Brain abscesses as a metastatic manifestation of strangles: symptomatology and the use of magnetic resonance imaging as a diagnostic aid

REASONS FOR PERFORMING STUDY: The occurrence of unexpectedly high numbers of horses with neurological signs during two outbreaks of strangles required prompt in-depth researching of these cases, including the exploration of magnetic resonance imaging (MRI) as a possible diagnostic technique. OBJECTIVES: To describe the case series and assess the usefulness of MRI as an imaging modality for cases suspected of space-occupying lesions in the cerebral cavity. METHODS: Four cases suspected of suffering from cerebral damage due to Streptococcus equi subsp. equi infection were examined clinically, pathologically, bacteriologically, by clinical chemistry (3 cases) and MRI (2 cases). In one case, MRI findings were compared to images acquired using computer tomography (CT). RESULTS: In all cases, cerebral abscesses positive for Streptococcus equi subsp. equi were found, which explained the clinical signs. Although the lesions could be visualised with CT, MRI images were superior in representing the exact anatomic reality of the soft tissue lesions. CONCLUSIONS: The diagnosis of bastard strangles characterised by metastatic brain abscesses was confirmed. MRI appeared to be an excellent tool for the imaging of cerebral lesions in the horse. POTENTIAL CLINICAL RELEVANCE: The high incidence of neurological complications could not be explained but possibly indicated a change in virulence of certain strains of Streptococcus equi subsp. equi. MRI images were very detailed, permitting visualisation of much smaller lesions than demonstrated in this study and this could allow prompt clinical intervention in less advanced cases with a better prognosis. Further, MRI could assist in the surgical treatment of brain abscesses, as has been described earlier for CT.     

Use of a flexible fiberoptic laparoscope as a diagnostic aid in cattle

This study was performed to examine the use of a flexible fiberoptic colonoscope as a diagnostic aid in cattle. Examinations were carried out on a group of normal animals and the effects of laparoscopy on hematological parameters measured. The use of laparoscopy in the diagnosis of left displacement of the abomasum and traumatic reticuloperitonitis was assessed in two separate groups of patients. The results were compared to clinical diagnosis and exploratory laparotomy. No effect was demonstrated on the results of haematological examination in the normal cows and the procedure was concluded to be safe and innocuous. Right flank laparoscopy was not useful in detecting left displacement of the abomasum in any case in this study was not helpful in making a diagnosis. The difficulties of current methods of diagnosing left displacement of the abomasum are discussed. Laparoscopy was useful in detecting and characterizing the lesions of traumatic reticuloperitonitis and was concluded to be superior to clinical examination as a diagnostic test.     

An evaluation of positive contrast vaginourethrography as a diagnostic aid in the bitch

The contribution of vagino-urethrography to the diagnosis of disorders of the lower urogenital tract in 123 bitches was evaluated. It was found to be particularly valuable in animals with urinary incontinence, vaginal discharge, dysuria and physical vaginal abnormalities. Determination of vaginal volume in 69 bitches has enabled a dosage of contrast medium to be suggested.     

Assessment of plasma anti-elastin antibodies for use as a diagnostic aid for chronic progressive lymphoedema in Belgian Draught Horses

Diagnosis of chronic progressive lymphoedema (CPL) in draught horses, including the Belgian Draught Horse, is mainly based on clinical evaluation of typical lower limb lesions. A deficient perilymphatic elastic support, caused by a pathological elastin degradation in skin and subcutis, has been suggested as a contributing factor for CPL. Elastin degradation products induce the generation of anti-elastin Ab (AEAb), detectable in horse serum by ELISA. For a clinically healthy group of draught horses, a significantly lower average AEAb-level than 3 clinically affected groups (mild, moderate and severe symptoms) was demonstrated previously. To improve CPL-diagnosis, we evaluated the AEAb-ELISA as an in vitro diagnostic aid in individual horses. Test reproducibility was assessed, performing assays independently in 2 laboratories on a total of 345 horses. Possible factors associated with AEAb-levels (age, gender, pregnancy, test lab and date of blood collection) were analyzed using a mixed statistical model. Results were reproducible in both laboratories. AEAb-levels in moderately and severely affected horses were significantly higher than in healthy horses. Nevertheless, this was only demonstrated in barren mares, and, there was a very large overlap between the clinical groups. Consequently, even when a high AEAb cut-off was handled to obtain a reasonable specificity of 90%, a very low sensitivity (21%) of AEAb for CPL-diagnosis was obtained. Results on the present sample demonstrate that the described ELISA procedure is of no use as a diagnostic test for CPL in individual horses.     

Rhinoscopy: a diagnostic aid?

Sixty dogs with confirmed chronic nasal disease were examined rhinoscopically. The relative merits of the otoscope, an arthroscope and a flexible bronchoscope as instruments are discussed. Rhinoscopy has a limited place in the investigation of chronic nasal discharge in the dog due to the volume of discharge present and induced haemorrhage. It is most useful in cases of destructive rhinitis (including aspergillosis) and foreign body obstruction.     

