Gabapentin, melatonin, and acepromazine combination prior to hospital visits decreased stress scores in aggressive and anxious dogs in a prospective clinical trial.

OBJECTIVE: To evaluate sedative and behavioral effects of a client-administered preappointment protocol with PO gabapentin and melatonin and oral-transmucosal acepromazine (GMA protocol). ANIMALS: 45 client-owned dogs between 1 and 12 years old that underwent standardize examinations between February and August 2021. METHODS: In this clinical trial, dogs with a history of anxiety, fearfulness, and/or aggression during hospital visits were assessed and videotaped before (baseline) and after administration of the GMA protocol. For the second visit, owners administered PO gabapentin (20 to 25 mg/kg) in the evening prior to the next visit and PO gabapentin (20 to 25 mg/kg), PO melatonin (3 to 5 mg/dog), and oral-transmucosal acepromazine (0.05 mg/kg) 90 to 120 minutes prior to the second appointment. Examinations were performed, and behavioral stress and sedation levels were evaluated with semiquantitative rating scales. Randomized videos were analyzed, and a paired t test was used to compare stress and sedation scores between baseline and GMA. A Pearson correlation coefficient was used to evaluate the effect of age on the scores. RESULTS: Stress scores were significantly lower after the GMA protocol, and sedation scores were significantly higher when compared to baseline (21.84 vs 27.11 and 1.39 vs 0.68, respectively). A significant correlation between increasing age and lower stress scores post-GMA and higher sedation scores post-GMA were observed. CLINICAL RELEVANCE: Preappointment administration of the GMA protocol reduced signs of stress, fear, and fear-based aggression during hospital visits and provided sedation in this dog population. This protocol could represent an adjunct tool for veterinarians to improve quality of care and reduce animal-related injury.

Post-operative Pain Assessment Following Tooth Extraction Using Liposomal Encapsulated Bupivacaine as a Local Anesthetic in Dogs.

The objective of this study was to evaluate owner assessment of appetite, demeanor, and mouth soreness following dental extractions in dogs receiving either bupivacaine hydrochloride (BH) or liposomal encapsulated bupivacaine (LEB) for dental blocks. Thirty healthy, adult dogs requiring dental extractions were enrolled in the study. All procedures were completed with dogs under general anesthesia. A non-steroidal anti-inflammatory drug was administered subcutaneously in the preoperative period. Dogs were randomly assigned to receive BH or LEB. An owner assessment to evaluate appetite, demeanor, and soreness of mouth was completed at the end of both the first and second day after discharge from the hospital. The total of the owner assessments for day 1 and both days combined was significantly lower for dogs receiving LEB (P = .007). There were no differences in the number of extractions (P = .21), time from block to evaluations (P = .07), in-hospital pain assessments (P = .99), or number of dogs requiring rescue analgesia (P = .99). This study concluded, dogs that received LEB for dental blocks had improved appetite and demeanor, and reduced soreness of mouth, as evaluated by the owner two days postoperatively, when compared to dogs who received BH.

Anesthetic Considerations in Dogs and Cats with Diabetes Mellitus.

Understanding the effects of diabetes and hyperglycemia on hydration, acid-base status, and immune function is paramount to safely anesthetizing diabetic cats and dogs. Preoperative stabilization of glucose concentrations, hydration, and electrolyte imbalances is key to minimizing morbidity and mortality. Blood glucose monitoring perioperatively will help guide insulin and dextrose administration. Specific anesthetic considerations, and peri-anesthetic management of animals with diabetes mellitus, including anesthetic drugs and recommended insulin protocols are discussed.

Effect of inhaled albuterol on whole blood potassium concentrations in dogs.

