Prospective, randomized surgical trials with pre-defined objective measures would be required to further evaluate the clinical importance of these preliminary findings which suggest that TPLO may help stabilize the cranial tibial thrust as originally proposed.

Objective evaluation of patellar ligament changes following tibial plateau leveling osteotomy (TPLO) for cranial cruciate ligament injury has not been published to date. In this study, the patellar ligament was evaluated using radiographs and high-resolution ultrasound in 31 stifles (29 dogs) preoperatively and at 1 month (n=31), 2 months (n=18), and 6 months (n=13) postTPLO. A ratio of the thickness of the proximal to distal patellar ligament was determined for all radiographs evaluated. Ultrasound evaluation included proximal, middle, and distal mid-sagittal thickness and transverse thickness, and transverse area measurements. Subjective grading (0 being normal through a scale of 3) of the ultrasound changes was also performed at each evaluation. Significant thickening of the distal patellar ligament was noted postoperatively as evidenced by thickness and area measurements and a decreased radiographic ratio (P < 0.01). Preoperative patellar ligament thickness and area were similar at the proximal, middle and distal sites. Ultrasound-derived thickness and area measurements of the distal patellar ligament were increased at 1 and 2 months (P < 0.01). The radiographic ratio was significantly decreased at 1, 2 and 6 months (P < 0.01). Subjectively, all patellar ligaments scored a 0 preoperatively and 16/31 received a score of 2 or 3 during follow-up evaluation. Additionally, these dogs had ultrasonographic and radiographic changes consistent with distal patellar ligament thickening. Body weight (kg) and postoperative TPLO angle had a significant influence on 1-month postoperative distal patellar ligament area using a stepwise logistic model (P < 0.05). Patellar ligament desmitis is a common postoperative sequela to the TPLO procedure, however its clinical significance (i.e., correlation with a residual lameness) was not evaluated in this study.

Twenty-three foals, between 1 and 7 months old, with signs of acute respiratory distress, were examined at the Veterinary Medical Teaching Hospital (VMTH), University of California, Davis, between 1984 and 1989. Characteristic features included sudden onset of severe respiratory distress and tachypnea, cyanosis unresponsive to nasal oxygen, pyrexia, hypoxemia, hypercapneic respiratory acidosis, poor response to treatment, and histopathologic lesions of bronchiolitis and bronchointerstitial pneumonia. Seven of the 23 foals were normal before the onset of respiratory distress, 3 foals were found dead, a 3 13 foals were being treated for respiratory tract infections at the time of presentation. Laboratory data obtained for 13 horses showed increased plasma fibrinogen concentration (630.7 f 193 mg/dL), leukocytosis (18,607 * 7,784/~L), and neutrophilia (13,737 f 8,21l/pL). Thoracic radiographs showed a diffuse increase in interstitial and bronchointerstitial pulmonary opacity and, in 5 foals, an alveolar pulmonary pattern of increased density was also seen. In 3 foals heavy interstitial infiltration proceeded to a coalescing nodular radiographic appearance. Microbiological culture of tracheobronchial aspirates (TBA) from 9 foals yielded bacterial growth, but no one bacterial species was consistently isolated. Microbiological culture of postmortem specimens of the lung from 6 foals yielded growth of bacteria that included Escherichia coli, Enterobacter spp., Proteus mirabilis, Klebsiella pneumoniae, Rhodococcus equi, or ,f3-hemolytic Streptococcus spp. Tracheobronchial aspirates from 4 foals and lung samples collected from a further 4 foals a t necropsy yielded no bacterial growth. Cultures were not taken from two foals premortem or postmortem. Virologic examination of TBA, lung tissue, or pooled organ tissue from 12 foals was negative. Viral culture of TBA from 1 foal showed cytopathic effects and positive immunofluorescence for equine herpes virus type I1 (EHV-11). In addition to the 3 foals that were found dead, 11 foals died or were euthanatized. Pathologic lesions were limited to the lungs in 50% of the foals; the remainder also had bowel lesions suggestive of hypoxic injury. The predominant histopathologic pulmonary lesions included bronchiolitis, bronchiolar and alveolar epithelial hyperplasia, and necrosis. Many bronchioles were filled with mucoid and fibrinocellular exudate. The peribronchiolar interstitium and adjacent alveolar spaces were also infiltrated with inflammatory cells and contained proteinaceous edema fluid. Type I1 cell hyperplasia and hyaline membrane formation were observed in the majority of foals and in 2 foals alveolar multinucleate giant cells were also present. Nine of 13 foals (69%) on which treatment was attempted a t the V M T H survived after aggressive medical care that included external thermoregulatory control, oxygen by nasal insufflation, antimicrobial drugs, bronchodilating agents,

The medical records and magnetic resonance (MR) images of dogs with an acquired trigeminal nerve disorder were reviewed retrospectively. Trigeminal nerve dysfunction was present in six dogs with histologic confirmation of etiology. A histopathologic diagnosis of neuritis (n=2) or nerve sheath tumor (n=4) was made. Dogs with trigeminal neuritis had diffuse enlargement of the nerve without a mass lesion. These nerves were isointense to brain parenchyma on T1-weighted (T1W) precontrast images and proton-density-weighted (PDW) images and either isointense or hyperintense on T2-weighted (T2W) images. Dogs with a nerve sheath tumor had a solitary or lobulated mass with displacement of adjacent neuropil. Nerve sheath tumors were isointense to the brain parenchyma on T1W, T2W, and PDW images. All trigeminal nerve lesions enhanced following contrast medium administration. Atrophy of the temporalis and masseter muscles, with a characteristic increase in signal intensity on T1W images, were present in all dogs.

