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An intact female 2-year-old boxer presented with polydipsia, polyuria, and decreased feed intake. Palpation of the abdomen was painful. Sonography revealed an abdominal mass of the left kidney causing displacement of the organs located in the cranial and mid-abdomen. Dimen sion and invasiveness of the process were evaluated both by contrast enhanced ultrasound (CEUS) and contrast-enhanced computed tomography. Histopathological examination of a biopsy sample revealed a nephroblastoma. The case report describes the clinical, sonographic, and computed tomographic results and the outcome in the untreated dog over a period of 5 months., Competing Interests: Die Autoren bestätigen, dass kein Interessenkonflikt besteht., (Georg Thieme Verlag KG Stuttgart · New York.)

An 11-year-old female Sheltie was presented with inappetence and a progressive increase in abdominal distention. Abdominal ultrasound revealed a large cystic mass in the midabdomen and cystic lesions in the right liver lobe and in the caudal pole of the left kidney. Histopathologic examination of the resected tissue revealed a myelolipoma of the spleen, dispersed splenic tissue in the liver and dispersed uterine and salpinx tissues in the kidney. This report describes the clinical, ultrasonographic and computed tomographic features and the results of histopathology. In addition to the abnormally large and cystic myelolipoma of the spleen, the great number of choristomas is remarkable, which has not previously been documented in a dog., Competing Interests: Die Autoren bestätigen, dass kein Interessenkonflikt besteht., (Schattauer GmbH.)

Objective: Ultrasound-guided biopsies are obtained generally to reach a sound diagnosis in the case of sonographically detectable hepatic changes. The most common and well-known complication associated with ultrasound-guided biopsies is haemorrhage after sampling, which may lead to the patient's death. The aim of this study was to evaluate a possible association between alterations in the coagulation parameters and sonographically observable haemorrhage following liver biopsies., Materials and Methods: Dogs and cats in which an ultrasound-guided biopsy of the liver had been performed were retrospectively enrolled in the study. Inclusion criteria were thoroughly documented sonographic findings and the results of the coagula tion parameter thromboplastin time or a combination of the activated partial thromboplastin time and prothrombin time. The incidence of post-interventional ascites and possible risk factors were evaluated., Results: A total of 105 patients met the inclusion criteria and the data of 94 dogs (89.5 %) and 11 cats (10.5 %) were analysed. Post-interventional complications occurred in 26 of 105 patients (24.8 %), 21.9 % being minor and 2.9 % being major. Free abdominal fluid after intervention was sonographically detected in 22 of 94 dogs (23.4 %) and four of 11 cats (36.4 %). Three of 10 dogs (2.9 %) with a clinically significant prolongated coagulation time of > 25 % had ascites after biopsy. Only a small amount of fluid was detected in two of these three dogs, while a moderate amount of ascites was observed in the third dog. One of two cats with a prolonged coagulation time of > 25 % developed a moderate amount of ascites after the puncture. No statistically significant association was found between the occurrence of post-interventional ascites and a prolongation of the coagulation time., Conclusion: According to the study results, there is no obvi ous correlation between alterations in coagulation and haemorrhage after an ultrasound-guided liver biopsy., Competing Interests: Die Autoren bestätigen, dass kein Interessenkonflikt besteht., (Schattauer GmbH.)

In recent years, several new studies on anaesthesia for caesarean section have been published. This paper refers to these and ground-breaking research on risk factors affecting the puppies. Based on the available evidence, a recommendation for an anaesthetic procedure is given and in addition, alternatives are discussed. Induction with propofol or alfaxalone and maintenance by inhalation anaesthesia appears to be the method with the least risk. Intraoperatively, an adequate and low-risk analgesia is achieved by an epidural anaesthesia. Opioids allow an adequate maternal pain management after delivery of the puppies as well as postoperatively. A stabilisation of the dam before induction and an optimised oxygen supply are additional basal requirements.

