Evaluation of the analgesic effect of fentanyl-ketamine and fentanyl-lidocaine constant rate infusions in isoflurane-anesthetized dogs undergoing thoracolumbar hemilaminectomy.

OBJECTIVE: To evaluate anesthetic conditions and postoperative analgesia with the use of intraoperative constant rate infusions (CRIs) of fentanyl-lidocaine or fentanyl-ketamine in dogs undergoing thoracolumbar hemilaminectomy. STUDY DESIGN: Prospective, randomized, blinded, clinical study. ANIMALS: A total of 32 client-owned dogs. METHODS: Dogs were premedicated with fentanyl (5 µg kg-1) administered intravenously (IV), anesthesia was induced with IV alfaxalone and maintained with isoflurane. Fentanyl (0.083 µg kg-1 minute-1) was infused IV with either ketamine (0.5 mg kg-1; then 40 µg kg-1 minute-1; group KF) or lidocaine (2 mg kg-1; then 200 µg kg-1 minute-1; group LF) assigned randomly. Heart rate, noninvasive arterial pressures, respiratory rate, esophageal temperature, end-tidal partial pressure of carbon dioxide and isoflurane concentration were recorded throughout anesthesia. Maintenance of anesthesia, recovery and postoperative pain (Glasgow Composite Pain Scale) were scored. Cardiopulmonary data were analyzed using a two-way anova with repeated measures, demographics of the two groups with a t test, and scores with Mann-Whitney U test, with p < 0.05. RESULTS: All dogs recovered from anesthesia without complications. No significant difference was found between groups for cardiopulmonary variables, total anesthesia time, sedation score and requirement for postoperative sedation or for rescue analgesia. Anesthetic maintenance score was of lower quality in KF than in LF [median (interquartile range): 0 (0-0.5) versus 0 (0-0); p = 0.032)], but still considered ideal. Recovery score was higher and indicative of less sedation in LF than in KF [1 (1-1.5) versus 0.5 (0-1); p < 0.0001]. Pain score was higher in KF than in LF [2 (1-3) versus 1 (1-2); p = 0.0009]. CONCLUSIONS AND CLINICAL RELEVANCE: Both CRIs of KF and LF provided adequate anesthetic conditions in dogs undergoing thoracolumbar hemilaminectomy. Based on requirement for rescue analgesia, postoperative analgesia was adequate in both groups.

Review of non-invasive blood pressure measurement in animals: Part 2 - Evaluation of the performance of non-invasive devices.

Arterial blood pressure is a common parameter evaluated in conscious and anesthetized veterinary patients for a variety of reasons. Non-invasive blood pressure measurement techniques, such as Doppler ultrasound and oscillometry, are attractive in certain veterinary patients due to their availability and ease of use. The greatest limitation to non-invasive blood pressure monitoring can be its inaccuracy, particularly in hypotensive or hypertensive patients and in certain species. Part 1 of this 2-part review summarized the current techniques available to non-invasively measure arterial blood pressure in veterinary species and discussed validation of non-invasive devices. Part 2 summarizes the veterinary literature that evaluates the use of non-invasive blood pressure measurement techniques in conscious and anesthetized species and develops general conclusions for proper use and interpretation of non-invasive blood pressure devices.

Mesure de la pression sanguine de manière non-invasive chez les animaux. Partie 2 ­ Évaluation de la performance des équipements non-invasifs. La pression sanguine artérielle est un paramètre fréquemment évalué chez les patients vétérinaires conscients et anesthésiés pour une variété de raisons. Les techniques noninvasives de mesure de la pression sanguine, telles que les ultrasons Doppler et l'oscillométrie, sont intéressantes chez certains patients vétérinaires étant donné leur disponibilité et leur facilité d'utilisation. La principale limitation du suivi de la pression sanguine par des méthodes non-invasives peut être son imprécision, particulièrement chez des patients hypotensifs ou hypertensifs, et chez certaines espèces. La première partie de cette revue en deux parties résumait les techniques présentement disponibles pour mesurer de manière non-invasive la pression sanguine artérielle chez des espèces animales et discutait de la validation des équipements non-invasifs. La deuxième partie résume la littérature vétérinaire qui évalue l'utilisation de techniques non-invasives de mesure de la pression sanguine chez des espèces conscientes et anesthésiées et développe des conclusions générales pour l'utilisation et l'interprétation appropriées des équipements non-invasifs de mesure de la pression sanguine.(Traduit par Dr Serge Messier).

