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.

Percutaneous ultrasound-guided cholecystocentesis: complications and association of ultrasonographic findings with bile culture results.

OBJECTIVES: To retrospectively evaluate cases presented for percutaneous ultrasound-guided cholecystocentesis for associated complications, identify risk factors associated with complications and to assess ultrasonographic findings and relate these to bacterial culture results. METHODS: Data on 300 patients presented for percutaneous ultrasound-guided cholecystocentesis were retrospectively collected and ultrasonographic images were assessed for defined structural changes. The incidence of major complications was determined. Multi-variable multi-level logistic regression was used to investigate the association of ultrasonographic findings with positive bile culture. RESULTS: Three hundred percutaneous ultrasound-guided cholecystocentesis procedures performed in 201 dogs and 51 cats were included; 35 patients had the procedure performed more than once. The overall incidence of major complications was 8 of 300 procedures (2·7%). Bile peritonitis occurred in 2 of 300 procedures (0·7%). An ultrasonographically abnormal gall bladder was found in 52% of cases and had a sensitivity, specificity and accuracy of 82, 55·7 and 61·5% respectively, to predict a positive bile culture. CLINICAL SIGNIFICANCE: Percutaneous ultrasound-guided cholecystocentesis is overall a safe technique when carried out in selected patients. Abnormal ultrasonographic findings are only a fair predictor of a positive bile culture.

Comparison between echocardiographic and non-ECG-gated CT measurements in dogs.

The aim of this study was to compare echocardiographic measurements with non-ECG-gated contrast-enhanced cardiac CT measurements in dogs. Fifty-seven dogs were included in the study. The following echocardiographic parameters were measured: M-mode interventricular septum in diastole and systole, left ventricular internal diameter in diastole and systole, left ventricular free wall in diastole and systole, 2D left atrial maximal diameter, 2D left atrium to aorta ratio in diastole, 2D aortic annulus in systole and 2D pulmonary annulus in diastole and systole. CT measurements were obtained from multiplanar reconstruction images, replicating the imaging planes used for 2D measurements on echocardiography. It was not possible to discriminate between systole and diastole. The results showed moderate Lin's concordance correlation coefficients between the left ventricular internal diameter in systole (0.77), the aortic annuli (0.84) and the pulmonary annuli in diastole (0.78) and systole (0.80). Low coefficients were obtained between the other parameters. Bland-Altman plots for the parameters with highest concordance correlation coefficients were calculated. They suggested equivalence between the measurements of the aortic annuli. Equivalence was not seen between the remaining echocardiographic and CT measurements. Therefore, non-ECG-gated CT is not a reliable way of quantitatively assessing cardiac size.

Prognostic value of early magnetic resonance imaging in dogs after traumatic brain injury: 50 cases.

BACKGROUND: The prognostic value of early magnetic resonance imaging (MRI) in dogs after traumatic brain injury (TBI) remains unclear. OBJECTIVES: Determine whether MRI findings are associated with prognosis after TBI in dogs. ANIMALS: Fifty client-owned dogs. METHODS: Retrospective study of dogs with TBI that underwent 1.5T MRI within 14 days after head trauma. MRI evaluators were blinded to the clinical presentation, and all images were scored based on an MRI grading system (Grade I [normal brain parenchyma] to Grade VI [bilateral lesions affecting the brainstem with or without any lesions of lesser grade]). Skull fractures, percentage of intraparenchymal lesions, degree of midline shift, and type of brain herniation were evaluated. MGCS was assessed at presentation. The presence of seizures was recorded. Outcome was assessed at 48 h (alive or dead) and at 3, 6, 12, and 24 months after TBI. RESULTS: Sixty-six percent of the dogs had abnormal MRI findings. MRI grade was negatively correlated (P < .001) with MGCS. A significant negative correlation of MRI grade, degree of midline shift, and percentage of intraparenchymal lesions with follow-up scores was identified. The MGCS was lower in dogs with brain herniation (P = .0191). Follow-up scores were significantly lower in dogs that had brain herniation or skull fractures. The possibility of having seizures was associated with higher percentage of intraparenchymal lesions (P = 0.0054) and 10% developed PTE. CONCLUSIONS AND CLINICAL IMPORTANCE: Significant associations exist between MRI findings and prognosis in dogs with TBI. MRI can help to predict prognosis in dogs with TBI.

Corpus callosal abnormalities in dogs.

