Use of CT sinography in 27 dogs and one cat

OBJECTIVES

To describe the clinical findings, imaging findings and outcome in patients in which CT sinography was performed, and assess to what degree this technique adds information about the extent of a tract or increases the accuracy of diagnosis of foreign bodies on CT.

MATERIALS AND METHODS

Retrospective review of medical records of 27 dogs and one cat with draining tracts that had CT sinography. Pre- and post-intravenous (IV) contrast CT series were compared with CT sinography in each patient.

RESULTS

Median duration of clinical signs before referral was 85 days (range 2 to 1478 days). The most common reported clinical signs were swelling (14/28, 50%) and regional pain (5/28, 18%). CT sinography revealed a more extensive tract than post-IV contrast CT in 21% cases. On post-IV contrast CT, 31% of foreign bodies were detected compared to 23% on CT sinography. All four foreign bodies detected by CT were observed in the non-contrast images. Surgery was performed after CT in 22 (79%) cases. Thirteen (46%) draining tracts resolved after surgery, three (11%) resolved without surgery, six (21%) persisted or recurred after surgery, and six (21%) were lost to follow-up.

CLINICAL SIGNIFICANCE

CT sinography provides limited additional information about the extent of draining tracts compared to pre- and post-IV contrast CT images and did not increase the number of foreign bodies identified.

Histiocytic sarcoma in miniature schnauzers: 30 cases

OBJECTIVES

To summarise the clinical presentation and outcomes in a series of miniature schnauzers diagnosed with histiocytic sarcoma.

MATERIALS AND METHODS

Retrospective review of medical records of miniature schnauzers diagnosed with histiocytic sarcoma between 2008 and 2019 at two referral centres in the UK. Signalment, clinical signs at initial presentation, imaging results and clinico- and histopathological findings, treatment type and outcome were recorded. Progression-free survival and overall survival time were calculated.

RESULTS

Thirty dogs were included. Twenty-four of 29 dogs undergoing imaging of the thorax had lung and/or mediastinal involvement. The median overall survival time for dogs that were not euthanased within 3 days of diagnosis was 117 days (range 10 to 790). Three dogs underwent surgery; 13 received treatment with lomustine as a sole therapy - with partial responses documented on imaging in five of six dogs and 11 of 13 showing clinical improvement.

CLINICAL SIGNIFICANCE

Histiocytic sarcoma should be considered as a differential diagnosis for miniature schnauzers with pulmonary masses. Although responses to treatment were common, they were usually short-lived because of the aggressive nature of the disease.

Diagnostic imaging observations in cats treated with the subcutaneous ureteral bypass system

OBJECTIVES

To describe pre- and post-operative ultrasonographic and fluoroscopic findings, including any abnormalities, in cats treated for ureteral obstruction with a subcutaneous ureteral bypass system.

METHODS

Retrospective review of imaging findings in cats with ureteral obstruction that had surgery to place the first version of the bypass system and at least one follow-up ultrasound or fluoroscopic study. Pre- and post-operative renal pelvic diameter on ultrasound, fluoroscopic appearance of the bypass system and any related abnormality were recorded.

RESULTS

Eighty-one cats were included (47 unilateral, 34 bilateral bypass systems). Median preoperative renal pelvic diameter was 9 mm (range 3 to 28 mm) and median renal pelvic diameter at the first postoperative ultrasound was 3 mm (range 2 to 23 mm). The median number of postoperative imaging studies was two (range 1 to 8) and the median follow-up period after surgery was 205 days (range 1 to 1378 days). Bypass system abnormalities were identified postoperatively in 43 (53%) cats, including nephrostomy or cystostomy catheter blockage due to an undetermined cause or kinking of the catheter, nephrostomy or cystostomy catheter leakage, non-obstructive kinking of the catheter and loose nephrostomy pig-tail loop. Many abnormalities required repeat surgery, but others were managed conservatively. Fifty-four percent of obstructed ureters became patent after bypass placement, although the majority remained slightly dilated or had irregular margins compatible with chronic inflammation.