The purpose of this retrospective study was to determine measurements of adrenal glands from longitudinal sonograms, in a large population of dogs and to correlate these measurements to age, sex and descriptors of body size. Dogs were selected from the clinic population presented for routine abdominal ultrasonography between September, 1991 and March, 1994. Dogs with elevated serum cholesterol or alkaline phosphatase levels, polyuria/polydipsia, and/or clinical diagnoses of adrenal pathology were excluded. Dogs with ultrasound-documented abnormalities (mass lesions, abnormal architecture) of either adrenal were not considered. Age, sex, weight and breed were recorded, and the body surface area of each dog was calculated. Adrenal length and caudal polar width were determined from longitudinal, two-dimensional ultrasound images. Adrenal measurements were compared with body size measurements and age using least squares linear regression analysis and the correlation coefficient (r) and coefficient of determination (r2) calculated. One hundred and ninety three dogs were included in the study, with a weight and body surface area range of 1.8-72 kg and 0.2-1.8 m2, respectively. The left adrenal gland (n = 182) length range was from 10.7 to 50.2 mm, and the range of the caudal polar widths was 1.9 to 12.4 mm. Right adrenal gland (n = 85) length range was from 10 to 39.3 mm, and the range of the caudal polar widths was from 3.1 to 12 mm. In dogs where both adrenal gland lengths were measured (n = 74), the right adrenal gland length was less than that of the left in 46 dogs, equal to the left in one dog, and greater than the length of the left in 27 dogs. The strongest linear association was noted between the left adrenal gland length and body weight (kg, r = 0.71, p < 0.0001) or body surface area (m2, r = 0.71, p < 0.0001). Similar significant association was noted between the right adrenal gland length and body weight (kg, r = 0.69, p < 0.0001). A significant positive association was also noted between age and left adrenal gland length, (r = 0.25, p = 0.009). The summation of all four adrenal measurement values (left length and width, right length and width) did slightly improve the correlation (r = 0.74, p < 0.0001) when compared with body weight (kg). There was not a significant difference in the adrenal measurements with regard to sex. With regard to the correlation coefficient values, there was no advantage noted to calculating the body surface area from body weight. The causes for the low degrees of the correlation between adrenal size and the variables investigated in this study are unknown; measurement error, effects of non-adrenal illness on adrenal size, and a non-linear or complex linear relationship between adrenal gland size (as measured by longitudinal parameters) and descriptors of body size are among possible explanations.

Computed tomography (CT) of the thorax was performed in 28 dogs and five cats and findings were compared with previous thoracic radiographs. The sample population included all animals that had thoracic radiographs and a CT study within 5 days of each other, where the complete imaging studies were available for review. Thoracic radiographs were considered indeterminate in 31 patients and CT examinations were done to acquire additional information. The presence of additional information from CT relating to presence of pathology, location of pathology, extent of pathology, and involvement of mediastinal structures was recorded. Whether there was a change in diagnosis based on the CT findings was also recorded. In only 4/33 animals (all dogs) did CT fail to provide any new information for the parameters evaluated when compared with survey thoracic radiographs. Additional information about the pathology that was present was gained by CT in 5/5 cats and 21/ 28 dogs. New information on compartmental location of pathology was seen in 4/5 cats and 19/28 dogs. New information on pathology extent was noted in 5/5 cats and 20/28 dogs. Additional information regarding involvement of mediastinal structures was obtained in 2/5 cats and 10/28 dogs. A change in diagnosis was made in 3/5 cats and 13/28 dogs. In conclusion, CT is a valuable tool for evaluating intrathoracic disease. CT provides additional cross-sectional anatomic information that can aid in anatomic localization and evaluation of the extent of the pathology in question.

Results suggest that despite substantial clinical abnormalities, dogs with bronchiectasis may survive for years. Certain purebred dogs and older dogs may have an increased risk of developing bronchiectasis.

Ultrasound-guided percutaneous trans-splenic portal scintigraphy (TSPS) using 99mTcO4(-) has been used to image the portal venous system in normal dogs. Compared with per-rectal portal scintigraphy, it provides higher count density, consistent nuclear venograms of the splenic and portal vein, and significantly decreased radiation exposures. This paper describes the use of TSPS for the diagnosis of portosystemic shunts in 28 dogs. TSPS was performed injecting 70 +/- 28 MBq of 99mTcO4(-) (mean +/- SD) into the splenic parenchyma with ultrasound guidance. A dynamic acquisition at a frame rate of four frames/s for 5 min was initiated after placement of the needle and approximately 2s prior to injection. All dogs had diagnoses confirmed via exploratory laparotomy or ultrasonographic identification of the shunting vessel(s). Three studies (10.7%) were nondiagnostic because of intraperitoneal rather than intrasplenic injection of the radionuclide. Three pathways were recognized on the scintigraphic images: (1) portoazygos shunts--the 99mTcO4(-) bolus traveled dorsally, running parallel to the spine and entering the heart craniodorsally; (2) single portocaval or splenocaval shunts--the 99mTcO4(-) bolus ran from the area of the portal vein/splenic vein junction in a linear fashion toward the caudal vena cava entering the heart caudally; (3) internal thoracic shunt-the 99mTcO4 bolus traveled ventrally along the thorax and abdomen entering the cranial aspect of the heart. Single and multiple shunts were easily distinguished. There were no distinguishing features between single intra and extrahepatic portocaval shunts.