Identification of the sacrococcygeal epidural space using the nerve stimulation test or the running-drip method in dogs.

OBJECTIVE: To compare the nerve stimulation test (group NS) with the running-drip method (group RUN) for successful identification of the sacrococcygeal (SCo) epidural space prior to drug administration in dogs. ANIMALS: A total of 62 dogs. STUDY DESIGN: A randomized clinical study. METHODS: Dogs requiring an epidural anaesthetic as part of the multimodal anaesthetic plan were randomly allocated to one of the two study groups. In group NS, the epidural space was located using an insulated needle connected to a nerve stimulator; in group RUN, the epidural space was identified using a Tuohy needle connected to a fluid bag elevated 60 cm above the spine via an administration set. The success of the technique was assessed 5 minutes after epidural injection by the disappearance of the patella reflex. Data were checked for normality, nonparametric data was analysed using a Mann-Whitney U test and success rate was analysed using a Fisher's exact test. The significance level was set at p < 0.05, and the results are presented in absolute values, percentage (95% confident interval) and median (range). RESULTS: The success in identification of the epidural space did not differ between groups NS and RUN [87.1% (70.2%-96.4%) versus 90.3% (74.2%-98%); p = 1.000]. The time required for identification of the epidural space was shorter in group RUN [26 (15-53) seconds] than in group NS [40 (19-137) seconds] (p = 0.0225). No other differences were found in any studied variables. CONCLUSION: and clinical relevance In this study, both RUN and NS techniques were successful in identifying the epidural space at the SCo intervertebral space. RUN requires no specialised equipment, can be performed rapidly and offers an alternative to the NS for use in general veterinary practice.

Radiographic, ultrasonographic, and computed tomographic characteristics of an accessory liver lobe in a cat.

A 5-year-old male Norwegian Forest cat presented with increased hepatic serum biochemical parameters. Abdominal radiography showed an oval cranioventral mass and ultrasound revealed a mobile mass attached to one hepatic lobe. Computed tomography (CT) confirmed that the mass was attached to the right medial liver lobe. Differential diagnoses were an accessory liver lobe, benign neoplasia, and focal nodular hyperplasia. The mass was removed and histopathology confirmed the mass to be normal liver tissue. Accessory liver lobe should be included in the differential diagnosis of a mobile cranial abdominal mass with a similar ultrasonographic or CT appearance to the liver.

Effects of midazolam before or after alfaxalone for co-induction of anaesthesia in healthy dogs.

OBJECTIVE: To study the effect of alternating the order of midazolam and alfaxalone administration on the incidence of behavioural changes, alfaxalone induction dose and some cardiorespiratory variables in healthy dogs. STUDY DESIGN: Prospective, randomized, controlled, clinical trial. ANIMALS: A total of 33 client-owned dogs undergoing elective procedures. METHODS: Following intramuscular acepromazine (0.02 mg kg-1) and morphine (0.4 mg kg-1) premedication, anaesthesia was induced intravenously (IV) with a co-induction of either midazolam (0.25 mg kg-1) prior to alfaxalone (0.5 mg kg-1; group MA), or alfaxalone followed by midazolam at identical doses (group AM). The control group (CA) was administered normal saline IV prior to alfaxalone administration. Additional alfaxalone (0.25 mg kg-1 increments) was administered as required in all groups until orotracheal intubation was possible. Changes in behaviour, quality of induction, ease of intubation and incidence of adverse events at induction were recorded. Heart rate (HR), respiratory rate (fR) and systolic arterial blood pressure (SAP) were measured before treatments (baseline values), 30 minutes after premedication and at 0, 2, 5 and 10 minutes postintubation. RESULTS: The incidence of excitement was higher in group MA compared with groups CA (p=0.005) and AM (p=0.013). The mean induction dose of alfaxalone was lower in group AM compared with group CA (p=0.003). Quality of induction and ease of intubation were similar among groups. Mean HR values decreased after premedication and increased after alfaxalone administration in all groups. Mean SAP values were similar between groups. The number of animals that required manual ventilation was higher in the MA group. CONCLUSIONS AND CLINICAL RELEVANCE: Despite a lower occurrence of adverse events at induction in group AM compared with group MA and a reduction of alfaxalone dose requirement in group AM compared with group CA, the use of an alfaxalone-midazolam co-induction does not seem to produce any cardiovascular or respiratory benefits in healthy dogs.

