Gerhard Oechtering

Noninvasive assessment of myocardial cell injury in dogs with suspected cardiac contusion

OBJECTIVES To determine the suitability of serologic biochemical tests to diagnose myocardial cell injury in dogs with suspected cardiac contusion. BACKGROUND Myocardial contusion after blunt thoracic trauma will frequently be overlooked or missed unless hemo-dynamic instability or dramatic electrocardiographic findings are observed. There are no available non-invasive tests to definitely detect blunt myocardial lesions in dogs. METHODS Circulating biochemical markers of skeletal muscle and myocardial cell integrity (aspartate aminotransferase, lactate dehydrogenase, a-hydroxybutyrate dehydrogenase, creatine kinase [CK], CK isoenzyme MB, and cardiac troponins I [cTnT] and T [cTnT]) were analyzed in 33 dogs with blunt chest injury and in 40 control dogs. Results were compared with ECG abnormalities diagnosed from serial short-time surface ECGs. RESULTS Cardiac TnI and CK-MB in serum were not detectable in 36 and 26 healthy dogs (median and range were 0 and 0 to 1.37 ng/ml and 0 and 0 to 3.17 ng/ml, respectively). Serum cTnT was not found in normal dogs. In dogs with thoracic trauma, circulating cTnI was elevated in 18 dogs (range 0 to 160.1 ng/ml), CK-MB in 14 dogs (range 0 to 24.9 ng/ml) and cTnT in 9 dogs (range 0 to 2.35 ng/ml), suggesting myocardial cell injury in 58% of dogs. Relevant electrocardiographic abnormalities were observed in 10/33 (30%) dogs. No differences in serum concentrations of markers of myocardial injury were found between dogs with or without relevant ECG abnormalities. CONCLUSION Myocardial cell injury is a frequent event in dogs with blunt thoracic trauma. Analysis of serum cTnI is more sensitive in detecting myocardial abnormalities than determination of circulating cTnT and CK-MB or electrocardiography.

Brachycephalic Feline Noses: CT and Anatomical Study of the Relationship between Head Conformation and the Nasolacrimal Drainage System

Aims A study was designed to evaluate the influence of head conformation on the course of the nasolacrimal drainage system (NDS) in 31 brachycephalic and 15 mesocephalic cats using computed tomography (CT), CT-dacryocystography and anatomical methods. Findings The higher the degree of brachycephalia, the more the facial bones and upper canine teeth are displaced dorsally (ie, the more pronounced the dorsorotation). Dorsorotation leads to abnormal dislocation of the ventral nasal concha and to almost horizontally rotated upper canine teeth, and thus a steeply oriented NDS. In severe brachycephalia the NDS is forced to pass below the canine tooth (adopt a V-shaped course) and the drainage function seems to be inefficient. Practical relevance The rotation of the upper canine teeth appears to provide a basis for classification of brachycephalia in cats. The authors recommend that breeders avoid breeding from individuals affected by this condition and to give preference to cats with longer facial bones.

Visual Estimation of Radioulnar Incongruence in Dogs Using Three‐Dimensional Image Rendering: An In Vitro Study Based on Computed Tomographic Imaging

OBJECTIVE To determine the sensitivity and specificity of visual estimation of radioulnar incongruence (RUI) in the canine elbow by use of 3-dimensional (3D) image rendering. STUDY DESIGN Experimentally induced negative and positive RUI. SAMPLE POPULATION Canine (>20 kg) cadaveric right thoracic limbs (n=8). METHODS Radial shortening and lengthening of 1 and 2 mm were performed extending an established surgical in vitro model of RUI. Based on transverse computed tomographic (CT) scans of each radioulnar conformation, the subchondral radioulnar joint surface was reconstructed and visualized. A total of 64 3D models of RUI were blindly evaluated in a random manner by 3 independent observers. RUI was estimated subjectively at 1 mm precisely (-2, -1, 0, +1, +2) by visual inspection of the 3D models. RESULTS Median sensitivity for identifying an incongruent joint was 0.86. Median specificity for identification of a congruent joint was 0.77. Analyzing the data only in respect to a congruent joint versus one with a shortened radius (positive RUI) resulted in a median sensitivity of 0.82, and a median specificity of 1.00. Interobserver agreement was 0.87. Repeatability was 0.96. CONCLUSION Estimation of positive and negative RUI based on 3D surface models of the radioulnar articulation mimics gross inspection in a noninvasive manner, the latter being the ultimate gold standard for definitive diagnosis of any radioulnar step. The proposed technique is precise, reliable, and repeatable in vitro. CLINICAL RELEVANCE Preoperative estimation of the type and degree of RUI is the basis for deciding which type of corrective or modifying osteotomy might be best suited to restore normal joint loads in vivo.

Value of low-field magnetic resonance imaging in diagnosing meniscal tears in the canine stifle: a prospective study evaluating sensitivity and specificity in naturally occurring cranial cruciate ligament deficiency with arthroscopy as the gold standard.

