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.

OBJECTIVE To evaluate the effects of 3 electrolyte solutions administered SC to experimentally dehydrated inland bearded dragons (Pogona vitticeps). ANIMALS 9 inland bearded dragons. PROCEDURES In a randomized, complete crossover study, experimental dehydration was induced by means of furosemide (10 mg/kg, SC, q 12 h for 4 doses), and then lactated Ringer solution, Plasma-Lyte A, or reptile Ringer solution (RRS; 1:1 mixture of 5% dextrose solution and isotonic crystalloid solution) was administered SC in a single 50-mL/kg dose in 3 treatments sessions separated by a minimum of 14 days. Food and water were withheld during treatment sessions. Plasma biochemical values, PCV, blood total solids and lactate concentrations, and plasma osmolarity were measured prior to (baseline) and 4 and 24 hours after fluid administration. RESULTS Administration of RRS resulted in severe hyperglycemia (mean ± SD plasma glucose concentration, 420 ± 62 mg/dL), compared with baseline values (190 ± 32 mg/dL), and this hyperglycemia persisted for at least 24 hours. It also resulted in significant reductions in plasma osmolarity and sodium and phosphorus concentrations, which were not observed after administration of the other 2 solutions. Administration of lactated Ringer solution caused no significant increase in blood lactate concentration. CONCLUSIONS AND CLINICAL RELEVANCE The changes in plasma glucose, sodium, and phosphorus concentrations and plasma osmolarity observed after SC administration of a single dose of RRS suggested this type of electrolyte solution should not be used for rehydration of bearded dragons. Rather, lactated Ringer solution or Plasma-Lyte A should be considered instead.

OBJECTIVE: To assess the analgesic efficacy of an IV constant rate infusion (CRI) of a morphine-lidocaine-ketamine (MLK) combination in calves undergoing umbilical herniorrhaphy. ANIMALS: 20 weaned Holstein calves with umbilical hernias. PROCEDURES: Calves were randomly assigned to receive a CRI of an MLK solution (0.11 mL/kg/h; morphine, 4.8 μg/kg/h; lidocaine, 2.1 mg/kg/h; and ketamine, 0.42 mg/kg/h) for 24 hours (MLK group) or 2 doses of flunixin meglumine (1.1 mg/kg, IV, q 24 h) and a CRI of saline (0.9% NaCl) solution (0.11 mL/kg/h) for 24 hours (control group). The assigned CRI was begun after anesthesia induction. A pain-scoring system and incisional algometry were used to assess pain, and blood samples were obtained to measure serum cortisol concentration at predetermined times for 120 hours after CRI initiation. RESULTS: Mean pain scores did not differ significantly between the MLK and control groups at any time. Mean algometry score for the MLK group was significantly greater (calves were less responsive to pressure) than that for the control group at 4 hours after CRI initiation. Mean cortisol concentration decreased over time for both groups and was significantly greater for the MLK group than the control group at 1, 4, and 18 hours after CRI initiation. CONCLUSIONS AND CLINICAL RELEVANCE: A CRI of MLK provided adequate postoperative analgesia to calves that underwent umbilical herniorrhaphy. However, the technical support required for CRI administration limits its use to hospital settings. Kinetic analyses of MLK infusions in cattle are necessary to establish optimal dosing protocols and withdrawal intervals.

The present study describes the serum biochemical alterations and histopathological abnormalities in the liver tissue of dogs with liver disease. A survey of hepatic lesions was conducted using ultrasound-guided percutaneous needle biopsies. The hematologic and biochemical changes in dogs with liver lesions were recorded. Chronic hepatitis was the most common liver histopathologic finding (37.9%). Other common findings included liver fibrosis (19.5%), vacuolar hepatopathy (10.3%), cholangiohepatitis (9.2%), hepatocellular carcinoma (4.6%), cholangitis (3.4%), cholangiocarcinoma (2.3%), and congestive hepatopathy (2.3%). Greater than 2-fold elevation of serum alanine aminotransferase (ALT) was a useful indicator, with a sensitivity of 40% to 65% for diagnosing all liver pathologies. Greater than 2-fold elevation of serum alkaline phosphatase (ALP) without significant elevation of ALT was useful for diagnosing liver diseases affected by inflammatory or regressive changes (sensitivity of 40% to 50%). Elevation of ALT, ALP, or a combination of ALT and ALP had a high sensitivity of up to 90% for identifying dogs with liver pathology. Hepatic injury and cholestasis enzymes should be interpreted together with patient history, clinical signs, and liver ultrasonographic appearance before performing a liver biopsy.

