IMAGING DIAGNOSIS—POLIOENCEPHALOMALACIA IN A CALF

A 2-month-old mix-breed calf developed acute blindness and ataxia. Serum thiamine concentration was deficient. In antemortem magnetic resonance imaging there were laminar T2-hyperintense regions extending along the cerebral cortex that primarily affected the gray matter. The lesions were relatively symmetric between the left and right hemispheres but no abnormalities were present at the frontal lobes. At necropsy, laminar autofluorescence of the cerebral cortex was observed under ultraviolet exposure at 365 nm, consistent with a diagnosis of polioencephalomalacia. Polioencephalomalacia in the bovine species is compared with that in other species, namely humans, dogs, and cats.     

PEROSOMUS ELUMBIS IN SHEEP

Eight lambs affected with perosomus elumbis were examined during a 3-year investigation; one died during birth, six died soon after birth without rising, and one died at two days. Typically, the affected lambs had an infantile pelvis, thinner and smaller femurs, tibias and metatarsal bones, muscular atrophy, arthrogryposis involving most joints of the hindlimbs, and five had tail malformations. Associated malformations were multiple and included atresia ani (5), unilateral renal agenesis (4), cryptorchidism (4), perineal and diaphragmatic hernias (1), synophthalmia (1), high septal defect (1), cerebellar hypoplasis (1), and hydrocephalus (1). Five of the affected lambs were males and three were females. The incidence of 0.18% in 4,417 lambs examined from a large sheep population over a 3-year period suggests that perosomus elumbis is not an uncommon congenital defect of sheep.     

IMAGING DIAGNOSIS—DUODENAL DIVERTICULUM IN A DOG

A young female Boxer had a history of chronic soft stool. Survey abdominal radiographs were unremarkable. A duodenal diverticulum was identified in abdominal ultrasound and barium upper-gastrointestinal contrast examinations. Before surgery a ^99mTc-pertechnetate study was performed to evaluate for ectopic gastric mucosa in the duodenal diverticulum. Focal abnormal increased radioactivity was identified in the right caudal abdominal quadrant. The diverticulum was excised. Upon histopathologic examination of the duodenal diverticulum, ectopic gastric mucosa was not identified but ectopic pancreatic tissue was found. Mild eosinophilic inflammation within the diverticulum was suspected to be the cause of the mild ^99mTc uptake seen in this dog.     

IMAGING DIAGNOSIS—BACTERIAL DISKOSPONDYLITIS IN A GOAT

A 3-year-old intact male Boer goat was evaluated for paraplegia. Computed tomography (CT) indicated the presence of diskospondylitis, which had previously not been reported in this species, and significant compressive myelopathy. Chronic bacterial pneumonia, epididymitis, nephritis, and soft-tissue abscesses were believed to result in hematogenous spread of bacteria to the affected disk spaces. Staphylococcus spp. and Archanobacterium pyogenes were both identified from postmortem cultures of the vertebral column.     

IMAGING DIAGNOSIS—PULMONARY INTERSTITIAL EMPHYSEMA IN A DOG

In humans, pulmonary interstitial emphysema is most frequently seen in ventilated preterm newborns with severe lung disease; it is less frequently reported in adults. We report on a mature dog with pneumopathy that underwent computed tomography (CT) imaging to further characterize the lung disease. A bronchiolar pattern and lobar opacification were seen on the CT images. Moreover, gas was detected along the course of the pulmonary vessels, presumably in the interstitium, as seen in pulmonary interstitial emphysema in humans. Sever lung disease and/or hyperventilation during anesthesia could be a possible explanation of pulmonary interstitial emphysema in this dog.     

IMAGING DIAGNOSIS—SUBLUMBAR PSEUDOMYCETOMA IN A PERSIAN CAT

A 6-year-old Persian cat was examined for constipation, anorexia, and vomiting that was subsequently found to be due to a pseudomycetoma originating from the descending colon and sublumbar region, and causing mechanical obstruction of the colon and rectum. Multiple discrete hyperechoic foci likely representing fungal grains within the lesion gave the mass a coarse echotexture on ultrasound and was supportive of the diagnosis and computed tomography allowed delineation the extent of the mass. A pseudomycetoma is a granulomatous/pyogranulomatous reaction that surrounds dermatophytic fungal hyphae. Definitive diagnosis of a dermatophytic pseudomycetoma requires identification of the etiologic agent by cultivation or immunohistochemical staining. A pseudomycetoma should be included in the differential diagnosis for an abdominal mass in a Persian cat, especially is accompanied by the sonographic findings noted above.     

IMAGING DIAGNOSIS—COMPLEX INTRAHEPATIC PORTOSYSTEMIC SHUNT IN A DOG

An unusual form of congenital intrahepatic portosystemic shunt was identified in a 3½-month-old female Labrador Retriever with neurologic signs. Ultrasonography and contrast-enhanced computed tomography were used to characterize the shunt morphology. An unusual, looping right-divisional shunt connected back to the portal vein that formed an ampula in the right-central portion of the liver. An irregularly shaped window-like opening connected the combined right-divisional loop and aneurysmal portal vein, and the caudal vena cava, while this vascular pool gradually fused more cranially. Imaging features of this complex vascular anomaly, which has not been previously reported, are presented.     

IMAGING DIAGNOSIS—DISCOSPONDYLITIS AND SEPTIC ARTHRITIS IN A DOG

A 6-year-old German Shepherd dog was evaluated for hind limb lameness. When a diagnosis, could not be achieved using radiography and ultrasonography, bone scintigraphy was performed to look for occult lameness or the presence of multiostic disease. Bone scintigraphy was useful in identification of increased radiopharmaceutical uptake in the thoracic spine and right coxofemoral joint, which directed further testing leading to the diagnosis of discospondylitis, septic arthritis of the coxofemoral joint, and a urinary tract infection.     

IMAGING DIAGNOSIS—HYPEROSTOSIS ASSOCIATED WITH MENINGIOMA IN A DOG

A 5-year-old neutered male Beagle mix dog had a 5-day history of generalized tonic-clonic seizures. Before the seizures, the dog had a 1-2-month history of progressive right hemiparesis. In computed tomography images, a presumed extraaxial mass with hyperostosis and destruction of the skull covering the mass were identified. Surgical excision was performed and the histopathologic diagnosis was meningioma. Hyperostosis is frequently associated with feline meningioma, but this report documents that hyperostosis may also occur secondary to meningioma in the dog.