IMAGING DIAGNOSIS-RADIOGRAPHIC, ULTRASONOGRAPHIC, AND COMPUTED TOMOGRAPHIC CHARACTERISTICS OF A DUODENAL DUPLICATION CYST IN A YOUNG CAT.

A 7-month-old, 2.8 kg, intact female Siamese cat was evaluated for repetitive and intermittent episodes of vomiting and anorexia. Abdominal palpation revealed a round, firm, nonpainful mass in the right cranial abdomen. Ultrasonography findings were consistent with a cystic structure adjacent to the descending duodenum. The structure exhibited a "muscular rim sign." A duodenal duplication cyst was confirmed by histopathological analysis. Computed tomography ruled out concurrent vertebral anomalies and clarified anatomic relationships for surgical planning. To the authors' knowledge, this is the first description of an ultrasound "muscular rim sign" in a duodenal duplication cyst in a cat.

Clinical efficacy and cardiorespiratory effects of intramuscular administration of alfaxalone alone or in combination with dexmedetomidine in cats.

OBJECTIVE: To investigate the sedative, anaesthetic and cardiorespiratory effects of intramuscular (IM) administration of alfaxalone alone or in combination with dexmedetomidine in cats. STUDY DESIGN: Blinded, randomized crossover study with a washout period of 15 days. ANIMALS: Seven adult cats, weighing 3.5 ± 0.7 kg. METHODS: Cats were assigned randomly to each of three treatments: A5 (alfaxalone 5 mg kg(-1) ), D20 A5 (dexmedetomidine 20 µg kg(-1) and alfaxalone 5 mg kg(-1) ) and D40 A5 (dexmedetomidine 40 µg kg(-1) and alfaxalone 5 mg kg(-1) ). Drugs were administered IM into the epaxial muscles. Sedation or anaesthesia scores were evaluated by a modified numerical rating scale. Times to extubation, head-lift, sternal recumbency and standing were recorded. Heart and respiratory rates, systolic arterial pressure, arterial oxygen saturation of haemoglobin, end-tidal carbon dioxide tension and rectal temperature were measured at 5, 10, 15, 20, 30, 45, 60, 90, 120 and 150 minutes after drug administration. Adverse events were recorded. Data were analysed by one-way anova with Tukey's post-hoc test for parametric values and, for non-normally distributed parameters, a Kruskal-Wallis test and Mann-Whitney U-test for two independent samples (p < 0.05). RESULTS: Sedation scores were significantly different among the treatments. Cats in A5 were deeply sedated, whereas cats administered dexmedetomidine were anaesthetized. The onset of action and the duration of anaesthesia were related to the dose of dexmedetomidine. Cardiorespiratory parameters remained stable in the A5 group. Lower heart rates, higher systolic blood pressures and occasional low pulse oximetry readings were observed in the dexmedetomidine groups. A limited number of adverse events (hyperkinesia, emesis) occurred during recovery. CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone administered IM induced sedation in cats. The addition of dexmedetomidine to alfaxalone induced general anaesthesia with a mild decrease in the heart rate and arterial oxygen saturation of haemoglobin.

IMAGING DIAGNOSIS-URETHROVAGINAL FISTULA CAUSED BY A MIGRATING GRASS AWN IN THE VAGINA.

A young intact female dog was presented with urinary incontinence. Abdominal ultrasound revealed the presence of hyperechoic linear structures within the cranial vagina suggestive of foreign material. A computed tomography (CT) retrograde vaginourethrogram demonstrated the presence of a fistulous tract between the urethra and vagina. A presumptive diagnosis of urethrovaginal fistula due to migration of foreign material was made. The grass awn was removed with vaginoscopic-guided retrieval. Fourteen days later, surgical repair of the fistula and an ovariohysterectomy were done. This case report emphasizes the usefulness of CT for diagnosis and precise anatomical localization of genitourinary tract fistulas.

