Comparison of a blind and an ultrasound-guided technique for Retrobulbar anesthesia in dogs undergoing unilateral subconjunctival enucleation.

OBJECTIVE: This study compared the quality of retrobulbar anesthesia using a blind inferior-temporal palpebral approach (ITP) with an ultrasound-guided supratemporal (ST) technique in dogs undergoing unilateral enucleation. ANIMAL STUDIED: Twenty-one client-owned dogs were undergoing enucleation. PROCEDURES: Dogs were randomly assigned to receive ITP (n = 10) or ST (n = 11) with 0.5% ropivacaine at 0.1 mL/cm of neurocranial length. The anesthetist was blinded to the technique. Intraoperative data included cardiopulmonary variables, inhalant anesthetics requirement, and requirement for rescue analgesia (intravenous fentanyl 2.5 mcg/kg). Postoperative data included pain scores, sedation scores, and need for intravenous hydromorphone (0.05 mg/kg). Treatments were compared using Wilcoxon's rank sum test or Fisher's exact test as appropriate. Comparison of variables over time were tested using a mixed effect linear model on rank. Significance was set at p = 0.05. RESULTS: Intraoperative cardiopulmonary variables and inhalant requirements were not different between groups. Dogs receiving ITP required median (interquartile range, IQR) 1.25 (0, 2.5) mcg/kg intraoperative fentanyl while those receiving ST required none (p < 0.01). Intraoperative fentanyl was required in 5/10 and 0/11 of dogs in the ITP and ST groups, respectively (p = 0.01). Postoperative analgesia requirements were not significantly different between groups; 2/10 and 1/10 dogs in the ITP and ST groups, respectively. Sedation score negatively affected pain score (p < 0.01). CONCLUSIONS: The ultrasound-guided ST technique was more effective at decreasing intraoperative opioid requirements than the blind ITP approach in dogs undergoing unilateral enucleation.

EVALUATION OF OSCILLOMETRIC BLOOD PRESSURE MEASUREMENT USING A FINGER CUFF IN ANESTHETIZED CHIMPANZEES (PAN TROGLODYTES).

Cardiovascular disease is common among chimpanzees (Pan troglodytes), and serial blood pressure monitoring in conscious animals may improve disease surveillance and guide hypertension treatment strategies. The objective of this study was to compare the accuracy of a noninvasive, oscillometric blood pressure monitor using a finger blood pressure cuff with invasively measured blood pressure in anesthetized chimpanzees. Twelve chimpanzees were anesthetized with tiletamine-zolazepam intramuscularly, intubated, and maintained on inhaled isoflurane to effect. Blood pressure measurements, which included systolic arterial pressure (SAP), mean arterial pressure (MAP), and diastolic arterial pressure (DAP), were collected simultaneously from an oscillometric blood pressure cuff placed on a forelimb digit (FBP) and a direct arterial catheter (IBP) every 5-10 min while anesthetized. One hundred paired samples were collected, and results were compared using Bland-Altman plots and analysis. FBP showed good agreement with IBP for SAP, MAP, and DAP but consistently overestimated values compared with IBP. FBP may be useful for serial blood pressure monitoring in conscious chimpanzees.

Perianesthetic mortality in English Bulldogs: a retrospective analysis in 2010 - 2017.

BACKGROUND: Many veterinarians consider English Bulldogs to have a greater perianesthetic mortality risk. The aims of this study were to 1) determine total and anesthesia-related, perianesthetic mortality (PAM) rates in English Bulldogs (EB), 2) identify potential risk factors associated with mortality in EB, and 3) determine the difference in the perianesthetic mortality rates between EB, other-brachycephalic breeds (OB), and non-brachycephalic breeds (NB). Records from EB that were anesthetized between 2010 and 2017, were investigated. OB and NB were enrolled to match with each EB based on a procedure and age from the study period. Data collected in EB included: age, ASA status, weight, procedure types, anesthetic and analgesic management, anesthetic duration, anesthetic recovery location, and cause of death. Age and cause of death were determined from OB and NB. Fisher's exact test was used to compare PAM rate and age in EB, OB, and NB. Mann-Whitney U test was used to compare EB survivor and EB non-survivor. Logistic regression models were used to identify factors and odds ratio (OR) associated with PAM in EB. RESULT: Two hundred twenty nine EB, 218 OB, and 229 NB were identified. The total and anesthesia-related PAM rates in EB were 6.6 and 3.9%, respectively. EB had a greater total PAM rate compared with OB (p = 0.007). ASA status was different between survivors and non-survivors in EB (p < 0.01). Risk factors identified regardless of the cause of death were premedication with full µ opioids (OR = 0.333, p = 0.114), continuous infusion of ketamine post-operatively (OR = 13.775, p = 0.013), and acepromazine administration post-operatively (OR = 7.274, p = 0.004). The most common cause of death in EB was postoperative respiratory dysfunction (87.5%). CONCLUSION: Total and anesthesia-related mortality in EB is considerable. Most deaths in EB occurred during the postoperative period secondary to respiratory complications.