BACKGROUND: Albuterol by inhalation (IH) is a common treatment for hyperkalemia in humans but its effect on blood potassium concentrations in dogs is unknown. OBJECTIVE: Determine whether albuterol (IH) decreases blood potassium concentrations in healthy normokalemic dogs and if effects are dose-dependent. ANIMALS: Ten healthy dogs. METHODS: Prospective, crossover experimental study. Albuterol sulfate was administered at a low-dose (90 µg) in phase I and, 7 days later, high-dose (450 µg) in phase II. Blood potassium and glucose concentrations (measured via blood gas analyzer) and heart rates were obtained at baseline and then 3, 5, 10, 15, 30, 60, 90, 120, 180, and 360 minutes after inhaler actuation. RESULTS: Blood potassium concentrations decreased rapidly after albuterol delivery with a significant reduction compared to baseline within 30 minutes in both phases (P = .05). The potassium nadir concentration of phase I occurred at 60 minutes (mean, SD; 4.07 mmol/L, 0.4) and was significantly decreased from baseline, (4.30 mmol/L, 0.3; t(9) = 2.40, P = .04). The potassium nadir concentration of phase II occurred at 30 minutes (mean, SD; 3.96 mmol/L, 0.39) and was also significantly decreased from baseline, (4.33 mmol/L, 0.4; t(9) = 2.22, P = .05). The potassium nadir concentration decreased by 0.1 mmol/L for each 10 µg/kg increase in dose of albuterol (P = .01). Five dogs had ≥1 hyperglycemic measurement (ie, >112 mg/dL). No median heart rate was tachycardic nor was any mean blood glucose concentration hyperglycemic at any time point. CONCLUSION AND CLINICAL IMPORTANCE: Albuterol IH decreases blood potassium concentrations in a dose-dependent manner without clinically meaningful alterations to heart rate or blood glucose concentrations in healthy dogs. The mean decrease in potassium concentration at the high-dose of albuterol was modest (0.38 mmol/L).

Oral histiocytic sarcoma in a cat with mandibular invasion and regional lymph node metastasis.

CASE SUMMARY: An 11-year-old female spayed domestic medium-hair cat presented for dental prophylaxis, at which time no oral mass was appreciated. Fifteen days after a dental cleaning, a mass expanding the oral mucosa of the rostral mandible was identified. An incisional biopsy revealed that the oral mucosa was infiltrated by neoplastic round-to-spindloid mesenchymal cells arranged in streams and small, dense aggregates consistent with an undifferentiated sarcoma. The patient was managed medically for approximately 6 months following the diagnosis, but, owing to declining health, euthanasia was elected and a post-mortem examination was performed. On post-mortem examination, the previously described neoplastic cells were infiltrating the rostral mandible and had metastasized to the right submandibular lymph node. Immunohistochemistry performed during the postmortem examination found that neoplastic cells were positive for Iba-1, CD18 and CD204, and negative for MUM-1, S100, Melan-A and E-cadherin, favoring a diagnosis of oral histiocytic sarcoma. Although recently recognized in cats, feline oral histiocytic sarcoma is rare, the tumor's immunohistochemical profile is unstandardized, and the tumor's behavior and prognosis are unclear. The diagnosis is challenging if small incisional biopsies are submitted and the neoplasm is poorly differentiated. This case report discusses the clinical, macroscopic, microscopic and immunohistochemical features of oral histiocytic sarcoma in a cat with mandibular invasion and submandibular lymph node metastasis. RELEVANCE AND NOVEL INFORMATION: Feline primary oral histiocytic sarcoma is rare and tumor behavior and prognosis are unclear. This report broadens the immunohistochemical features of the tumor and recognizes mandibular invasion and submandibular lymph node metastasis.

Evaluation of the perioperative stress response from dexmedetomidine infusion alone, with butorphanol bolus or remifentanil infusion compared with ketamine and morphine infusions in isoflurane-anesthetized horses.

