Preoperative and postoperative stance analysis in dogs with patellar luxation confirms lameness improvement after surgery.

OBJECTIVE: To document and compare preoperative and postoperative stance analysis measurements in animals with naturally occurring patellar luxation. ANIMALS: 131 client-owned dogs surgically treated for naturally occurring unilateral or bilateral patella luxation between March 30, 2015, and February 12, 2020. PROCEDURES: Weight bearing as a percent body weight on each limb was recorded with the use of a platform device for analyzing stance (PetSafe Stance Analyzer; LiteCure LLC, Companion Animal Health) preoperatively and postoperatively for all dogs. Signalment, limb affected, lameness grade, luxation direction, luxation grade, and surgical procedure were collected from patient records and assessed for the effects of these variables on weight bearing preoperatively or at the first or second postoperative recheck examination. RESULTS: There were 61 males and 70 females, with a mean age and body weight of 4.62 years and 13.01 kg, included in the study. As age increased, body weight decreased in these dogs (P = .025). There was a statistically significant improvement in lameness after surgery (P = .008) at the second postoperative recheck examination. Lameness significantly decreased as postoperative time increased (P < .001, r = 0.503). As age increased, lameness at the initial visit decreased compared to younger dogs but not significantly (P = .062). There was no significant effect of preoperative luxation grade, luxation direction, surgical procedure, or sex when comparing initial lameness or lameness at recheck examination. CLINICAL RELEVANCE: Surgical correction of patella luxation improves lameness as measured by postoperative stance analysis. Preoperative luxation grade or direction, surgical procedure performed, and sex of the animal did not significantly affect outcome in this group of dogs.

A three-portal laparoscopic hysterectomy in a chimpanzee (Pan troglodytes) with a uterine manipulator and vessel sealing device.

OBJECTIVE: To report the treatment and outcome of a a captive chimpanzee (Pan troglodytes) undergoing 3-portal laparoscopic hysterectomy. Additionally, the technique used for successful urinary catheterization is described. ANIMALS: A 29-year-old female intact chimpanzee with uterine bleeding. STUDY DESIGN: Clinical case report. METHODS: Uterine changes consistent with adenomyosis and/or endometriosis were noted on abdominal ultrasonographic and computed tomographic examinations. A urinary catheter was placed before a 3-portal laparoscopic hysterectomy with a uterine manipulator (VCare) and a vessel sealer (Ligasure). The uterus was submitted for histopathology. RESULTS: Preoperative urinary catheterization was achieved with several modifications and prevented bladder protrusion into the surgical field. Laparoscopy provided excellent visualization of the pelvic structures and VCare effectively maneuvered the uterus for a safe and efficient dissection. The use of the vessel sealer was effective, and bleeding was minimal. Anesthesia and surgery lasted 240 and 150 minutes, respectively. No complications were encountered. Histopathological changes of the uterus were consistent with adenomyosis and myometrial hyperplasia. The chimpanzee recovered uneventfully and returned to normal behavior with no recurrence of uterine bleeding 5 months after surgery. CONCLUSION: The 3-portal laparoscopic technique reported here allowed hysterectomy without complication in this chimpanzee. Urinary catheterization was technically challenging but successful.

Long-acting injectable methadone (methadone-fluconazole) provides safe and effective postoperative analgesia in a randomized clinical trial for dogs undergoing soft tissue surgery.

