OBJECTIVE To evaluate the plasma disposition of mycophenolic acid (MPA) and its derivatives MPA glucuronide and MPA glucoside after twice-daily infusions of mycophenolate mofetil (MMF) in healthy cats for 3 days and to assess the effect of MMF administration on peripheral blood mononuclear cell (PBMC) counts and CD4+-to-CD8+ ratios. ANIMALS 5 healthy adult cats. PROCEDURES MMF was administered to each cat (10 mg/kg, IV, q 12 h for 3 days). Each dose of MMF was diluted with 5% dextrose in water and then administered over a 2-hour period with a syringe pump. Blood samples were collected for analysis. A chromatographic method was used to quantitate concentrations of MPA and its metabolites. Effects of MMF on PBMC counts and CD4+-to-CD8+ ratios were assessed by use of flow cytometry. RESULTS All cats biotransformed MMF into MPA. The MPA area under the plasma concentration–time curve from 0 to 14 hours ranged from 14.6 to 37.6 mg·h/L and from 14.4 to 22.3 mg·h/L after the first and last infusion, respectively. Total number of PBMCs was reduced in 4 of 5 cats (mean ± SD reduction, 25.9 ± 15.8% and 26.7 ± 19.3%) at 24 and 48 hours after the end of the first infusion of MMF, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Plasma disposition of MPA after twice-daily IV infusions for 3 days was variable in all cats. There were no remarkable changes in PBMC counts and CD4+-to-CD8+ ratios.

OBJECTIVE To investigate the effects of respiratory phase, body position, beam center location, and gastric distention on radiographic assessment of liver size in dogs. ANIMALS 12 Beagles. PROCEDURES Liver length and the ratio of liver length to T11 length were determined on lateral radiographic views obtained with various techniques. Images were acquired at maximal expiration or maximal inspiration, with dogs in right or left recumbency, with the beam centered on the caudal border of the scapula or the 13th rib, and after food was withheld or with gastric distention. Effects on organs adjacent to the liver were assessed with CT. Changes of the thoracic cavity during the respiratory cycle were investigated with fluoroscopy. RESULTS Liver length was significantly greater on radiographs obtained at maximal expiration than at maximal inspiration, but there was no increase in the ratio of liver length to T11 length. Body position, beam center location, and gastric distention did not significantly affect liver size. For CT, location of the spleen and stomach and location or size of the liver did not change markedly between right and left recumbency. Fluoroscopy revealed that thoracic width was less at maximal expiration than maximal inspiration. CONCLUSIONS AND CLINICAL RELEVANCE Liver length was greater at maximal expiration than at maximal inspiration because of a smaller thoracic width. Body position, beam center location, and gastric distention did not affect liver length. The ratio of liver length to T11 length was not significantly affected by any of the factors investigated.

Separation anxiety and noise aversion are common behavioral problems in dogs. They elicit fear responses such as cowering, seeking out the owner, and attempting to escape. This can result in property damage, injury to the dog, and disruption of the owner-pet bond, possibly leading to pet abandonment or euthanasia. A novel botanical anxiolytic product was evaluated for safety in dogs as the target animal species. Its intended use is for the treatment and prevention of anxiety and noise aversion in dogs. It contains a defined mixture of Souroubea spp. vine and Platanus spp. bark, delivering the active principle, betulinic acid, at a recommended dose of 1 mg/kg body weight (BW). In the current target animal safety study, 16 healthy male beagle dogs were administered either a placebo or the newly formulated botanical tablets at 0.5×, 2.5×, or 5× the recommended dose (1 mg/kg BW) over 28 d. The dogs were monitored for occurrence of any systemic or local adverse events. In the investigation presented here, there were no clinically significant adverse effects following treatment, as determined by clinical observations, physical examinations, BW, hematology, clinical biochemistry, and urinalysis. Pharmacokinetic analysis demonstrated that the concentration of betulinic acid in serum was below 0.020 μg/mL in treated animals. Under the conditions of these studies, the formulated blend of S. sympetala and P. occidentalis, when administered up to 5× the intended dose for 28 consecutive d, showed no adverse effects on the health of dogs.

Mycoplasma hyorhinis (MHR) causes polyserositis and lameness in grower pigs. While herd-specific vaccines for this bacterium are being marketed, there are currently no licensed, commercially available vaccines for MHR. The objective of this study was to develop a challenge model in cesarean-derived, colostrum-deprived (CDCD) pigs using cell-associated MHR that results in both severe pericarditis and lameness, in order to evaluate suitable vaccine candidates. We investigated administering MHR to 7-week-old pigs over 3 d using 3 different routes compared to administering MHR on a single day using 1 of 3 routes. Pigs were monitored for 21 d for signs of lameness and well-being. At the end of the study, pigs were examined for evidence of polyserositis and arthritis associated with Mycoplasma. Results indicate that clinical manifestation of disease depended more on the route of administration than on the total dose given. A single intravenous (IV) administration of MHR resulted in extensive polyserositis, while a single intranasal (IN) administration showed little to no signs of disease. A single intraperitoneal (IP) administration did not induce the same level of polyserositis as observed in the IV group, but did result in an increased incidence of lameness. Furthermore, pigs administered MHR by IP (Day 0), IV (Day 1), and IN (Day 2) on 3 consecutive days showed a more robust disease manifestation, which resulted in both polyserositis and lameness. Optimization of this group showed that elimination of the 3rd-day IN challenge had no detrimental effect on clinical outcomes. The consecutive day administration of cell-associated MHR will allow polyserositis and lameness to be simultaneously evaluated in future vaccine trials.