OBJECTIVE: To evaluate perioperative stress-related hormones in isoflurane-anesthetized horses administered infusions of dexmedetomidine alone or with butorphanol or remifentanil, compared with ketamine-morphine. STUDY DESIGN: Randomized, prospective, nonblinded clinical study. ANIMALS: A total of 51 horses undergoing elective surgical procedures. METHODS: Horses were premedicated with xylazine, anesthesia induced with ketamine-diazepam and maintained with isoflurane and one of four intravenous infusions. Partial intravenous anesthesia (PIVA) was achieved with dexmedetomidine (1.0 µg kg-1 hour-1; group D; 12 horses); dexmedetomidine (1.0 µg kg-1 hour-1) and butorphanol bolus (0.05 mg kg-1; group DB; 13 horses); dexmedetomidine (1.0 µg kg-1 hour-1) and remifentanil (3.0 µg kg-1 hour-1; group DR; 13 horses); or ketamine (0.6 mg kg-1 hour-1) and morphine (0.15 mg kg-1, 0.1 mg kg-1 hour-1; group KM; 13 horses). Infusions were started postinduction; butorphanol bolus was administered 10 minutes before starting surgery. Blood was collected before drugs were administered (baseline), 10 minutes after ketamine-diazepam, every 30 minutes during surgery and 1 hour after standing. Mean arterial pressure (MAP), pulse rate, end-tidal isoflurane concentration, cortisol, nonesterified fatty acids (NEFA), glucose and insulin concentrations were compared using linear mixed models. Significance was assumed when p < 0.05. RESULTS: Within D, cortisol was lower at 120-180 minutes from starting surgery compared with baseline. Cortisol was higher in KM than in D at 60 minutes from starting surgery. Within all groups, glucose was higher postinduction (except DR) and 60 minutes from starting surgery, and insulin was lower during anesthesia and higher after standing compared with baseline. After standing, NEFA were higher in KM than in DB. In KM, MAP increased at 40-60 minutes from starting surgery compared with 30 minutes postinduction. CONCLUSIONS AND CLINICAL RELEVANCE: Dexmedetomidine suppressed cortisol release more than dexmedetomidine-opioid and ketamine-morphine infusions. Ketamine-morphine PIVA might increase catecholamine activity.

Evaluation of the time to desensitization of the larynx of cats following topical lidocaine application.

OBJECTIVES: The objective of this study was to evaluate the time to decreased reactivity of the arytenoid cartilages in cats after application of topical lidocaine. METHODS: One hundred and ten mixed-breed cats were randomly assigned to one of five groups based on the time between application of lidocaine and stimulation of the larynx: 5 (T5), 15 (T15), 30 (T30), 45 (T45) or 60 (T60) s. Cats were premedicated with dexmedetomidine, ketamine and buprenorphine. Anesthesia was induced with propofol to effect. Lidocaine 2% (2 mg/kg) was applied topically to the vocal cords using a catheter attached to a syringe under direct laryngoscopy. After lidocaine application, the designated time elapsed and the vocal cords were stimulated with the patient end of an endotracheal tube. Severity of reaction was reported as none, mild, moderate or severe. All cats were intubated after the reactivity score was recorded. Anesthesia was maintained with isoflurane and 100% oxygen while cats were spayed or castrated. Cats were monitored in recovery for signs of respiratory complications and pain. RESULTS: There was a significant difference in overall reactivity score between T5 and T45 (P = 0.0038). Also, there was a significant difference in the number of cats with no reaction compared with cats with any reaction between T5 and T30 (P = 0.03), as well as between T5 and T45 (P = 0.0028). No cat had a severe reactivity score at T45 or T60. All cats were successfully intubated. There were no complications during intubation, maintenance of anesthesia or recovery. CONCLUSIONS AND RELEVANCE: As the lowest overall reactivity score occurred at T45, it is recommended to wait at least 45 s after application of topical lidocaine before attempting tracheal intubation.

Changes in CO-oximetry values and pulse oximetry in isoflurane-anesthetized dogs with and without nitrous oxide.

Concentrations of 64% to 70% nitrous oxide (N2O) provide intra-operative analgesia. Clinically, pulse oximeter estimation (SpO2) of oxygen (O2) hemoglobin saturation (SaO2) was observed to decrease with N2O. Absorption atelectasis from breathing O2 was thought to decrease arterial partial pressure of O2 (PaO2) below 70 mmHg and reduce SaO2 and SpO2 when N2O was used. Administering N2O from the beginning of the anesthesia might prevent atelectasis development and low PaO2. The study was done in 2 parts (P < 0.05). In Part 1, isoflurane-anesthetized dogs undergoing ovariohysterectomy (n = 15 each group) breathed N2O from anesthesia start (N2Oearly) or 1 hour later (N2Olate). SpO2, CO-oximetry values, and PaO2 were compared to dogs breathing O2 throughout anesthesia (control). Timing of N2O introduction did not affect PaO2 (lowest = 94 mmHg), SaO2, or SpO2. With N2O, the lowest SpO2 value was 91% and corresponded to a PaO2 of 151 mmHg. Carboxyhemoglobin increased (highest = 2.7%) and SaO2 decreased with N2O (lowest = 96.7%). In Part 2, to replicate findings, 10 isoflurane-anesthetized dogs breathed N2O, then O2. With N2O, SaO2 did not decrease, but carboxyhemoglobin increased and returned to baseline once N2O was discontinued. The dog with the highest carboxyhemoglobin (2%) had an SaO2 of 96.8% (PaO2 = 93 mmHg). Carboxyhemoglobin and SaO2 changes were not clinically significant. Pulse oximetry did not reliably estimate SaO2 but N2O was not always a factor.