OBJECTIVE: To assess the pharmacokinetics, clinical efficacy, and adverse effects of injectable methadone with the pharmacokinetic enhancer fluconazole (methadone-fluconazole), compared with the standard formulation of injectable methadone, in dogs after ovariohysterectomy. We hypothesized that 2 doses of methadone-fluconazole would provide 24 hours of postoperative analgesia. ANIMALS: 3 purpose-bred dogs (pharmacokinetic preliminary study) and 42 female dogs from local shelters (clinical trial) were included. PROCEDURES: Pharmacokinetics were preliminarily determined. Clinical trial client-owned dogs were blocked by body weight into treatment groups: standard methadone group (methadone standard formulation, 0.5 mg/kg, SC, q 4 h; n = 20) or methadone-fluconazole group (0.5 mg/kg methadone with 2.5 mg/kg fluconazole, SC, repeated once at 6 h; n = 22). All dogs also received acepromazine, propofol, and isoflurane. Surgeries were performed by experienced surgeons, and dogs were monitored perioperatively using the Glasgow Composite Measure Pain Scale-Short Form (CMPS-SF) and sedation scales. Evaluators were masked to treatment. RESULTS: Findings from pharmacokinetic preliminary studies supported that 2 doses of methadone-fluconazole provide 24 hours of drug exposure. The clinical trial had no significant differences in treatment failures or postoperative CMPS-SF scores between treatments. One dog (methadone-fluconazole group) had CMPS-SF > 6 and received rescue analgesia. All dogs had moderate sedation or less by 1 hour (methadone-fluconazole group) or 4 hours (standard methadone group) postoperatively. Sedation was completely resolved in all dogs the day after surgery. CLINICAL RELEVANCE: Methadone-fluconazole with twice-daily administration was well tolerated and provided effective postoperative analgesia for dogs undergoing ovariohysterectomy. Clinical compliance and postoperative pain control may improve with an effective twice-daily formulation.

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

Laryngeal function in normal dogs administered isoflurane following partial clearance of alfaxalone or propofol.

OBJECTIVE: To assess laryngeal function in normal dogs administered isoflurane following partial clearance of alfaxalone or propofol. STUDY DESIGN: Randomized experimental crossover study. ANIMALS: A group of 12 purpose-bred, male Beagle dogs. METHODS: Dogs were randomly assigned to one of two treatments: alfaxalone-isoflurane (ALF-ISO) or propofol-isoflurane (PRO-ISO) and anesthetized for three video laryngoscopy examinations. The alternate treatment occurred after ≥ 14 days interval. Examinations were performed after induction of anesthesia (LS-A), after 20 minutes of breathing isoflurane via a facemask (LS-B) and after a further 20 minutes of isoflurane (LS-C). Parameters of objective laryngeal function included inspiratory rima glottidis surface area (RGSA-I), expiratory rima glottidis surface area (RGSA-E) and % RGSA increase, calculated from three consecutive respiratory cycles in the final 15 seconds of each video laryngoscopy examination. The % RGSA increase was calculated using [(RGSA-I - RGSA-E)/RGSA-E] × 100. Subjective laryngeal function was evaluated independently by two experienced surgeons blinded to treatment. RESULTS: The % RGSA increase within each treatment was greater for LS-B and LS-C than for LS-A (ALF-ISO: p = 0.03, PRO-ISO: p = < 0.001). There was no difference within each treatment from LS-B compared with LS-C. RGSA-I increased within each treatment from LS-A to both LS-B and LS-C (ALF-ISO: p = 0.002) and to LS-C (PRO-ISO: p = 0.006). Subjective laryngeal function scores improved from LS-A to LS-C. CONCLUSIONS AND CLINICAL RELEVANCE: Laryngeal function improved from postinduction examination following either 20 or 40 minutes of anesthesia with isoflurane via facemask. This study demonstrates that isoflurane may have a lesser effect on arytenoid abduction activity compared with more commonly used intravenous induction anesthetics (alfaxalone and propofol).

Perioperative analgesia associated with oral administration of a novel methadone-fluconazole-naltrexone formulation in dogs undergoing routine ovariohysterectomy.

