Successful medical management of an epidural abscess in a dog

A seven-month-old entire male dobermann presented with acute onset neck pain and left thoracic limb lameness. The dog had a similar episode eight weeks before presentation that responded to meloxicam. A cervical spinal epidural abscess secondary to Staphylococcus pseudintermedius bacteraemia was diagnosed following investigations, including MRI of the cervical vertebral column and blood cultures. Treatment with cephalexin, gabapentin and meloxicam was started. The dog was doing clinically well one month later. A control MRI and radiographs of the cervical vertebral column showed evidence of discospondylitis and resolution of the primary lesion, therefore the treatment course with cephalexin was continued. Three months after initial presentation the clinical signs had resolved, radiographs showed improvement of the discospondylitis and antibiotics were stopped. Seven months later the dog continued doing well with no relapse

Use of computed tomography to define a sacral safe corridor for placement of 2.7 mm cortical screws in feline sacroiliac luxation

Objectives: This study aimed to define a safe corridor for 2.7 mm cortical sacroiliac screw insertion in the dorsal plane (craniocaudal direction) using radiography and CT, and in the transverse plane (dorsoventral direction) using CT in feline cadavers. A further aim was to compare the values obtained by CT with those previously reported by radiography in the transverse plane. Methods: Thirteen pelvises were retrieved from feline cadavers and dissected to expose one of the articular surfaces of the sacrum. A 2.7 mm screw was placed in the sacrum to a depth of approximately 1 cm in each exposed articular surface. Dorsoventral radiography and CT scanning of each specimen were performed. Multiplanar reconstructions were performed to allow CT evaluation in both the dorsal and transverse planes. Calculations were made to find the maximum, minimum and optimum angles for screw placement in craniocaudal (radiography and CT) and dorsoventral (CT) directions when using a 2.7 mm cortical screw. Results: Radiographic measurement showed a mean optimum craniocaudal angle of 106° (range 97–112°). The mean minimum angle was 95° (range 87–107°), whereas the mean maximum angle was 117° (108–124°). Measurement of the dorsal CT scan images showed a mean optimum craniocaudal angle of 101° (range 94–110°). The mean minimum angle was 90° (range 83–99°), whereas the mean maximum angle was 113° (104–125°). The transverse CT scan images showed a mean dorsoventral minimum angle of 103° (range 95–113°), mean maximum angle of 115° (104–125°) and mean optimum dorsoventral angle of 111° (102–119°). Conclusions and relevance: An optimum craniocaudal angle of 101° is recommended for 2.7 mm cortical screw placement in the feline sacral body, with a safety margin between 99° and 104°. No single angle can be recommended in the dorsoventral direction and therefore preoperative measuring on individual cats using CT images is recommended to establish the ideal individual angle in the transverse plane

Machine learning predicts histologic type and grade of canine gliomas based on MRI texture analysis.

Conventional MRI features of canine gliomas subtypes and grades significantly overlap. Texture analysis (TA) quantifies image texture based on spatial arrangement of pixel intensities. Machine learning (ML) models based on MRI-TA demonstrate high accuracy in predicting brain tumor types and grades in human medicine. The aim of this retrospective, diagnostic accuracy study was to investigate the accuracy of ML-based MRI-TA in predicting canine gliomas histologic types and grades. Dogs with histopathological diagnosis of intracranial glioma and available brain MRI were included. Tumors were manually segmented across their entire volume in enhancing part, non-enhancing part, and peri-tumoral vasogenic edema in T2-weighted (T2w), T1-weighted (T1w), FLAIR, and T1w postcontrast sequences. Texture features were extracted and fed into three ML classifiers. Classifiers' performance was assessed using a leave-one-out cross-validation approach. Multiclass and binary models were built to predict histologic types (oligodendroglioma vs. astrocytoma vs. oligoastrocytoma) and grades (high vs. low), respectively. Thirty-eight dogs with a total of 40 masses were included. Machine learning classifiers had an average accuracy of 77% for discriminating tumor types and of 75.6% for predicting high-grade gliomas. The support vector machine classifier had an accuracy of up to 94% for predicting tumor types and up to 87% for predicting high-grade gliomas. The most discriminative texture features of tumor types and grades appeared related to the peri-tumoral edema in T1w images and to the non-enhancing part of the tumor in T2w images, respectively. In conclusion, ML-based MRI-TA has the potential to discriminate intracranial canine gliomas types and grades

Feline gastrointestinal eosinophilic sclerosing fibroplasia presenting as a rectal mass.