Background: Early extubation after cardiac surgery is associated with decreased hospital stay and resource savings with similar mortality and has led to the widespread use of early extubation protocols. In the Vascular Quality Initiative, there is significant regional variation in the frequency of extubation in the operating room (endovascular aneurysm repair [EVAR], 77%-97%; open repair, 30%-70%) after repair of intact abdominal aortic aneurysms (AAAs). However, the effects of extubation practices on patient outcomes after repair of AAAs are unclear., Methods: All patients undergoing repair of an intact AAA in the Vascular Study Group of New England from 2003 to 2015 were evaluated. Patients undergoing concomitant procedures or conversions were excluded. Timing of extubation was stratified for EVAR (operating room, <12 hours, >12 hours) and open repair (operating room, <12 hours, 12-24 hours, >24 hours). Prolonged hospital stay was defined as >2 days after EVAR and >7 days after open repair. Univariate and multivariable analyses were completed, and independent predictors of extubation outside of the operating room were identified., Results: There were 5774 patients evaluated (EVAR, 4453; open repair, 1321). After both EVAR and open repair, respiratory complications, prolonged hospital stay, and discharge to a skilled nursing facility (SNF) increased with intubation time. After adjustment, the odds of complications increased with each 12-hour delay in extubation: respiratory (EVAR: odds ratio [OR], 4.3 [95% confidence interval (CI), 3.0-6.1]; open repair: OR, 1.8 [95% CI, 1.5-2.2]), prolonged hospital stay (EVAR: OR, 2.7 [95% CI, 2.0-3.8]; open repair: OR, 1.3 [95% CI, 1.1-1.4]), and discharge to SNF (EVAR: OR, 2.0 [95% CI, 1.5-2.8]; open repair: OR, 1.4 [95% CI, 1.1-1.6]). Predictors of extubation outside of the operating room after EVAR included increasing age (OR, 1.5; 95% CI, 1.2-1.8), congestive heart failure (OR, 1.9; 95% CI, 1.2-3.0), chronic obstructive pulmonary disease (OR, 2.0; 95% CI, 1.4-2.9), symptomatic aneurysm (OR, 3.8; 95% CI, 2.3-5.7), and increasing diameter (OR, 1.01; 95% CI, 1.01-1.01). After open repair, increasing age (OR, 1.4; 95% CI, 1.1-1.6), congestive heart failure (OR, 1.8; 95% CI, 1.01-3.3), dialysis (OR, 2.8; 95% CI, 1.7-70), symptomatic aneurysm (OR, 2.8; 95% CI, 1.9-4.3), and hospital practice patterns (OR, 1.01; 95% CI, 1.01-1.01) were predictive of extubation outside of the operating room., Conclusions: The benefits of early extubation in cardiac patients are also seen after AAA repair. Suitable patients should be extubated in the operating room to decrease respiratory complications, length of stay, and discharge to an SNF. Early extubation protocols should be considered to reduce regional variation in extubation practices and to improve patient outcomes., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate airway obstruction due to abnormal intranasal anatomy in 3 brachycephalic dog breeds using computed tomography and rhinoscopy., Study Design: Prospective clinical study., Animals: A total of 132 brachycephalic dogs (66 Pugs, 55 French Bulldogs, and 11 English Bulldogs) with severe respiratory distress due to brachycephalic syndrome., Methods: Computed tomography and anterior and posterior rhinoscopy were performed to evaluate endonasal obstruction., Results: All dogs had abnormal conchal growth that obstructed the intranasal airways. Rostral aberrant turbinates (RAT) were common in Pugs (90.9%) but less frequent in French (56.4%) and English (36.4%) Bulldogs. Caudal aberrant turbinates (CAT) obstructing the nasopharyngeal meatus were commonly found in all breeds (66.7%). Deviation of the nasal septum was an almost consistent finding in Pugs (98.5%) but was less common in bulldogs. Obstructing turbinates had multiple points of mucosal contact responsible for obstruction of the intranasal airway. Interconchal and intraconchal mucosal contacts were evident in 91.7% of dogs., Conclusion: Selective breeding for short head conformation reduces the size of the nasal cavities to such an extent that intranasal structures grow aberrantly and malformed, leading to obstructed air conducting spaces. Intranasal airway obstruction of brachycephalic dogs may contribute to their exercise and heat intolerance because of impaired pulmonary ventilation and compromised thermoregulatory functions of the canine nose. Failure to address intranasal obstruction might be an explanation for lack of therapeutic success after conventional surgery for brachycephalic syndrome. Future consideration should be given to the diagnosis, management, and treatment of this newly described aspect of airway obstruction., (© Copyright 2016 by The American College of Veterinary Surgeons.)

