Echocardiographic measurement of the mitral valve in normal Cavalier King Charles spaniels: repeatability, optimal future study methods, and preliminary reference intervals.

INTRODUCTION/OBJECTIVES: Cavalier King Charles spaniels (CKCS) are ideal candidates for longitudinal study of myxomatous mitral valve (MV) disease and stage B1 clinical trials; however, the optimization of MV measurement acquisition and repeatability must be better defined to realize this potential. Additionally, breed-specific reference ranges for CKCS MV measurements are lacking. Study objectives were to assess measurement repeatability and define optimal methods for the longitudinal study of echocardiographic MV anatomy and to define preliminary, two-dimensional echocardiographic reference ranges for MV measurements in CKCS. ANIMALS: Forty CKCS between 10 and 24 months old. MATERIALS AND METHODS: Pre- and post-sedation two-dimensional echocardiographic images optimized for the MV were obtained. The length, width, and area of the anterior and posterior leaflets and the diameter of the MV annulus at end-diastole and end-systole were measured. Measurement repeatability was assessed using % coefficient of variation and repeatability coefficients. RESULTS: Intraoperator repeatability was best for the operator with previous MV measurement experience, with comparable results for the experienced operator measuring the second operator's images, mimicking a core echocardiography laboratory setting. Except for MV annulus diameter at end-systole, sedation had no significant effect on any MV measurements, nor did it impact measurement repeatability. Preliminary, breed-specific reference ranges were defined for the population, with CKCS often noted to have a larger annular diameter at end-systole than end-diastole. CONCLUSIONS: Optimal methods for longitudinal study of the MV in CKCS have been proposed, as have two-dimensional preliminary echocardiographic reference ranges for CKCS MV measurements. The MV annulus in CKCS may differ from other breeds.

Extracorporeal shockwave therapy raises mechanical nociceptive threshold in horses with thoracolumbar pain.

BACKGROUND: Although extracorporeal shockwave therapy (ESWT) is a common treatment for horses with back pain, effects on mechanical nociceptive threshold (MNT) and multifidus muscle cross sectional area (CSA) in the spine are unknown. OBJECTIVES: To evaluate effects of ESWT on spinal MNT and multifidus muscle CSA in horses with thoracolumbar pain. STUDY DESIGN: Non-randomised trial. METHODS: Thoracolumbar spines of 12 horses with thoracolumbar pain were radiographed to document existing pathology. Each horse received three ESWT treatments, 2 weeks apart (days 0, 14, 28). Palpation scores were documented (days 0, 45 and 65). Ultrasonographic CSA of left and right multifidus muscles was recorded at T12, T14, T16, T18, L3 and L5 (days 0, 45 and 65). MNT was measured at the same spinal sites every 7 days (day 0-56). RESULTS: Mechanical nociceptive threshold in 10/12 horses (83%) was greater at each time point compared with day 0 (P < 0.05). Mechanical nociceptive threshold increased at all time points at six sites in 2/12 (16%), at five sites in 3/12 (25%), at four sites in 4/12 (33%) and at one site in 1/12 (8%; P < 0.05). Mechanical nociceptive threshold average per cent  increase from day 0 to 56 was 64% for the thoracic region (T12-T18) and 29% for the lumbar region (L3-L5). There was no statistical difference in MNT from day 35 to 56 (P = 0.25). A bimodal analgesic trend was observed following ESWT. Degree of radiographic change was not associated with response to treatment. No significant change in multifidus muscle CSA was observed. MAIN LIMITATIONS: Small study size and lack of control group. CONCLUSIONS: Three treatments of ESWT 2 weeks apart raised MNT over a 56-day period in horses with back pain, but did not influence change in CSA of the multifidus muscle. While ESWT appears justifiable for analgesia, physiotherapeutic techniques may be necessary in conjunction for concurrent muscle rehabilitation.

Immunogenicity of Potomac horse fever vaccine when simultaneously co-administered with rabies vaccine in a multivalent vaccine or as two monovalent vaccines at separate sites.