CLINICAL SIGNIFICANCE

Bypass abnormalities, mainly tube blockage, occurred frequently in cats treated for ureteral obstruction. Ultrasonography and fluoroscopy were useful for postoperative examination, including documenting renewed ureteral patency and investigation of suspected abnormalities.

CT findings in Pneumocystis carinii pneumonia in five dogs

Pneumocystis carinii pneumonia is a rare disease in dogs. It is primarily reported in cavalier King Charles spaniels and miniature dachshunds with suspected underlying immunodeficiency. This case series reports the findings in five dogs (four cavalier King Charles spaniels and one Bedlington terrier) with confirmed P. carinii pneumonia. Thoracic (CT) revealed ground glass opacity of the pulmonary parenchyma with a diffuse or multifocal distribution. The severity of this pattern was variable. Less consistent imaging findings included parenchymal bands, bronchial dilation and signs consistent with pulmonary hypertension. Four dogs recovered well with treatment and there was resolution of CT abnormalities in all dogs with follow-up.

How useful is abdominal ultrasonography in dogs with diarrhoea?

OBJECTIVE

To assess the utility of abdominal ultrasonography in the diagnostic work-up of dogs with diarrhoea.

METHODS

Retrospective cross-sectional study based on a referral population of dogs with diarrhoea. Associations between the clinical signs, use of abdominal ultrasonography, results of abdominal ultrasonography and subsequent work-up were examined. The utility of abdominal ultrasonography was scored as high, moderate, none or counterproductive based on review of medical records.

RESULTS

Medical records of 269 dogs were reviewed, of which 149 (55%) had abdominal ultrasonography. The most frequent result was no ultrasonographic abnormalities affecting the intestine in 65 (44%) dogs. Ultrasonography results were associated with subsequent work-up as follows: (1) no detected abnormalities and dietary trial; (2) focal thickening of the intestinal wall, loss of intestinal wall layers or enlarged abdominal lymph nodes and ultrasound-guided fine-needle aspirates; (3) diffuse thickening of the intestinal wall or hyperechoic striations in the small intestinal mucosa and endoscopy; and (4) small intestinal foreign body and coeliotomy. Abdominal ultrasonography was considered to be diagnostic without further testing in only four (3%) dogs: two had a portosystemic shunt identified ultrasonographically, one had a linear foreign body and one had a perforated pyloric ulcer. Abdominal ultrasonography had moderate utility in 56 (38%) dogs and no utility in 79 (53%) dogs. Abdominal ultrasonography was considered counterproductive in 10 (7%) dogs because results were either falsely negative or falsely positive.

CLINICAL SIGNIFICANCE

These results should prompt clinicians to reconsider routine use of abdominal ultrasonography in dogs with diarrhoea.

Acceptance rates for manuscripts submitted to veterinary peer-reviewed journals in 2012

REASONS FOR PERFORMING STUDY

Relatively few journals publish their annual acceptance rate, although this figure is of scientific and academic interest.

OBJECTIVES

To determine the acceptance rate for manuscripts submitted to veterinary peer-reviewed journals during 2012 and to determine the proportions of submitted manuscripts that were accepted without revision, accepted after revision or rejected.

STUDY DESIGN

Self-reporting email questionnaire

METHODS

Editors of 118 peer-reviewed journals listed in the Web of Science in the subject category veterinary sciences were invited by email to submit data pertinent to manuscripts submitted to their journal in 2012.

RESULTS

Data were received from 30 (26%) journals. Mean ± s.d. acceptance rate was 47 ± 15%. On average 3 ± 5% submitted manuscripts were accepted without revision, 44% ± 15% manuscripts were accepted after revision, 4 ± 4% manuscripts were withdrawn by authors, 46 ± 17% manuscripts were rejected and 3 ± 5% manuscripts were still pending at the end of the study period.