Two self-made low-fidelity models for simulation of canine intubation and canine female urinary catheterization were developed and evaluated. We used a study design that compares acquired skills of two intervention groups and one control group in a practical examination. Fifty-eight second-year veterinary medicine students received a theoretical introduction to intubation and were randomly divided into three groups. Group I (high-fidelity) was then trained on a commercially available Intubation Training Manikin (item #2006, Veteffects), group II (low-fidelity) was trained on our low-fidelity model, and group III (text) read a text describing intubation of the dog. Forty-seven fifth-year veterinary medicine students followed the same procedure for training urinary catheterization using the commercially available Female Urinary Catheter Training Manikin (Paws 2 Claws), our self-made model, and text. Outcomes were assessed in a practical examination on a cadaver using an Objective Structured Clinical Examination (OSCE) checklist. Considering a value of p≤.05 significant, intervention groups performed significantly better than the text groups. Group I (high-fidelity) and group II (low-fidelity) showed no significant differences (p≤.684, intubation; p≤.901, urinary catheterization). We thereby conclude that low-fidelity models can be as effective as high-fidelity models for clinical skills training.

Objective: To evaluate the frequency of different sonographic splenic disorders in dogs with different anatomic forms of malignant lymphoma. Additionally, the occurrence of the moth-eaten pattern in the parenchyma of the spleen in patients with diseases other than lymphoma should be investigated., Material and Methods: Retrospective analysis of patient data collected from dogs histologically or cytologically diagnosed with malignant lymphoma and for which ultrasonographic images were available before the initiation of therapy. Patient data from dogs with a moth-eaten pattern within the splenic parenchyma were evaluated separately. Exclusion criterion was the administration of cytostatic agents prior to diagnosis., Results: In 84% of 164 dogs with malignant lymphoma, an altered pattern of the spleen was diagnosed ultrasonographically. Ninety-four of these 137 patients had a moth-eaten pattern of the splenic parenchyma and 43 dogs displayed abnormalities in the form of splenomegaly, coarse echotexture or other changes of the parenchyma. When a moth-eaten pattern was diagnosed, the affected dogs suffered significantly more often from a multicentric lymphoma (95%) than from any other anatomical lymphoma form. Only one dog displayed a moth-eaten pattern of the splenic parenchyma without diagnosis of a malignant lymphoma. The positive predictive value of the moth-eaten pattern for malignant lymphoma was 99% and, in particular, for the multicentric lymphoma this was 95%. In total, 84% of the 164 dogs displayed a multicentric lymphoma, 5% a mediastinal or a cutaneous lymphoma, respectively, 4% a gastrointestinal lymphoma, and one animal had an ocular or renal lymphoma, respectively., Conclusion and Clinical Relevance: Sonographic changes of the spleen are often diagnosed in dogs with malignant lymphoma, independent of the anatomical lymphoma form. When the moth-eaten pattern is observed, it is very likely that the affected dog suffers from a malignant lymphoma, most probably a multicentric lymphoma.