Non-invasive blood pressure measurement in animals: Part 1 - Techniques for measurement and validation of non-invasive devices.

Arterial blood pressure is a common parameter evaluated in conscious and anesthetized veterinary species. Non-invasive blood pressure measurement techniques, such as Doppler ultrasonic flow detector and oscillometry, are attractive in certain animals due to their availability and ease of use. The greatest limitation to non-invasive blood pressure monitoring can be its inaccuracy, particularly in hypotensive or hypertensive patients and in certain species. Part 1 of this 2-part review summarizes the current techniques available to non-invasively measure arterial blood pressure in animals and discusses validation of non-invasive devices. Part 2 summarizes the veterinary literature that evaluates the use of non-invasive blood pressure measurement techniques in conscious and anesthetized species and develops general conclusions for proper use and interpretation of data from non-invasive blood pressure devices.

Mesures de la pression sanguine chez les animaux de manière non-invasive: Partie 1 ­ Techniques pour mesurer et validation d'appareils non-invasifs. La pression sanguine artérielle est un paramètre fréquemment évalué chez les espèces animales conscientes et anesthésiées. Des techniques non-invasives de mesure de la pression sanguine, telles que le détecteur ultra-sonique de flot Doppler et l'oscillométrie, sont attirantes chez certains animaux étant donné leur disponibilité et facilité d'utilisation. La plus grande limitation au suivi non-invasif de la pression sanguine peut être son imprécision, particulièrement chez les patients hypotensifs ou hypertensifs et chez certaines espèces. La partie 1 de cette revue en deux parties résume les techniques présentement disponibles pour mesurer de manière non-invasive la pression sanguine artérielle chez des animaux et discute la validation d'équipements non-invasifs. La partie 2 résume la littérature vétérinaire qui évalue l'utilisation de techniques de mesure non-invasives de la pression sanguine chez des espèces conscientes et anesthésiées et développe des conclusions générales pour l'utilisation appropriée et l'interprétation des données obtenues d'équipements noninvasifs de mesure de la pression sanguine.(Traduit par Dr Serge Messier).

Comparison of calculated lumbosacral epidural volumes of injectate using a dose regimen based on body weight versus length of the vertebral column in dogs.

OBJECTIVE: To compare volumes for epidural injection calculated on body weight or the length from sacrococcygeal space to occipital crest in dogs. STUDY DESIGN: Prospective study. ANIMALS: A total of 431 dogs weighing mean ± standard deviation (range) 24.6 ± 16.1 (1.3-88.0) kg and with vertebral column length 67.6 ± 38.4 (24.8-119.4) cm. METHODS: Dogs were separated into specific weight groups and body condition scores (BCS; 1-5): small (<10 kg), medium 10 to <25 kg), large (25 to <45 kg) and giant (≥45 kg). Calculations for a lumbosacral epidural dose were 0.2 mL kg-1 and for vertebral column length: 0.05 mL cm-1 (<50 cm), 0.07 mL cm-1 (50 to <70 cm), 0.08 mL cm-1 (70 to <80 cm), and 0.11 mL cm-1 (≥80 cm). A split plot anova (p < 0.05) with weight, length and BCS as factors was used. RESULTS: A significantly larger volume was calculated for length than for weight in small (p < 0.0001-0.0003, BCS 2-5), medium (p < 0.0001-0.0076, BCS 2-5), and large dogs (p ≤ 0.0007-0.0019, BCS 2,3). In large (BCS 4,5) and giant dogs (BCS 2,3), both calculated volumes were similar. In giant dogs (BCS 4,5), a significantly smaller volume was calculated for length (p ≤ 0.0002-0.0165). Regardless of BCS, small (2.18 versus 1.12), medium (3.99 versus 3.16), and large dogs (7.38 versus 6.82) had larger calculated volumes (mL) for length than for weight (p < 0.0001), whereas giant dogs (10.04 versus 10.91) had smaller calculated volumes. CONCLUSIONS: and clinical relevance Mathematically, the epidural volume of injectate varies with the calculation method and is affected by BCS. Small and medium dogs have larger calculated volumes based on length than on weight, and this difference tends to disappear or revert as size increases.

