The objective of the present study was to evaluate the ability of estrogen to promote induced tibial fracture healing in a rat model. The study was conducted on 14 albino rats divided into two equal groups (seven rats in each group). The first group considered as a control group. The second group was injected estradiol solution 0.1 mg/kg into the fracture gap. The progress of healing in each group was evaluated by clinical, radiography, ultrasonography and pathological examinations. The healing process was observed to be superior in the estrogen group compared to the control one. Estrogen was found to promote healing of injured bone and is suggested to be used in cases of complicated or delayed bone fracture.

OBJECTIVE To characterize the patterns associated with Lorenz plots (LPs) or Poincaré plots derived from the Holter recordings of dogs with various cardiac rhythms. ANIMALS 77 dogs with 24-hour Holter recordings. PROCEDURES A 1-hour period from the Holter recordings from each of 20 dogs without arrhythmias and from each of 57 dogs with arrhythmias (10 each with supraventricular premature complexes, complex supraventricular ectopy, ventricular premature complexes, complex ventricular ectopy, and atrial fibrillation, and 7 with high-grade second-degree atrioventricular block) were used to generate the LPs. Patterns depicted in the LPs were described. RESULTS Arrhythmia-free Holter recordings yielded LPs with a Y-shaped pattern and variable silent zones. Recordings with single premature complexes yielded LPs with double side and triple side lobes. Complex ectopy was denoted by dots clustered in the lower left corner of the LPs. The LPs of recordings with atrial fibrillation had fan patterns consistent with a nonlinear relationship between atrial electrical impulses and atrioventricular nodal conduction. The recordings with atrioventricular block yielded LPs with island patterns consistent with variable atrioventricular nodal conduction. CONCLUSIONS AND CLINICAL RELEVANCE Distinct LP patterns were identified for common cardiac rhythms of dogs, supportive of nonrandom mechanisms as the cause of most rhythms. Visual interpretation of an LP generated from a Holter recording may aid in determining the arrhythmia type and understanding the arrhythmia's mechanism in dogs and other species.

OBJECTIVE To identify the optimal ventilation pressure for ventilated postmortem CT assessment of the lungs in cadaveric dogs and compare the optimal ventilation pressures between dogs with and without focal lung lesions. SAMPLE 12 cadaveric dogs. PROCEDURES CT was performed with dogs positioned in sternal recumbency within 30 to 180 minutes after death. After orotracheal intubation, lungs were aerated to ventilation pressures of 0, 10, 15, 20, 25, 30, and 35 cm H2O. Lung attenuation measurements were made at 5 predetermined anatomical locations with use of a multi-image analysis graphic user interface tool. Lungs were considered hyperaerated (−1000 to −901 HU), normo-aerated (−900 to −501 HU), poorly aerated (−500 to −101 HU), and nonaerated (−100 to 100 HU) on the basis of lung attenuation values. Optimal ventilation pressure was defined as the pressure at which the percentage of normo-aerated lung was greatest. For analysis, dogs were assigned to one group when focal lung lesions were evident and to another group when lesions were not evident. RESULTS Median optimal ventilation pressure was significantly higher for those dogs with lung lesions (35 cm H2O), compared with those without (25 cm H2O). CONCLUSIONS AND CLINICAL RELEVANCE A ventilation pressure of 35 cm H2O may be considered for ventilated postmortem CT to determine the presence of focal lung lesions; however, further investigation is required.

While serum amyloid A (SAA) has been investigated as a potential marker for septic arthritis in horses, no study has reported on whether SAA can be used to detect eradication of joint infection. Therefore, the objective of this study was to investigate whether the eradication of joint infection in experimentally induced septic arthritis in horses can be detected using serum and synovial fluid SAA. A total of 17 horses were randomly assigned to 3 groups. A middle carpal joint of each horse was injected with saline (control group, n = 3), lipopolysaccharide (LPS) (nonseptic synovitis group, n = 6), or Escherichia coli (septic arthritis group, n = 8) on day 0. Starting on day 1, horses underwent treatment for septic arthritis. Sequential samples of serum and synovial fluid were collected, and quantification of SAA was carried out. Concentrations of serum and synovial fluid SAA were compared among groups and time points. A concurrent study was conducted and determined that infection was eradicated on day 4 in this experimental model of septic arthritis. Concentrations of serum and synovial fluid SAA rapidly increased after inoculation of E. coli and were highest on day 3 and day 4, respectively. Thereafter, both serum and synovial fluid SAA decreased with eradication of joint infection, although they remained significantly increased from baseline until day 9 and day 10, respectively. Serum and synovial fluid SAA did not increase in the control or nonseptic synovitis group. These findings suggest that serial measurements rather than a single measurement of SAA are required to determine eradication of infection from septic arthritis in horses.