OBJECTIVE To evaluate the sensitivity and specificity of low-field magnetic resonance imaging (lfMRI) for detection of meniscal tears in the canine stifle. STUDY DESIGN Double-blinded prospective clinical study. ANIMALS Forty-two consecutive stifles of dogs (>or=20 kg; n=34) with clinical and radiologic signs suspicious for cranial cruciate ligament (CCL) insufficiency. METHODS Each stifle had 7 predefined lfMRI sequences using a 0.5 T magnet with a human knee coil. After lfMRI, diagnostic arthroscopy was performed by 1 surgeon unaware of the MRI findings. After completion of the study MRI images were read by 1 investigator, unaware of the intraoperative findings. RESULTS At arthroscopy, 22 stifles had meniscal tears requiring subtotal meniscectomy. Of these only 14 were identified by lfMRI. Overall sensitivity and specificity of lfMRI for detection of meniscal tears were 0.64 (95% confidence interval [95% CI]=0.43, 0.80) and 0.90 (95% CI=0.70, 0.97), respectively. Positive and negative predictive values were 0.88 (95% CI=0.64, 0.97) and 0.69 (95% CI=0.50, 0.83), respectively. Neither the state of dislocation of vertical longitudinal tears nor the amount of CCL rupture had an influence on lfMRI accuracy (P=1.00). CONCLUSION lfMRI was of low diagnostic accuracy in detecting meniscal tears, when compared with arthroscopy. Especially negative lfMRI findings should be interpreted with caution. CLINICAL RELEVANCE When using lfMRI as a noninvasive preoperative screening tool for the diagnosis of meniscal tears, a high percentage of missed meniscal tears has to be expected.

How does severe brachycephaly affect dog’s lives? Results of a structured preoperative owner questionnaire

Brachycephalic syndrome (BS) is a complex canine disease, which is characterized by diverse clinical signs primarily involving the respiratory and gastrointestinal systems. Through a structured owner questionnaire, the present study investigated how owners perceived the frequency and severity of a broad spectrum of welfare-relevant impairments caused by this hereditary disease. One hundred owners of brachycephalic dogs (Pugs and French bulldogs) referred for surgical treatment of BS completed the questionnaire. As a basis for comparison, 20 owners of mesocephalic dogs also completed part of the questionnaire. Questionnaire responses revealed that in addition to the well-known respiratory signs, brachycephalic dogs experienced severe exercise intolerance and prolonged recovery time after physical exercise (88%), significant heat sensitivity (more severe signs at temperatures above 19°C; 50%) and a variety of sleep problems (56%). To our knowledge, this is the first study using a structured owner questionnaire specifically to investigate a broad range of problems caused by selective breeding for brachycephaly. In particular, decreased exercise tolerance, increased recovery time due to heat intolerance and the extent of sleep problems have either been underestimated in the past, or have severely worsened over recent generations of dogs. The extent and severity of clinical signs and their impact on quality of life greatly exceeded our expectations. This study emphasizes the major impact that selective breeding for extreme brachycephalic features has on animal welfare.

Is routine pre-anaesthetic haematological and biochemical screening justified in dogs?

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 dogs 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.

Partial Lateral Corpectomy of the Thoracolumbar Spine in 51 Dogs: Assessment of Slot Morphometry and Spinal Cord Decompression

Objective: To report slot morphometry, degree of spinal decompression, and factors influencing decompression after partial lateral corpectomy (PLC) of the thoracolumbar spine in dogs with intervertebral disc disease. Study Design: Case series. Animals: Dogs (n=51) with predominantly ventrally located spinal cord compression. Methods: PLC (n=60) were performed. Spinal cord compression was determined by computed tomographic (CT) myelography (n=46), myelography (n=2) or magnetic resonance imaging (n=3). Postsurgical CT images were used to evaluate slot dimensions and orientation, and spinal cord decompression. The influence of age, body weight, breed, breed type (chondrodystrophic, nonchondrodystrophic), disc location, lateralization and mineralization, presurgical compression, slot morphometry, and surgeon on degree of decompression were evaluated. Results: Mean slot depth was 64.1% of vertebral body width; mean height, 43.0% of vertebral body height; mean cranial extension, 29.5%; median caudal extension, 22.0% vertebral body length; mean angulation from horizontal, 6.3°. Decompression was satisfactory in 90% of sites after PLC (58% complete, 32% good). None of the analyzed factors significantly influenced decompression. All lumbar spine PLC resulted in complete or good decompression compared with 83% after thoracic PLC (P=.052). Deeper slots tended to allow more complete decompression (P=.058). Conclusions: Thoracolumbar PLC results in satisfactory decompression in most cases with a better outcome in the lumbar spine than the thoracic spine. Achieving a slot depth equal to 2/3 of vertebral body width might facilitate complete decompression.OBJECTIVE To report slot morphometry, degree of spinal decompression, and factors influencing decompression after partial lateral corpectomy (PLC) of the thoracolumbar spine in dogs with intervertebral disc disease. STUDY DESIGN Case series. ANIMALS Dogs (n=51) with predominantly ventrally located spinal cord compression. METHODS PLC (n=60) were performed. Spinal cord compression was determined by computed tomographic (CT) myelography (n=46), myelography (n=2) or magnetic resonance imaging (n=3). Postsurgical CT images were used to evaluate slot dimensions and orientation, and spinal cord decompression. The influence of age, body weight, breed, breed type (chondrodystrophic, nonchondrodystrophic), disc location, lateralization and mineralization, presurgical compression, slot morphometry, and surgeon on degree of decompression were evaluated. RESULTS Mean slot depth was 64.1% of vertebral body width; mean height, 43.0% of vertebral body height; mean cranial extension, 29.5%; median caudal extension, 22.0% vertebral body length; mean angulation from horizontal, 6.3°. Decompression was satisfactory in 90% of sites after PLC (58% complete, 32% good). None of the analyzed factors significantly influenced decompression. All lumbar spine PLC resulted in complete or good decompression compared with 83% after thoracic PLC (P=.052). Deeper slots tended to allow more complete decompression (P=.058). CONCLUSIONS Thoracolumbar PLC results in satisfactory decompression in most cases with a better outcome in the lumbar spine than the thoracic spine. Achieving a slot depth equal to 2/3 of vertebral body width might facilitate complete decompression.