BACKGROUND: Potomac horse fever (PHF) is a potentially fatal enterocolitis of horses caused by Neorickettsia risticii. The disease was originally recognised almost 40 years ago in the state of Maryland in the US. It is now known to occur in many areas of North America, as well as having been described in South America and Europe. Monocomponent PHF vaccines are available, but clinical protection with vaccination has been reported to be inconsistent. OBJECTIVES: This study was designed to assess the immunogenicity of a commercially available Potomac Horse Fever (PHF) vaccine when administered as either a monovalent PHF vaccine simultaneously co-administered with a separate monovalent Rabies vaccine or as a multivalent PHF/Rabies vaccine in horses. STUDY DESIGN: Randomised parallel group trial. METHODS: Ninety-one client or University owned horses participated in this open-label randomised study, with 45 horses receiving the monovalent vaccines at separate sites and 46 receiving the multivalent vaccine at a single site. Serum PHF IFA titres were determined twice prior to vaccination and at 1, 2 and 3 months after vaccination. RESULTS: Both vaccination protocols exhibited poor immunogenicity, with only one-third of all the animals demonstrating seroconversion, defined as an increase in titre of greater than 400 over baseline, at any time point after vaccination. The monovalent PHF vaccine exhibited significantly greater immunogenicity in terms of the number of horses exhibiting seroconversion, as compared to the multivalent vaccine, at one (20 vs. 11, P = 0.03) and two (18 vs. 9, p = 0.02) months post vaccination. The monovalent PHF vaccine also exhibited significantly greater immunogenicity in terms of the median (interquartile range) IFA titres, as compared to the multivalent vaccine, at one (800 [200-1600] vs. 400 [200-800], P = 0.009) and 2 months (400 [200-1600] vs. 400 [100-800], P = 0.02) post vaccination. There was no significant difference between groups at 3 months in either seroconversion rate or median IFA titers. MAIN LIMITATIONS: This study did not assess the actual protective effects of PHF vaccination but rather used the serologic response to vaccination as a surrogate biomarker of immunity. CONCLUSIONS: The multivalent PHF/Rabies vaccine exhibited lower immunogenicity as compared to the monovalent PHF vaccine co-administered with a separate Rabies vaccine.

Short-term outcome and risk factors for post-operative complications following umbilical resection in 82 foals (2004-2016).

BACKGROUND: Umbilical remnant infection and patent urachus are an important cause of morbidity for the equine neonate. Left untreated, fatal complications can develop. Identifying risk factors for post-operative complications after surgery are important for estimating prognosis. OBJECTIVES: To identify risk factors associated with post-operative complications in foals undergoing umbilical remnant resection due to patent and/or infected umbilical remnants. STUDY DESIGN: Retrospective case series. METHODS: Foals undergoing umbilical remnant resection due to patent urachus or infected remnants at the Marion duPont Scott Equine Medical Center from 2004 to 2016 were included in the study. Data were obtained from medical records and associations between outcomes and post-operative complications, and pre or intraoperative clinical variables were assessed using bivariable and multivariable analyses. RESULTS: Eighty-two foals underwent umbilical remnant resection of which 73 (89.0%) survived to discharge. The urachus was the most commonly affected structure being patent and/or infected in 84.1% of cases. Concurrent diseases were present in 60.6% of foals prior to surgery, with diarrhoea and septic arthritis being most common. The presence of preoperative septic arthritis and/or physitis were significantly associated with nonsurvival (OR 33; 95% confidence interval 1.1-985.2; P = 0.04). Longer anaesthesia time (OR 1.4; 95% confidence interval 1.1-1.7; P = 0.02) and failure of passive transfer of immunoglobulins (OR 5.9; 95% confidence interval 1.2-29.04; P = 0.03) were associated with increased odds for post-operative complications. MAIN LIMITATIONS: It is not known if medical treatment alone would have been successful in foals that did not receive preoperative medical treatment. CONCLUSIONS: Overall survival is high after surgical excision of umbilical remnants. The presence of preoperative septic arthritis and/or physitis was associated with decreased survival and failure of passive transfer of immunoglobulins and longer anaesthesia times were associated with increased odds for post-operative complications.

Prevalence of hyoid injuries in dogs and cats undergoing computed tomography.

Fractures of the hyoid bones have been reported occasionally in dogs, but the prevalence and significance of hyoid injury in dogs and cats are unknown. In human beings, hyoid injury is rare and usually is caused by direct trauma to the greater cornu, which are analogous to the paired canine and feline thyrohyoid bones. The aim of this study was to describe the prevalence and morphology of hyoid bone injury detected in dogs and cats undergoing computed tomography (CT) for unrelated disease. CT studies of 293 dogs and 100 cats from 2012 to 2016 were identified and reviewed retrospectively. Hyoid fracture (total of eight bones) or luxation (total of four sites) was present in 9/293 (3.1%) dogs, but none of the cats. One dog had bilateral fractures and one dog had bilateral luxations. The most frequently fractured bone was the epihyoid bone (4/8 fractures). Fracture margins were tapered and sclerotic, consistent with chronic non-union. There was no history of trauma, dysphagia or dyspnea in 7/9 dogs with hyoid fractures. Hyoid bone injury, particularly epihyoid bone fracture, may be an incidental finding in dogs.