OBJECTIVE To investigate mechanisms by which anti-inflammatory doses of orally administered intermediate-acting glucocorticoids (prednisone) could predispose dogs to progression of heart disease or congestive heart failure. ANIMALS 11 client-owned dogs with allergic dermatitis and 11 matched healthy control dogs. PROCEDURES Clinicopathologic, echocardiographic, and hemodynamic variables were measured. Dogs with allergic dermatitis then received prednisone (1 mg/kg, PO) once daily for 14 consecutive days beginning on day 0 (baseline), followed by a tapering and washout period; control dogs received no treatment. Measurements were repeated on days 7, 14, and 35. Linear mixed modeling was used to compare changes in variables across measurement points and between dog groups. RESULTS Prednisone administration caused no significant changes in serum sodium or potassium concentration, blood glucose concentration, or target echocardiographic variables. The change from baseline in systolic arterial blood pressure at day 7 was significantly greater in prednisone-treated dogs than in control dogs. Expected changes in hematologic and serum biochemical values with prednisone administration (neutrophilia, eosinopenia, isosthenuria, and high serum alkaline phosphatase and alanine aminotransferase activities) also occurred in the prednisone-treated dogs. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that anti-inflammatory doses of orally administered glucocorticoids have the potential to adversely impact cardiac function in dogs by causing an increase in blood pressure and thus increased cardiac afterload.

OBJECTIVE To compare time to achieve vascular access (TTVA) between an ultrasound-guided technique (UST) and landmark-based technique (LMT) for central venous catheter (CVC) placement in healthy anesthetized dogs. ANIMALS 39 purpose-bred hounds. PROCEDURES Anesthetized dogs that were hemodynamically stable following completion of a terminal surgical exercise were enrolled in the study during 2 phases, with a 45-day intermission between phases. For each dog, a UST and LMT were used for CVC placement via each external jugular vein by 2 operators (criticalist and resident). The TTVA and number of venipuncture attempts and catheter redirections were recorded for each catheterization. Placement of the CVC was confirmed by contrast fluoroscopy. After euthanasia, a gross dissection was performed during which a hematoma score was assigned to the catheter insertion site. For each phase, nonlinear least squares estimation was used for learning curve analysis of the UST. RESULTS Median TTVA, number of venipuncture attempts and catheter redirections, and hematoma score did not differ significantly between the 2 operators for either technique. Median TTVA for the UST (45 seconds) was significantly longer than that for the LMT (7 seconds). Learning curve analysis indicated that 8 and 7 UST catheterizations were required to achieve performance stability in phases 1 and 2, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the UST was comparable to the LMT for CVC placement in healthy dogs. The extra time required to perform the UST was not clinically relevant. Additional studies evaluating the UST for CVC placement in clinically ill dogs are warranted.

OBJECTIVE To compare the leak pressure and amount of time required to perform closure for 2 double-layer esophagotomy closure techniques. SAMPLE 28 intrathoracic esophageal segments harvested from 38 porcine cadavers. PROCEDURES Longitudinal 3-cm esophagotomy incisions made in porcine cadaveric esophagi were closed with 2 double-layer closure techniques. Fifteen incisions were closed with a simple interrupted pattern, and 13 incisions were closed with a simple continuous pattern. Leak pressure, bursting wall tension, and closure time were compared between suture patterns by use of a t test or Mann-Whitney rank sum test. RESULTS Median leak pressures differed significantly between segments closed with the simple interrupted pattern (16.0 mm Hg; range, 5.4 to 54.9 mm Hg) and the simple continuous pattern (38.7 mm Hg; range, 11.3 to 81.9 mm Hg). Median bursting wall tension differed significantly between the simple interrupted pattern (0.63 × 10(5) dynes/cm; range, 0.16 × 10(5) dynes/cm to 2.89 × 10(5) dynes/cm) and the simple continuous pattern (1.79 × 10(5) dynes/cm; range, 0.44 × 105 dynes/cm to 4.70 × 10(5) dynes/cm). Mean ± SD closure time differed significantly between the simple interrupted pattern (19.2 ± 2.0 minutes) and the simple continuous pattern (14.7 ± 1.5 minutes). CONCLUSIONS AND CLINICAL RELEVANCE In the study reported here, double-layer simple continuous closure resulted in a higher median postoperative leak pressure and higher median postoperative bursting wall tension and could be performed more rapidly than the double-layer simple interrupted closure on these porcine cadaveric specimens.