Objective: The aim of this study was to assess the potential benefit of computer-assisted detection (CAD) of pulmonary nodules in veterinary medicine. Therefore, the CAD rate was compared to the detection rates of two individual examiners in terms of its sensitivity and false-positive findings., Materials and Methods: We included 51 dogs and 16 cats with pulmonary nodules previously diagnosed by computed tomography. First, the number of nodules ≥ 3 mm was recorded for each patient by two independent examiners. Subsequently, each examiner used the CAD software for automated nodule detection. With the knowledge of the CAD results, a final consensus decision on the number of nodules was achieved. The software used was a commercially available CAD program., Results: The sensitivity of examiner 1 was 89.2%, while that of examiner 2 reached 87.4%. CAD had a sensitivity of 69.4%. With CAD, the sensitivity of examiner 1 increased to 94.7% and that of examiner 2 to 90.8%., Conclusion and Clinical Relevance: The CAD-system, which we used in our study, had a moderate sensitivity of 69.4%. Despite its severe limitations, with a high level of false-positive and false-negative results, CAD increased the examiners' sensitivity. Therefore, its supportive role in diagnostics appears to be evident.

Objective: Characterization of the disorders of abdominal lymph nodes in dogs with malignant lymphoma and evaluation of the Solbiati-Index (SI) and the relationship between the short axis and the length of the lymph node (S  :  L ratio) as malignancy criteria., Material and Methods: Retrospective analysis of data from dogs with malignant lymphoma. Inclusion criteria were cytological or histological diagnosis of the malignant lymphoma and an ultrasound examination of the abdomen prior to initiation of therapy. Criterion for exclusion was the application of a cytostatic agent prior to diagnosis. Furthermore, abdominal lymph nodes with non-neoplastic disorders were examined, when sonography as well as cytological/histological examinations were available., Results: A total of 261 lymph nodes (127 dogs) with malignant lymphoma and 17 lymph nodes (nine dogs) with benign disorders were evaluated. Sonography revealed massively rounded, clearly enlarged lymph nodes in 115/127 dogs (91%) with malignant lymphoma, while the lymph nodes of the other 12 dogs (9%) displayed an enlargement in the long axis. All 17 lymph nodes with benign disorders were enlarged in the long axis. The nodal parenchyma of 91% of the 127 dogs (malignant lymphoma) presented as hypoechoic to anechoic, and the cortex and medulla could not be differentiated. In the remaining 9% of dogs, a physiological isoechoic nodal parenchyma was observed. The parenchyma of lymph nodes with benign disorders was sonographically inconspicuous. In 71% of the 127 dogs with malignant lymphoma, the SI was < 2 and the S  :  L ratio > 0.5 (indicative for malignancy). Of the nine dogs with benign lymph node disorders, 71% had an SI of > 2 and 76% of them had an S  :  L ratio < 0.5 (indicative of a benign process)., Conclusion and Clinical Relevance: The significant increase in the size, rounding and hypoechoic changes in the lymph nodes in dogs with malignant lymphoma are indicative parameters of malignancy. In addition, the SI and the S:L ratio serve as a differentiation between benign and malign processes. Because of blurred boundaries between the malignant and benign changes, the various parameters should always be considered in conjunction.