Seroprevalence of Borrelia burgdorferi in Horses Presented for Coggins Testing in Southwest Virginia and Change in Positive Test Results Approximately 1 Year Later.

BACKGROUND: Lyme disease can affect people, dogs, and horses, but it remains poorly understood, especially in the horse. Determining the seroprevalence of Borrelia burgdorferi in horses in different geographic areas will enable better understanding of the epidemiology of the disease, thus improving diagnosis and treatment of affected animals. HYPOTHESIS: To determine the seroprevalence of B. burgdorferi in horses in southwest Virginia. ANIMALS: Horses presented for routine Coggins testing from January 2013 to January 2014 had additional blood drawn for Lyme Multiplex Assay testing. METHODS: Of 492 samples collected, 250 samples were analyzed using the Lyme Multiplex Assay. Of the 83 horses that had positive test results to at least 1 outer surface protein (Osp), 63 were available for follow-up testing 5-17 months later (June 2014). RESULTS: Thirty-three percent of horses had positive results for antibodies to at least 1 Osp. Horses with a positive outer surface protein F (OspF) result were older (14.5 ± 0.79) than horses with a negative OspF result (11.6 ± 0.53). Of the horses available for follow-up testing, 63% had the same result as that of the initial test. There was no difference in test result between initial and follow-up testing. CONCLUSIONS: Horses seropositive to B. burgdorferi are common in Virginia, and older horses are more likely to have a positive test result for OspF than younger horses. Follow-up testing indicated that the majority of horses that were positive on initial testing did not have a different test result 5-17 months later.

Comparison of autogenous cancellous bone grafting and extracorporeal shock wave therapy on osteotomy healing in the tibial tuberosity advancement procedure in dogs. Radiographic densitometric evaluation.

OBJECTIVES: To compare optical values in the osteotomy gap created after a tibial tuberosity advancement (TTA) treated with autogenous cancellous bone graft, extracorporeal shock wave therapy, a combination of autogenous cancellous bone graft and extracorporeal shock wave therapy, and absence of both autogenous cancellous bone graft and extracorporeal shock wave therapy using densitometry. METHODS: Dogs that were presented for surgical repair of a cranial cruciate ligament rupture were randomly assigned to one of four groups: TTA with autogenous cancellous bone graft (TTA-G), TTA with autogenous cancellous bone graft and extracorporeal shock wave therapy (TTA-GS), TTA with extracorporeal shock wave therapy (TTA-S), and TTA with no additional therapy (TTA-O). Mediolateral radiographs at zero, four and eight weeks after surgery were evaluated to compare healing of the osteotomy gap via densitometry. An analysis of variance was used to compare the densitometric values between groups. RESULTS: At four weeks after surgery, a significant difference in osteotomy gap density was noted between TTA-GS (8.4 millimetres of aluminium equivalent [mmAleq]) and TTA-S (6.1 mmAleq), and between TTA-GS (8.4 mmAleq) and TTA-O (6.4 mmAleq). There were no significant differences noted between any groups at the eight week re-evaluation. CLINICAL SIGNIFICANCE: There were no significant differences in the osteotomy gap density at eight weeks after surgery regardless of the treatment modality used. The combination of autogenous cancellous bone graft and extracorporeal shock wave therapy may lead to increased radiographic density of the osteotomy gap in the first four weeks after surgery. Densitometry using an aluminium step wedge is a feasible method for comparison of bone density after TTA in dogs.

The effect of enalapril on furosemide-activated renin-angiotensin-aldosterone system in healthy dogs.