Point-of-care viscoelastic coagulation assessment in healthy dogs during the perianesthetic period.

BACKGROUND: The viscoelastic coagulation monitor (VCM Vet) is a novel, portable device that provides a global assessment of hemostasis. The study aims were to evaluate serial viscoelastic analysis during the perianesthetic period in healthy dogs and to compare the agreement between two VCM Vet devices. Twenty healthy dogs undergoing orthopedic surgery were enrolled. Whole blood samples were collected from an intravenous catheter at four time points: baseline, 15 min after premedication, 60 min after inhalant initiation, and 60 min after inhalant termination. Viscoelastic tests were performed in duplicate on different devices, providing: clot time (CT; seconds), clot formation time (CFT; seconds), alpha angle (α; degrees), amplitude (units) at 10 (A10) and 20 (A20) minutes post clot time, maximum clot firmness (MCF; units), and lysis index (%) at 30 (Li30) and 45 (Li45) minutes post maximum clot formation. RESULTS: One hundred sixty samples were analyzed. The speed of CT and CFT significantly decreased an average of 25.5 s (95% confidence interval [CI]15.9-35.0) and 6.9 s (95% CI 3.1-10.7) per time point, respectively. There were no significant changes in clot strength or lysis variables. The Bland-Altman style plot shows an acceptable rate of agreement for all variables with intra-class correlation ranging from 0.64-0.94. CONCLUSION: The rate of clot formation (CT and CFT) decreased over the perianesthetic period in healthy dogs undergoing surgery. These changes were small and occurred without changes in clot strength or fibrinolysis rate, thus were not clinically relevant. There was clinically acceptable consistency between devices.

EFFECTS OF TRICAINE METHANESULFONATE IN A MANAGED COLLECTION OF MOON JELLYFISH (AURELIA AURITA).

The moon jellyfish (Aurelia aurita) is a scyphozoan frequently maintained in public and private aquaria. Little research has been conducted to investigate the effects of various drugs, such as anesthetics, in this species. Tricaine methanesulfonate (MS-222), a common immersion anesthetic for fish and amphibians, was evaluated in a managed population of moon jellyfish. Twenty-four clinically healthy jellyfish were assigned into three groups of eight for trials of 0.3 g/L MS-222 (low concentration [LC]), 0.6 g/L MS-222 (high concentration [HC]), and a saltwater control. The goal was to evaluate the effects of MS-222 administration on moon jellyfish movement and response to stimuli. Movement and response to stimuli were measured via rocking and probe stimulus tests and observations of bell contraction quality and body tone. These tests were performed at baseline and throughout both drug exposure and recovery periods. A threshold drug effect was defined based on systematic scoring criteria. Additionally, elastomer tags were administered to four of eight animals in each MS-222 group to evaluate response to tag placement after drug exposure. Threshold drug effect was achieved in six of eight individuals in the LC group and eight of eight individuals in the HC group. The LC group had median threshold and recovery times of 12.2 and 10.1 min, respectively, while the HC group had median threshold and recovery times of 4.0 and 19.9 min, respectively. The HC group had significantly faster time to threshold drug effect (P < 0.001) and longer recovery times (P= 0.005) than the LC group. In both the LC and HC tagged group, three of four jellyfish had no reaction to tag placement. All animals recovered uneventfully, and there were no mortalities. MS-222 at 0.3 and 0.6 g/L decreased movement and response to stimuli in moon jellyfish.

SEDATIVE AND CARDIORESPIRATORY EFFECTS OF INTRAMUSCULAR ALFAXALONE AND BUTORPHANOL AT TWO DOSAGES IN FERRETS (MUSTELA PUTORIUS FURO).