Anatomical characterization of the brachial plexus in dog cadavers and comparison of three blind techniques for blockade.

OBJECTIVES: To describe the ventral spinal nerve rami contribution to the formation of the brachial plexus (BP), and to compare ease of performing and nerve staining between three blind techniques for BP blockade in dogs. STUDY DESIGN: Prospective, randomized, blind study. ANIMALS: A total of 18 dog cadavers weighing 28.2 ± 9.7 kg (mean ± standard deviation). METHODS: Dogs were randomly assigned to two of three BP treatments: traditional approach (TA), perpendicular approach (PA), and axillary approach (AA). Dye (0.2 mL kg-1) was injected in the left BP using a spinal needle; another BP treatment was used in the right BP. Landmarks (L) included: L1, midpoint between point of the shoulder and sixth cervical (C6) transverse process; L2, scapulohumeral joint; and L3, first rib. For TA, the needle was introduced craniocaudally through L1, medial to the limb and cranial to L3. For PA, the needle was directed perpendicular and caudal to L2, aligned with L1, until cranial to L3. For AA, the needle was directed ventrodorsally, parallel and cranial to L3 until at L1. All BPs were scored for dyeing quality [0 (poor) to 5 (excellent)]. The left BP was dissected for nerve origins. Durbin test was used to compare scores (p < 0.05). RESULTS: In all dogs, the musculocutaneous nerve originated from C7 and C8; the radial nerve from C8, the first thoracic vertebra (T1) (16/18 dogs) and C7 (2/18); and the median and ulnar nerves from C8, T1 (17/18) and C7 (1/18). Respective raw scores and adjusted scores for the incomplete block design were not significantly different (p = 0.72; ranks TA 16.5, PA 19.0, AA 18.5). CONCLUSIONS AND CLINICAL RELEVANCE: The musculocutaneous, median, ulnar and radial nerves originate from C7, C8 and T1. Regardless of the technique, knowledge of anatomy and precise landmarks are relevant for correct dye dispersion.

Intra-operative hyperthermia in a young Angus bull with a fatal outcome.

A healthy, 9-month-old black Angus bull was presented for elective penile-preputial translocation and caudal epididymectomy. After premedication and induction, general anesthesia was maintained with inhalant anesthetic. Over an hour into the anesthetic period the bull developed severe hyperthermia and hypercapnia that resulted in fatality despite treatment efforts.

Hyperthermie peropératoire chez un jeune taureau Angus produisant un résultat mortel. Un taureau Black Angus en santé et âgé de 9 mois a été présenté pour une translocation pénile-préputiale non urgente et une épididymectomie caudale. Après la prémédication et l'induction, l'anesthésie générale a été maintenue avec un anesthésique par inhalation. Une heure après le début de la période d'anesthésie, le taureau a développé une hyperthermie et une hypercapnie graves qui ont entraîné la mort malgré des efforts de traitements.(Traduit par Isabelle Vallières).

Bilateral laryngeal paralysis in a dog secondary to laryngeal osseous metaplasia.

A 7-year-old spayed female Lurcher was evaluated for a chronic history of increased upper respiratory noise. Advanced imaging including digital radiography and pre- and post-contrast computed tomography (CT) scan confirmed the presence of an ill-defined soft tissue mineralized mass of the ventral larynx. Histopathology demonstrated pleocellular myositis and fasciitis with osseous metaplasia.