Description and Evaluation of Dye and Contrast Media Distribution of Ultrasound-Guided Rectus Sheath Block in Cat Cadavers.

The rectus sheath block is an ultrasound-guided anaesthetic technique which aims to provide analgesia to the abdominal midline. This study aimed to assess the distribution of 0.4 mL kg-1 of a mixture of methylene blue and iopromide injected into each hemiabdomen in the internal rectus sheath in cat cadavers. We hypothesise that this technique would be feasible and would cover the rami ventrales of the last thoracic and the first lumbar spinal nerves. The study was divided into two phases. Phase 1 aimed to study the anatomical structures of the ventral abdominal wall (four cats were dissected). Phase 2 (ten cadavers) consisted of an ultrasound-guided injection of the mixture mentioned above and the assessment of its distribution by computed tomography and anatomical dissection. The results showed the staining of the cranioventral abdominal wall with a craniocaudal spread of four (three to eight) vertebral bodies. Methylene blue stained three (one to four) rami ventrales, affecting T10 (60%), T11 (100%), T12 (90%), T13 (50%) and L1 (5%). Based on these results, it could be stated that this technique could supply anaesthesia to the midline of the abdominal midline cranial to the umbilicus in clinical patients, but it may not be able to provide anaesthesia to the middle and caudal midline abdominal region.

Effects of altering the sequence of midazolam and propofol during co-induction of anaesthesia.

OBJECTIVE: To assess the effects of varying the sequence of midazolam and propofol administration on the quality of induction, cardiorespiratory parameters and propofol requirements in dogs. STUDY DESIGN: Randomized, controlled, clinical study. ANIMALS: Thirty-three client owned dogs (ASA I-III, 0.5-10 years, 5-30 kg). METHODS: Dogs were premedicated with acepromazine (0.02 mg kg(-1) ) and morphine (0.4 mg kg(-1) ) intramuscularly. After 30 minutes, group midazolam-propofol (MP) received midazolam (0.25 mg kg(-1) ) intravenously (IV) before propofol (1 mg kg(-1) ) IV, group propofol-midazolam (PM) received propofol before midazolam IV at the same doses, and control group (CP) received saline IV, instead of midazolam, before propofol. Supplementary boluses of propofol (0.5 mg kg(-1) ) were administered to effect to all groups until orotracheal intubation was completed. Behaviour after midazolam administration, quality of sedation and induction, and ease of intubation were scored. Heart rate (HR), respiratory rate, and systolic arterial blood pressure were recorded before premedication, post-premedication, after midazolam or saline administration, and at 0, 2, 5, and 10 minutes post-intubation. End-tidal CO2 and arterial oxygen haemoglobin saturation were recorded at 2, 5 and 10 minutes post-intubation. RESULTS: Quality of sedation and induction, and ease of intubation were similar in all groups. Incidence of excitement was higher in the MP compared to CP (p = 0.014) and PM (p = 0.026) groups. Propofol requirements were decreased in MP and PM groups with respect to CP (p < 0.001), and in PM compared to MP (p = 0.022). The HR decreased after premedication in all groups, and increased after midazolam and subsequent times in MP (p = 0.019) and PM (p = 0.001) groups. Incidence of apnoea and paddling was higher in CP (p = 0.005) and MP (p = 0.031) groups than in PM. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of midazolam before propofol reduced propofol requirements although caused mild excitement in some dogs. Administration of propofol before midazolam resulted in less excitatory phenomena and greater reduction of propofol requirements.

Imaging diagnosis-infiltrative lipoma causing spinal cord and lumbar nerve root compression in a dog.

A 12-year-old, male, fox terrier dog presented with an abnormal gait of the left pelvic limb. Computed tomography revealed a large, homogeneous, hypoattenuating, noncontrast enhancing mass within the left epaxial muscles that invaded the L5-6 vertebral canal and caused spinal cord compression. Imaging findings were consistent with an infiltrative lipoma. The mass was removed and a left hemilaminectomy was performed in the affected area. Histopathology confirmed the mass to be an infiltrative lipoma. The dog recovered and regained neurologic function within 2 weeks. Computed tomography assisted preoperative planning by characterizing the shape, size, and location of the mass.