Veterinary care of ferrets often requires chemical restraint. This study hypothesized that IM alfaxalone and butorphanol would result in clinically useful sedation without clinically relevant cardiorespiratory effects. Twelve healthy 15-mo-old ferrets of equal sexes weighing 0.75 to 1.66 kg were enrolled. Using a prospective, blinded design, ferrets randomly received either IM alfaxalone 2.5 mg/kg and butorphanol 0.2 mg/kg (low dose [LD]) or IM alfaxalone 5 mg/kg and butorphanol 0.2 mg/kg (high dose [HD]) (n = 6/group). Sedation times and induction and recovery scores were recorded by a blinded observer. Anesthetic monitor placement was attempted in all recumbent ferrets, and physiologic parameters and reflexes were recorded every 5 min until return of spontaneous movement. Data were assessed for normality using a Shapiro-Wilk normality test and analyzed by two-sample t test or Mann-Whitney U test; one ferret in HD was excluded. Ferrets in LD and HD exhibited moderate and marked sedation, with one of six and four of five ferrets tolerating monitor placement, respectively. Mean ± SD time to first effects, recumbency, and recovery in LD and HD was 2.30 ± 1.13 and 2.054 ± 1.12 (P = 0.7240), 2.87 ± 1.25 and 2.72 ± 1.41 (P = 0.8529), and 65.43 ± 32.43 and 52.30 ± 13.19 (P = 0.4212), respectively. Median (range) duration of recumbency in LD and HD was 31.12 (25.58-115.72) and 35.47 (28.27-44.42) min (P = 0.3290), respectively. Among monitored ferrets, transient mild hypotension and hypoxemia were observed. Intramuscular alfaxalone 5 mg/kg with butorphanol 0.2 mg/kg provided clinically useful sedation in ferrets with mild transient cardiorespiratory derangements.

A preoperative bupivacaine retrobulbar block offers superior antinociception compared with an intraoperative splash block in dogs undergoing enucleation.

PURPOSE: Investigate nociception differences in dogs undergoing enucleation administered bupivacaine either via preoperative retrobulbar block (pRB) or intraoperative splash block (iSB). METHODS: Prospective, randomized, double-masked, clinical comparison study. Dogs undergoing unilateral enucleation were randomized to two groups: one received bupivacaine pRB and saline iSB of the same volume, and the other received saline pRB and bupivacaine iSB. The following intraoperative parameters were recorded: heart rate (HR), respiratory rate (RR), end-tidal CO2 (EtCO2 ); systolic, mean, and diastolic arterial blood pressure (SAP, MAP, and DAP respectively); inspired end-tidal isoflurane concentration (EtISOIns), and expired end-tidal isoflurane concentration (EtISOExp). Pain scores were recorded pre- and postoperatively. Analgesic rescue was documented. Surgical hemorrhage and postoperative bruising and swelling were graded subjectively by the surgeon (HDW) and study coordinator (AEZ). RESULTS: A significant (P = .0399) increase from baseline in overall mean heart rate was recorded in iSB bupivacaine patients (n = 11) compared with pRB bupivacaine patients (n = 11), with no significant differences in other intraoperative physiologic parameters, or pain scores. More analgesic rescue events occurred in iSB bupivacaine patients compared to pRB bupivacaine patients. A near-significant increase in intraoperative bleeding (P = .0519), and a significant increase in bruising (P = .0382) and swelling (P = .0223) was noted in the iSB bupivacaine group. CONCLUSIONS: Preoperative retrobulbar block bupivacaine is more effective than an iSB bupivacaine at controlling both intraoperative and postoperative nociception in dogs undergoing enucleation. Additionally, iSB causes more postoperative bruising and swelling and may be associated with increased intraoperative hemorrhage.

EVALUATION OF POTASSIUM CHLORIDE ADMINISTERED VIA THREE ROUTES FOR EUTHANASIA OF ANESTHETIZED KOI (CYPRINUS CARPIO ).

Immersion in tricaine methanesulfonate (MS-222) is insufficient for euthanasia in at least one species of fish. The current study investigated the effectiveness of potassium chloride (KCl) to euthanize anesthetized koi (Cyprinus carpio). Twenty-eight healthy koi were anesthetized via immersion in 500 mg/L of buffered MS-222 for 10-12 min, manually removed to room air, and randomly administered 10 mEq/kg KCl (333 mg/ml) via one of three routes-intracardiac injection (IC) (n = 7), intracoelomic injection (ICe) (n = 7), or topical instillment over the gill filaments bilaterally (T) (n = 7)-or received no treatment (control, C) (n = 7). A Doppler ultrasonic flow detector was placed over the heart, and sounds were assessed continuously from immediately prior to treatment until 5 min posttreatment and every 5 min thereafter until Doppler sound cessation, resumption of operculation, or 30 min. Time to Doppler sound cessation or resumption of operculation was recorded. Doppler sound cessation occurred in 7/7 fish in IC (median 0.08, range 0-2.75 min) and 1/7 fish in T (10 min). In T, ICe, and C, 6/7, 7/7, and 7/7 fish, respectively, maintained Doppler sounds to 30 min. All fish in ICe (7/7) and C (7/7) resumed operculation with median (range) times of 22 (7-30) min and 16 (9-29) min from treatment, respectively. Intracardiac KCl at 10 mEq/kg rapidly ceases Doppler sounds and is a successful technique for euthanasia of anesthetized koi. Intracoelomic and topical KCl at 10 mEq/kg were not effective for euthanasia of koi.