Paralysie laryngée bilatérale chez un chien secondaire à la métaplasie osseuse. Une chienne Lurcher stérilisée âgée de 7 ans a été évaluée pour une anamnèse chronique de bruit des voies respiratoires supérieures. Une imagerie avancée, dont une radiographie numérique et une image par tomodensitométrie avant et après contraste a confirmé la présence d'une masse minéralisée floue de tissus mous dans le larynx ventral. Unexamen histopathologique a démontré une myosite pléocellulaire et une fasciite avec une métaplasie osseuse.(Traduit par Isabelle Vallières).

Hepatic alveolar hydatid disease (Echinococcus multilocularis) in a boxer dog from southern Ontario.

A 2-year-old boxer dog from southern Ontario was evaluated because of acute onset lethargy. Exploratory laparotomy revealed a hemorrhagic, destructive, liver mass. Histology, immunohistochemistry, and polymerase chain reaction confirmed Echinococcus multilocularis as the cause of the hepatic mass. This constitutes the first description of endemic E. multilocularis in Ontario.

Hydatidose alvéolaire hépatique(Echinococcus multilocularis)chez un chien Boxer du Sud de l'Ontario. Un chien Boxer âgé de 2 ans du Sud de l'Ontario a été évalué en raison d'un début soudain d'une léthargie. Une laparatomie exploratoire a révélé une masse hépatique hémorragique et destructrice. L'histologie, l'immunohistochimie et l'amplification en chaîne par la polymérase ont confirmé Echinococcus multilocularis comme la cause de la masse hépatique. Il s'agit de la première description d'E. multilocularis endémique en Ontario.(Traduit par Isabelle Vallières).

Comparison of the effect of three intramuscular sedation protocols on packed cell volume and total protein in cats.

OBJECTIVES: The aim of this study was to evaluate the change in packed cell volume (PCV) and total protein following intramuscular preanesthetic sedation with one of three drug combinations in cats. METHODS: Thirty client-owned cats were enrolled in this prospective, randomized, blinded, clinical study. A venous blood sample was obtained prior to administration of any sedation and PCV, total protein, electrolytes (Na+, K+, Cl-, iCa2+), glucose and lactate were measured. Cats were randomly assigned to receive one of three intramuscular sedation protocols (n = 10 cats/protocol): methadone 0.2 mg/kg + acepromazine 0.02 mg/kg (MA), methadone 0.2 mg/kg + dexmedetomidine 5 µg/kg (MD) or methadone 0.2 mg/kg + midazolam 0.2 mg/kg + alfaxalone 2 mg/kg (MMA). Twenty-five minutes later, cats were assessed for level of sedation followed by another venous blood sampling to evaluate the same variables as above. RESULTS: There were no significant differences in demographics (age, weight, sex) between groups. Level of sedation was significantly higher in MMA cats. Within groups, after premedication, PCV and hemoglobin significantly decreased in all groups, total protein significantly decreased in the MA and MMA groups and glucose significantly increased in the MD group. For electrolytes, statistical changes were not clinically relevant; Cl- mean difference was significantly different between MA and MD; in the MD group Na+ and Cl- significantly decreased and in the MMA group Cl- significantly increased. CONCLUSIONS AND RELEVANCE: All three sedation protocols caused significant decreases in PCV and hemoglobin in healthy cats.

A randomized clinical trial to compare ketamine-butorphanol-azaperone-medetomidine and detomidine-etorphine-acepromazine for anesthesia of captive Przewalski horses (Equus przewalskii).

