Computed tomographic characteristics of confirmed and presumed noncutaneous pythiosis in 25 dogs.

Pythium insidiosum is an aquatic oomycete that causes granulomatous infection in dogs, most commonly cutaneous and gastrointestinal. Ultrasonographic characteristics of gastrointestinal pythiosis have been described; occasionally, CT is utilized in the clinical setting, and CT features of pythiosis have not been published. The purpose of this retrospective, multicenter, descriptive study is to describe CT characteristics of noncutaneous canine pythiosis. The following CT parameters were recorded: lesion anatomic location, number, shape, margination, size, attenuation pre- and postcontrast, enhancement pattern, lymph nodes affected, other lesions identified, and presence of peritoneal effusion or steatitis. Descriptive statistics demonstrating the frequency of lesion appearances were performed. Twenty-five dogs with noncutaneous pythiosis lesions that underwent CT were included; 19 had primarily gastrointestinal infections, four primarily arterial infections, one intrathoracic and intra-abdominal infection, and one primary pulmonary infection. In dogs with primary gastrointestinal infection, lesions were most common at the ileocolic junction and were most frequently focal, well-defined, moderate to marked circumferential wall thickening that was homogeneous and smoothly marginated precontrast, with moderate heterogeneous contrast enhancement. Most dogs had involvement of multiple gastrointestinal regions. Of four dogs with primary arterial involvement, three had large aneurysmal dilatations of the cranial mesenteric artery with severe mural thickening. All dogs had regional lymphadenopathy, which was variable but generally mild. Nine dogs had peritoneal effusion; six dogs had steatitis. CT features of pythiosis can overlap with neoplasia, but pythiosis should be considered as a differential, especially in young dogs. Findings supported using CT as an adjunct imaging test for increasing clinical suspicion of noncutaneous pythiosis.

Comparison of high-field MRI and multidetector CT for grading Chiari-like malformation and syringomyelia in Cavalier King Charles Spaniels.

Chiari-like malformation (CM) and syringomyelia (SM) are common illnesses that can cause debilitating neuropathic pain in Cavalier King Charles spaniels (CKCS). The current imaging modality to screen CKCS for CM/SM is MRI of the brain and cervical spine. Magnetic resonance imaging provides good soft tissue detail and contrast of the cerebellum and cervical spinal cord. Computed tomography (CT) is another cross-sectional imaging technique that facilitates brain and neck evaluation; however, soft tissue resolution does not match that of MRI. Computed tomography benefits include identification of concurrent craniocervical junction anomalies (atlantooccipital overlap) and shorter imaging/anesthesia times with the ability to use only sedation. The aim of this retrospective, method comparison study is to assess the utility of multidetector CT for screening CM and SM in CKCS as compared to high-field MRI. Three groups of observers with different levels of experience graded CM and SM based on the British Veterinary Association/Kennel Club CM/SM classification criteria. Thirty CKCS underwent multidetector CT and 3 Tesla MRI studies. Computed tomography and MRI studies were reviewed at different timepoints to minimize bias. Computed tomography has lower Cohen's Kappa agreement for each observer group compared to MRI. The intraclass correlation coefficient averaging CM and SM for all groups was excellent using MRI, while CT was poor for SM and moderate for cerebellar herniation. Greater observer experience resulted in a higher agreement for CT and MRI. Magnetic resonance imaging should remain the standard for screening of CM and SM as CT can result in misclassification and greater disagreement.

Ultrasound characteristics of feline urinary bladder transitional cell carcinoma are similar to canine urinary bladder transitional cell carcinoma.

Feline transitional cell carcinoma (TCC) is a rare neoplasia of cats with an estimated prevalence of 0.18%. Cats with TCC share clinical signs with common pathologies like feline idiopathic cystitis or urinary tract infections. Nonspecific clinical signs include hematuria, pollakiuria, or stranguria. The literature lacks a feline-specific ultrasound description of TCC. The aim of this multicenter retrospective descriptive study was to report ultrasound findings of a collection of feline TCC and then assess if feline TCC and canine TCC have similar ultrasound appearances. It was hypothesized that the ultrasound characteristics would be similar between feline and canine TCC. Ultrasound studies were assessed for tumor shape, number of isolated mural masses, location within the bladder, presence of Doppler signal, echogenicity of urine, mineralization within the mass, extension of the mass into the proximal urethra or ureters, urethral/ureteral obstruction, pyelectasia, and sublumbar lymphadenopathy. Feline studies were compared to 20 cases of confirmed canine TCC. A total of 20 cats with histologically or cytologically confirmed diagnosis of TCC were included. Feline and canine TCC had similarities when viewed using ultrasound. Statistically significant differences were identified for location of the bladder mass (cats were more likely to be mid-body vs trigonal in dogs, P = .011) and urethral extension of the tumor was less likely in cats than dogs (P = .0436). Based on this sample of 20 cats, feline TCC was most commonly a singular, broad-based mass within the mid-body or apex of the urinary bladder.