The effect of aquapuncture at Pericardium 6 (PC-6) on dexmedetomidine-induced nausea and vomiting in cats.

OBJECTIVE: To determine the effect of aquapuncture at acupuncture point Pericardium 6 (PC-6) on the incidence of dexmedetomidine-induced vomiting and nausea in cats. STUDY DESIGN: Randomized, prospective, crossover study. ANIMALS: A group of 22 cats, 14 females and eight males, aged 1-12 years and weighing 3.8-5.9 kg. METHODS: Each cat was administered treatments in random order at ≥1 week intervals. For treatment (DEX-A), cats were administered PC-6 stimulation by aquapuncture (0.25 mL/250 µg vitamin B12 injection subcutaneously at PC-6). After 30 minutes, dexmedetomidine (10 µg kg-1) was administered intramuscularly (IM). For control treatment (DEX), cats were administered only dexmedetomidine (10 µg kg-1) IM. Incidence of vomiting, number of vomiting episodes and time to first vomiting were recorded by an observer unaware of treatment allocation. At 30 minutes after dexmedetomidine administration, atipamezole (0.1 mg kg-1) was injected IM. Behavior was video recorded and later scored by two observers for clinical signs of nausea. A regression model (analysis of covariance) was used to detect the influence of aquapuncture on vomiting and nausea. Significance was set at p < 0.05. RESULTS: Of 21 cats, 18 (85%) and 16 cats (76%) vomited in DEX-A and DEX, respectively. There was no significant difference in the incidence of vomiting (p = 0.55), number of vomiting episodes (p = 0.55), mean time to vomit (p = 0.88) or nausea score (p = 0.51) between DEX-A and DEX. CONCLUSIONS AND CLINICAL RELEVANCE: PC-6 aquapuncture did not reduce the incidence of dexmedetomidine-induced vomiting or severity of nausea in cats.

IMMERSION IN TRICAINE METHANESULFONATE (MS-222) IS NOT SUFFICIENT FOR EUTHANASIA OF SMOKEY JUNGLE FROGS (LEPTODACTYLUS PENTADACTYLUS).

Although tricaine methanesulfonate (MS-222) immersion has historically been standard of care for fish and anuran euthanasia, recent research has proven it insufficient for euthanasia of goldfish. To assess appropriateness for humane euthanasia of anurans, this study evaluated the efficacy of MS-222 in Smokey Jungle Frogs (Leptodactylus pentadactylus). Eighteen frogs (21-33 g) were exposed to one of three MS-222 concentrations via partial immersion: 2.5 g/L for 90 min (M2.5/90), 5 g/L for 60 min (M5/60), or 10 g/L for 60 min (M10/60). Physiologic parameters and times to loss of spontaneous movement, righting reflex, and noxious stimulus response were recorded. Following exposure, frogs were rinsed with dechlorinated water, and time to cessation of heart beat was recorded. Survival in M2.5/90, M5/60, and M10/60 was one of six, zero of six, and zero of six, respectively. In M2.5/90, three of six frogs had continued purposeful, spontaneous movement throughout exposure. In M5/60 and M10/60, median (range) time to initial loss of movement was 14.3 (5.5-30.0) and 7.6 (4.8-19.7) min, respectively. Twelve of 18 frogs among all groups demonstrated a median (range) of two (one to six) episodes of regained consciousness with purposeful, spontaneous movement following loss of noxious stimulus response. Median (range) time to heart beat cessation in M2.5/90, M5/60, and M10/60 was 150 (135-210), 157.5 (60-225), and 90 (75-210) min, respectively. Although death was achieved in 17 of 18 frogs, given the repeated events of regained consciousness, MS-222 immersion when used at concentrations ≤10 g/L did not result in rapid and distress-free death and is not sufficient for humane euthanasia in this species.

Pharmacokinetics and pharmacodynamic effects in koi carp (Cyprinus carpio) following immersion in propofol.