CONCLUSIONS

With so few manuscripts accepted without revision, prospective authors must expect to expend time and effort revising and resubmitting their manuscripts for publication. Although authors are frequently able to correct manuscript flaws identified by reviewers, the knowledge that less than half submitted manuscripts are accepted might help stimulate prospective authors to try to submit better quality manuscripts.

Pulmonary lipoma in a dog

An eight-year-old, neutered, male German short-haired pointer was presented for a chronic cough and an intrathoracic mass. Computed tomography revealed a mass with low attenuation in the right caudal lung lobe that invaded the principal bronchi. The mass was removed by right caudal and accessory lung lobectomy. The histopathological diagnosis was pulmonary lipoma. The clinical signs resolved following surgery. There was no evidence of recurrence or de novo lesions on computed tomography performed 12 months post-surgery. To the authors' knowledge, this is the first report of a pulmonary lipoma in a dog.

Effects of surgical implants on high-field magnetic resonance images of the normal canine stifle

To determine the effect of surgical implants on the depiction of canine stifle anatomy in magnetic resonance (MR) images, three canine cadaver limbs were imaged at 1.5 T before and after tibial plateau leveling osteotomy (TPLO), tibial tuberosity advancement (TTA), and extra-capsular stabilization (ECS), respectively. Susceptibility artifacts associated with implants were identified in MR images as a signal void and/or signal misregistration, which obscured or distorted the anatomy. Using the preoperative images as a reference, articular structures of the stifle in postoperative images were graded using an ordinal scale to describe to what degree each anatomic structure could be evaluated for clinical purposes. The TPLO implant, which contains ferromagnetic stainless steel, produced marked susceptibility artifacts that obscured or distorted most stifle anatomy. The titanium alloy TTA implants and the stainless steel crimps used for ECS produced susceptibility artifacts that mainly affected the lateral aspect of the stifle, but allowed the cruciate ligaments and medial meniscus to be evaluated satisfactorily. Susceptibility artifact was significantly less marked in images obtained using turbo spin-echo (TSE) sequences than in sequences employing spectral fat saturation. Clinical MR imaging of canine stifles containing certain metallic implants is feasible using TSE sequences without fat saturation.

Canine intracranial neoplasia: clinical risk factors for development of epileptic seizures

OBJECTIVES

To identify clinical risk factors for seizures in dogs with intracranial neoplasia.

METHODS

A cross-sectional retrospective study of 68 dogs with histopathologically confirmed primary or secondary intracranial neoplasia, complete clinical history and magnetic resonance imaging of the brain was conducted. Signalment and clinical history were retrieved from clinical records and magnetic resonance images of the brain were re-evaluated. Prevalence of findings was compared between dogs with and without seizures.

RESULTS

Forty-two dogs had tumour-related seizures, the remaining 26 were seizure-free. Tumour types included meningioma (23 dogs with and 5 without seizures), glioma (9 dogs with and 6 without seizures), choroid plexus tumour (2 dogs without seizures), neuroblastoma (1 dog with seizures) and metastatic/invasive tumours including lymphoma (9 dogs with and 13 without seizures). On the basis of multi-variable logistic regression analysis, risk factors for seizures associated with intracranial neoplasia were magnetic resonance imaging findings consistent with the presence of neoplastic tissue in frontal lobe [odds ratio (OR) 9·61; 95% confidence interval (CI) 2·59 to 35·61], marked gadolinium enhancement (OR 10·41; 95% CI 2·07 to 52·30) and magnetic resonance imaging findings of subfalcine and/or subtentorial herniation (OR 3·88; 95% CI 1·10 to 13·71).

CLINICAL SIGNIFICANCE

Dogs with primary or secondary intracranial neoplasia are at risk of seizures, particularly those with tumours that affect the frontal lobe, enhance markedly with gadolinium, or cause subfalcine and/or subtentorial herniation.