Studies in our laboratory have revealed that furosemide-induced RAAS activation, evaluated via the urine aldosterone-to-creatinine ratio (UAldo:C), was not attenuated by the coadministration of benazepril, while enalapril successfully suppressed amlodipine-induced urinary aldosterone excretion. This study was designed to evaluate the efficacy of enalapril in suppressing ACE activity and furosemide-induced circulating RAAS activation. Failure to do so would suggest that this failure may be a drug class effect. We hypothesized that enalapril would suppress ACE activity and furosemide-induced circulating RAAS activation. Sixteen healthy hound dogs. The effect of furosemide (2 mg/kg PO, q12 h; Group F) and furosemide plus enalapril (0.5 mg/kg PO, q12 h; Group FE) on circulating RAAS was determined by plasma ACE activity, 4-6 h post-treatment, and urinary A:C on days -1, -2, 1, 4, and 7. There was a significant increase in the average urine aldosterone-to-creatinine ratio (UAldo:C) after administration of furosemide (P < 0.05). Enalapril inhibited ACE activity (P < 0.0001) but did not significantly reduce aldosterone excretion. A significant (P < 0.05) increase in the UAldo:C was maintained for the 7 days of the study in both groups. Enalapril decreased plasma ACE activity; however, it did not suppress furosemide-induced RAAS activation, as determined by the UAldo:C. While enalapril blunts ACE activity, the absence of circulating RAAS suppression may be due to angiotensin II reactivation, alternative RAAS pathways, and furosemide overriding concurrent ACE inhibition, all indicating the existence of aldosterone breakthrough (ABT). Along with similar findings with benazepril, it appears that failure to suppress aldosterone suppression with furosemide stimulation may be a drug class effect. The discrepancy between the current data and the documented benefits of enalapril likely reflects the efficacy of this ACE inhibitor in suppressing tissue RAAS, variable population responsiveness to ACE-inhibition, and/or providing additional survival benefits, possibly through as yet unknown mechanisms.

Aldosterone breakthrough with benazepril in furosemide-activated renin-angiotensin-aldosterone system in normal dogs.

Pilot studies in our laboratory revealed that furosemide-induced renin-angiotensin-aldosterone system (RAAS) activation was not attenuated by the subsequent co-administration of benazepril. This study was designed to evaluate the effect of benazepril on angiotensin-converting enzyme (ACE) activity and furosemide-induced circulating RAAS activation. Our hypothesis was that benazepril suppression of ACE activity would not suppress furosemide-induced circulating RAAS activation, indicated by urinary aldosterone concentration. Ten healthy hound dogs were used in this study. The effect of furosemide (2 mg/kg p.o., q12h; Group F; n = 5) and furosemide plus benazepril (1 mg/kg p.o., q24h; Group FB; n = 5) on circulating RAAS was determined by plasma ACE activity, 4-6 h posttreatment, and urinary aldosterone to creatinine ratio (UAldo:C) on days -1, -2, 1, 3, and 7. There was a significant increase in the average UAldo:C (µg/g) after the administration of furosemide (Group F baseline [average of days -1 and -2] UAldo:C = 0.41, SD 0.15; day 1 UAldo:C = 1.1, SD 0.56; day 3 UAldo:C = 0.85, SD 0.50; day 7 UAldo:C = 1.1, SD 0.80, P < 0.05). Benazepril suppressed ACE activity (U/L) in Group FB (Group FB baseline ACE = 16.4, SD 4.2; day 1 ACE = 3.5, SD 1.4; day 3 ACE = 1.6, SD 1.3; day 7 ACE = 1.4, SD 1.4, P < 0.05) but did not significantly reduce aldosterone excretion (Group FB baseline UAldo:C = 0.35, SD 0.16; day 1 UAldo:C = 0.79, SD 0.39; day 3 UAldo:C 0.92, SD 0.48, day 7 UAldo:C = 0.99, SD 0.48, P < 0.05). Benazepril decreased plasma ACE activity but did not prevent furosemide-induced RAAS activation, indicating aldosterone breakthrough (escape). This is particularly noteworthy in that breakthrough is observed at the time of initiation of RAAS suppression, as opposed to developing after months of therapy.

Longitudinal prevalence of hypertension, proteinuria, and retinopathy in dogs with spontaneous diabetes mellitus.

BACKGROUND: The prevalence and progression of vascular complications of spontaneous diabetes mellitus (DM) in dogs have not been described. OBJECTIVES: To investigate the effects of duration of disease, as estimated by time since DM diagnosis, and glycemic control on prevalence of systemic hypertension, proteinuria, and diabetic retinopathy in dogs with spontaneous DM. ANIMALS: Seventeen client-owned dogs with spontaneous DM. METHODS: Prospective, longitudinal observational study. Dogs with DM of less than 1 year's duration were recruited and evaluated once every 6 months for 24 months. Recorded measures included indirect BP, urine albumin, protein and creatinine concentrations, serial blood glucose and serum fructosamine concentrations, ophthalmic examination, and a standardized behavioral questionnaire. RESULTS: Eleven dogs completed the 2-year follow-up period, during which the highest recorded prevalence of systolic and diastolic hypertension was 55 and 64%, respectively. Prevalence of microalbuminuria and elevated urine protein:creatinine ratio (UPC) ranged up to 73 and 55%, respectively. Prevalence of retinopathy ranged up to 20%. No significant effect of time since DM diagnosis or glycemic control was detected for any of the measures examined. Additionally, no significant associations between BP, urine albumin concentration, UPC and retinopathy were detected. CONCLUSIONS AND CLINICAL RELEVANCE: With the exception of proteinuria, which was substantial in some cases, clinically deleterious diabetic vascular complications were not identified in dogs in this study.