OBJECTIVE: To test the hypothesis that plasma propofol concentration (PPC) is associated with anesthetic effect in koi carp administered propofol by immersion. STUDY DESIGN: Prospective study. ANIMALS: Twenty mature koi carp (mean ± standard deviation, 409.4 ± 83.7 g). METHODS: Fish were immersed in propofol (5 mg L-1). Physiological variables and induction and recovery times were recorded. In phase I, blood was sampled for PPC immediately following induction and at recovery. In phase II, following induction, fish were maintained with propofol (4 mg L-1) via a recirculating system for 20 minutes. Following established induction, blood was sampled at 1, 10 and 20 minutes. In phase III (n = 19), fish were anesthetized as in phase II with blood sampled nine times in a sparse sampling strategy. Simultaneously, a pharmacodynamics rubric was used to evaluate anesthetic depth. PPC was determined using high performance liquid chromatography with fluorescence detection. Following evaluation of normality, data were analyzed using paired t test or Spearman correlation test (significance was set at p < 0.05). RESULTS: In phase I, mean PPCs at induction (20.12 µg mL-1) and recovery (11.62 µg mL-1) were different (p < 0.001). In phase II, only mean PPCs at induction (17.92 µg mL-1) and 10 minutes (21.50 µg mL-1) were different (p = 0.013). In phase III, a correlation between PPCs and the pharmacodynamic rubric scores was found (p < 0.001, r = -0.93). There was no correlation between PPCs and recovery time (p = 0.057, r = 0.433). A two-compartment open model was chosen for the pharmacokinetic model. Absorption rate constant, elimination rate constant and intercompartmental rate constant were 0.48, 0.006 and 0.02 minute-1, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Measurable PPCs were achieved in koi carp anesthetized with propofol by immersion. Anesthetic depth of fish was negatively correlated with PPCs, but recovery time was not.

PROPOFOL AS AN IMMERSION ANESTHETIC AND IN A MINIMUM ANESTHETIC CONCENTRATION (MAC) REDUCTION MODEL IN GOLDFISH (CARASSIUS AURATUS).

Propofol is a novel immersion anesthetic in goldfish ( Carassius auratus ). Objectives were to characterize propofol as an anesthetic and assess its suitability in a minimum anesthetic concentration (MAC) reduction model. Using a crossover design, eight goldfish were submerged in 1, 5, or 10 mg/L propofol. Data included induction time, recovery time, heart rate, opercular rate, and response to supramaximal stimulation. Baseline MAC (Dixon's up-and-down method) was determined, and 15 fish were anesthetized with propofol on 4 consecutive days with MAC determination on the fifth day, weekly, for 1 mo. Using a crossover design, MAC of propofol (n = 15) was determined 1 hr following administration of i.m. butorphanol 0.05, 0.5, and 1 mg/kg, dexmedetomidine 0.01, 0.02, and 0.04 mg/kg, ketoprofen 0.5, 1, and 2 mg/kg, morphine 5, 10, and 15 mg/kg, or saline 1 ml/kg. Comparisons were performed with Wilcoxon signed-rank tests (P < 0.05) and Tango's score confidence interval. Propofol at 1 mg/L did not produce anesthesia. Induction time with 10 mg/L (112, 84-166 s) was faster than 5 mg/L (233, 150-289 s; P = 0.0078). Heart and opercular rates for 5 and 10 mg/L were 36 (24-72) beats/min, 58 (44-68) operculations/min and 39 (20-48) beats/min, 57 (48-80) operculations/min, respectively. Recovery time was 249 (143-396) s and 299 (117-886) s with 5 and 10 mg/L, respectively. Response to supramaximal stimulation was not significantly different with 5 mg/L (1/8) compared with 10 mg/L (0/8). Baseline and weekly MAC following daily exposure was 8.4 and 9.0, 8.1, 8.1, and 8.7 mg/L, respectively. MAC reduction was no more than 8% following any drug or dosage. Propofol at 5 and 10 mg/L produced anesthesia, and anesthetic needs were similar following repeated exposure. Propofol was not suitable to test MAC reduction in goldfish in this study.

Perianesthetic morbidity and mortality in dogs undergoing cervical and thoracolumbar spinal surgery.