Does choice of imaging modality affect outcome in dogs with thoracolumbar spinal conditions?

OBJECTIVES

A retrospective cross-sectional study was done to look for differences in outcome in canine spinal patients that had myelography compared to those that had magnetic resonance imaging.

METHODS

Medical records of dogs with spinal conditions in the period January 2004 to December 2007 were reviewed. Data on patient age, gender, breed, size, neurolocalisation, rate of onset, imaging modality, time taken to image, type of treatment, neurological grade at admission and discharge, length and cost of hospitalisation and status at discharge were collected. Only dogs with neurological grade 3 to 6 with signs referable to the thoracolumbar spine were included.

RESULTS

Of 107 dogs that met the inclusion criteria, 66 (62%) had myelography and 41 (38%) had magnetic resonance imaging. Using multivariable analyses, non-chondrodystrophoid breed, increasing age and higher neurological grade at admission were found to be associated negatively with survival. Neurological grade 5 at admission was found to be associated positively with likelihood of neurological improvement. Male gender, higher neurological grade at admission and medical treatment were associated negatively with length of hospitalisation. magnetic resonance imaging, surgical treatment and period of hospitalisation were associated positively with total cost of hospitalisation.

CLINICAL SIGNIFICANCE

No significant association was found between type of imaging and any patient outcome variables except cost of hospitalisation, which was higher for dogs having magnetic resonance imaging. Although magnetic resonance imaging may be considered advantageous compared to myelography because it is non-invasive and provides superior anatomical detail for surgical guidance, no beneficial effect on outcome of dogs with non-ambulatory thoracolumbar spinal disease was found.

Multi-focal cerebral oligoastrocytoma in a puppy

A nine-month-old puppy was presented for investigation of seizures. Neurological deficits were found localising to the prosencephalon, mesencephalon and myelencephalon. Magnetic resonance imaging identified multiple, large lesions involving both cerebral hemispheres. Management with antiepileptic and immunomodulatory drugs was instituted; however, the seizures became progressively refractory and the puppy was euthanased. Histopathology following post-mortem examination found a mixed glial cell tumour with discrete areas where neoplastic cells appeared oligodendroglial or astrocytic. Primary intracranial neoplasia is a rare cause of neurological disease in young dogs. Moreover, this case is unusual in terms of both the mixed glial nature of the neoplasm and also its multi-focal distribution.

Radiographic appearance of cardiogenic pulmonary oedema in 23 cats

OBJECTIVE

To describe the radiographic appearance of pulmonary oedema in cats with cardiac failure.

METHODS

Thoracic radiographs of 23 cats presented to a first opinion practice with signs of cardiac failure were reviewed. All cats had tachypnoea and/or dyspnoea and enlarged left atrium on echocardiography.

RESULTS

Pulmonary oedema was characterised radiographically by an increased opacity associated with a range of patterns and variable distribution. All cats had evidence of a reticular or granular interstitial pattern. This occurred in combination with alveolar pattern in 19 (83 per cent) cats, including six with air bronchograms, with increased diameter of pulmonary vessels in 16 (71 per cent) cats and with bronchial pattern in 14 (61 per cent) cats. The distribution of pulmonary oedema was considered to be diffuse/non-uniform in 14 (61 per cent) cats, diffuse/uniform in four (17 per cent) cats, multi-focal in four (17 per cent) cats and focal in the remaining one (4 per cent). Nine (39 per cent) cats were considered to have a regional distribution of oedema, including five (22 per cent) with a ventral distribution, three (13 per cent) with a caudal distribution and one (4 per cent) cat with a hilar distribution. The distribution of pulmonary opacities was bilaterally symmetrical in five (22 per cent) cats.

CLINICAL SIGNIFICANCE

The variable appearance of feline pulmonary oedema is likely to complicate its radiographic diagnosis.