BACKGROUND: Corpus callosal abnormalities (CCA) in dogs have been only sporadically reported and are poorly characterized. HYPOTHESIS/OBJECTIVES: To describe the clinical presentation and magnetic resonance imaging (MRI) characteristics of dogs with CCA. ANIMALS: Fifteen client-owned dogs. METHODS: Retrospective study. Records of the contributing institutions were reviewed to identify dogs diagnosed with malformations affecting the corpus callosum (CC); cases in which the CCA was thought to be secondary were excluded. RESULTS: The most represented breeds were Staffordshire Bull Terriers (5/15) and Miniature Schnauzers (3/15; n = 3, 20%) and the mean age at time of presentation of 19 months (range 3-81 months). The clinical signs most commonly reported were adipsia/hypodipsia with associated hypernatremia (12/15), tremors (6/15), and seizures (6/15). Review of the MR images revealed that 10 dogs had absence of the rostral CC and hypoplasia of the caudal portion, 4 dogs had a diffusely hypoplastic and dysplastic CC, and 1 dog had a diffusely hypoplastic CC. In 14 cases, there was abnormal cortical development with fusion of the ventral frontal lobes and part of the diencephalon, indicating lobar holoprosencephaly. CONCLUSIONS AND CLINICAL IMPORTANCE: Previous literature has mainly associated CCA with adipsia and only 12 of 15 dogs in the current series demonstrated this abnormality. There are different degrees of the malformation but in 10 dogs the rostral portion of the CC is most severely affected. Fourteen dogs have simultaneous fusion of the midline structures rostral to the CC; this region has several structures involved in thirst regulation and might explain this derangement.

Sensitivity and specificity of MRI for detecting facial nerve abnormalities in dogs with facial neuropathy.

Idiopathic facial neuropathy in dogs is conventionally diagnosed by exclusion of structural and metabolic causes of a single cranial neuropathy. To investigate the reliability and validity of MRI for supporting a diagnosis of facial neuropathy in dogs, we examined MR images of the brainstem from 20 dogs with presumed idiopathic facial neuropathy, and 20 control dogs. Two different types of MRI sequence were compared: volumetric interpolated breath-hold examination MRI (VIBE-MRI), and conventional T1-weighted MRI. Three independent observers, blinded to the case details, were presented with VIBE-MR images in a random order, and were required to indicate the presence of hyperintensity of the facial nerve following intravenous contrast administration. The vestibulocochlear nerve was also assessed, and the whole process was repeated for conventional post-contrast T1-weighted images. Following contrast administration, the sensitivity of VIBE-MRI for detecting facial nerve abnormalities ranged from 86 per cent to 96 per cent, and the specificity from 87 per cent to 92 per cent; conventional T1-weighted images yielded a sensitivity of only 39 per cent - 65 per cent, and a specificity of 94 per cent - 96 per cent. MRI was not a sensitive detector of vestibulocochlear nerve abnormalities in 14 dogs with concurrent vestibular dysfunction. This study shows that VIBE-MRI is a robust technique for confirming presumed idiopathic facial neuropathy in dogs, and suggests an inflammatory component to this condition in a high proportion of dogs.

Surgical management of first caudal nerve root foraminal compression secondary to intervertebral disc disease in a Cocker Spaniel.

A nine-year-old spayed female Cocker Spaniel was investigated for an eight week history of licking and rubbing at the tail base, dullness, and signs of pain on manipulation of the tail. Left-sided intraforaminal compression of the first caudal nerve root due to intervertebral disc disease was diagnosed by radiographic, computed tomography, and magnetic resonance imaging examinations. The dog was nonresponsive to conservative medical therapy. A decompressive left-sided first-second caudal (Cd1-Cd2) foraminotomy was performed. Postoperative computed tomography confirmed surgical decompression of the involved nerve root. At the one month follow-up examination there was marked improvement in clinical signs. At two months, clinical signs were completely resolved and there was not any evidence of recurrence twelve months after surgery. Intervertebral disc disease should be considered as a differential diagnosis in dogs with discomfort at the tail base or signs of pain on manipulation of the tail. Surgical decompression may be indicated for management of these cases. This is the first report of diagnosis and surgical management of caudal intervertebral disc disease by foraminotomy in the dog. Surgical decompression by foraminotomy may therefore be a treatment option for this condition.

Pneumorrhachis in a rottweiler.

An 8·5-year-old, female, neutered, Rottweiler was presented for investigation of progressive ataxia of one week duration. Proprioception was absent in the left pelvic limb and reduced on the right, thoracolumbar hyperalgesia was evident and pelvic limb segmental spinal reflexes were normal. Magnetic resonance imaging (MRI) demonstrated a spherical region of signal void compressing the spinal cord between the fifth and sixth thoracic vertebrae and several non-compressive degenerate intervertebral discs. Computed tomography (CT) of the region confirmed the findings and identified the lesion as gas. A dorsolateral hemilaminectomy was performed to decompress the spinal cord and achieved complete resolution of the clinical signs on examination after 3 months. This is the first known reported case of spontaneous pneumorrhachis in a veterinary patient.