Intramedullary spinal cord neoplasia in 53 dogs (1990-2010): distribution, clinicopathologic characteristics, and clinical behavior.

BACKGROUND: Intramedullary neoplasms of the canine spinal cord are infrequently reported. OBJECTIVE: To describe distribution, clinicopathologic characteristics, radiographic findings, and clinical features of canine intramedullary spinal tumors. METHODS: Retrospective series of histologically confirmed canine intramedullary spinal tumors. Contingency tables were generated for categorical variables (breed, sex, treatment, pain, chief complaint, localization, histology, imaging, and site). Associations were assessed by Fisher's exact, Wilcoxon rank sum test, t-test, and one-way ANOVA. RESULTS: Intramedullary spinal cord tumors comprised 16% (53/331) of all tumors of the spinal cord. Primary tumors were diagnosed in 66% (35/53) of cases, with neuroepithelial-origin tumors comprising 51% (18/35) of all primary neoplasms. Intraparenchymal metastases of transitional cell carcinoma and hemangiosarcoma accounted for 66% (6/18 each) of all secondary tumors. Primary tumors were more likely to affect younger dogs. Dogs with intramedullary metastases were most commonly presented for primary myelopathic signs (8/18, 44%). The majority of all tumors (52.8%) occurred in the T3-L3 spinal cord segments. All dogs with cervical neurolocalization had primary tumors. Dogs with metastatic lesions had a shorter duration of clinical signs before presentation, but there was no difference in survival time between dogs with primary as compared with secondary tumors. CONCLUSIONS: Intramedullary spinal cord tumors are uncommon. Primary intramedullary spinal cord tumors are more common than secondary intramedullary spinal cord tumors and tend to occur in the cervical spinal cord of younger dogs. Intramedullary metastases occur in older dogs, are rarely asymptomatic, and neurologic dysfunction is a common clinical presentation. Dogs with primary tumors may have a protracted clinical course compared with those with intramedullary metastases.

The effects of a novel lateral extracapsular suture system on the kinematics of the cranial cruciate deficient canine stifle.

OBJECTIVE: To evaluate the relative position of the femur and tibia in cranial cruciate ligament-intact stifles, cranial cruciate ligament-deficient stifles, and cruciate-deficient stifles following lateral extracapsular suture system (LESS) stabilization under load at specific joint angles. STUDY DESIGN: In vitro biomechanical study. METHODS: Twenty pelvic limbs from 11 dogs were used to evaluate the relative position of the femur and tibia between three stifle conditions (cranial cruciate ligament-intact, cranial cruciate ligament-deficient, and LESS-stabilized) at a load of 30% of body weight and stifle angles of 125°, 135°, and 145° using electromagnetic tracking sensors. RESULTS: Cranial cruciate ligament-deficient stifles had significantly greater (p <0.0001) cranial displacement and internal rotation of the tibia relative to the femur than cranial cruciate ligament-intact or LESS stifles at all stifle angles. Cranial displacement of the tibia relative to the femur for cranial cruciate ligament-intact and LESS stifles were not significantly different from one another at a stifle angle of 125°, but were significantly different at stifle angles of 135° (p = 0.0182) and 145° (p = 0.0012). There was no significant difference in internal rotation of the tibia relative to the femur between the cranial cruciate ligament-intact and LESS stifles at any of the stifle angles. CLINICAL SIGNIFICANCE: The LESS procedure effectively decreased cranial tibial displacement and eliminated internal rotation of the tibia relative to the femur in the cranial cruciate ligament-deficient stifles at stifle angles of 125°, 135°, and 145° in vitro.

Ultrasonographic findings of the pancreas in cats with elevated serum pancreatic lipase immunoreactivity.