OBJECTIVE: To compare ketamine-butorphanol-azaperone-medetomidine (KBAM) to detomidine-etorphine-acepromazine (DEA) for field anesthesia in captive Przewalski horses (Equus przewalskii). ANIMALS: 10 adult Przewalski horses. PROCEDURES: A prospective randomized crossover trial was conducted. Each horse was immobilized once with KBAM (200 mg ketamine, 109.2 mg butorphanol, 36.4 mg azaperone, and 43.6 mg medetomidine) and once with DEA (40 mg detomidine premedication, followed 20 minutes later by 3.9 to 4.4 mg etorphine and 16 to 18 mg acepromazine). Both protocols were administered by IM remote dart injection with a washout period of 6 months between treatments. Selected cardiorespiratory variables and quality of anesthesia were recorded. Antagonists were administered IM (KBAM, 215 mg atipamezole and 50 mg naltrexone; DEA, 4 mg RX821002 and 100 mg naltrexone). RESULTS: All horses were anesthetized and recovered uneventfully. Inductions (DEA, 6.8 min; KBAM, 11.6 min; P = 0.04) and recoveries (DEA, 3.2 min; KBAM, 19.6 min; P < 0.01) were faster with DEA compared with KBAM. Quality scores for induction and recovery did not differ between protocols, but maintenance quality was poorer for DEA (P < 0.01). Clinical concerns during DEA immobilizations included apnea, severe hypoxemia (arterial partial pressure of oxygen < 60 mm Hg), muscle rigidity, and tremors. Horses treated with KBAM were moderately hypoxemic, but arterial partial pressures of oxygen were higher compared with DEA (P < 0.01). CLINICAL RELEVANCE: Captive Przewalski horses are effectively immobilized with KBAM, and this protocol results in superior muscle relaxation and less marked hypoxemia during the maintenance phase, but slower inductions and recoveries, compared with DEA.

Bovine IFNGR2, IL12RB1, IL12RB2, and IL23R polymorphisms and MAP infection status.

Mycobacterium avium ssp. paratuberculosis (MAP) infection causes a chronic granulomatous inflammatory condition of the bovine gut that is characterized by diarrhea, progressive weight loss, and emaciation, and ultimately leads to loss in productivity and profitability of dairy operations. The host cytokine machinery is known to play an important role in protecting against MAP infection. Therefore, the goal of the present study was to assess whether polymorphisms in candidate genes encoding important cytokines and cytokine receptors are associated with MAP infection status of dairy cattle. MAP infection status was evaluated based on serum and milk enzyme-linked immunosorbent assays (ELISAs) for MAP-specific antibodies. Twenty previously reported polymorphisms in genes encoding bovine interferon gamma (IFNG), IFNGR1, IFNGR2, IL22, IL22RA1, IL12RB1, IL12RB2, and IL23R were genotyped in a resource population of 446 dairy Holsteins with known MAP infection status, and logistic regression was used to assess the statistical association with a binomial MAP infection status phenotype. Four SNPs in IFNGR2, IL12RB1, IL12RB2, and IL23R were found to be associated with the MAP infection status of the resource population. These results underscore the importance of cytokines and their receptors in conferring protection against MAP infection and warrant further functional characterization of these associations.

Sympathomimetics in veterinary species under anesthesia.

Sympathomimetic drugs mimic the physiological action of the sympathetic nervous system through interaction with adrenergic receptors. These drugs are commonly used to provide cardiovascular support in many veterinary species. Despite their common use, the literature evaluating their effectiveness can be somewhat limited depending on the species. This review details the mechanism of action of various sympathomimetic drugs and summarizes the literature that is available describing the efficacy of these drugs and their use in anesthetized veterinary species.

Alternatives to Opioid Analgesia in Small Animal Anesthesia: Alpha-2 Agonists.

Alpha-2 agonists have potent analgesic effects, in addition to their sedative actions. Alpha-2 agonists provide analgesia through any of several routes of administration, including parenteral, oral, epidural or intrathecal and intraarticular, because of spinal and supraspinal actions. Systemic doses are short acting, whereas local administration at the site of action result in longer analgesic effects. The potent cardiovascular and respiratory effects of alpha-2 agonists should be considered when used as analgesics.

Comparison of 3 blind brachial plexus block techniques during maintenance of anesthesia and postoperative pain scores in dogs undergoing surgical procedures of the thoracic limb.