Computed tomographic and magnetic resonance imaging features of canine segmental caudal vena cava aplasia.

OBJECTIVE: To describe the computed tomographic and magnetic resonance imaging features of segmental caudal vena cava aplasia and associated vascular anomalies in dogs. METHODS: A retrospective study was performed reviewing computed tomographic and magnetic resonance imaging archives of eight institutions for dogs with segmental caudal vena cava aplasia. Inclusion criteria included a computed tomographic or magnetic resonance imaging study and supportive diagnostic and follow-up information. Abdominal vessels were reviewed for size, shape, location and course (including tributaries and branches) and classified as normal, abnormal or shunt vessels. RESULTS: Ten dogs with segmental caudal vena cava aplasia were identified. In all dogs, postrenal caval blood was shunted to either a right or a left azygos vein, with seven different angiographic patterns. Affected dogs were predominantly female (70 per cent) and young (mean 2.6 years). Additional portocaval and porto-azygos shunt vessels were identified in two cases each. Computed tomographic angiography and magnetic resonance angiography depicted details of abdominal vessels including thrombus formation in one dog. CLINICAL SIGNIFICANCE: Segmental caudal vena cava aplasia is a vascular congenital anomaly in the dog that can be associated with thrombosis and portosystemic shunts. Computed tomographic angiography and magnetic resonance angiography are excellent tools to demonstrate the complex vascular anatomy and to guide treatment planning for portosystemic shunts and thrombolytic therapy.

Detection of spinal cord compression in dogs with cervical intervertebral disc disease by magnetic resonance imaging.

The medical records and magnetic resonance images of 33 dogs with surgically confirmed Hansen type I cervical intervertebral disc disease were reviewed. Fourteen of the dogs were chondrodystrophic and 19 were not chondrodystrophic. The most common clinical sign was neck pain, which affected 28 of the dogs, and 23 of the dogs were able to walk. Fifteen of the dogs had developed clinical signs acutely, within the previous 24 hours. On cross-sectional images the median area of spinal cord compression was 26 per cent (range 11 to 71 per cent) of the normal spinal cord area. The degree of spinal cord compression was significantly associated with the dogs' presurgical neurological status but not with their postsurgical neurological status. The dogs with an acute onset of clinical signs had more severe neurological dysfunction before surgery, but their condition improved more as a result of surgery.

Solitary extramedullary plasmacytoma of the canine larynx.

An 11-year-old, female, spayed cocker spaniel was presented with dysphonia caused by a solitary laryngeal mass. Excisional biopsy was performed, and a diagnosis of plasmacytoma was made on the basis of histological examination. Further investigations showed no signs of systemic involvement. Coarse fractionated radiation therapy failed to control the tumour. Therapy was successfully instituted with a conventional combination chemotherapy protocol over a period of 14 months. The dog remains disease free 30 months after diagnosis. Most solitary, extramedullary plasmacytomas in dogs arise in the gastrointestinal tract, with fewer reports in other sites. The larynx is an uncommon sight of involvement in any species, and to the authors' knowledge, this is the first report of this tumour type in the canine larynx. In contrast to the therapeutic benefits reported in humans, the combination of surgery and radiation therapy was unsuccessful in this case, although sustained remission was gained following chemotherapy.

Ultrasonographic diagnosis of unusual portal vascular abnormalities in two cats.

Two cases of ascites secondary to portal vascular abnormalities associated with portal hypertension are described. In the first case a five-month-old cat was presented with recurrent ascites and investigations showed that the underlying cause was a hepatic arteriovenous fistula. Ultrasonography showed direct communication of the coeliac artery and right branch of the portal vein. There was also hepatofugal flow in the main portal vein consistent with portal hypertension. The ultrasonographic features were similar to those seen in dogs with hepatic arteriovenous fistulae. In the second case, ascites, portal hypertension and an intraluminal mass in the main portal vein was diagnosed in a 16-year-old cat that had been presented with hyperthyroidism and hepatomegaly. Acquired portosystemic collaterals involving the left renal vein were present. Additional diagnostic investigations were not permitted. Ultrasonography was useful in both cases to document portal hypertension and the underlying cause.

Clinical and topographic magnetic resonance characteristics of suspected brain infarction in 40 dogs.