Objective: The aim of this study was to measure the thickness of the soft palate at specific locations in normocephalic dogs using sonography and computed tomography (CT), and to subsequently compare the two different methods., Material and Methods: A total of 15 normocephalic dogs were examined under general anesthesia. The CT was performed while patients were in a sternal recumbent position, their mouth held open by placing their upper jaw on a positioning device. Dorsal recumbency together with submental and midsagittal positioning of the transducer were chosen for sonography. Measurements were made in both sonographic and reconstructed sagittal CT images. Two measuring points (MP) were defined for measuring the cranial and the middle part of the soft palate (MP1: 1 cm caudal to the transition from the hard to the soft palate; MP2: at the origin of the dorsal pharyngeal muscles). It was investigated whether repeated procedures with one measuring method provided consistent values and, furthermore, whether the two different measuring methods (sonography and CT) provided comparable data., Results: The data acquired by repeat measurements within one method corresponded very well. However, the data provided by the two different measurement methods showed varying results for the first measuring point and was even greater for the second measuring point. Sonography overestimated the measurements obtained by CT by up to 0.26 cm for MP1 and up to 0.79 cm for MP2., Conclusion: Due to the significant discrepancies in their results, the two measurement methods are not interchangeable. Sonography showed good reliability for repeat measurements. Consequently, the variable values between CT and sonography appeared to result from differing examination conditions. Sonography may be a rapid and non-invasive diagnostic tool to measure soft palate thickness if the applied method proves to be applicable in clinical practice.

Early recognition of a cardio-pulmonary arrest (CPA) is crucial for patient survival. Every non-breathing and non-responsive patient should be considered to have CPA, and examination of the vital signs should last no longer than 5-10 seconds. If in doubt, effective chest compressions should be started immediately (frequency of 100-120 compressions per minute, compression depth one third to half of the chest diameter, full chest wall recoil between the compressions, no interruption, change of compressing person every 2 minutes). Furthermore, the patient should be intubated and ventilated as early as possible with a frequency of 10 breaths per minute and a volume of 10 ml/kg. Additional measures include monitoring (electrocardiogram, end-expiratory carbon dioxide concentration), placement of an intravenous or intraosseous catheter, administration of opioid-, benzodiazepine- and/or α2-antagonists and ECG-dependent therapy to restore spontaneous circulation. In the case of asystole and pulseless electric activity, epinephrine (0.01 mg/kg every 3-5 minutes, alternative dose concept: 0.1 mg/kg epinephrine) is advised. In the case of CPA due to elevated vagal tonus or bradycardia, atropine should be given (0.04 mg/kg every 3-5 minutes). If ventricular fibrillation or pulseless ventricular tachyarrhythmia is present, defibrillation is the therapy of choice. When this is not possible, amiodarone (5 mg/kg) or lidocaine (2 mg/kg) should be administered. Furthermore, 100% oxygen should be given during resuscitation, while only a few patients benefit from infusion therapy. Following the return of spontaneous circulation, intensive care of the patient is necessary. This involves intense monitoring and support of the haemodynamic situation using intravenous fluids, vasopressors and positive inotropic drugs as well as an improvement of gas exchange and neuroprotection.

Purpose: The aim of this study was to characterize the normal sonographic anatomy of the soft palate in dogs., Materials and Methods: The study was performed on seven canine heads via a submental and intraoral approach. The detected anatomical structures were then reexamined via a submental approach in a water bath. Each anatomic layer was subsequently dissected starting with the submental layers and working towards the soft palate. After every preparation a sonographic examination was carried out., Results: Differentiation between the soft palate and the surrounding oropharyngeal tissue can be effectively achieved. Using the submental approach, the transition between hard palate and soft palate as well as the middle section of the soft palate were distinguished from other oropharyngeal structures in all cases. Visualization of the caudal part of the velum and evaluation of the echogenicity of the soft palate were difficult and not always possible. In the two brachycephalic dogs of the study, it was challenging to distinguish the soft palate from the surrounding tissue., Conclusion: The sonographic appearance of the canine soft palate in cadavers was described in this study. The submental approach allows differentiation between intraoral structures. Evaluation of the echogenicity and length of the soft palate is limited., (© Georg Thieme Verlag KG Stuttgart · New York.)