Congenital oesophageal stricture in a Japanese shiba inu

An 11-week-old, female, Japanese shiba inu, weighing 1.3 kg, was presented with a history of intermittent regurgitation since birth. An oesophagram showed a partial obstruction of the caudal cervical oesophagus associated with a narrow, transverse tissue band. Following surgical resection, the regurgitation resolved and the dog attained a normal bodyweight. Histological examination revealed focally hyperplastic epithelium with dense fibrous underlying connective tissue forming the band. The diagnosis was a congenital oesophageal stricture.

Errors in radiographic interpretation made by veterinary students

As a means of identifying student weaknesses in radiographic interpretation that could be used as foci for teaching, a cohort of 96 students joining the final-year radiology rotation were randomly allocated to one of three radiographic interpretation quizzes, each based on radiographs of small-animal patients together with the signalment and a brief, relevant history. Students' quiz scores were analyzed by multiple logistic regression, using an outcome variable with the score for each item as numerator and maximum possible mark as denominator. Students' median quiz score was 49% of the maximum (range 23-80%). Students were more likely to gain a mark for items based on abnormal radiographs than for those based on normal radiographs (odds ratio 3.4, p < 0.001). Skeletal radiographs were associated with lower scores (OR 0.75, p = 0.03). The fewest marks were awarded for interpretation of a radiograph of a normal canine stifle and interpretation of a radiograph of a normal canine pelvis; these items were misinterpreted as abnormal by 86% and 80% of the students, respectively. Students' tendency to over-interpret normal radiographs may reflect a lack of knowledge of radiographic anatomy or an unrealistically high expectation that the radiographs are abnormal.

Brain and spinal cord haemorrhages associated with Angiostrongylus vasorum infection in four dogs

Multifocal haemorrhages associated with Angiostrongylus vasorum infection were observed in the central nervous system of four dogs with neurological signs including depression, seizures, spinal pain and paresis. In magnetic resonance images the majority of the lesions were isointense or slightly hyperintense in T1-weighted images, hyperintense in T2-weighted images and hypointense in T2*-weighted (gradient echo) images, compatible with haemorrhages more than seven days old. Lesions were found in the brain of three of the dogs and in the spinal cord of two. The cerebrospinal fluid contained high concentrations of protein and evidence of erythrophagia. All the dogs had coagulopathy and pulmonary haemorrhage of varying severity. A vasorum larvae were detected in the faeces of each of the dogs. Neural A vasorum was confirmed at postmortem examination in two dogs.

Doppler ultrasonographic assessment of closure of the ductus venosus in neonatal Irish wolfhounds

The normal appearance and closure time of the ductus venosus of 22 neonatal Irish wolfhounds from three unrelated litters were determined by repeated two-dimensional, grey-scale and colour-flow Doppler ultrasound examinations. A left intercostal approach was used to identify the ductus venosus, which appeared as a parallel-sided or cone-shaped vessel connecting a left-sided intrahepatic branch of the portal vein with a confluence of veins on the cranial aspect of the liver. Doppler signals indicative of patent ductus venosus were obtained in nine of nine puppies on day 2, 11 of 17 on day 4, five of 22 on day 6, none of nine on day 9 and none of eight on day 10.

Treatment of a prolapsed lumbar intervertebral disc in a ferret

A seven-month-old, male ferret had acute paraplegia and radiographs showed signs of disc prolapse between the second and third lumbar vertebrae (L2/3). Hemilaminectomy was performed to decompress the spinal cord. Histological examination revealed that the extradural material was consistent with annulus fibrosus and the L2/3 articular facets were enlarged as a result of bone remodelling. The ferret became ambulatory one month postoperatively. Five months postoperatively, the ferret had normal posture with mild proprioceptive deficits in the pelvic limbs, and fusion of the L2 and L3 vertebral bodies.