Recumbency affects respiratory mechanics and oxygenation in anesthetized horses. Changes in pleural and abdominal pressures that can impair ventilation have not been described in all recumbencies. The objective of this study was to determine the effects of patient positioning on transdiaphragmatic pressure and selected hemodynamic variables. Horses were maintained under total intravenous general anesthesia with nasal oxygen supplementation. Transnasal balloon catheters in the stomach and thoracic esophagus were used to measure intrathoracic and gastric pressures in standing horses and in anesthetized horses positioned in right and left lateral recumbency, dorsal recumbency, reverse Trendelenburg position, and Trendelenburg position. Transdiaphragmatic pressure was calculated as the difference between gastric and intrathoracic pressures. Measurements of oxygen saturation (SpO(2)), heart rate, systolic, diastolic and mean arterial pressures, and respiratory rate were obtained every 5 minutes. When compared to dorsal recumbency, gastric expiratory pressure is decreased in the standing position. Thoracic expiratory pressure is decreased in standing and reverse Trendelenburg. Transdiaphragmatic expiratory pressure and SpO(2) are decreased in Trendelenburg. Heart rate is increased in reverse Trendelenburg. Systolic, diastolic, and mean arterial pressures are decreased in reverse Trendelenburg and increased in left lateral and right lateral recumbency. We found that there is wide variation in respiratory pressures between horses and positions and they are not predictive of associated changes in hemodynamic variables.

Although hepatobiliary disease is common in cats, little is known about the bile composition in either these diseased states or in healthy cats. The objectives of this study were to evaluate several analytes from the bile of healthy cats and to investigate the usefulness of measuring these variables to predict bacterial cholangitis. Cats were prospectively enrolled and divided into 3 groups: 21 healthy cats (group 1) and 14 cats with suspected hepatobiliary disease: 9 without bacterial biliary infection (group 2) and 5 with bacterial biliary infection (group 3). Percutaneous ultrasound-guided cholecystocentesis was conducted on each cat. Bile cytology and culture were carried out and bile was analyzed for pH, lactate, and glucose levels using several point-of-care (POC) devices. Reference values for several bile analytes in healthy cats were calculated and are presented in this study. Neither the pH (P = 0.88) nor the lactate concentration (P = 0.85) was significantly different among the 3 groups. Sodium concentration was significantly higher in group 3 than in group 2 (P < 0.05). Bile pH, lactate, and glucose levels were unable to predict the presence of a bacterial infection in the bile.

Recent studies have found that anemia and anisocytosis are precipitating factors for certain heart diseases in dogs. This study evaluated the prevalence and correlation of anemia and red blood cell distribution width (RDW) in dogs with heartworm disease (HWD). The study population consisted of 20 healthy control dogs and 86 dogs with HWD: 28 dogs with no clinical signs or pulmonary hypertension (Group 1), 42 dogs with mild clinical signs but no pulmonary hypertension (Group 2), and 16 dogs with severe clinical signs and pulmonary hypertension (Group 3). Along with echocardiographic interrogation of pulmonary hypertension, red blood cell (RBC) profiles were evaluated, including RDW. The total number of red blood cells (tRBCs), hematocrit (HCT), and hemoglobin (HGB) concentration was significantly lower in Group 3 dogs compared to control dogs (P < 0.05), while the RDW was significantly higher in Group 3 dogs than in control dogs (P < 0.05). The RDW was closely correlated to other RBC profiles and the presence of pulmonary hypertension (P < 0.05). The severity of tricuspid regurgitant gradient (TRG) was closely correlated with Hb and tRBC (P < 0.05), but not with the RDW and reticulocyte count. This study finding indicated that anemia and anisocytosis are common complications in dogs with severe clinical signs and pulmonary hypertension caused by heartworm disease (HWD). It would therefore be beneficial for clinicians to routinely check red blood cell (RBC) profiles, including RDW, in order to monitor the progression of heartworm disease in dogs.