The influence of the application modes (bolus injection, infusion) of the sonographic signal enhancers Levovist was investigated in a total of 24 dogs. The animals in the bolus group were given 0.2 ml/kg body mass Levovist at a concentration of 300 mg/ml while in the other group the same amount was continuously injected over a time of two minutes. Signal enhancement was measured by an audiodoppler. Contrast duration above six, twelve, 18 and 24 dB and maximum signal enhancement were determined for each application mode. The comparison of these parameters showed that a statistically significant longer contrast duration (significance level p less than 0,05) at 0 and 6 dB can be achieved by continuous injection. Bolus application, on the other hand, resulted in significantly higher maximum contrast enhancement. With time consuming investigations (perfusiondiagnostic, shuntdiagnostic) the contrast effect can be partly extended with continuous injection but the technical requirements are higher and there is the risk that the acoustic properties of the microbubbles are negatively influenced.

Objective: Kidney failure after anaesthesia constitutes a serious clinical complication. A number of patients suffer from compensated kidney insufficiency, which may be transformed into an acute kidney insufficiency through additional stress, such as an operation and anaesthesia. The aim of the present study was to investigate the effects of a neurolept analgesia with acepromazine on sonographically accessible blood perfusion parameters., Material and Methods: Following anaesthesia with acepromazine/l-methadone (0.1 mg/kg BW acepromazine, 0.5 mg/kg BW l-methadone) a sonographic examination of the left kidney was performed in 19 clinically healthy foxhound and beagle dogs. Every 5 minutes resistance index and pulsatility index as well as invasive blood pressure were measured and digitally recorded., Results: Within 5 minutes after induction of anaesthesia a transient increase of the mean arterial blood pressure occurred. After 10 minutes the blood pressure decreased to the initial value and remained essentially constant to the end of the investigation. Resistance index and pulsatility index showed a similar behaviour: After a small initial decrease during the first 5 minutes both parameters displayed a significant increase. This rise was very pronounced up to approximately 15 minutes and then flattened significantly until the end of the test period after 30 minutes. The values corresponded to those found in vessel stenosis., Conclusion and Clinical Relevance: Due to the described changes this type of anaesthesia should not be used in dogs with nephropathy, even though the results of this experimental study might not be necessarily transferable to the clinical patient.

Background and Purpose: Complications of primary nasoplasty, at the time of definitive primary cheiloplasty, are underreported in the literature. This study endeavors to examine the occurrences of these complications at our cleft-craniofacial center, in an effort to identify causative factors and management strategies. A case series of patients with postoperative nasal complications after primary cleft lip nasal surgery is presented., Methods: A retrospective chart review of primary cleft lip nasal repairs was conducted at our cleft-craniofacial center between January 2003 and December 2007. Consecutive cases of 3 staff surgeons were evaluated. Specific data points included number and type of complications, subsequent required interventions, and relevant history, with particular attention paid to the details of the primary nasoplasty., Results: Eighty-six primary cleft lip nasoplasties were completed between the years 2003 and 2007. Six complications (6.9%) related to the primary cleft lip nasoplasty were identified. Four patients (4.6%) experienced nasal tip infections; all 4 required surgical drainage. Twenty-four patients (27.9%) undergoing primary cleft lip and nose repair had postoperative nostril conformers placed, and 2 (8.3%) of them experienced complications deemed conformer related., Conclusions: Postoperative nasal complications of primary cheiloplasty occur and are likely underreported. In this series, complications resulted from infection, often occurring late, and secondary to the use of nostril conformers. Surgeon awareness and caregiver education, to identify the early signs of postoperative nasal complications, are critical to the successful treatment of these occurrences. Although this study did not intend on examining antibiotic use, the significance of nasal tip infections might support the regular use of antibiotics in this population, and the use of postoperative nostril conformers must be followed closely.

A 13-yr-old Amur tiger (Panthera tigris altaica) was presented for an acute onset of paraplegia. Spinal imaging that included plain radiographs, myelography, and computed tomography performed under general anesthesia revealed lateralized spinal cord compression at the intervertebral disc space L4-5 caused by intervertebral disc extrusion. This extrusion was accompanied by an extensive epidural hemorrhage from L3 to L6. Therefore, a continuous hemilaminectomy from L3 to L6 was performed, resulting in complete decompression of the spinal cord. The tiger was ambulatory again 10 days after the surgery. This case suggests that the potential benefit of complete spinal cord decompression may outweigh the risk of causing clinically significant spinal instability after extensive decompression.