Radiographic findings in 16 dogs infected with Angiostrongylus vasorum

Thoracic radiographs of 16 dogs infected naturally with Angiostrongylus vasorum showed signs of bronchial thickening, an interstitial pattern and a multifocal and/or peripheral alveolar pattern. In dogs treated with fenbendazole, follow-up radiographs showed that the alveolar pattern had resolved and a mild, hazy interstitial pattern had developed. In contrast with dogs with heartworm (Dirofilaria immitis), no pulmonary vascular lesions were identified.

Material in the middle ear of dogs having magnetic resonance imaging for investigation of neurologic signs

The aim of this study was to determine the prevalence and potential significance of finding material in the middle ear of dogs having magnetic resonance (MR) imaging. Of 466 MR studies reviewed, an increased signal was identified in the tympanic bulla in 32 (7%) dogs. Cavalier King Charles spaniels, Cocker spaniels, Bulldogs, and Boxers were over-represented compared to the population of dogs having MR imaging. Five (16%) dogs had definite otitis media and one (3%) had a meningioma invading the middle ear. Of the remaining dogs, 13 (41%) had possible otitis media and 13 (41%) had neurologic conditions apparently unrelated to otitis media. The most common appearance of material in the middle ear was isointense in T1-weighted images and hyperintense in T2-weighted images. There was no apparent correlation between the signal characteristics of the material and the diagnosis. Enhanced signal after gadolinium administration was observed affecting the lining of the bulla in dogs with otitis media and in dogs with unrelated neurologic conditions. In dogs without clinical signs of otitis media, finding an increased signal in the middle ear during MR imaging may reflect subclinical otitis media or fluid accumulation unrelated to inflammation. Brachycephalic dogs may be predisposed to this condition.

Neurological signs and results of magnetic resonance imaging in 40 cavalier King Charles spaniels with Chiari type 1-like malformations

In human beings a Chiari type 1 malformation is a developmental condition characterised by cerebellar herniation and syringohydromyelia. Abnormalities compatible with such a malformation were identified by magnetic resonance imaging in 39 cavalier King Charles spaniels with neurological signs and in one neurologically normal cavalier King Charles spaniel that was examined postmortem. The dogs with these abnormalities had a wide variety of neurological signs, but there was no apparent correlation between the neurological signs and the severity of cerebellar herniation, syringohydromyelia or hydrocephalus.

Radiographic signs in cats with nasal disease

Radiographic signs in 64 cats that had radiography as part of the diagnostic work-up for suspected nasal disease were reviewed in a blinded fashion. Final diagnoses in these cats were rhinitis in 27, primary nasal neoplasia in 21 and non-nasal disease in 16. The signs with highest predictive value for nasal neoplasia were displacement of midline structures (73%), unilateral generalised soft tissue opacity (70%), unilateral generalised loss of turbinate detail (69%) and evidence of bone invasion (64%). The only radiographic finding that occurred more frequently in cats with rhinitis was a nasal cavity within normal limits, and the predictive value of this sign was only 38%. Radiographic signs in cats with nasal neoplasia are similar to those reported in dogs, whereas the radiographic signs in cats with rhinitis are variable and non-specific, and may be absent.

Right-to-left shunting patent ductus arteriosus with pulmonary hypertension in a cat

A 16-month-old, neutered female domestic shorthaired cat had tachypnoea, inappetence and a heart murmur, which had been first detected at eight weeks old. Diagnosis of reverse shunting patent ductus arteriosus and pulmonary hypertension was based on a detailed two-dimensional and Doppler echocardiographic examination. This report documents the clinical and imaging findings in this rare feline condition.