OBJECTIVE: To determine perioperative analgesia associated with oral administration of a novel methadone-fluconazole-naltrexone formulation in dogs undergoing routine ovariohysterectomy. ANIMALS: 43 healthy female dogs. PROCEDURES: Dogs were randomly assigned to receive the methadone-fluconazole-naltrexone formulation at 1 of 2 dosages (0.5 mg/kg, 2.5 mg/kg, and 0.125 mg/kg, respectively, or 1.0 mg/kg, 5.0 mg/kg, and 0.25 mg/kg, respectively, PO, q 12 h, starting the evening before surgery; n = 15 each) or methadone alone (0.5 mg/kg, SC, q 4 h starting the morning of surgery; 13). Dogs were sedated with acepromazine, and anesthesia was induced with propofol and maintained with isoflurane. A standard ovariohysterectomy was performed by experienced surgeons. Sedation and pain severity (determined with the Glasgow Composite Pain Scale-short form [GCPS-SF]) were scored for 48 hours after surgery. Rescue analgesia was to be provided if the GCPS-SF score was > 6. Dogs also received carprofen starting the day after surgery. RESULTS: None of the dogs required rescue analgesia. The highest recorded GCPS-SF score was 4. A significant difference in GCPS-SF score among groups was identified at 6:30 am the day after surgery, but not at any other time. The most common adverse effect was perioperative vomiting, which occurred in 11 of the 43 dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of a methadone-fluconazole-naltrexone formulation at either of 2 dosages every 12 hours (3 total doses) was as effective as SC administration of methadone alone every 4 hours (4 total doses) in dogs undergoing routine ovariohysterectomy. Incorporation of naltrexone in the novel formulation may provide a deterrent to human opioid abuse or misuse.

Clinical and pharmacokinetic interactions between oral fluconazole and intravenous ketamine and midazolam in dogs.

OBJECTIVE: To evaluate drug interactions between fluconazole and the intravenous (IV) anesthetic induction agents, ketamine and midazolam. STUDY DESIGN: Randomized parallel study. ANIMALS: A group of 12 adult healthy Beagle dogs. METHODS: Dogs were randomly allocated to two groups of six dogs. Dogs in group KM were administered IV ketamine (7 mg kg-1) and IV midazolam (0.25 mg kg-1), and dogs in group KMF were administered fluconazole (5 mg kg-1) orally 12 and 24 hours prior to ketamine-midazolam using the same doses as KM. Sedation scores (0-4) were assigned by investigators unaware of group assignment. Heart rate (HR) and times to sternal and standing were obtained and compared between groups for differences with p < 0.05 considered statistically significant. Blood was obtained and plasma drug concentrations were measured using liquid chromatography-mass spectrometry. RESULTS: The times to sternal, mean 32.3 and 24.6 minutes, for groups KMF and KM, respectively, were not different between the groups. The time to standing, 73 and 36 minutes in groups KMF and KM, respectively, was significantly different (p = 0.002). The duration of elevated HR compared with baseline was longer in KMF (110 minutes) than in KM (25 minutes) (p < 0.05). In group KMF, one dog developed hyperthermia (40.6 °C), which resolved spontaneously. The clearance of ketamine and midazolam was significantly slower (approximately 50%) and the area under the curves were significantly higher (two-fold) in group KMF (p = 0.02). CONCLUSIONS AND CLINICAL RELEVANCE: A significant interaction between oral fluconazole and IV ketamine-midazolam occurred, but the effects appear minor in healthy dogs. Based on these data, a single dose of ketamine-midazolam is not contraindicated in dogs treated with fluconazole, but the duration of effects and pharmacokinetics are altered.

High efficiency graphene solar cells by chemical doping.

We demonstrate single layer graphene/n-Si Schottky junction solar cells that under AM1.5 illumination exhibit a power conversion efficiency (PCE) of 8.6%. This performance, achieved by doping the graphene with bis(trifluoromethanesulfonyl)amide, exceeds the native (undoped) device performance by a factor of 4.5 and is the highest PCE reported for graphene-based solar cells to date. Current-voltage, capacitance-voltage, and external quantum efficiency measurements show the enhancement to be due to the doping-induced shift in the graphene chemical potential that increases the graphene carrier density (decreasing the cell series resistance) and increases the cell's built-in potential (increasing the open circuit voltage) both of which improve the solar cell fill factor.