 42.5% (17/40) of horses; designation of unilateral versus bilateral was not recorded in the remaining 4 horses. Horses with pneumothorax secondary to pleuropneumonia more commonly had unilateral pneumothorax (64.7% for unilateral vs 29.4% for bilateral; not specified for 1 horse). Horses with pneumothorax secondary to pleuropneumonia were less likely to survive than horses with pneumothorax secondary to other causes (35.3 vs 69.6% survived, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Pleuropneumonia is an important cause of pneumothorax in horses. Classic clinical signs of pneumothorax may not be evident. Radiography, ultrasonography, or both may be required for diagnosis. Prognosis for survival is better for horses with pneumothorax not associated with pleuropneumonia.     

Long-term outcome of horses with a slab fracture of the central or third tarsal bone treated conservatively: 25 cases (1976-1993)

OBJECTIVE: To determine clinical features of horses with a slab fracture of the central or third tarsal bone and to report outcome of horses in which treatment did not include surgery. DESIGN: Retrospective study. ANIMALS: 25 horses (14 Standardbreds, 6 Thoroughbreds, 5 Quarter Horses). PROCEDURE: Medical records of horses with a slab fracture of the central (n = 9) or third (16) tarsal bone were reviewed. Only horses for which treatment consisted of confinement to a stall were included in this study. Clinical features and radiographic findings were recorded and summarized. Outcome was determined for racing breeds by obtaining official lifetime race results. Outcome for Quarter Horses was determined by phone survey of the owners. RESULTS: 16 (64%) horses had a successful outcome. Ten of 14 (71%) Standardbreds and 2 of 6 Thoroughbreds returned to racing and started at least 5 races after injury. Four of 5 Quarter Horses for which follow-up information was available successfully returned to their previous activity. Sex, age, limb affected, or gait was not associated with final outcome. Percentage of racehorses with central tarsal bone fractures that had a successful outcome (2/7) was significantly less than percentage with third tarsal bone fractures that did (10/13). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that enforced rest without surgical fixation can be an effective therapeutic option for horses with a slab fracture of the central or third tarsal bone, even if athletic function is expected.