Prevalence of Gastroesophageal Reflux in Cats During Anesthesia and Effect of Omeprazole on Gastric pH.

BackgroundGastroesophageal reflux (GER) is poorly characterized in anesthetized cats, but can cause aspiration pneumonia, esophagitis, and esophageal stricture formation.ObjectiveTo determine whether pre-anesthetic orally administered omeprazole increases gastric and esophageal pH and increases serum gastrin concentrations in anesthetized cats, and to determine the prevalence of GER using combined multichannel impedance and pH monitoring.AnimalsTwenty-seven healthy cats undergoing elective dental procedures.MethodsProspective, double-masked, placebo-controlled, randomized clinical trial. Cats were randomized to receive 2 PO doses of omeprazole (1.45-2.20 mg/kg) or an empty gelatin capsule placebo 18-24 hours and 4 hours before anesthetic induction. Blood for measurement of serum gastrin concentration was collected during anesthetic induction. An esophageal pH/impedance catheter was utilized to continuously measure esophageal pH and detect GER throughout anesthesia.ResultsMean gastric pH in the cats that received omeprazole was 7.2 ± 0.4 (range, 6.6-7.8) and was significantly higher than the pH in cats that received the placebo 2.8 ± 1.0 (range, 1.3-4.1; P < .001). Omeprazole administration was not associated with a significant increase in serum gastrin concentration (P = .616). Nine of 27 cats (33.3%) had ≥1 episode of GER during anesthesia.Conclusions and clinical relevancePre-anesthetic administration of 2 PO doses of omeprazole at a dosage of 1.45-2.20 mg/kg in cats was associated with a significant increase in gastric and esophageal pH within 24 hours, but was not associated with a significant increase in serum gastrin concentration. Prevalence of reflux events in cats during anesthesia was similar to that of dogs during anesthesia

Evaluation of butorphanol, medetomidine and midazolam as a reversible narcotic combination in free-ranging African lions (Panthera leo)

Objective To evaluate the effects of the combination butorphanol, medetomidine and midazolam (BMM) and its reversibility in lions. Study design Prospective clinical trial. Animals Thirty free-ranging lions, 10 male and 20 female, weighing 81–210 kg. Methods Lions were immobilised with butorphanol mean 0.31 ± SD 0.034 mg kg-1, medetomidine 0.052 ± 0.006 mg kg-1, midazolam 0.21 ± 0.024 mg kg-1 and hyaluronidase 1250 IU administered intramuscularly with a dart gun. Upon recumbency, physiological parameters and anaesthetic depth were monitored 10–15 minutes after darting (T1) and repeated every 10 minutes for a further 30 minutes (T2, T3, T4). Arterial blood gas analyses were performed at T1 and T4. At the end of the procedure, 45–60 minutes after initial darting, immobilisation was reversed with naltrexone 0.68 ± 0.082 mg kg-1, atipamezole 0.26 ± 0.031 mg kg-1, and flumazenil 0.0032 ± 0.0007 mg kg-1 administered intravenously and subcutaneously. Results The BMM combination rapidly induced immobilisation and lateral recumbency was reached within 7.25 ± 2.3 minutes. Median induction score [scored 1 (excellent) to 4 (poor)] was 1.4 (range 1–2). Cardio-respiratory parameters were stable. Heart rate varied from 32 to 72 beats per minute, respiratory rate from 14 to 32 breaths minute-1 and rectal temperature from 36.6 to 40.3 C. No sudden arousals were observed. Arterial blood gas analyses revealed a mean pH of 7.33, PaCO2 of 33 mmHg and PaO2 of 87 mmHg. Mild to moderate hypoxemia was seen in four lions. Recovery was smooth and lions were walking within 4.4 ± 4.25 minutes. Median recovery score [scored 1 (excellent) to 4 (poor)] was 1.3 (range 1–2). Conclusion and clinical relevance The drug combination proved to be effective in immobilising freeranging healthy lions of both sexes with minimal cardio-respiratory changes

Treatment of acute pain in cats

The cat's popularity as a pet continues to grow, with the most recent surveys showing approximately 17% of the population live with cats. This increased popularity of cats invariably means that more cats are presented to veterinary surgeons for surgery and treatment of painful conditions, but it seems that the treatment of pain in the cat has lagged behind that of other species. Lack of analgesic administration may well stem from the difficulties in assessing pain in the cat, but is probably compounded by the false perceptions of the likelihood of severe side effects occurring more frequently with the use of opioids and non-steroidal anti-inflammatory drugs in cats, thereby inadvertently denying them the analgesics they require. This article complements a previous article covering the assessment of acute pain in the cat (White, 2016); the aim of this second article is to provide an evidence-based framework to follow for the treatment of acute pain in the cat

Parent-Metabolite Pharmacokinetic Models for Tramadol – Tests of Assumptions and Predictions