Results of myelography in seven dogs with myelomalacia

Myelomalacia is a hemorrhagic infarction of the spinal cord that can occur as a sequel to acute spinal cord injury. Myelomalacia may be focal or diffuse; the diffuse form is typically associated with cranial migration of neurologic signs ("ascending syndrome") and is often fatal. In a retrospective study of seven affected dogs, diffuse myelomalacia was associated with intervertebral disc extrusion in five dogs, focal myelomalacia was associated with fibrocartilagenous embolus in one dog, and had no apparent cause in one dog. The myelographic signs included a variable degree of contrast medium infiltration into the spinal cord in six dogs (86%) and/or spinal cord swelling in six dogs (86%). In one dog with focal myelomalacia, the only myelographic sign was spinal cord swelling.

Accuracy of survey radiographic diagnosis of intervertebral disc protrusion in dogs

To assess the diagnostic accuracy of survey radiography for canine thoracolumbar intervertebral disc protrusion, survey radiographs (lateral and ventrodorsal) of 64 dogs with surgically-confirmed thoracolumbar intervertebral disc protrusion, 51 dogs with negative myelograms and 29 dogs with various spinal conditions other than disc protrusion were reviewed by three independent observers who were unaware of any clinical information. There were marked differences in observer performance for diagnosis of intervertebral disc protrusion, although there were no significant differences in intraobserver diagnostic accuracy for small vs. large dogs. Accuracy of observers for determining sites of intervertebral disc protrusion using survey radiography was in the range 51-61%. All observers had low accuracy for identification of second sites of intervertebral disc protrusion. The most useful radiographic sign, narrowed intervertebral space, had only moderate sensitivity (range 64-69%) and moderate predictive value (range 63-71%) for intervertebral disc protrusion. Vacuum phenomenon was an infrequent but accurate sign of intervertebral disc protrusion. Recognition of multiple radiographic signs of intervertebral disc protrusion at one site was associated with increased accuracy of diagnosis. No observer was accurate enough to justify attempting targeted surgical treatment of intervertebral disc protrusion without myelography.

Acute intervertebral disc extrusion in a cat: clinical and MRI findings

A 5 year old, neutered male, domestic shorthaired cat had acute left hemiparesis and Horner's syndrome. Magnetic resonance imaging (MRI) revealed a loss of the normal signal from the nucleus pulposus of the intervertebral disc at C3/4, narrowing of the ventral subarachnoid space and slight dorsal displacement of the spinal cord and a focal hyperintense lesion affecting the left side of the spinal cord at the same level. The presumptive diagnosis was focal spinal cord oedema associated with intervertebral disc extrusion. A traumatic aetiology was suspected. The cat was treated conservatively and improved gradually over a period of 6 months.

Assessment of survey radiography as a method for diagnosis of congenital cardiac disease in dogs

In order to assess the diagnostic accuracy of survey radiography for canine congenital cardiac anomalies, thoracic radiographs of 57 dogs with congenital cardiac anomalies, 31 normal dogs and 27 dogs with acquired cardiac disease were mixed, and reviewed by two independent observers, who were blinded to any patient information. The congenital anomalies were aortic stenosis (n=25), pulmonic stenosis (n=10), patent ductus arteriosus (n=9), ventricular septal defect (n=8), tricuspid dysplasia (n=3) and mitral dysplasia (n=2). Both observers were moderately accurate at identifying dogs with cardiac disease. Their ability to distinguish dogs with congenital versus acquired cardiac disease was poorer and this assessment was probably influenced by the recognition of patients that were skeletally immature, which biased observers towards a diagnosis of congenital cardiac anomaly. The diagnosis rate for specific congenital anomalies was also poor (the differential list included a correct diagnosis in only 40 and 37 per cent of cases). Radiographic signs of specific cardiac chamber enlargement or pulmonary vascular abnormalities were recognised by both observers in only 20 per cent of instances in which they might be expected. They were, however, recognised more frequently in dogs with anomalies that imposed a volume load on the heart than in dogs with anomalies that induced a pressure load on the organ. It is concluded that survey radiography is an inaccurate method for diagnosis of canine congenital cardiac anomalies because of the difficulty of recognising radiographic signs, which are not present in many cases.