Modified Ultrasound-Guided Dorsal Quadratus Lumborum Block in Cat Cadavers.

The quadratus lumborum (QL) block is an ultrasound-guided locoregional anesthesia technique which aims to provide analgesia to the abdomen. The main objective of this study was to assess a modified ultrasound-guided dorsal QL block in cat cadavers. For this purpose, a volume of 0.4 mL kg-1 of a mixture of iopromide and methylene blue was administered between the psoas minor muscle and the vertebral body (VB) of the first lumbar vertebra, and its distribution was assessed in thirteen cat cadavers. We hypothesized that this injection point would be feasible, offering a more cranial distribution of the injectate and a more consistent staining of the truncus sympathicus. The study was divided into two phases. Phase 1 consisted of an anatomical study (three cadavers were dissected). Phase 2 consisted of the ultrasound-guided administration of the injectate and the assessment of its distribution by computed tomography and anatomical dissection. The results showed a consistent distribution of contrast media within five (4-8) VBs from T10 to L5. Methylene blue stained three (2-6) rami ventrales, affecting T11 (10%), T12 (20%), T13 (60%), L1 (85%), L2 (95%) and L3 (65%). The truncus sympathicus was dyed in all cadavers with a spread of five (3-7) VBs. Finally, the splanchnicus major nerve was stained in all cadavers (100%). These results suggest that this technique could provide analgesia to the abdominal viscera and the abdominal wall, probably with the exception of the cranial aspects of the abdominal wall.

An Ultrasound-Guided Latero-Ventral Approach to Perform the Quadratus Lumborum Block in Dog Cadavers.

The QL block is a high-level locoregional anesthesia technique, which aims to provide analgesia to the abdomen. Several approaches of the QL block have been studied to find out which one allows a greater distribution of the injectate. The aim of this study is to compare the traditional interfascial QL block (IQL) with a new latero-ventral approach (LVQL). We hypothesize that this new approach could be safer and easier to perform, since the injectate is administered more superficially and further away from vital structures. Our second objective is to assess whether a higher volume of injectate (0.6 mL/kg) could reach the ventral branches of the last thoracic nerves, leading to a blockade of the cranial abdomen. Six thawed canine cadavers (12 hemiabdomens) were used for this purpose. Both approaches were performed in all cadavers. A combination of methylene blue/iopromide was administered to each hemiabdomen, randomly assigned to the LVQL or IQL. No differences were found regarding the ease of perform the LVQL with respect to IQL. The results show that both techniques reached the ventral branches from L1 to L3, although only the IQL consistently stained the sympathetic trunk (5/6 IQL vs. 1/6 LVQL). The use of a higher volume did not enhance a more cranial distribution of the injectate.

Ultrasound-guided 'two-in-one' femoral and obturator nerve block in the dog: an anatomical study.

OBJECTIVE: To evaluate the dye extent and distribution at the lumbar plexus (LP) of three volumes of local anaesthetic-methylene-blue solution administered close to the femoral nerve (FN) by the use of a ventral ultrasound (US)-guided suprainguinal approach (SIA). STUDY DESIGN: Prospective experimental trial. ANIMALS: Twenty mongrel canine cadavers weighing 17.7 ± 3.8 kg (mean ± SD). METHODS: The left and right LP of two cadavers were dissected to identify the FN, obturator nerve (ON) and lateral femoral cutaneous nerve (LFCN). The extent and distribution of dye at the LP of each of three volumes of injectate of 0.2, 0.4 and 0.6 mL kg(-1) administered close to the FN by a ventral US-guided SIA then were studied in a further 18 dog cadavers (n = 6 per group). Staining of ≥2 cm along the target nerves was indicative of sufficient spread to produce a nerve block. RESULTS: The ventral US-guided SIA allowed the observation of the FN within the iliopsoas muscle (IPM) in a total of 17 cadavers. The assessment of the dye extent and distribution revealed a similar pattern regardless of the injected volume. From the injection site, the spreading of injectate occurred in cranial, lateral and caudal directions. The FN and ON were effectively stained in all the cases. The LFCN was not effectively stained in any case. CONCLUSIONS AND CLINICAL RELEVANCE: A volume of 0.2 mL kg(-1) administered close to the FN by a ventral US-guided SIA produced a sufficient distribution of the injectate within the IPM to produce effective staining of the FN and ON. This US-guided technique may be an appropriate alternative to previously reported techniques based on electrolocation to block the FN and ON in the dog.