Objectives: To determine if routine haematological and biochemical screening is of benefit in dogs requiring anaesthesia and to establish the most useful tests for pre-anaesthetic risk assessment., Animals: One thousand five hundred and thirty-seven client-owned dogs undergoing surgery at the University of Leipzig between January 2003 and April 2004., Materials and Methods: After obtaining a standardized history and a physical examination, all dogs requiring anaesthesia were assigned to an ASA physical status group, their needs for pre-anaesthetic therapy determined and an anaesthetic protocol proposed. Haematological (haematocrit, red blood cell count, white blood cell count, platelet count and haemoglobin concentration) and serum biochemistry tests (plasma urea, creatinine, glucose, total protein, sodium and potassium concentration; serum alanine aminotransferase, alkaline phosphatase and lipase activity) were then performed in all animals. The results of these were then used to: 1) re-define each dog's ASA physical status; 2) determine any altered requirement for pre-anaesthetic therapy; 3) re-determine the suitability of the dog to undergo surgery; and 4) re-examine the suitability of the original proposed anaesthetic protocol., Results: The history and clinical examination in 1293 out of 1537 dogs (84.1%) revealed that haematological and biochemical tests would have been considered unnecessary under normal conditions. Of these, 63.9% were categorized as ASA 1, 28.5% as ASA 2, and 7.6% at higher risk. In some dogs, screening tests showed abnormal results: 16.7% of 1293 dogs had abnormal plasma urea levels, with 5.9% of values above the reference range. However, only 104 dogs (8%) would have been re-categorized at a higher physical status category had the laboratory results been available. Additional screening data indicated that surgery would have been postponed in 10 dogs (0.8%) additional pre-anaesthetic therapy would have been provided in 19 animals (1.5%) and the anaesthetic protocol altered in two dogs (0.2%)., Conclusion: The changes revealed by pre-operative screening were usually of little clinical relevance and did not prompt major changes to the anaesthetic technique., Clinical Relevance: In dogs, pre-anaesthetic laboratory examination is unlikely to yield additional important information if no potential problems are identified in the history and on physical examination.

Two young adult Yorkshire terriers had neurologic signs consistent with forebrain and brainstem involvement or forebrain involvement alone. On magnetic resonance imaging studies there were asymmetric bilateral lesions mainly in the cerebral cortex, and in the diencephalon. These areas were hyperintense on T2-weighted and FLAIR images, but hypointense or isointense on T1-weighted images. Lesions had a varying degree of contrast enhancement. Areas which were isointense on T1-weighted images had no contrast enhancement or only foci of contrast enhancement. Lesions with hypointensity in T1-weighted images had no enhancement or more frequently ring-like enhancement around the lesion. Necrotizing encephalitis was confirmed pathohistologically in both dogs. The degree of contrast enhancement appeared to be related to the degree of lymphohistiocytic inflammation on histologic examination.

All anaesthetic drugs and techniques inhere risks, that can cause illness and death even in the sound. Beside this common anaesthetic risk caused by anaesthesia itself, risks specific for the patient and the surgery, the influence of the anaesthetist and the available facilities are additional factors contributing to the risk involved for any particular animal. In this article the factors in anaesthetic risk and their importance for the individual risk of a patient are discussed. Distinct is that a systemic disease and the resulting incapacity stand for a much higher risk than anaesthesia by itself or the surgery. Beside the preoperative physical status the urgency of the operation has a decisive influence upon the anaesthetic risk. Deficient monitoring and an unrecognized and/or untreated respiratory depression are the most common reasons for anaesthetic death in veterinary medicine. The anaesthetist has a profound bearing on the degree of risk to which a patient is exposed, because most of the avoidable anaesthetic mishaps are caused by human mistakes. The individual anaesthetic risk of a patient is determined with the help of the preanaesthetic examination. Referring to the factors in anaesthetic risk strategies for the prevention of anaesthetic mishaps and complications are discussed.