BACKGROUND: Pancreatitis is a common disease in cats that is difficult to diagnose. HYPOTHESIS/OBJECTIVES: To determine the sensitivity and specificity of ultrasonographic changes of the pancreas with serum feline pancreatic lipase immunoreactivity (fPLI) as the standard for diagnosis of pancreatitis. ANIMALS: 35 cats with clinical signs consistent with pancreatitis with an abdominal ultrasound examination and serum fPLI concentration measured within 3 days of the ultrasound. METHODS: Retrospective study: Pancreatic thickness, pancreatic margination, pancreatic echogenicity, and peripancreatic fat echogenicity were evaluated. Sensitivity and specificity were calculated with an elevated serum fPLI concentration indicative of pancreatitis as the standard for diagnosis. RESULTS: Serum fPLI was elevated and diagnostic for pancreatitis in 19 of 35 cats. The single ultrasound characteristic with the highest sensitivity was hyperechoic peripancreatic fat at 68% (95% confidence interval = 44-87%), indicating a moderate probability that cats with pancreatitis will have this abnormality on ultrasonographic examination. Specificity was >90% for each of increased pancreatic thickness, abnormal pancreatic margin, and hyperechoic peripancreatic fat. The sensitivity and specificity of ultrasound were 84% (95% confidence interval = 60-97%) and 75% (95% confidence interval = 48-93%), respectively, in cats with elevated serum fPLI indicative of pancreatitis. CONCLUSIONS AND CLINICAL IMPORTANCE: The presence of a thick left limb of the pancreas, severely irregular pancreatic margins, and hyperechoic peripancreatic fat in cats with appropriate clinical signs and elevated serum fPLI are highly supportive of pancreatitis.

A comparison of hepatic sonographic features and histopathologic diagnosis in canine liver disease: 138 cases.

BACKGROUND: Ultrasound examination is commonly used in the diagnostic evaluation of liver disease in dogs. HYPOTHESIS/OBJECTIVES: To determine if hepatic sonographic features were predictive of findings on liver histopathology. We hypothesized that there would be a relationship between sonographic features and the category of liver disease based on histologic assessment. ANIMALS: One hundred and thirty-eight dogs in which the liver was evaluated by both abdominal ultrasound examination and histopathologic examination. Twenty-five dogs were included in each of the following categories based on histopathology: normal, degenerative, vascular, inflammatory, and neoplasia. Thirteen dogs had nodular regeneration. METHODS: Retrospective study. Medical records of dogs from 2005 to 2010 were searched for cases in which the liver was evaluated by abdominal ultrasound examination as well as by histopathology. After independent evaluation of ultrasound images, the recorded sonographic features were analyzed to identify abnormalities associated with each histopathologic diagnosis or degree of fibrosis. RESULTS: Sixty-four percent of sonographically unremarkable livers had histologic abnormalities. Both microhepatia and the identification of abnormal vasculature were significantly associated with a histopathologic diagnosis of vascular disease. Hepatic masses were significantly associated with a diagnosis of neoplasia. Dilated common bile duct and thickened gall bladder wall were significantly associated with hepatitis. There were no sonographic findings consistently present with hepatic fibrosis. CONCLUSION AND CLINICAL IMPORTANCE: Although some ultrasonographic findings, including masses, microhepatia, anomalous veins, and biliary changes, are associated with specific histopathologic abnormalities, sonographic findings are inconsistently detected in many disorders. Overall, hepatic ultrasonographic abnormalities have substantial limitations in predicting the underlying disease.

Effect of tibial insertion site for lateral suture stabilization on the kinematics of the cranial cruciate ligament deficient-stifle during early, middle and late stance: an in vitro study.

OBJECTIVE: To evaluate the effect of two tibial attachment sites for lateral suture stabilization (LSS) on the three-dimensional femorotibial translational and rotational movements of the cranial cruciate ligament- deficient canine stifle during the early, middle and late stance phases. STUDY DESIGN: In vitro biomechanical study: 32 hindlimbs from 16 canine cadavers. METHODS: Limbs were mounted in a testing jig and an electromagnetic tracking system was used to determine the three-dimensional femorotibial translational and rotational movements under 33% of body weight load during early, middle and late stance in the following sequence: cranial cruciate ligament-intact, cranial cruciate ligament-deficient and LSS with the distal anchor through the tibial tuberosity (LSSTT) or through the cranial eminence of the extensor groove (LSSEG). The proximal anchor point was the lateral femorofabellar ligament. RESULTS: Post-LSS stifle three-dimensional femorotibial translational and rotational movements were more comparable to normal than post-transection movements for both techniques. Both LSS techniques restored femorotibial movements in cranial cruciate ligament-deficient stifles to varying amounts but neither technique successfully restored normal three-dimensional femorotibial movements. The LSSEG improved femorotibial movements of the cranial cruciate ligament-deficient stifle in the medial-lateral direction and axial rotation but performed poorly in restoring femorotibial movements in the cranial-caudal direction as compared to the LSSTT. CLINICAL SIGNIFICANCE: Both the LSSTT and LSSEG techniques failed to completely restore normal three-dimensional femorotibial translational and rotational movements in cranial cruciate ligament-deficient stifles in vitro.