Ultrasonographic assessment of the renal size using a kidney length to vertebral body length ratio in cats.

Ultrasonographic assessment of the renal size can provide useful clinical information, in combination with other ultrasonographic parameters. The aims of this study were to establish the agreement between the ultrasonographic and radiographic measurements of the kidneys (K) and vertebral bodies (L5 and L6), to establish an ultrasonographic measurement of kidney-to-vertebral body (L5 and L6) ratio to estimate the renal size in cats, and to assess the impact of age, body weight, sex, and gonadal status on the ultrasonographic measurements of the kidneys, vertebral bodies, and ratios. The vertebral bodies of L5 and L6 were chosen as they were easy to identify with ultrasonography (US) using the lumbosacral junction as a landmark, and they are not usually affected by vertebral anomalies. A total of 60 cats (19 intact males, 12 neutered males, 17 intact females, and 12 neutered females) were included in the study. The cats were divided into three age groups (<7 months, 7 months-7 years, and >7 years), two body weight categories (≤ 3.5 kg and >3.5 kg), and two sex and gonadal status groups (male and female, and intact and neutered, respectively). Measurements of the renal and vertebral body length were performed on the radiographic and ultrasonographic images. Two different ratios were obtained, namely, K/L5 and K/L6. There was no significant difference between the length of both kidneys and the length of the vertebral bodies of L5 and L6 on ultrasonographic or radiographic images. There was a good agreement between ultrasonographic and radiographic measurements of both kidneys and vertebral bodies. In conclusion, the kidney length to L6 length ratio obtained was 1.81 ± 0.20 (1.76-1.86), which was useful for evaluating the size of the feline kidney and was not influenced by the age, body weight, sex, or gonadal status.

Evaluation of High-Volume Injections Using a Modified Dorsal Quadratus Lumborum Block Approach in Canine Cadavers.

The quadratus lumborum (QL) block targets the fascial plane surrounding the QL muscle providing abdominal somatic and visceral analgesia. The extension of its analgesic effects is a subject of research, as it could not cover areas of the cranial abdomen in dogs. This study assesses in eight thawed canine cadavers, the distribution of high-volume injections (0.6 mL kg-1 of a mixture of methylene blue and iopromide) injected between the psoas minor muscle and the vertebral body of L1. Anatomical features of the area of interest were studied in two cadavers. In another six dogs, QL blocks were performed bilaterally under ultrasound-guidance. The distribution of contrast was evaluated by computed tomography (CT). Hypaxial abdominal muscles were dissected to visualize the dye spread (spinal nerves and sympathetic trunk) in 5 cadavers. The remaining cadaver was refrozen and cross-sectioned. CT studies showed a maximum distribution of contrast from T10 to L7. The methylene blue stained T13 (10%), L1 (100%), L2 (100%), L3 (100%), L4 (60%) and the sympathetic trunk T10 (10%), T11 (20%), T12 (30%), T13 (70%), L1 (80%), L2 (80%), L3 (60%) and L4 (30%). These findings may suggest that despite the high volume of injectate administered, this modified QL block could not produce somatic analgesia of the cranial abdomen, although it could provide visceral analgesia in dogs.

The bispectral index during recovery from halothane and sevoflurane anaesthesia in horses.