OBJECTIVE To determine whether jejunal serosal patches could securely seal large, open defects in duodenal segments harvested from canine cadavers and to compare intraluminal pressures at which leakage first occurred and maximal intraluminal pressures for repaired duodenal segments between 2 suture patterns. SAMPLE Duodenal and jejunal segments from 9 canine cadavers. PROCEDURES 20 constructs were created through repair of large, open duodenal defects with circumferential suturing of an intact jejunal segment (jejunal serosal patch). Constructs were randomly assigned to have the serosal patch anastomosed to the duodenal segment by a simple continuous or simple interrupted suture pattern. The pressure at which the first leakage was observed and the maximum pressure obtained during testing were recorded and compared between suture patterns. RESULTS Initial leakage pressure was significantly higher with the simple interrupted pattern (mean ± SD, 68.89 ± 5.62 mm Hg), compared with the simple continuous pattern (59.8 ± 20.03 mm Hg). Maximum intraluminal pressures did not significantly differ between the simple interrupted (91 ± 8.27 mm Hg) and simple continuous patterns (90.7 ± 16.91 mm Hg). All constructs, regardless of suture pattern, withstood supraphysiologic pressures. CONCLUSIONS AND CLINICAL RELEVANCE Jejunal serosal patches adequately sealed large, open duodenal defects and prevented leakage in these constructs. Constructs with simple continuous or simple interrupted suture patterns withstood physiologic and supraphysiologic intraluminal pressures, although constructs with a simple interrupted suture pattern initially leaked at higher pressures.

OBJECTIVE To establish a method for evaluation of the efficacy of a classical swine fever virus (CSFV) subunit vaccine in rabbits as determined via humoral immune responses to the virus. ANIMALS 40 specific pathogen–free rabbits. PROCEDURES Rabbits were randomly assigned to 4 groups (10 rabbits/group) for SC injection of 0.05, 0.1, and 0.2 mL of a CSFV subunit E2 vaccine (representing 1.15, 2.3, or 4.6 μg of E2 protein/dose, respectively) or saline (0.9% NaCl) solution. Blood samples were collected 21 days after vaccination for measurement of the antibody response against CSFV via ELISA and virus neutralization methods. On the same day, the CSFV Chinese (C) strain was injected into an ear vein. Vaccine efficacy was determined by monitoring of rabbits for pyrexia for 4 days and measurement of viral copies in spleen lysates at the end of the study. Reproducibility of the antibody response was tested with 2 other batches of the vaccine at the minimum immunization dose identified for the initially tested batch. RESULTS The E2 protein dose of the initially tested vaccine was positively correlated with the antibody response and protection rate in rabbits. The identified minimum immunization dose per rabbit was 0.1 mL, representing an E2 protein content of approximately 2.3 μg, and reproducibility of the antibody response to vaccination with the 2 other batches at this dose was good. CONCLUSIONS AND CLINICAL RELEVANCE A method was established in rabbits for evaluation of the efficacy of a CSFV subunit vaccine that could help in the optimization of later large-scale vaccine production and quality control processes as well as in the clinical application of the vaccine.

OBJECTIVE To determine the pharmacokinetics of danofloxacin following IM administration of a single dose (10 mg/kg) in koi (Cyprinus carpio). ANIMALS 69 healthy adult koi housed in a 980-L flow-through-system tank. PROCEDURES 3 fish were kept as untreated controls, and the remaining 66 fish were assigned to 11 treatment groups with 6 fish/group. Fish in the treatment groups were given a single dose of danofloxacin (10 mg/kg) IM in the left epaxial musculature. Fifteen, 30, and 45 minutes and 1, 4, 12, 24, 72, 96, 120, and 144 hours after administration of danofloxacin, fish in each treatment group were euthanized, and blood samples and samples of liver, spleen, gill, anterior kidney, posterior kidney, skin and muscle, and scales were collected. Plasma and tissue drug concentrations were determined by liquid chromatography–tandem mass spectrometry, and noncompartmental pharmacokinetic analyses were performed. Tissues from the untreated control fish and fish euthanized 144 hours after danofloxacin administration were examined histologically. RESULTS Maximum plasma concentration (mean, 8,315.7 ng/mL) was reached approximately 45 minutes after danofloxacin administration; plasma elimination half-life was 15 hours. Danofloxacin was detected in all examined tissues from all 6 fish euthanized 15 minutes after drug administration and was detected in some tissues from 3 of the 6 fish euthanized 144 hours after drug administration. For all tissues, results of histologic examination were unremarkable. CONCLUSIONS AND CLINICAL RELEVANCE IM administration of a single dose (10 mg/kg) of danofloxacin in koi resulted in rapid absorption, with maximum plasma concentration reached approximately 45 minutes after drug administration; the drug could still be detected in some tissues 144 hours after administration.