Des concentrations de 64 % à 70 % d'oxyde nitreux (N2O) apporte une analgésie intra-opératoire. Cliniquement, il a été noté que l'estimation par oxymétrie de pouls (SpO2) de la saturation en oxygène (O2) de l'hémoglobine (SaO2) diminuait avec le N2O. Une atélectasie d'absorption due à la respiration d'O2 était suspectée diminuer la pression artérielle partielle en O2 (PaO2) sous la valeur de 70 mmHg et réduire SaO2 et SpO2 lorsque le N2O était utilisé. L'administration de N2O depuis le début de l'anesthésie pourrait prévenir le développement d'atélectasie et une faible PaO2.La présente étude a été réalisée en deux parties (P < 0,05). Dans la Partie 1, des chiennes anesthésiées à l'isoflurane soumis à une ovariohystérectomie (n = 15 dans chaque groupe) ont respiré du N2O depuis le début de l'anesthésie (N2Oearly) ou 1 heure plus tard (N2Olate). Les valeurs de SpO2, d'oxymétrie de CO, et de PaO2 furent comparées à celles de chiens respirant O2 tout au long de l'anesthésie (témoin). Le moment d'introduction du N2O n'a pas affecté PaO2 (plus basse = 94 mmHg), SaO2 ou SpO2. Avec le N2O, la plus basse valeur de SpO2 était 91 % et correspondait à une PaO2 de 151 mmHg. La carboxyhémoglobine augmenta (plus élevée = 2,7 %) et SaO2 diminua avec le N2O (plus basse = 96,7 %).Dans la Partie 2, pour reproduire les résultats, 10 chiens anesthésiés avec de l'isoflurane ont respiré du N2O, puis O2. Avec le N2O, SaO2 n'a pas augmenté, mais la carboxyhémoglobine augmenta et retourna à la valeur de base une fois que le N2O fut arrêté. Le chien avec la valeur de carboxyhémoglobine la plus élevée (2 %) avait une SaO2 de 96,8 % (PaO2 = 93 mmHg). Les changements de valeurs de carboxyhémoglobine et de SaO2 n'étaient pas cliniquement significatifs. L'oxymétrie de pouls n'estimait pas de manière fiable SaO2 mais le N2O n'était pas toujours un facteur.(Traduit par Docteur Serge Messier).

Total intravenous anesthesia with alfaxalone, dexmedetomidine and remifentanil in healthy foals undergoing abdominal surgery.

OBJECTIVE: To evaluate effects of anesthesia induced with alfaxalone and maintained with alfaxalone, dexmedetomidine and remifentanil infusions in foals. STUDY DESIGN: Prospective, experimental study. ANIMALS: A group of six healthy foals [median (range) 11 (8-33) days] undergoing abdominal surgery. METHODS: Intravenous (IV) dexmedetomidine (3-7µgkg-1) provided sedation for insertion of a pulmonary artery catheter. IV anesthesia was induced with alfaxalone (2mgkg-1) and maintained with alfaxalone (6mgkg-1hour-1), dexmedetomidine (1µgkg-1hour-1) and remifentanil (3µgkg-1hour-1). Foals were endotracheally intubated and lungs were mechanically ventilated with oxygen. Cardiac output (thermodilution), heart rate and systemic arterial pressure were measured. Arterial and mixed venous blood was analyzed for PO2 and PCO2, and glucose, lactate and electrolyte concentrations. Anesthetic depth was subjectively assessed. Systemic vascular resistance (SVR), oxygen utilization and intrapulmonary shunt were calculated. Preinduction (PB) or 10 minutes postinduction (+10B) data were used as baselines with one-way analysis of variance for repeated measures. Data are mean ± standard deviation; significance was p ≤ 0.05. RESULTS: Duration of anesthesia was 129 ± 22minutes. One foal was administered additional alfaxalone (0.5mgkg-1) following induction. Cardiac index decreased to 107 ± 31 and 87 ± 21mLkg-1minute-1 at 60 and 80minutes, respectively, compared with PB (157 ± 33mLkg-1minute-1). SVR increased to 1223 ± 166dynessecond-1cm-5 at 80minutes compared with +10B (704 ± 247dynessecond-1cm-5). Mean arterial pressures were 63-128mmHg. Time from stopping infusions to standing was 46-106minutes. All foals were hypothermic (<36°C) and three foals were administered atipamezole (0.05mgkg-1) intramuscularly during recovery. CONCLUSION: and clinical relevance Combined alfaxalone-dexmedetomidine-remifentanil provided suitable anesthesia to permit laparotomy in foals. At the doses evaluated, prolonged recovery may occur.