OBJECTIVE: To record the bispectral index (BIS) when horses moved during either halothane or sevoflurane anaesthesia and when they made volitional movements during recovery from these anaesthetics. STUDY DESIGN: Randomized prospective clinical study. ANIMALS: Twenty-five client-owned horses undergoing surgery aged 8.8 (+/- 5.3; 1-19) years (mean +/- SD; range). METHODS: Baseline BIS values were recorded before pre-anaesthetic medication (BIS(B)) and during anaesthesia (BIS(A)) maintained with halothane (group H; n = 12) or sevoflurane (group S; n =13) at approximately 0.8-0.9 x minimum alveolar concentrations (MAC). Bispectral indices were recorded during the surgery when unexpected movement occurred (BIS(MA)), during recovery when the first movement convincingly associated with consciousness was observed (BIS(M1)) and once sternal recumbency was achieved (BIS(ST)). RESULTS: No significant difference in BIS(M1) was found between halothane- (85 +/- 7; 75-93) and sevoflurane- (87 +/- 10; 70-98) anaesthetized horses although BIS(A) was significantly (p = 0.0002) lower in group S (62 +/- 7; 53-72) than group H (74 +/- 7; 60-84). Differences between BIS(M1) and BIS(A) were significant in sevoflurane (p = 0.00001) and halothane recipients (p = 0.002) but were greater in group S (25 +/- 9; 4-38) compared with group H (12 +/- 10; -9-25). In six of eight horses, BIS(MA) values ranged between those recorded during anaesthesia and at first movement. CONCLUSIONS AND CLINICAL RELEVANCE: Bispectral indices appear to approximate levels of unconsciousness, suggesting that monitoring the BIS may assist equine anaesthesia. However, it does not predict intra-operative movement.

Pharmacokinetics and sedative effects of alfaxalone with or without dexmedetomidine in rabbits.

This study aimed to investigate the specific pharmacokinetic profile and effects of alfaxalone after intravenous (IV) and intramuscular (IM) administration to rabbits and evaluate the potential interaction with dexmedetomidine. The study design was a blinded, randomized crossover with a washout period of 2 weeks. Five New Zealand white rabbits were used. Each animal received single IV and IM injections of alfaxalone at a single dose of 5 mg/kg, and single IV and IM injections of alfaxalone (5 mg/kg) combined with dexmedetomidine (100 µg/kg) administered intramuscularly. Blood samples were collected at predetermined times and analysed by high-performance liquid chromatography. The plasma concentration-time curves were analysed by non-compartmental analysis. Sedation/anaesthesia scores were evaluated by a modified numerical rating scale. At pre-determined time points heart and respiratory rates were measured. Times to sternal recumbency and standing position during the recovery were recorded. Concentrations of alfaxalone alone were very similar (slighty smaller) to concentrations when alfaxalone was combined with dexmedetomidine, after both routes of administration. Dexmedetomidine enhanced and increase the duration of the sedative effects of alfaxalone. In conclusion, alfaxalone administered in rabbits provides rapid and smooth onset of sedation. After IV and IM injections of alfaxalone combined with dexmedetomidine, a longer MRT and a deeper and extended sedation have been obtained compared to alfaxalone alone. Consequently, alfaxalone alone or in combination with dexmedetomidine could be useful to achieve respectively moderate to deep sedation in rabbits.

Short-Term Effects of Deliberate Subparaneural or Subepineural Injections With Saline Solution or Bupivacaine 0.75% in the Sciatic Nerve of Rabbits.