Case summary A 9-year-old neutered male cat was referred owing to dyschezia and weight loss. Abdominal CT revealed a heterogeneous mass in the rectum and thickening of one caudal mesenteric lymph node. The mass induced a focal rectal obstruction. Cytological evaluation of fine-needle aspirates showed signs of mixed inflammation for the rectal mass and a reactive lymph node. Because a definite diagnosis was not achieved, complete resection of the mass via a dorsal approach to the rectum was attempted. Histopathology confirmed complete removal and diagnosed feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF). The cat was treated with psyllium husks and lactulose after surgery. In the postoperative year, the owner reported normal behaviour, food intake and defecation of the patient. Dyschezia reoccurred 14 months after surgery. Imaging revealed recurrence of a rectal mass. Owing to clinical deterioration, the owner elected for euthanasia. Relevance and novel information This is the first report of rectal FGESF with dyschezia and weight loss as the main clinical signs. The case demonstrates an acceptable outcome for more than 1 year without additional immunosuppressive therapy, and emphasises that FGESF must be considered as a differential diagnosis for rectal masses in cats

Grading of oligodendroglioma in dogs based on magnetic resonance imaging.

BACKGROUND Oligodendroglioma (OG) accounts for 22% of primary brain tumors in dogs. Oligodendroglioma in dogs is graded as low-grade (II) or high-grade (III), based on the presence of microvascular proliferation and necrosis. OBJECTIVE To investigate if magnetic resonance imaging (MRI) features differ between OG II and III in dogs. ANIMALS Thirty-two dogs with histological diagnosis of intracranial OG and MRI. METHODS Retrospective descriptive study. Histology was reviewed to grade OG according to the revised classification. Brain MRI results were reviewed following criteria including contrast enhancement (CE) pattern, presence of cystic structures, gradient-recalled-echo (GRE) signal voids, and necrosis based on signal intensity, as well as diffusion-weighted imaging characteristics. The MRI features were compared between OG II and III using Fisher's exact tests and logistic regression models. RESULTS Histology identified 8 dogs with OG II (25%) and 24 with OG III (75%). All OG III showed moderate-to-marked CE including 18/24 (75%) with a ring pattern. These features were not seen in OG II. Heterogeneity, cystic structures, GRE signal voids, and necrosis were associated with OG III. No difference in diffusion characteristics was detected between OG II and III. CONCLUSION AND CLINICAL IMPORTANCE Moderate-to-marked CE and ring pattern were present in dogs with OG III but not in OG II. The presence of cystic structures, GRE signal voids, and necrosis was strongly associated with OG III. Although the importance of brain tumor grading in dogs with regard to prognosis and treatment options remains unknown, the results indicate that MRI reflects the histological features used for grading OG in dogs

Cryptococcosis with ocular and central nervous system involvement in a 3‐year‐old dog

To date, cryptococcosis remains sporadic in Europe, and this is a case of canine cryptococcosis with ocular and CNS involvement in continental Europe with identification of the organism on cerebral spinal fluid (CSF) cytology and description of the clinical and MRI features, and outcome

Clinical and magnetic resonance imaging findings of a cerebellar medulloblastoma in a heifer

Key Clinical Message Reports of medulloblastoma in cattle are scarce; however, this neoplasm should be included as a differential diagnosis in cases of cerebellar or central vestibular signs in young cattle. The MRI appearance of the medulloblastoma reported here, previously unreported in cattle, consisted of a T1‐weighted hypointense and T2‐weighted heterogeneously hyperintense intra‐axial mass

Clinical and magnetic resonance imaging features of lymphoma involving the nervous system in cats