Diagnostic utility of abdominal ultrasonography in dogs with chronic diarrhea.

BACKGROUND: Chronic diarrhea is common in dogs and has many causes. Ultrasonographic descriptions of many gastrointestinal diseases have been published, but the diagnostic utility of ultrasonography in dogs with chronic diarrhea has not been investigated. HYPOTHESIS: Diagnostic utility of abdominal ultrasound will be highest in dogs with GI neoplasia and lowest in those with inflammatory disorders. ANIMALS: 87 pet dogs with chronic diarrhea. METHODS: Prospective study in which medical records were reviewed and contribution of abdominal ultrasound toward making diagnosis was scored. RESULTS: In 57/87 (66%) of dogs, the same diagnosis would have been reached without ultrasonography. In 13/87 (15%) of dogs, the ultrasound examination was vital or beneficial to making the diagnosis. Univariable analysis identified that increased diagnostic utility was associated with weight loss (P = .0086), palpation of an abdominal or rectal mass (P = .0031), diseases that commonly have mass lesions visible on ultrasound examination (P < .0001), and a final diagnosis of GI neoplasia. Multivariable regression indicated that utility of abdominal ultrasonography would be 30 times more likely to be high in dogs in which an abdominal or rectal mass was palpated (odds ratio 30.5, 95% CI 5.5-169.6) (P < .0001) versus dogs without a palpable mass. In 15/87 (17%) of dogs, additional benefits of ultrasonography to case management, independent of the contribution to the diagnosis of diarrhea, were identified. CONCLUSIONS AND CLINICAL IMPORTANCE: Overall, the diagnostic utility of abdominal ultrasonography was low in dogs with chronic diarrhea. Identification of factors associated with high diagnostic utility is an indication to perform abdominal ultrasonography in dogs with chronic diarrhea.

Reproductive effects of prolonged experimentally induced hypothyroidism in bitches.

BACKGROUND: Hypothyroidism has detrimental effects on reproduction in females of many species. Studies of hypothyroidism in bitches are limited and results conflicting. HYPOTHESIS: Hypothyroidism interferes with reproductive function and health of offspring in bitches. ANIMALS: A total of 9 healthy mixed-breed bitches (control) and 9 mixed breed bitches with hypothyroidism induced by radioactive iodine administration. METHODS: Dogs in both groups were bred 20.9 ± 4.0 and 56 ± 7.6 weeks after radioiodine administration in the hypothyroid group and again after levothyroxine was administered for 37 ± 14 weeks to hypothyroid dogs. Measures of the estrus cycle, fertility, gestation, whelping, and pup health were evaluated at each breeding. Comparisons were made between hypothyroid and control dogs as well as within groups between times. RESULTS: Pregnancy was documented in all dogs in both groups at the 1st breeding, 4/8 and 6/6 untreated hypothyroid and control dogs, respectively, at the 2nd breeding, and 6/6 and 5/6 treated hypothyroid and control dogs, respectively, at the 3rd breeding. Periparturient mortality was higher and birth weight was lower in pups born to untreated hypothyroid dogs compared with control dogs or treated hypothyroid dogs. There was no difference in interestrus interval, gestation duration, breeding behavior, interval between birth of pups, or serum progesterone concentrations at any breeding between or within groups. Resolution of hypothyroidism reversed the detrimental effects of thyroid hormone deficiency on reproduction. CONCLUSIONS AND CLINICAL IMPORTANCE: Hypothyroidism causes reversible periparturient mortality and low birth weight in offspring. Further investigation is necessary to determine if fertility is affected.

Effects of high and moderate non-structural carbohydrate hay on insulin, glucose, triglyceride, and leptin concentrations in overweight Arabian geldings.