A novel pin distraction device for arthroscopic assessment of the medial meniscus in dogs.

OBJECTIVE To describe an extra-articular joint distractor for meniscal examination and treatment during canine stifle arthroscopy. STUDY DESIGN Case series. ANIMALS Dogs >or=20 kg with suspected cranial cruciate ligament (CrCL) deficiency. METHODS A custom designed linear side bar was constructed to allow invasive pin distraction of the stifle joint. Its design efficacy for distraction of the medial joint compartment, observation and probing of the medial meniscus, and value during meniscal surgery was evaluated by clinical use. RESULTS Application of the stifle distractor medial to the stifle joint using 2 negative threaded pins was easily performed percutaneously without the need of power equipment; however, unintended intra-articular placement of 1 threaded pin occurred in 2 stifles, without appreciable consequence to joint function. Observation as well as thorough probing of the caudal horn of the medial meniscus, even in the presence of a prominent remnant of the CrCL or severe periarticular fibrosis, was possible. Partial meniscectomy was effectively performed as needed without apparent damage to the associated articular surfaces. CONCLUSIONS Distraction and translation of the medial compartment of the stifle joint using invasive pin distraction allowed observation and palpation of the caudal horn of the medial meniscus so that assessment and treatment were readily accomplished without apparent morbidity. CLINICAL RELEVANCE With careful attention to accurate pin placement, invasive pin distraction of the medial compartment of the canine stifle joint may improve arthroscopic evaluation and treatment of meniscal pathology.

Blindness as a sign of proventricular dilatation disease in a grey parrot (Psittacus erithacus erithacus).

An approximately eight-year-old female grey parrot (Psittacus erithacus erithacus) was presented with a two months history of blindness. The radiographic examination showed a dilatation of the proventriculus, ventriculus and gut. Ophthalmoscopy and electroretinography revealed degeneration of the retina. A proventricular dilatation disease was suspected. The bird was euthanased because of deteriorating condition and poor prognosis. The pathological examination showed an atrophy of the ventricular muscles and lymphoplasmacytic infiltrates of the myenteric plexus of the proventriculus, ventriculus and gut as well as moderate lymphoplasmacytic infiltrates of the cerebrum with moderate neuronophagia. Lymphoplasmacytic infiltrates in the retina, indicating proventricular dilatation disease, and subsequent retinal degeneration were found. A potential common aetiology for proventricular dilatation disease and blindness is discussed.

Diagnostic Yield and Adverse Effects of MRI‐Guided Free‐Hand Brain Biopsies through a Mini‐Burr Hole in Dogs with Encephalitis

BACKGROUND The diagnosis of encephalitis is usually presumptive based on MRI, cerebrospinal fluid analysis, or both. A definitive diagnosis based on histopathology, however, is required for optimizing treatment strategies. OBJECTIVE To investigate the diagnostic yield and adverse effects of minimally invasive brain biopsies in dogs with encephalitis. ANIMALS Seventeen dogs with suspected encephalitis, based on MR imaging and cerebrospinal fluid analysis. METHODS Retrospective study. Minimally invasive, free-hand brain biopsy specimens were taken from forebrain lesions through a 4-mm burr hole using a Sedan side-cutting needle. Routine histopathological examination was performed. The adverse effects were assessed by MRI evaluations after biopsy procedure (12/17) and by sequential neurological examinations. RESULTS The overall diagnostic yield with regard to a specific type of encephalitis was 82%. Encephalitis was evident in an additional 12%, but a specific disease could not be determined. There were no deaths caused by the biopsy procedure itself, but the indirect case fatality rate was 6%. Morbidity was 29%, including stupor, seizures, tetraparesis, hemiparesis, ataxia, and loss of conscious proprioception. All these signs resolved within 3-14 days. CONCLUSIONS AND CLINICAL IMPORTANCE Minimally invasive brain biopsy in dogs with suspected encephalitis leads to a definite diagnosis in the majority of dogs, allowing for a specific treatment. The advantages of a definite diagnosis outweigh potential case fatality rate and temporary neurological deficits.