The evaluation of postmortem ocular fluid analysis as a diagnostic aid in sows

This study was undertaken to evaluate the diagnostic usefulness of postmortem ocular fluid analysis in estimating the antemortem status of various serochemical constituents. Chemical values of serum and aqueous and vitreous humors were compared following different procedures. A blood sample and the 2 eyes were collected from each of 100 sows at a nearby abattoir. The results obtained from immediate centrifugation of ocular fluids after sampling were compared with those samples in which centrifugation was delayed by 2 hours. Two different postmortem intervals were used for sampling ocular fluids, 2 and 24 hours. Concentrations of urea, calcium, phosphorus, potassium, sodium, and chloride were determined from serum and humors. Delayed centrifugation did not affect chemical values of ocular fluids nor the relationships between serum and humors. Phosphorus and potassium values increased significantly with the postmortem interval in both aqueous and vitreous humors. The relationships between chemical values of ocular fluids and serum were determined using simple linear regression. There was a poor correlation between ocular fluid and serum values for all electrolytes; a significant correlation was found only for urea concentrations in both humors.     

Repetitive stimulation of the common peroneal nerve as a diagnostic aid for botulism in foals

Background: Botulism is a potentially fatal paralytic disorder for which definitive diagnosis is difficult. Objectives: To determine if repetitive stimulation of the common peroneal nerve will aid in the diagnosis of botulism in foals. Animals: Four control and 3 affected foals. Methods: Validation of the test in healthy foals for its comparison in foals with suspected botulism. Controls were anesthetized and affected foals were sedated to avoid risks of anesthesia. The common peroneal nerve was chosen for its superficial location and easy access. Stimulating electrodes were placed along the common peroneal nerve. For recording, the active and reference electrodes were positioned over the midpoint and distal end of the extensor digitorum longus muscle, respectively. Repeated supramaximal stimulation of the nerve was performed utilizing a range of frequencies (1–50 Hz). Data analysis consisted of measuring the amplitude and area under the curve for each M wave and converting these values into percentages of decrement or increment based on the comparison of subsequent potentials to the initial one (baseline) within each set. Results: A decremental response was seen at all frequencies in control foals. Decremental responses also were observed in affected foals at low frequencies. An incremental response was seen in all affected foals at 50 Hz. Conclusions and Clinical Importance: Decreased baseline M wave amplitudes with incremental responses at high rates are supportive of botulism. Repetitive nerve stimulation is a safe, simple, fast, and noninvasive technique that can aid in the diagnosis of suspected botulism in foals.     

Ultrasound-guided biopsy as a diagnostic aid in three horses with a cranial mediastinal lymphosarcoma

An ultrasound examination of the thorax of three horses which were performing poorly or had mild signs of colic showed that they had a cranial mediastinal mass and a pleural effusion. A cytological examination of the pleural fluid showed that it did not contain neoplastic cells. A histological examination of an ultrasound-guided core biopsy of the cranial mediastinal mass showed that in each of the three horses it was a lymphosarcoma.     

Evaluation of a catheter biopsy technique as a diagnostic aid in lower urinary tract disease

The catheter biopsy technique described by Melhoff and Osborne (1977) has been evaluated as a diagnostic aid in lower urinary tract disease in 21 animals. Of 16 animals in which the final diagnosis was known, the diagnosis suggested by the biopsy was accurate in 15. The equipment required for obtaining a biopsy is inexpensive and readily available and the method can be recommended for use in veterinary practice.     

Preliminary results on the use of diagnostic ultrasonography as a management tool to quantify egg production potential in breeding ostrich (Struthio camelus australis) females

An ostrich breeding flock, joined as individual breeding pairs (n = 136 pairs), was used to investigate the possibility of diagnostic ultrasonography as a method to predict the reproductive performance of ostrich females during a breeding season. Follicular activity was easily detected and quantified by using diagnostic ultrasonography. One to 8 follicles were recorded in 25% of females scanned at the beginning of the 9-month breeding season. At the end of the breeding season, 1-3 follicles were observed in 28.7% females. Females in which follicular activity was observed came into production earlier than those in which no follicles were observed, with the mean (+/- SE) number of days to the production of the 1st egg being 22.3 +/- 12.5 and 87.4 +/- 7.2 days, respectively. Females in which follicular activity was observed at the beginning of the breeding season, produced on average 181% more eggs during the 1st month of the breeding season (P < 0.01) than females in which no follicular activity was observed (6.67 +/- 0.70 vs 2.37 +/- 0.41 eggs). Egg production over the first 2 months of breeding and over the entire breeding season were similarly affected (P < 0.01), with the mean number of eggs produced over the first 2 months of the breeding season being 14.7 +/- 1.5 for females with observed follicular activity and 7.4 +/- 0.9 eggs for females with no observed follicular activity. Females in which follicular activity was observed at the end of the breeding season produced on average 108% more eggs (P < 0.01) during the last month of the breeding season than females in which no follicular activity was observed (2.77 +/- 0.43 vs. 1.33 +/- 0.27 eggs). There was a tendency (P = 0.06) for egg production over the last 2 months to be similarly affected (6.10 +/- 0.85 vs 4.19 +/- 0.54 eggs). No relationship with egg production over the entire breeding season was found for the end-of-the-breeding-season observations. Diagnostic ultrasonography can thus be used as a management tool to identify reproductively healthy ostrich females and also females with a higher egg production potential over a period of 2 months after or prior to assessment. Future studies should focus on the development of the technique to predict reproductive performance over entire breeding seasons for selection purposes.     