Desaturation times between dogs preoxygenated via face mask or flow-by technique before induction of anesthesia.

OBJECTIVE: To compare time to desaturation after induction of anesthesia following administration of oxygen via face mask or flow-by for 3 minutes. STUDY DESIGN: Randomized crossover study. ANIMALS: A group of six healthy adult dogs weighing 15.0 ± 3.4 kg. METHODS: Dogs were anesthetized twice separated by 14 days. Intramuscular administration of dexmedetomidine (4 µg kg-1), acepromazine (0.01 mg kg-1) and butorphanol (0.2 mg kg-1) provided sedation for percutaneous insertion of a catheter into the tracheal lumen. The tip was advanced to the thoracic inlet and position confirmed using fluoroscopy. Using a sample aspiration rate 200 mL minute-1, inspired (FIO2) and end-tidal oxygen (Fe'O2) were measured. Oxygen (100 mL kg-1 minute-1) was delivered into a circle delivery system and administered to the dog for 3 minutes via face mask or flow-by from the circle Y-piece 2.5 cm from the nares. Then, propofol was administered to induce anesthesia and apnea. A pulse oximeter (lingual probe) measured hemoglobin saturation (SpO2). At SpO2 90% (desaturation point), an endotracheal tube was inserted to allow administration of oxygen and artificial ventilation. Arterial blood and data were collected at baseline (before oxygen administration), 5 seconds after induction of anesthesia, and every 30 seconds until the desaturation point was reached. Data were analyzed using an unpaired and paired t test with (p < 0.05). RESULTS: FIO2, Fe'O2 and PaO2 (mean ± standard deviation) were significantly higher after mask preoxygenation [89.7 ± 5.5%, 83.0 ± 7.6% and 394 ± 112 mmHg (52.4 ± 14.9 kPa)] compared with flow-by [30.0 ± 5.4%, 22.7 ± 3.8% and 133 ± 22 mmHg (17.7 ± 2.9 kPa)], respectively. Time to desaturation was significantly longer after mask treatment compared with flow-by (187 ± 67 versus 66 ± 17 seconds). CONCLUSIONS AND CLINICAL RELEVANCE: Mask preoxygenation provided longer time to desaturation compared with the flow-by technique tested.

Cystic fibrosis swine fail to secrete airway surface liquid in response to inhalation of pathogens.

Cystic fibrosis is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) channel, which can result in chronic lung disease. The sequence of events leading to lung disease is not fully understood but recent data show that the critical pathogenic event is the loss of the ability to clear bacteria due to abnormal airway surface liquid secretion (ASL). However, whether the inhalation of bacteria triggers ASL secretion and whether this is abnormal in cystic fibrosis has never been tested. Here we show, using a novel synchrotron-based in vivo imaging technique, that wild-type pigs display both a basal and a Toll-like receptor-mediated ASL secretory response to the inhalation of cystic fibrosis relevant bacteria. Both mechanisms fail in CFTR-/- swine, suggesting that cystic fibrosis airways do not respond to inhaled pathogens, thus favoring infection and inflammation that may eventually lead to tissue remodeling and respiratory disease.Cystic fibrosis is caused by mutations in the CFTR chloride channel, leading to reduced airway surface liquid secretion. Here the authors show that exposure to bacteria triggers secretion in wild-type but not in pig models of cystic fibrosis, suggesting an impaired response to pathogens contributes to infection.