Ultrasonographic findings in 50 dogs with retrobulbar disease

Records of 50 dogs with signs of retrobulbar disease that had ultrasonography and diagnosis based on results of cytopathology or histopathology were reviewed retrospectively. Abnormalities were identified ultrasonographically in 43 (86%) dogs. Mass effect was identified in 42% of dogs with neoplasia and 30% of dogs with abscess. Ten of 11 (91%) orbital bone lesions were in dogs with retrobulbar neoplasia. A cavitary lesion was recognized ultrasonographically in 75% of dogs with salivary mucocele and 50% of dogs with retrobulbar abscess. Neoplasms occurred predominantly on the ventral or medial aspect of the orbit, or both, which reflects invasion by nasal or sinus neoplasms. Presence of orbital bone lesions or a mass on the medial aspect of the orbit suggests neoplasia; however, other ultrasonographic signs were nonspecific.

Use of breed-specific ranges for the vertebral heart scale as an aid to the radiographic diagnosis of cardiac disease in dogs

The vertebral heart scale was measured on right lateral recumbent thoracic radiographs of 320 dogs of six popular breeds, including for each breed at least 20 dogs with no clinical signs of cardiovascular or respiratory disease and at least 19 dogs with cardiac or respiratory disease. There were significant differences between the mean values of the scale for the different breeds; the normal boxer dogs had a significantly higher mean value than the normal dogs of all the other breeds, and the labrador retrievers had a significantly higher mean value than all the other breeds except the boxer and the cavalier King Charles spaniel. For all the breeds except the boxer, there was a trend for dogs with cardiac disease (but not respiratory disease) to have higher mean values on the scale than normal dogs of the same breed; however, at the optimal value of the scale for distinguishing between dogs of each breed with and without cardiac disease, the sensitivity and specificity were relatively low, in the range 58 to 83 per cent. The scale was most accurate for the diagnosis of cardiac disease in the Yorkshire terrier and the cavalier King Charles spaniel, breeds affected by predominantly dilative forms of cardiac disease. In contrast, it was very inaccurate in the boxer, a breed that has a higher incidence of cardiac diseases associated with concentric hypertrophy.

Results of magnetic resonance imaging in dogs with vestibular disorders: 85 cases (1996-1999)

OBJECTIVE

To determine results of magnetic resonance (MR) imaging in dogs with vestibular disorders (VD) and correlate results of MR imaging with clinical findings.

DESIGN

Retrospective study.

ANIMALS

85 dogs.

PROCEDURE

Information on signalment, clinical signs, and presumptive lesion location was obtained from the medical records, and MR images were reviewed.

RESULTS

27 dogs had peripheral VD, 37 had central VD, and 21 had paradoxical VD. Of the 27 dogs with peripheral VD, 11 (41%) had MR imaging abnormalities involving the ipsilateral tympanic bulla compatible with otitis media (6 also had abnormalities involving the petrous portion of the ipsilateral temporal bone compatible with otitis interna), 7 (26%) had MR imaging abnormalities compatible with middle ear neoplasia, 2(7%) had an ipsilateral cerebellopontine angle lesion, and 7 (26%) did not have MR imaging abnormalities. All dogs with central and paradoxical VD had abnormalities evident on MR images. Of the 37 dogs with central VD, 13 (35%) had an extra-axial lesion, 6 (16%) had an intra-axial lesion, and 18 (49%) had multiple intra-axial lesions. In 23 (62%) dogs with central VD, lesions on MR images corresponded with location suspected on the basis of clinical signs. Of the 21 dogs with paradoxical VD, 12 (57%) had an extra-axial lesion, 5 (24%) had an intra-axial lesion, and 4 (19%) had multiple intra-axial lesions. Location of lesions on MR images agreed with location suspected on the basis of clinical signs in 19 (90%) dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that MR imaging may be helpful in the diagnosis and treatment of VD in dogs.