The objective of this study was to determine the effects of high and moderate non-structural carbohydrates (NSC) hay on insulin, glucose, triglyceride, and leptin concentrations in overweight Arabian geldings. Eight adult overweight (average BCS 7 [9-point scale]) Arabian geldings were fed each of two orchardgrass hays, high NSC (18% DM) and moderate NSC (12% DM), in a cross over design during two 28-day periods. Body weight and body condition score assessment along with blood sampling to measure insulin, glucose, leptin, and triglyceride concentrations were performed on days 0, 7, 14, 21 and 28 of each period. Effects of hay, period, day, and day*hay on plasma glucose and serum leptin were not detected. Serum insulin was influenced by hay (p = 0.001), day (p = 0.03), and day*hay (p = 0.04). Insulin concentrations were higher on day 7 in the high NSC group (15.6 µIU/ml) than the moderate NSC group (9.5 µIU/ml), but not by day 14 (p = 0.0007). Plasma triglyceride was influenced by period (p = 0.0003), day*period (p < 0.0001), and day*hay (p = 0.02). Hyperinsulinaemia was not observed in the overweight Arabian geldings fed either a moderate or high NSC hay.

Implications of urine F2-isoprostane metabolite concentration in horses with colic and its potential use as a predictor for surgical intervention.

REASONS FOR PERFORMING STUDY: F2-isoprostanes have been used extensively to quantify lipid peroxidation in association with risk factors in various diseases. Horses with colic may have intestinal ischaemia and/or inflammation characterised by oxidative stress and increased production of isoprostanes. OBJECTIVES: To gather preliminary data regarding the feasibility of using urine F2-isoprostanes and isoprostane metabolites as early screening tools for the presence of gastrointestinal disease requiring surgical intervention in horses and ultimately develop a stall-side test capable of identifying these horses as early as possible for timely referral. METHODS: Concentrations of urine isoprostane and isoprostane metabolite were determined by mass spectroscopy and normalised to urine creatinine (Cr) concentrations in urine samples from 42 healthy control horses and 43 horses with gastrointestinal pain or colic. RESULTS: Horses with colic were treated medically (n = 21) or surgically (n = 22). Mean ± s.d. concentrations of urine isoprostane and isoprostane metabolite were significantly higher in horses with colic (2.94 ± 1.69 and 0.31 ± 0.22 ng/mg Cr, respectively), compared to control horses (1.89 ± 1.39 and 0.22 ± 0.08 ng/mg Cr, respectively). Mean urine isoprostane metabolite concentrations were significantly higher in horses undergoing surgery (0.38 ± 0.28 ng/mg Cr) compared to controls and medical colics (0.26 ± 0.11 ng/mg Cr). Nonsurvivors had significantly higher mean urine isoprostane metabolite concentrations (0.47 ± 0.39 ng/mg Cr) than control or surviving colic horses (0.29 ± 0.24 ng/mg Cr). CONCLUSIONS: Measurement of urine isoprostane metabolite concentration may be a useful prognostic indicator in equine colic. POTENTIAL RELEVANCE: Urine isoprostane metabolites may aid in early recognition of surgical colic. Isoprostanes are a potential therapeutic target to prevent further systemic and gastrointestinal tissue injury in horses with colic.

Effect of stifle angle on the magnitude of the tibial plateau angle measurement in dogs with intact and transected cranial cruciate ligament. A cadaveric study.

OBJECTIVE: To determine the effect of stifle angle on the magnitude of the radiographic tibial plateau angle (TPA) in normal and cranial cruciate ligament (CCL) -deficient stifles. METHODS: Three pairs of canine cadaver hindlimbs from three skeletally mature dogs were positioned in a custom-made positioning device. A lateral radiograph of each specimen was obtained before and after transection of the CCL at four stifle angles (90°, 110°, 135° and 140-150° [i.e. maximum extension]), based on goniometric measurements. Four observers determined the radiographic TPA twice for each radiograph with a minimum of two days between each measurement. The radiographic TPA measurements in all specimens at different stifle angles with intact CCL and transected CCL were compared with mixed-model ANOVA. The effect of stifle angle, CCL transection, and interaction between the two on observer TPA measurement variability was also determined using the coefficient of variation. RESULTS: Tibial plateau angle was not statistically different in the stifle angles for either the intact or transected CCL. There was also no statistical difference for TPA between intact and transected CCL groups at each of the stifle angles. Stifle angle, CCL transection and interaction between the two did not have any significant effect for intra-observer and inter-observer variation. CLINICAL SIGNIFICANCE: The angle of the stifle during radiography does not influence the magnitude of the TPA measurement as determined on true lateral radiographs of the stifle and tibia in cadaveric canine limbs.