OBJECTIVE: To evaluate and compare perioperative morbidity and mortality in dogs undergoing cervical and thoracolumbar spinal surgery. STUDY DESIGN: Prospective case series. ANIMALS: 157 dogs undergoing cervical or thoracolumbar spinal surgery. METHODS: Data were collected sequentially on canine cases presented from the Neurology Section of the North Carolina State University Veterinary Teaching Hospital for anesthesia and surgery for cervical spinal cord disease. Simultaneously, data were collected on all thoracolumbar spinal surgery cases during the same time period. Data included signalment, drugs administered, surgical approach, disease process, cardiac arrhythmias during anesthesia, and outcome. RESULTS: Data were collected from 164 surgical events in 157 dogs. There were 52 cervical approaches; four dorsal and 48 ventral. All thoracolumbar surgeries were approached dorsolaterally. Four dogs 4/52 (7.6%) undergoing a cervical approach did not survive to discharge. Two dogs (2/8; 25%) underwent atlanto-axial (AA) stabilization and suffered cardiovascular arrest and two dogs (2/38; 5.2%) undergoing cervical ventral slot procedures were euthanized following anesthesia and surgery due to signs of aspiration pneumonia. All dogs undergoing thoracolumbar surgery survived until discharge (112/112). Mortality in dogs undergoing cervical spinal surgery was greater compared with dogs undergoing thoracolumbar spinal surgery (p = 0.009), however, in dogs undergoing decompressive disc surgery, intraoperative death rates were not different between dogs undergoing a cervical compared with thoracolumbar approaches (p = 0.32) nor was there a significant difference in overall mortality (p = 0.07). CONCLUSION AND CLINICAL RELEVANCE: Overall, dogs undergoing cervical spinal surgery were less likely to survive until discharge compared with dogs undergoing thoracolumbar spinal surgery. Mortality in dogs undergoing cervical intervertebral disc decompression surgery was no different than for dogs undergoing thoracolumbar intervertebral disc decompression surgery. However, dogs undergoing cervical intervertebral disc decompression surgery should be considered at risk for aspiration pneumonia.

Prevalence of onychectomy in cats presented for veterinary care near Raleigh, NC and educational attitudes toward the procedure.

OBJECTIVE: The current prevalence of onychectomy (declawing) in cats is unknown, and education regarding the procedure appears to vary greatly among veterinary schools. The purpose of this project was to determine the prevalence of onychectomized cats near Raleigh, NC and to document the frequency and style (laboratory or lecture) with which the procedure is taught in USA veterinary schools. ANIMALS: One thousand seven hundred ninety four cats ranging in age from 8 days to 21 years, of which 938 (52.3%) were female and 1719 (95.8%) were sterilized. METHODS: Data were collected over a 10-week period regarding cats seen for appointments in five veterinary facilities (two cat-only, two general, and one tertiary). Data collection included signalment and onychectomy status. During this time, 28 veterinary schools were polled regarding education of veterinary students in onychectomy. RESULTS: Three hundred and seventy four (20.8%) cats had undergone onychectomy. A significantly higher percentage of declawed cats were seen in the general practices compared with the other practice types (p < 0.030). Younger cats had a higher rate of onychectomy (p < 0.001). Twenty-six veterinary schools responded to the survey (93%). Fourteen (54%) of the responding schools did not include in their core curriculum a lecture or surgical laboratory providing instruction in the onychectomy procedure. CONCLUSIONS AND CLINICAL RELEVANCE: Almost 21% of cats seen in veterinary hospitals near Raleigh, NC were declawed. Less than 50% of veterinary schools in the USA include a mandatory lecture or laboratory to teach the procedure. There appears to be a discrepancy between the popularity of the onychectomy procedure and the emphasis placed on relevant instruction in veterinary schools in the USA.

The efficacy of alfaxalone for immersion anesthesia in koi carp (Cyprinus carpio).

OBJECTIVE: To characterize the physiologic and behavioral effects of a single induction dose and two maintenance doses of alfaxalone delivered by water immersion in the anesthesia of koi (Cyprinus carpio). STUDY DESIGN: Prospective, within-subject complete crossover design. ANIMALS: Six adult koi (Cyprinus carpio) with a median body weight of 344.5 g (range 292.0-405.0 g). METHODS: Koi were immersed in water containing 10 mg L(-1) alfaxalone until immobile and then maintained with alfaxalone at either 1 or 2.5 mg L(-1) via a recirculating water system. Times for anesthetic induction and recovery periods were recorded. Physiologic and blood gas parameters were evaluated before, during and after the anesthetic trial. Response to noxious stimuli was also assessed. RESULTS: Median anesthesia induction time for all fish was 5.4 minutes. Median recovery time was 11.8 and 26.4 minutes in the 1.0 and 2.5 mg L(-1) doses, respectively, which were significantly different (p = 0.04). Cessation of opercular movement occurred in 0/6 and 4/6 fish exposed to 1.0 and 2.5 mg L(-1) dose respectively. No difference was observed in median heart rate over the duration of the anesthetic events. Response to noxious stimulation was 4/6 and 0/6 in the 1.0 and 2.5 mg L(-1) doses respectively. Oxygenation and ventilation did not change during the experiment, but there was a significant decrease in blood pH along with an increase in blood lactate concentration. CONCLUSION AND CLINICAL RELEVANCE: Administration of alfaxalone, via water immersion, as an induction and maintenance anesthesia agent provided rapid and reliable anesthesia of koi with no mortality. The maintenance dose of 2.5 mg L(-1) was sufficient to prevent response to noxious stimuli but was associated with a clinically relevant depression in opercular rate.