The continuous fiberoptical measurement of the mixed venous partial oxygen saturation is described. It is an enrichment of the diagnostical possibilities in veterinary medicine. In the horse it is of great interest, because disturbances of the pulmonary gas exchange and the myocardial function are common in the anaesthetised horse, and reliable methods of assessing the cardiac output are rare. Using this monitoring technique in nearly 100 equine high risk patients facilitated insight into the complex changes of the pulmonary, cardiac and circulatory function in the anaesthetised horse. The registered data are the basis of the presented case reports. Values measured "behind the tissue" are influenced by the oxygen supply and the oxygen consumption within the periphery. Changes of the mixed venous oxygen status can be caused by a disturbance of the arterial oxygen status, by a insufficient performance of the cardiovascular system or by a change in metabolic activity. Being a multifactorial influenced parameter the mixed venous oxygen saturation can only be interpreted in connection with other parameters. The mixed venous oxygen status gives global information about the whole organism, but it is not able to inform about the oxygen supply of single organs. From our own personal experience it reflects an aggravation of the patient very early and reliable.

Capnography measures carbon dioxide concentration or partial pressure of the respiratory gas continuously and non-invasively. The endtidal value is of great diagnostic value, it corresponds approximately to the arterial value, except for ventilation-perfusion-mismatching (horse), shunting (horse), or increased dead-space-ventilation (panting in the dog). Capnography primarily serves for monitoring of spontaneous and artificial ventilation, it is a reliable method for detecting hypo- and hyperventilation. Because metabolism and circulation influence the amount of carbon dioxide eliminated in the lung, capnography monitors these functions too. The plotting of the carbon dioxide concentration as a carbon dioxide-time-diagram draws attention to malfunctions of the equipment. Technical problems of capnography depend on the design of the capnograph (main- or side-stream) used as well as on the weight of the patient. In the discussion the value of pulse oximetry and capnography in detection of critical events during anaesthesia is compared. Capnography is superior to pulse oximetry in the capability to detect critical events. But pulse oximetry complements capnography perfectly, both methods together give a good impression of the patient's state of health.

Two non-invasive continuous techniques for monitoring the respiratory function during anaesthesia have been established during the last year: pulse oximetry for monitoring the adequate oxygen supply and capnography for measuring the carbon dioxide elimination. In human medicine both are accepted as essential monitors with great reliability. Whether clinical use and interpretation can be transferred to animals without any restrictions will be discussed by looking on the physical and engineering background as well as the physiologic interpretation of the measured variable and their capability to detect critical events during administration of anaesthesia. Part I: Pulse oximetry measures the arterial oxygen saturation continuously and non-invasively. Its application in veterinary medicine must be discussed critically concerning the method as well as the interpretation. The information obtained is very different during injectable and inhalant anaesthesia. Respiratory depression is easy to detect while the animal breathes room air spontaneously. Is the inspired air enriched with oxygen, like during inhalant anaesthesia, normal values of oxygen saturation can mask the respiratory insufficiency and may give a false sense of security.

Xylazine and Ketamine were used for anaesthesia in 250 adult horses. This combination is useful both for induction and maintenance of anaesthesia. The induction with Xylazine and Ketamine has been successful not only with foals but also with high risk patients such as horses with colic. During the maintenance of anaesthesia Xylazine/Ketamine can be used with injectable anaesthetics as well as with volatile anaesthetics at the same time. A form of injection anaesthesia for short-time surgical procedures like castration and wound repair is presented. The maintenance of a Thiobarbiturate/Guaifenesin anaesthesia with Xylazine/Ketamine seems to be suitable for field conditions.