The degree of analgesia provided by blind techniques for brachial plexus blocks (BPBs) has not been compared in clinical cases undergoing surgery of the thoracic limb. The objective of this study was to evaluate the anesthetic conditions and postoperative analgesia resulting from 3 different BPB local anesthetic techniques in canine patients undergoing such surgery. Twenty-four client-owned dogs received a standardized premedication/induction protocol (hydromorphone and acepromazine/propofol), maintained with isoflurane in oxygen using mechanical ventilation, in a prospective, randomized, blinded clinical trial. Before surgery, dogs received 1 of 3 anatomical BPB techniques: traditional, perpendicular, or axillary, with 0.2 mL/kg body weight (BW) of bupivacaine 0.5%. Cardiorespiratory variables and isoflurane end-tidal concentrations were recorded throughout anesthesia. Scores for anesthetic maintenance (0-best to 4-responsive), recovery quality (0-not responsive to 3-responsive), and Glasgow pain scale were recorded for up to 24 h postoperatively. All dogs recovered uneventfully from anesthesia and no differences in the measured variables or scores were noted among groups, during and after anesthesia. When thoracic limb amputations in each of the 3 groups (n = 9; 4 in traditional, 3 in perpendicular, 2 in axillary) were compared to the other surgical procedures (n = 15); however, scores for anesthetic maintenance were higher [0 (0 to 1) versus 0 (0 to 0); median (interquartile range)], recovery [1 (0 to 2) versus 0 (0 to 0)], and pain [2.4 (2.4 to 3.0) versus 1.6 (1.4 to 2.2)] in the first 3 h post-extubation. Surgery times were also longer with amputations [115 min (100 to 138 min) versus 50 min (41 to 90 min)]. The 3 BPB techniques provided similar anesthesia and postoperative pain scores. Despite higher pain scores in thoracic limb amputations than in less invasive surgeries, the BPB appeared to provide significant comfort.

Le degré d'analgésie fournie par les blocs à l'aveugle du plexus brachial (BPBs) n'a pas été comparé lors de cas cliniques soumis à une chirurgie du membre thoracique. La présente étude visait à évaluer les conditions anesthésiques et l'analgésie post-opératoire résultant de trois techniques différentes d'anesthésie locale par BPB chez des patients canins soumis à une chirurgie. Vingt-quatre chiens appartenant à des propriétaires ont reçu une prémédication/induction standardisée (hydromorphone et acépromazine/propofol), avec maintien à l'isoflurane dans de l'oxygène en utilisant une ventilation mécanique, dans une étude clinique prospective, randomisée, et à l'aveugle. Avant la chirurgie, les chiens ont reçu un BPB par une des trois techniques anatomiques : traditionnelle, perpendiculaire, ou axillaire, avec 0,2 mL/kg de poids corporel de bupivacaïne 0,5 %. Les variables cardiorespiratoires et les concentrations d'isoflurane en fin d'expiration furent enregistrées tout au long de l'anesthésie. Les pointages pour le maintien de l'anesthésie (0-meilleur à 4-réactif), la qualité du rétablissement (0-non réactif à 3-réactif), et l'échelle de la douleur de Glasgow ont été notés jusqu'à 24 h post-opération. Tous les chiens ont récupéré sans problème de l'anesthésie et aucune différence mesurable dans les variables mesurées ou les pointages ne fut notée parmi les groupes, durant ou après l'anesthésie. Toutefois, lorsque les amputations du membre thoracique dans chacun des trois groupes (n = 9; 4 dans la traditionnelle, 3 dans la perpendiculaire, 2 dans l'axillaire) furent comparées aux autres procédures chirurgicales (n = 15), les pointages pour le maintien de l'anesthésie étaient plus élevés [0 (0 à 1) versus 0 (0 à 0); médiane (écart interquartile)], rétablissement [1 (0 à 2) versus 0 (0 à 0)], et douleur [2,4 (2,4 à 3,0) versus 1,6 (1,4 à 2,2)] dans les 3 h suivant l'extubation. La durée des chirurgies étaient également plus longues lors des amputations [115 min (100 à 138 min) versus 50 min (41 à 90 min)]. Les trois techniques de BPB produisaient des pointages similaires d'anesthésie et de douleur postopératoire. Malgré des pointages de douleur plus élevés lors d'amputations du membre thoracique que lors de chirurgies moins invasives, les BPB semblent fournir un confort significatif.(Traduit par Docteur Serge Messier).