Background: Ultrasound (US)-guided techniques for peripheral nerve blockade have revealed that intraneural injections are relatively frequent and not necessarily associated with neurological deficits. Objectives: To evaluate the short-term effects of deliberate injections performed under direct vision in two different sites of the sciatic nerve (ScN). Material and Methods: Seventy-two New Zealand white rabbits randomly assigned to one of four experimental groups (n = 18) were employed. All procedures were conducted at a proximal femoral level where the ScN incorporates the common peroneal nerve and the tibial nerve (TN). Fixed volumes of 0.5 ml of saline solution (ES group) or bupivacaine 0.75% (EB group) were administered extrafascicularly inside the paraneurium of the ScN or intrafascicularly (IS and IB groups) under the epineurium of the TN. Cross-sectional area (CSA) and relative echogenicity (RE) of the entire ScN were determined by US before injections, after injections, and at 3 and 7 days. ScN samples were obtained for structural and ultrastructural histopathological studies. Proprioceptive, sensorial, and motor function were clinically evaluated on a daily basis. Results: The CSA of the ScN increased significantly immediately after injections when compared with pre-injection values in all groups (p < 0.05). The RE of the ScN decreased in relation to pre-injection values in all groups (p < 0.05). The CSA and RE of the ScN returned to normal values 7 days after injections in almost all groups. Injected nerves showed histological signs of mild perineural inflammation. Histopathological scores were not significantly different between groups (p > 0.05). The architecture of the ScN was preserved in all rabbits at 3 days and in 31/32 rabbits at 7 days. A focal area of damaged nerve fibers with degeneration of the axons and myelin sheath affecting the TN was observed in one rabbit of the IB group. Nerve function was not clinically impaired in any case. Conclusion: Despite the lack of severe nerve disruption observed in most rabbits, the evidence of a focal area of damaged nerve fibers in one rabbit injected intrafascicularly with bupivacaine confirms that intrafascicular injections should be avoided as they may increase the risk of nerve damage.

Anaesthetic and cardiorespiratory effects of romifidine/ketamine combinations in cats.

OBJECTIVE: To study the anaesthetic and cardiorespiratory effects of intramuscular (IM) administration of different combinations of romifidine and ketamine in cats. STUDY DESIGN: Prospective, randomized, cross-over experiment. Animals Seven healthy adult cats weighing (mean +/- SD) 3.4 +/- 0.7 kg and aged 4.6 +/- 3.2 years. METHODS: Animals received romifidine 100 microg kg(-1) with ketamine 7.5 (R100/K7.5) and 10 mg kg(-1) (R100/K10), romifidine 200 microg kg(-1) with ketamine 5 (R200/K5), 7.5 (R200/K7.5) and 10 mg kg(-1) (R200/K10) by IM injection. The time required to perform orotracheal intubation (IT) was measured and the ease of intubation assessed. The onset of anaesthesia (OA), duration of anaesthesia (DA) and anaesthesia recovery times (AR) were measured. Analgesia and muscle relaxation scores were recorded every 5 minutes for 60 minutes after OA. Heart rate, systolic arterial pressure, arterial haemoglobin saturation, respiratory rate, end-tidal carbon dioxide and oesophageal temperature were also measured. RESULTS: The IT, OA and DA were not significantly different between the treatments. The analgesia and muscle relaxation scores were similar between all treatments at most time points. The cardiorespiratory variables were not significantly different between the treatments in most cases. The adverse effects were dose dependent and similar to those previously described for other combinations of alpha(2)-agonists and ketamine. CONCLUSIONS AND CLINICAL RELEVANCE: Anaesthesia produced by the studied combinations of romifidine and ketamine may only be reliable when conducting brief and noninvasive procedures in cats. The OA times were slower and the DA shorter than those reported for other alpha-2 agonists combined with ketamine. A dose-related increase in the intensity of the anaesthetic effects could not be demonstrated in this study.

Postanesthetic brachial triceps myonecrosis in a Spanish-bred horse.

This report describes a case of postanesthetic brachial triceps myonecrosis affecting only the left forelimb of a horse. A fatal unilateral postanesthetic myonecrosis has not been previously reported in the horse. This article describes the factors in the horse's history, the anesthetic protocol, and the treatment that may have led to this condition.

Ultrasonographic, computed tomographic and magnetic resonance imaging anatomy of the normal canine stifle joint.

Ultrasonographic (US), magnetic resonance (MR) and computed tomographic (CT) images of normal canine stifle joints were obtained and compared with plastinated cross-sectional slices of cadaver specimens from the same dogs. The bony and articular structures were identified and correlated with the three diagnostic imaging modalities. These results provide an atlas of normal cross-sectional US, MR and CT anatomy of the canine stifle, which can be used for the interpretation of stifle images from any of these imaging modalities.