OBJECTIVE To evaluate 2 methods of surveying free-roaming cats (Felis catus) and identify factors potentially associated with the presence of such cats in a mixed-urban environment. ANIMALS Free-roaming cats on and near The Ohio State University campus. PROCEDURES The university campus and surrounding areas were divided into zones classified by land-use category; 100 zones were selected for surveillance of free-roaming cats by the line-transect method (with visual observation). Twenty-three of the 100 zones were selected for surveillance by the trail-camera method (motion-triggered still photography). Food resources in the study site were mapped, and the presence of other animal species was recorded with trail cameras. Potential associations between the number of cat sightings and variables of interest were assessed by statistical methods, RESULTS There were 6 cat sightings in 5 zones and 92 cat sightings in 9 zones with the line-transect and trail-camera methods, respectively. Cats were most frequently detected off campus and in urban land-use zones. The number of cat sightings with trail cameras was significantly correlated with the density of food resources but not wildlife sightings in the area and was significantly greater at night than during the day. CONCLUSIONS AND CLINICAL RELEVANCE The number of sightings with the trail-camera method was substantially higher than that obtained with the line-transect method; however, identification of individual cats was generally not possible, and population size could not be estimated with these methods. Communities considering population control for free-roaming cats should consider the use of trail cameras to identify areas with high free-roaming cat activity and observation at night to gather baseline data. Easily accessible food waste may attract free-roaming cats.

OBJECTIVE To determine the minimum alveolar concentration of desflurane (MACDES) and effects on cardiovascular variables in positive-pressure ventilated sheep. ANIMALS 13 adult female sheep. PROCEDURES Anesthesia was induced with desflurane. After a 30-minute equilibration at an end-tidal concentration of desflurane (etDES) of 10.5%, an electrical stimulus (5 Hz/ms and 50 mA) was applied for 1 minute or until gross purposeful movement occurred. The etDES was then changed by 0.5% (modified up-down method), depending on whether a positive motor response had been elicited, and stimulation was repeated. The MACDES was the etDES midway between a positive and negative response. After MACDES was determined, etDES was increased to 1.3 and 1.6 MACDES. Animals were allowed to equilibrate for 15 minutes, and cardiovascular, blood gas, acid-base, and hematologic variables were measured. Times to induction of anesthesia, extubation, attainment of sternal position, and standing and duration of anesthesia were recorded. RESULTS Mean ± SD MACDES was 9.81 ± 0.79%. Times to intubation, extubation, and standing were 4.81 ± 2.21 minutes, 14.09 ± 4.05 minutes, and 32.4 ± 12.5 minutes, respectively. Duration of anesthesia was 226 ± 22 minutes. Heart rate increased significantly at induction of anesthesia but otherwise remained at preanesthetic rates. Arterial blood pressures progressively decreased with increasing etDES; pressures increased slightly only in response to noxious stimulation. CONCLUSIONS AND CLINICAL RELEVANCE The MACDES determined here compared favorably with that determined for other sheep populations and indicated similar anesthetic potency as in other species. Desflurane caused dose-dependent arterial hypotension, which indicated the need for careful blood pressure monitoring.

OBJECTIVE To determine the in vitro effect of calcitriol on indicators of immune system function in endotoxin-primed blood samples from healthy dogs. SAMPLE Blood samples from 6 healthy adult dogs. PROCEDURES Leukocytes were primed by incubation of blood samples with lipopolysaccharide (LPS; endotoxin) or PBS solution (unprimed control group) for 1 hour. Following priming, blood samples were incubated with calcitriol (2 × 10(−7)M) or ethanol (control substance) for 24 hours. After sample incubation, LPS-stimulated leukocyte production of tumor necrosis factor (TNF) and interleukin-10 (IL10) was measured with a canine-specific multiplex assay, and apoptosis and toll-like receptor 4 (TLR4) expression were evaluated via flow cytometry. RESULTS LPS stimulation of unprimed leukocytes but not endotoxin-primed leukocytes resulted in a significant increase in TNF and IL10 production, confirming the presence of endotoxin tolerance in dogs in vitro. Endotoxin priming significantly increased neutrophil viability with no effect on lymphocyte viability or TLR4 expression by neutrophils and monocytes. Calcitriol exposure significantly decreased LPS-stimulated production of TNF by unprimed and endotoxin-primed leukocytes. Conversely, calcitriol exposure had no effect on IL10 production by unprimed leukocytes but did significantly increase IL10 production by endotoxin-primed leukocytes. Calcitriol had no significant effect on the degree of neutrophil or lymphocyte apoptosis, nor was neutrophil and monocyte TLR4 expression affected in unprimed or endotoxin-primed leukocytes. CONCLUSIONS AND CLINICAL RELEVANCE These data indicated that calcitriol induced an anti-inflammatory shift in unprimed and endotoxin-primed canine leukocytes in vitro, without compromising neutrophil and monocyte TLR4 expression or altering the viability of neutrophils and lymphocytes in canine blood samples.