Medical records of 40 dogs presented for evaluation of acute-onset, nonprogressive, intracranial dysfunction by means of magnetic resonance imaging (MRI) diagnosis of brain infarction were reviewed. Location of the brain infarcts was: 11 of 38, telencephalic; 8 of 38, thalamic/midbrain; 18 of 38, cerebellar; and 3 of 38, multifocal. Telencephalic infarcts developed within the territory of the middle cerebral (4/11), rostral cerebral (2/11), and striate (5/11) arteries. Thalamic/midbrain infarcts developed within the territory of perforating arteries of the caudal portion of the thalamus and rostral portion of the brainstem (8/8). All cerebellar infarcts (18/38) were within the territory of the rostral cerebellar artery or one of its branches. All infarcts appeared nonhemorrhagic, with marked contrast enhancement observed in only 3 of 38 dogs, all of which were imaged more than 7 days after the onset of signs of neurologic dysfunction. Diffusion-weighted imaging (DWI) sequences were available from 6 dogs, all imaged within 5 days of the onset of signs of neurologic dysfunction. Suspected infarcts were hyperintense on DWI sequences and were hypointense on the apparent diffusion coefficient map. Telencephalic infarcts caused abnormal mental status, contralateral postural reaction deficit, contralateral nasal hypalgesia, contralateral menace deficit, and ipsilateral circling. Thalamic/midbrain infarcts caused contralateral or ipsilateral postural reaction deficit, contralateral menace deficit, ipsilateral head tilt or turn, nystagmus, ventrolateral strabismus, and anisocoria. Cerebellar infarcts caused ipsilateral asymmetric cerebellar quality ataxia, head tilt, intermittent opisthotonus, nystagmus, and ipsilateral menace deficit with apparent normal vision.

Calvarial hyperostosis syndrome in two bullmastiffs.

Two bullmastiffs with calvarial hyperostosis syndrome are described and are the first documented examples in females. The clinical and radiologic features were similar to those previously reported in males. Magnetic resonance (MR) imaging findings have not previously been reported. One dog underwent MR imaging and abnormalities included thickening of the frontal bones with loss of normal fat signal and changes in the overlying soft tissues. In one of the dogs, long bone changes were seen in the femora and resembled those seen with craniomandibular osteopathy.

Ischaemic stroke in dogs and humans: a comparative review.

Cerebrovascular accidents, also known as strokes, are one of the major causes of disability and mortality among adult humans. The increased availability of magnetic resonance imaging in veterinary medicine means they are being increasingly recognised in dogs, too. Cerebrovascular accident is defined as the sudden onset of non-progressive, focal brain dysfunction as a result of ischaemic infarction or haemorrhage. Focal ischaemic stroke is caused by interruption of the arterial blood flow to a dependent area of brain parenchyma by a thrombus or an embolus. Once the diagnosis of ischaemic stroke is confirmed, potential sources of thrombosis or embolism should be investigated and treated accordingly. Dogs with ischaemic stroke tend to recover within several weeks with supportive care only.

Dysplasia of the caudal vertebral articular facets in four dogs: results of radiographic, myelographic and magnetic resonance imaging investigations.

Congenital anomalies of the vertebral column associated with aberrations of one of the primary vertebral ossification centres have been frequently described in the veterinary literature, but clinically significant abnormalities of secondary vertebral ossification centres, particularly involving the caudal articular processes, are much less frequently reported. This paper describes three dogs with aplasia and one dog with hypoplasia of the caudal vertebral articular processes. Thoracolumbar spinal cord compression and ataxia was evident in the three dogs with aplasia but no clinical signs were evident in the dog with hypoplasia. The radiographic appearance was similar in all four cases, with aplasia or hypoplasia of the caudal articular facets at one or more intervertebral joints in the thoracolumbar region. Bone proliferation was evident secondary to an associated degenerative joint disease. Compensatory hyperplasia of the adjacent cranial articular facets and ligamentum flavum protruded into the vertebral canal, resulting in a compressive myelopathy observed by myelography and magnetic resonance imaging.

Intracranial haemorrhage associated with Angiostrongylus vasorum infection in three dogs.

This report describes three dogs with intracranial haemorrhage secondary to severe coagulation defects associated with Angiostrongylus vasorum infection. The initial case was diagnosed at necropsy, with two subsequent cases diagnosed antemortem and successfully treated. The dogs ranged in age from 14 months to four years and were presented for evaluation of a severe, subacute onset of suspected cerebral disease. Magnetic resonance imaging performed on all three dogs was suggestive of multiple areas of intraparenchymal brain haemorrhage. Coagulation assays showed a consumptive coagulopathy resembling chronic disseminated intravascular coagulation. Postmortem examination of the initial case confirmed the presence of multiple intracranial and extracranial haemorrhages. An unexpected finding was that of a marked multifocal nematode infection of the lungs with an associated vasculopathy. The parasites were confirmed to be A vasorum. In the two other dogs, faecal examination by Baermann technique confirmed A vasorum infection. Both dogs were treated with fenbendazole and one was additionally given a plasma transfusion. Repeated coagulation assays were normal within one week. Neurological examinations were normal for both dogs within six weeks. This case series indicates that A vasorum infection should be considered as a possible aetiology of intracranial haemorrhage in dogs.