TOTAL ANOMALOUS PULMONARY VENOUS CONNECTION IN A FOAL

An 8-day-old Arabian-Morgan cross colt underwent cardiac evaluation. The foal was tachycardic, tachypneic, exercise intolerant and had a loud right-sided heart murmur and cyanotic mucous membranes. Total anomalous pulmonary venous connection was diagnosed with echocardiography and confirmed at postmortem examination. Total anomalous pulmonary venous connection is a very rare congenital cardiac abnormality that has not been reported before in the horse.     

Production and characterization of a monoclonal antibody specific to the M serotype of plum pox potyvirus

A monoclonal antibody to an Albanian isolate of plum pox potyvirus (PPV) was obtained (MAbAL), that specifically recognized strain M of this virus. The specificity of MAbAL, assessed by comparative ELISA on 130 PPV isolates of different geographical origin, 22 of which were also tested by comparative IC-PCR, gave consistent and highly reproducible results. MAbAL seems to be elicited by a stable surface determinant that makes it particularly suitable for successful use under a wide range of conditions. MAbAL is an useful addition to the panel of PPV-specific MAbs available to date.     

Diagnosis of Congenital Cardiac Right-to-left Shunts with 99mTc-macroaggregated Albumin

Diagnosing right-to-left congenital cardiac shunts can be difficult. Cardiac catheterization and angiocardiography represent the traditional gold standard for diagnosis, but they are invasive. Nuclear scintigraphy using 99mTc-macroaggregated albumin (MAA) has been employed in humans as an alternate method of diagnosis. This study reviews eight dogs presented for evaluation of a suspect right-to-left cardiac shunt that were examined using 99mTc-MAA. In all, 2-4 mCi (74-148 MBq) of reduced particle 99mTc-MAA were injected IV in a cephalic vein and static images of the whole body, including right and left lateral, dorsal, and ventral views, were acquired for 60 s and stored into a 256 x 256 x 16 matrix. Shunt fractions were calculated. One dog with radiopharmaceutical distribution limited to the lungs did not have a shunt. Seven dogs had distribution of the radiopharmaceutical outside the pulmonary capillary bed, indicating bypassing of the pulmonary capillary circulation due to a right-to-left shunt. Four dogs had 99mTc-MAA within the brain. Three dogs that did not have brain uptake, but instead had a sharp cutoff of radioactivity at the level of the front limbs and neck, were diagnosed with reverse patent ductus arteriosus (PDA). The asymmetric distribution of the radiopharmaceutical is due to the location of the shunt, distal to the brachiocephalic trunk and left subclavian artery. Shunt fractions of dogs with extrapulmonary radioactivity ranged from 40% to 59%. Nuclear scintigraphy with 99mTc-MAA is a quick alternative method of diagnosing right-to-left cardiac shunts that permits quantification of shunt fraction. Distinguishing between reverse PDA and other right-to-left shunts may be possible based on the radiopharmaceutical distribution.     

Computed tomography dacryocystography evaluation of the nasolacrimal apparatus

Computed tomography-dacryocystography (CT-DCG) was used to evaluate the nasolacrimal system in four patients (three dogs and one horse) that were admitted for evaluation of chronic epiphora, facial swelling, or facial trauma. The four patients are reviewed and the technique for performing CT-DCG is described. Additionally, the indications for this procedure are discussed. CT-DCG is advantageous because cross-sectional imaging provides superior resolution of the nasolacrimal apparatus and the relatively long, small-diameter, bony nasolacrimal canal in most veterinary patients.     

Magnetic resonance imaging of a brain abscess in a 10-month-old filly

The purpose of this paper was to correlate the magnetic resonance imaging (MRI) characteristics of a mature brain abscess in a horse with histopathologic alterations of brain tissue. Eight months after the onset of clinical signs, MRI of the brain of a 10-month-old filly was performed. A large space-occupying lesion in the right cerebral hemisphere was identified. This space-occupying lesion was delineated by a thick and well-defined capsule that was isointense to brain parenchyma on the T1-weighted images and with a markedly hypointense on the T2-weighted images. The identification of such a capsule is highly diagnostic of a mature brain abscess. The lesion seen on MR images was confirmed at necropsy where a large abscess of the right hemisphere was observed. Streptococcus zooepidemicus and Pseudomonas aeruginosa were isolated from the abscess. Based on histopathologic examination, the signal characteristics of the capsule on T1-weighted and T2-weighted images were found to be due to the presence of numerous hemosiderin-laden macrophages. These results are in agreement with previous studies on human patients. This report confirms the value of MRI in the diagnosis of equine brain diseases.     

Intramedullary Intervertebral Disk Extrusion in a Cat

Intervertebral disk extrusion is rarely reported in the cat. In this case, the clinical, radiologic, and magnetic resonance imaging findings of an acute intramedullary intervertebral disk extrusion in a 5-year-old domestic shorthaired cat are described. Radiographically, there was mineralized disk material within the vertebral canal. On magnetic resonance images, the disk material was found to be within the spinal cord. A linear disk trail extending from the disk space into the spinal cord may be specific for intramedullary disk extrusion.