The use of injectable alphaxalone as a single agent and in combination with ketamine, xylazine, and morphine in the Chilean rose tarantula, Grammostola rosea.

This study evaluated the use of the injectable anesthetic, alphaxalone, as a single agent and in combination with ketamine, xylazine, and morphine in the Chilean rose tarantula, Grammostola rosea. Between two and four animals were evaluated for each anesthetic protocol, and two unanesthetized animals were evaluated for comparative purposes. Anesthetic duration, depth, and quality were assessed by scoring responses to tactile and trichobothria stimulation, muscle tone, purposeful movement, righting response, and heart rate throughout each anesthetic event. Alphaxalone administered into the dorsal opisthosoma in the location of the heart at 200 mg/kg produced moderate anesthetic effect with a median duration of 28 min (n = 3; range 25-50). A combination of 200 mg/kg of alphaxalone and 20 mg/kg of ketamine induced a deep anesthetic state with a median anesthetic duration of 27 min (n = 4; range 16-42). The combination of 200 mg/kg of alphaxalone and 20 mg/kg of xylazine produced deep anesthesia with a median duration of 70 min (n = 4; range 37-207). Morphine administered at 5 mg/kg 30 min prior to injection with 200 mg/kg alphaxalone had anesthetic durations of 9 and 30 min (n = 2). Heartbeats could not be detected for periods of 7-27 min following anesthetic induction for the majority of animals receiving the alphaxalone/ketamine and alphaxalone/xylazine anesthetic combinations. No mortality was associated with any of the anesthetic protocols used; however, ambient temperature and ecdysis were identified as important factors that may alter response to anesthetics in these animals.

Alfaxalone as an intramuscular injectable anesthetic in koi carp (Cyprinus carpio).

Fish are commonly anesthetized with MS-222 (tricaine methanesulfonate), a sodium-channel-blocker used as an immersion anesthetic, but its mechanism of action as a general anesthetic is uncertain. Alfaxalone is a neurosteroid that acts at the GABA(A) receptors. Alfaxalone has been evaluated and was deemed successful as an immersion agent in koi carp. Alfaxalone is an effective intramuscular anesthetic in multiple species. A reliable intramuscular anesthetic in fish would be useful in multiple settings. The purpose of this study was to investigate alfaxalone as an intramuscular injectable anesthetic agent in koi carp (Cyprinus carpio). Eight koi carp were utilized in a crossover design. In each trial, six fish received 1 mg/kg, 5 mg/kg, or 10mg/kg of alfaxalone intramuscularly. They were assessed every 15 min for opercular rate and sedation score. The sedation score was based on a visual scale from 0 to 5, 0 indicating no response and 5 indicating absent righting reflex and anesthesia. Anesthetized koi were placed on a fish anesthesia delivery system (FADS). Time to anesthesia/recovery was recorded and heart rate was recorded every 15 min. Anesthesia was achieved in 0/6, 1/6, and 5/6 fish at 1, 5, and 10 mg/kg, respectively. Duration of anesthesia for one fish at 5 mg/kg was 2 hr. At 10 mg/kg, median anesthesia duration was 6.5 (3-10) hr. At 10 mg/kg, prolonged apnea (2-3 hr) was observed in 3/6 fish, 2/3 died under anesthesia, and 1/3 recovered 10 hr post-injection. Median peak sedation scores were 1.5, 2.5, and 5, at 1, 5, and 10 mg/kg, respectively. A dosage of 10 mg/kg alfaxalone resulted in 33% mortality. The duration of anesthesia and opercular rate were unpredictable. Due to variation in response despite consistent conditions, as well as risk of mortality, intramuscular alfaxalone cannot be recommended for anesthesia in koi carp.

Apheresis in three dogs weighing <14 kg.