Googling for a veterinary diagnosis: A replication study using Google as a diagnostic aid

BackgroundThe purpose of this study was to replicate in the veterinary context a BMJ study using Google to assist in diagnosis of complex cases.Hypothesis/ObjectivesTo assess percentage of diagnoses identified using Google as a diagnostic aid in veterinary medicine.AnimalsNone; 13 cases in cats and 17 in dogs published in JAVMA.MethodsCross‐sectional survey of Google results from searches using keywords generated independently by a generalist and a specialist veterinarian who reviewed the published case history and diagnostic components while blind to the diagnosis. They offered diagnoses and generated up to 5 search strategies for each case. The top 30 Google results for each search were reviewed by the generalist to inform a final Google‐aided diagnosis. Both veterinarians'' initial diagnoses and the Google‐aided diagnoses were compared with the published diagnoses.ResultsGoogle searching led to 52 diagnoses out of 60 possible. Twenty‐two (42%, 95% confidence interval [95% CI] 29%‐55%) Google‐aided diagnoses matched the JAVMA diagnosis. This accuracy rate does not differ significantly from 58% (n = 15/26, 95% CI 38%‐77%) identified in the BMJ study. Google‐aided results were not statistically different from those achieved unaided by each veterinarian (33%, 95% CI 16%‐50%).Conclusions and Clinical ImportancePublished information found searching Google using keywords related to complicated or unusual cases could assist veterinarians to reinforce their initial diagnosis or consider other differential diagnoses. Search strategies using words representing either signs or the preliminary diagnoses can yield results useful to confirming a correct diagnosis.     

Immunohistochemical differentiation of reactive from malignant mesothelium as a diagnostic aid in canine pericardial disease

Objectives

To develop a provisional immunohistochemistry panel for distinguishing reactive pericardium, atypical mesothelial proliferation and mesothelioma in dogs.

Materials and Methods

Archived pericardial biopsies were subject to haematoxylin and eosin staining, immunohistochemistry for cytokeratin, vimentin, insulin‐like growth factor II mRNA‐binding protein 3, glucose transporter 1 and desmin. Samples were scored for intensity and number of cells stained.

Results

Ten biopsies of reactive mesothelium, 17 of atypical mesothelial proliferation, 26 of mesothelioma and five of normal pericardium were identified on the basis of haematoxylin and eosin staining. Cytokeratin and vimentin were expressed in all biopsies, confirming mesothelial origin. Normal pericardial samples had the lowest scores for insulin‐like growth factor II mRNA‐binding protein 3, glucose transporter 1 and desmin. Mesothelioma and atypical proliferative samples were similar to each other, with higher scores for insulin‐like growth factor II mRNA‐binding protein 3 and glucose transporter 1 than the reactive samples. Desmin staining was variable. Insulin‐like growth factor II mRNA‐binding protein 3 was the best to distinguish between disease groups.

Clinical Significance

An immunohistochemistry panel of cytokeratin, vimentin, insulin‐like growth factor II mRNA‐binding protein 3 and glucose transporter 1 could provide superior information compared with haematoxylin and eosin staining alone in the diagnosis of cases of mesothelial proliferation in canine pericardium, but further validation is warranted.     

Analysis of peritoneal fluid as a diagnostic aid in grass sickness (equine dysautonomia)

The analysis of peritoneal fluid is of value in the differential diagnosis of equine colic but its characteristics have not been evaluated in grass sickness. Peritoneal fluid was collected from 15 normal horses and from 11 cases of medical colic, 11 cases of surgical colic, 20 cases of acute grass sickness and 13 cases of subacute grass sickness. The fluid was analysed for its appearance, total and differential white cell count, specific gravity, total protein concentration and total and intestinal alkaline phosphatase activity. Fluid from cases of medical colic was normal in these respects. Surgical cases were unique in having bloodstained fluid with a high alkaline phosphatase activity. Grass sickness cases had a higher specific gravity and protein content than the cases of medical colic although the appearance of the fluid was similar. Grass sickness cases were distinguishable from cases of surgical colic on the basis of the appearance of the fluid and its lower alkaline phosphatase activity.