Allometric principles were used to discern cross-species differences in (±)-tramadol disposition and formation of its primary analgesic metabolite, (±)-O-desmethyl-tramadol (M1). Species differences in formation of M1 may help predict the analgesic effectiveness of tramadol. Tramadol was administered intravenously by a zero-order (constant infusion) process or rapid bolus dose and racemic concentrations of tramadol and M1 measured. Data were pooled to define differences between species (human, rat, cat, dog, goat, donkey and horse). A two-compartment linear disposition model with first-order elimination was used to describe tramadol and M1 disposition. Slow metabolizers were detected in 6% of the population and tramadol clearance to M1 was 16.2% that of extensive metabolizers. Tramadol clearance to M1 was slower and tramadol clearance by other pathways was faster in rats, dogs, and horses compared to humans. There are substantial differences between species in the pharmacokinetics of tramadol and its M1 metabolite, which are not explained by differences in body weight. The hypothesis that volumes of distribution are similar across species was shown not to be true. M1 exposure in the goat, donkey and cat was comparable to humans, which indicates it is likely to be an effective analgesic at typically used doses in these species but not in dogs or horses

Concentrations of medetomidine enantiomers and vatinoxan, an α2-adrenoceptor antagonist, in plasma and central nervous tissue after intravenous coadministration in dogs

Objective To quantify the peripheral selectivity of vatinoxan (L-659,066, MK-467) in dogs by comparing the concentrations of vatinoxan, dexmedetomidine and levo-medetomidine in plasma and central nervous system (CNS) tissue after intravenous (IV) coadministration of vatinoxan and medetomidine. Study design Experimental, observational study. Animals A group of six healthy, purpose-bred Beagle dogs (four females and two males) aged 6.5 +/- 0.1 years (mean +/- standard deviation). Methods All dogs were administered a combination of medetomidine (40 mu g kg(-1)) and vatinoxan (800 mu g kg(-1)) as IV bolus. After 20 minutes, the dogs were euthanized with an IV overdose of pentobarbital (140 mg kg(-1)) and both venous plasma and CNS tissues (brain, cervical and lumbar spinal cord) were harvested. Concentrations of dexmedetomidine, levomedetomidine and vatinoxan in all samples were quantified by liquid chromatography-tandem mass spectrometry and data were analyzed with nonparametric tests with post hoc corrections where appropriate. Results All dogs became deeply sedated after the treatment. The CNS-to-plasma ratio of vatinoxan concentration was approximately 1:50, whereas the concentrations of dexmedetomidine and levomedetomidine in the CNS were three- to seven-fold of those in plasma. Conclusions and clinical relevance With the doses studied, these results confirm the peripheral selectivity of vatinoxan in dogs, when coadministered IV with medetomidine. Thus, it is likely that vatinoxan preferentially antagonizes alpha(2)-adrenoceptors outside the CNS.Peer reviewe

Sedative and analgesic effects of intravenous xylazine and tramadol on horses

This study was performed to evaluate the sedative and analgesic effects of xylazine (X) and tramadol (T) intravenously (IV) administered to horses. Six thoroughbred saddle horses each received X (1.0 mg/kg), T (2.0 mg/kg), and a combination of XT (1.0 and 2.0 mg/kg, respectively) IV. Heart rate (HR), respiratory rate (RR), rectal temperature (RT), indirect arterial pressure (IAP), capillary refill time (CRT), sedation, and analgesia (using electrical stimulation and pinprick) were measured before and after drug administration. HR and RR significantly decreased from basal values with X and XT treatments, and significantly increased with T treatment (p < 0.05). RT and IAP also significantly increased with T treatment (p < 0.05). CRT did not change significantly with any treatments. The onset of sedation and analgesia were approximately 5 min after both X and XT treatments; however, the XT combination produced a longer duration of sedation and analgesia than X alone. Two horses in the XT treatment group displayed excited transient behavior within 5 min of drug administration. The results suggest that the XT combination is useful for sedation and analgesia in horses. However, careful monitoring for excited behavior shortly after administration is recommended

Indexing cardiovascular and respiratory variables: allometric scaling principles

To describe the allometric scaling principles underlying appropriate indexing of cardiovascular and respiratory measurements obtained in adult mammals, and to propose guidelines for indexing experimental cardiovascular and respiratory data.PubMed, using the terms 'allometry', 'allometric', 'indexing', 'cardiovascular' and 'respiratory'.Indexing of cardiopulmonary variables is commonly used in attempts to account for the effects of body size on measurements and to standardize them. Some cardiopulmonary variables have been indexed using various functions of body mass in a process that often ignores the underlying relationship between the variable of interest and body size, as described in the allometry literature. This can result in a failure to ideally reduce the effect of body size on measurements in a manner that highlights differences. We review how commonly measured cardiopulmonary variables are related to body mass in mammalian species according to the allometry literature, and offer suggestions on how this information can be used to appropriately index cardiopulmonary variables in a simple and informative manner