HISTORY: CaridianBCT apheresis machines require a ~285 mL priming volume (extracorporeal blood) that is withdrawn from the patient in ~10 minutes. Therefore, apheresis in dogs has generally been limited to dogs > ~20 kg to assure <20% of the blood volume is removed in the priming phase. ANIMALS/PHYSICAL EXAMINATION: Three dogs weighing <14 kg (13.6, 10.5, and 9.9 kg) with lymphoma that underwent apheresis. MANAGEMENT: The dogs were premedicated for placement of apheresis catheters with hydromorphone (0.1 mg kg(-1) ) IM. Anesthesia was induced with propofol, to effect, intravenously and general anesthesia was maintained with isoflurane in oxygen. Following catheter placement, dogs were allowed to recover from isoflurane but were kept sedated with either a dexmedetomidine constant rate infusion (CRI) or a propofol CRI. Real time autologous blood priming was not performed in any of the dogs. Instead, priming solutions were composed of a combination of hetastarch, lactated Ringer's solution, and/or autologous blood that was harvested 4 days before the procedure. During apheresis, dogs received anticoagulant citrate-dextrose, solution-A (ACD-A) to prevent clotting and 10% calcium gluconate as needed to maintain normal ionized calcium concentrations. Dogs were monitored for cardiovascular and cardiopulmonary stability, anemia and lactic acidosis. FOLLOW-UP: All of the dogs had cardiovascular and cardiopulmonary values within clinically acceptable ranges. Immediately following apheresis all of the dogs were mildly to moderately anemic (PCV; 17-35%) although none of the dogs required a transfusion or had an increased lactate concentration. CONCLUSIONS: Dogs as small as 9.9 kg can successfully undergo apheresis with a variety of priming solutions. Dexmedetomidine or propofol given as a CRI provides sufficient sedation for this procedure.

Efficacy of alfaxalone for intravascular anesthesia and euthanasia in blue crabs (Callinectes sapidus).

The objective of this study was to characterize the behavioral effects and changes in heart rate of four doses of alfaxalone delivered by intravascular injection to blue crabs (Callinectes sapidus). Thirty (male, n = 27; female, n = 3) blue crabs were randomly assigned to one of four treatment groups of alfaxalone: eight animals were assigned to each of the 5-, 10-, and 15-mg/kg treatment groups, and the remaining six animals were assigned to the 100-mg/kg group. Times for anesthetic induction and recovery periods were recorded. Righting reflex, defensive posturing, and heart rate were evaluated before, during, and after the anesthetic trial. Anesthesia was induced in all 14 animals consolidated into the high-dosage group (15 mg/kg [n = 8] and 100 mg/kg [n = 6]), which was significantly greater than 8 of 16 animals in the low-dosage group (5 mg/kg [n = 2] and 10 mg/kg [n = 6]). Median anesthesia induction time for all crabs was 0.4 min, with no significant difference in induction time between groups observed. Median recovery time was 9.4 min (n = 2), 6.1 min (n = 5), 11.3 min (n = 8), and 66.1 min (n = 5) for the 5-, 10-, 15-, and 100-mg/kg groups, respectively. Recovery times were significantly longer for crabs exposed to an induction dose of 100 mg/kg compared with the 10- and 15-mg/kg induction doses. A significant decrease in the median heart rate was observed between the baseline value and that observed at both induction and 5 min postinjection in the 100-mg/kg dose trial. Two mortalities were observed during the anesthesia trials (n = 1, 10 mg/kg; n = 1, 100 mg/kg), both associated with the autotomization of limbs. In summary, the intravascular administration of alfaxalone at 15 mg/kg provided rapid and reliable sedation, whereas alfaxalone administered at 100 mg/kg produced rapid and long lasting anesthesia.

Development of a minimum-anesthetic-concentration depression model to study the effects of various analgesics in goldfish (Carassius auratus).

Teleost fish demonstrate the neurophysiologic capacity to experience pain and analgesia. A common model for assessing analgesic effect is the reduction of minimum anesthetic concentration (MAC). The present study adapted the model of MAC depression to evaluate the analgesic effects of morphine, butorphanol, medetomidine, and ketoprofen in goldfish (Carassius auratus). MAC was determined by an up-down method of sequential population sampling, anesthetizing fish with tricaine methanesulfonate (MS-222) in concentration increments of 10 parts per million (ppm), and using intramuscular needle insertion as a supramaximal noxious stimulus. Baseline MAC was determined in triplicate at the beginning (MACi) and conclusion (MACe) of the experiment (approximately 60 days). For drug trials, MAC was redetermined 1 hr after administration of morphine (10, 20, 40 mg/kg i.m.), butorphanol (0.1, 0.2, 0.4 mg/kg i.m.), medetomidine (0.01, 0.015, 0.025 mg/kg i.m.), ketoprofen (0.5, 1.0, 2.0 mg/kg i.m.), or saline control. Each drug/dose was tested in random order with a > 6-day washout period. MACi and MACf were 163 and 182 ppm, respectively, and were significantly different from each other (P = 0.02). All doses of morphine and ketoprofen decreased MAC below MACi. The highest dose of medetomidine decreased MAC below MACi. The lowest dose of butorphanol decreased MAC below MACi, but higher doses increased MAC above MACf. The authors conclude that MAC determination in fish using MS-222 was feasible and reproducible in the short term. The fact that MAC increased over time and/or exposure may limit the usefulness of MS-222 in MAC depression studies. Morphine and ketoprofen decrease anesthetic needs in goldfish and may provide analgesia.