Background: Lymphoma is the most common spinal cord neoplasm and second most common intracranial tumor in cats, but description of specific magnetic resonance imaging (MRI) features is lacking. Objective: Describe the clinical and MRI features of lymphoma affecting the central (CNS) or peripheral (PNS) nervous system or both in cats. Animals: Thirty‐one cats with confirmed cytological or histopathological diagnosis or both of lymphoma involving the CNS or PNS or both, and MRI findings of the lesions. Methods: Multicenter retrospective descriptive study. Signalment and medical information were recorded. Magnetic resonance imaging findings were reviewed by 3 observers following a list of predefined criteria and consensus was sought. Frequency distributions of the different categorical data were reported. Results: Median duration of clinical signs at time of presentation was 14 days (range, 1‐90). Neurological examination was abnormal in 30/31 cats. On MRI, lesions affecting the CNS were diagnosed in 18/31 cats, lesions in both CNS and PNS in 12/31, and lesions in the PNS only in 1/31. Intracranial lesions were diagnosed in 22 cats (extra‐axial, 7/22; intra‐axial, 2/22; mixed, 13/22), and spinal lesions were diagnosed in 12 (6/12 involving the conus medullaris and lumbosacral plexuses). Infiltration of adjacent extra‐neural tissue was present in 11/31 cases. Contrast enhancement was seen in all lesions, being marked in 25/30. Meningeal enhancement was present in all but 2 cases. Several distinct MRI patterns were observed. Conclusions and Clinical Importance: Nervous system lymphoma in cats has a wide range of MRI features, of which none is pathognomonic. However, together with clinical data and cerebrospinal fluid (CSF) analysis, MRI may provide a strong tentative antemortem diagnosis

Dilated cardiomyopathy in a cat with congenital hyposomatotropism.

Case summary A 7-month-old domestic shorthair cat was presented for evaluation of stunted growth, recurrent hypoglycaemia during the first months of its life and altered mentation. Complete blood count and biochemistry were unremarkable, except for mildly elevated serum creatinine concentration (despite low muscle mass) and concurrent isosthenuria. Hyposomatotropism was diagnosed based on persistent low circulating insulin-like growth factor 1 concentrations and a lack of response of circulating growth hormone (GH) concentration after the administration of GH-releasing hormone. Other endocrinopathies such as hypothyroidism and hypoadrenocorticism were excluded. MRI of the brain revealed a fluid-filled empty sella tursica, consistent with a pituitary cyst and atrophy/hypoplasia of the pituitary. Echocardiography was unremarkable at the time of diagnosis of hyposomatotropism. Three months later, ovariohysterectomy revealed immature ovaries, raising the suspicion of luteinising and follicle-stimulating hormone deficiency. At 1 year of age, the cat developed congestive heart failure secondarily to dilated cardiomyopathy (DCM) with severely reduced left ventricular systolic function and died a few days later. Pathology showed atrophy of the adenohypophysis, epithelial delineation of the pituitary cysts, mild cardiomegaly, multifocal fibrosis of the left ventricle and a mild, multifocal, chronic epicarditis. Relevance and novel information GH deficiency is a very rare endocrinopathy in cats. This is the first case to describe the development of DCM with concurrent hyposomatotropism, which has previously been reported in human medicine. Other notable abnormalities that could be related to GH deficiency are juvenile self-limiting hypoglycaemia, behavioural changes and possible nephropathy

Traumatic skull fractures in dogs and cats: A comparative analysis of neurological and computed tomographic features

Background Traumatic skull fractures (TSF) are relatively frequent in dogs and cats, but little information is available regarding their clinical and imaging features. Hypothesis/Objectives To describe the neurological and computed tomographic (CT) features of a large cohort of dogs and cats with TSF. Animals Ninety‐one dogs and 95 cats with TSF identified on CT. Methods Multicenter retrospective comparative study. Signalment, cause of trauma, fracture locations and characteristics, presence of neurological deficits, and 1‐week survival were recorded. Fractures were classified according to the extent of fragmentation and displacement. Results The cranial vault was affected more frequently in dogs (P = .003), whereas the face and base of the cranium more often was affected in cats (P < .001). Cats presented with multiple fractures more frequently (P < .001). All animals with TSF in the cranial vault were more likely to develop neurological signs (P = .02), especially when depressed fractures were present (95% confidence interval [CI], 1.7‐8.2; P = .001). Animals with TSF located only in the facial region were less likely to have neurological signs (odds ratio with Mantel‐Haenszel's method [ORMH], 0.2; 95% CI, 0.1‐0.6; P = .004). Most affected animals (84.9%) survived the first week post‐trauma. Death was more likely with fractures of the cranial vault (P = .003), especially when fragmented (P = .007) and displaced (P = .004). Conclusions and Clinical Importance Traumatic skull fracture distribution and patterns are different between dogs and cats. Cranial vault fractures were associated with neurological deficits and worse survival. The presence of TSF alone should not be considered a negative prognostic factor because most affected animals survived the first week