OBJECTIVE To determine the efficacy and duration of effect for liposomal bupivacaine following perineural administration to the medial and lateral palmar digital nerves of horses. ANIMALS 9 nonlame mares. PROCEDURES For each horse, 2 mL of liposomal bupivacaine (13.3 mg/mL; total dose, 53.2 mg or approx 0.11 mg/kg) or sterile saline (0.9% NaCl) solution was injected adjacent to the medial and lateral palmar digital nerves at the level of the distal aspect of the proximal sesamoid bones of a randomly selected forelimb. Twenty-one days later, the opposite treatment was administered in the contralateral forelimb. A digital algometer was used to measure the mechanical nociceptive threshold (MNT) immediately before and at predetermined times for 48 hours after injection of each treatment. The mean MNT was compared between the 2 treatments at each measurement time. RESULTS The mean MNT for the liposomal bupivacaine-treated limbs was significantly greater (ie, the limb was less sensitive) than that for the saline-treated limbs between 30 minutes and 4 hours after treatment injection. Following liposomal bupivacaine administration, 1 horse developed mild swelling at the injection sites that resolved without treatment within 24 hours. No other adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that liposomal bupivacaine is another option for perineural anesthesia in horses. Further research is necessary to determine the optimal dose and better elucidate the duration of effect for the drug when used for palmar digital nerve blocks in horses.

The objectives of this study were to describe the in vitro antimicrobial susceptibility and clinical significance of Proteus mirabilis in canine bacteriuria and to identify the risk factors associated with P. mirabilis urinary tract infections. This is a retrospective observational study of 48 P. mirabilis-positive canine urinary cultures. Only 22 of the 48 P. mirabilis isolates (45.8%) were non-susceptible to at least one tested antimicrobial. Most P. mirabilis isolates (98%) were susceptible to enrofloxacin, 93.7% to amoxicillin/clavulanic acid, and 85.4% to ampicillin, cephalothin, and trimethoprim-sulfamethoxazole. Five multidrug-resistant isolates were detected (10.4%). A significant increase in antimicrobial resistance was observed over the study period. Positive P. mirabilis cultures were associated with bacterial cystitis in 36 of 39 dogs (92.3%), pyelonephritis in 2 of 39 dogs (5.1%), and one dog had both bacterial cystitis and pyelonephritis (2.5%). There was no subclinical bacteriuria. Most urinary tract infections were complicated as risk factors were identified in 37 of 39 dogs (94.8%). The most commonly identified risk factors were the presence of a contaminated peri-vulvar area with urine/feces or a hypoplastic vulva. To conclude, P. mirabilis bacteriuria was associated with upper and lower urinary tract infections in this study and was found more frequently in complicated bacterial cystitis. Multidrug-resistant isolates and increased P. mirabilis antimicrobial resistance have been identified over the last 10 years, but most isolates remain susceptible to first-line antimicrobials such as amoxicillin and trimethoprim-sulfamethoxazole.

Immunohistochemistry has been used extensively to evaluate protein expression in clinical and research settings. However, immunohistochemistry is not always successful in veterinary medicine due to the lack of reliable antibody options, poor tissue preservation, labor-intensive staining, and antigen-retrieval optimization processes. RNAscope in-situ hybridization (ISH) is a powerful technology that uses a specific sequence probe to identify targeted mRNA. In this study, we demonstrate RNAscope ISH in 4 common canine malignancies, which are traditionally diagnosed by histopathology and immunohistochemistry. Probes were designed for commonly targeted mRNA markers of neoplastic tumors; these included c-kit in mast cell tumor, microphthalmia-associated transcription factor in malignant melanoma, ionized calcium-binding adapter molecule(-1) in histiocytic sarcoma, and alkaline phosphatase in osteosarcoma. A strong staining signal was obtained by these 4 targets in each canine malignancy. These results support the use of RNAscope ISH for definitive diagnosis in canine malignancies.