Computed tomography and magnetic resonance imaging of thoracic chordoma in a Bengal tiger (Panthera tigris tigris).

A Bengal tiger was presented for evaluation of weakness, ataxia and inappetance. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass extending from the T7-8 vertebral body to the left rib and compressing the spinal cord. On CT, the bone destruction and sequestrum were shown. On MRI, the multilobulated mass appeared hypo- to isointense in T1-weighted and hyperintense in T2-weighted images. The tiger died after imaging, most likely from renal failure. Chordoma without metastasis was diagnosed on necropsy. The imaging characteristics were similar to those found in chordoma in humans. This report describes the use of CT and MRI in an exotic species.

Chordoma of the thoracic vertebrae in a Bengal tiger (Panthera tigris tigris).

A 19-year-old female Bengal tiger (Panthera tigris tigris) was presented with hind limb weakness, ataxia and respiratory distress. Computed tomography revealed a mass between the left side of the T7 vertebra and the base of the left 7th rib. The tiger then died, and necropsy was performed. Grossly, the vertebral mass was 6 × 5.7 × 3 cm, and invaded the adjacent vertebral bone and compressed the T7 spinal cord. Histologically, the mass was composed of large, clear, vacuolated and polygonal cells with osteochondral matrix. Cellular and nuclear atypia were moderate. The vacuolated cells stained positively for cytokeratin and vimentin and negatively for S-100. Based on these findings, the present case was diagnosed as a vertebral chordoma; the first report in a tiger.

Relationship between major histocompatibility complex class I expression and prognosis in canine mammary gland tumors.

The aim of this study was to evaluate MHC class I expression and prognosis using tumor tissues surgically removed from 9 dogs with mammary gland carcinomas and from 13 dogs with complex carcinomas. We assessed MHC class I expression and its correlation with tumor size, B2M expression, infiltration of lymphocytes, histological grade and prognosis. Hematoxylin and eosin-stained sections were histologically graded using the Elston and Ellis grading method. MHC class I expression on tumor cells was evaluated using the avidin-biotin peroxidase complex method. Loss of MHC class I expression from canine mammary gland carcinomas was significantly correlated with poor prognosis (P<0.05). Loss of MHC class I expression showed no association with poor prognosis in canine mammary gland complex carcinomas, because the data were not balanced. Only 1 of 13 (7.6%) canine mammary gland complex carcinomas showed loss of MHC class I expression. All 13 of these dogs showed good prognosis. Thus, the low frequency of MHC class I expression loss from canine mammary gland complex carcinomas may be associated with good prognosis. Taken together, these results suggest that loss of MHC class I expression may be associated with poor prognosis in canine mammary gland carcinomas.

Surfactant protein-A concentration in sera from dogs with pulmonary parenchymal diseases.

Pulmonary surfactant protein A (SP-A) is used as a biomarker to understand the clinical features of pulmonary diseases and associated prognostic indices in human medicine. This study was conducted to investigate whether or not serum SP-A concentration can be used as a biomarker for identifying pulmonary parenchymal diseases in dogs. Thirty-two dogs with pulmonary parenchymal diseases, 34 with nonrespiratory diseases and 57 healthy dogs were included. Serum SP-A concentration was measured in all dogs using sandwich enzyme linked immunosorbent assay with an anti-dog SP-A polyclonal antibody. Median serum SP-A concentration in healthy dogs was <2.0 ng/ml, whereas that in dogs with aspiration pneumonia (n=11), primary lung tumors (n=9) and blunt traumatic lung injury (BTLI; n=12) was 3.1, 7.2 and 2.6 ng/ml, respectively; these values were significantly higher than those in healthy dogs. The serum SP-A concentration in dogs with nonrespiratory diseases was comparable with that in healthy dogs. No correlation was observed between the serum SP-A and plasma C-reactive protein concentrations in dogs with aspiration pneumonia and BTLI. There was a significant correlation between the serum SP-A concentration and thoracic radiographic changes in dogs with BTLI. These findings suggest that the serum SP-A concentration may be a useful clinical biomarker of alveolar damage that can be used for differential diagnosis of pulmonary parenchymal diseases and nonrespiratory diseases in dogs.

Spinal cord trauma in a cat caused by ingestion of a splinter.

A 5-month-old male Abyssinian presented with right hemiplegia. Cervical radiographs, haematology and serum biochemistry were normal. A foreign body was identified on computed tomography (CT) and magnetic resonance imaging (MRI). Removal of the foreign body was carried out via a dorsal approach between the occipital bone and the C1 vertebral body using intra-operative CT. No complications were encountered. Thirty days after surgery, the cat was ambulatory.

Detection of chromogranin A in the adrenal gland extracts of different animal species by an enzyme-linked immunosorbent assay using Thomsen-Friedenreich antigen-specific Amaranthus caudatus lectin.

The reactivity of different lectins with crude chromogranin A (CgA) obtained from different animals, namely, cow, horse, dog, pig, and dolphin, was examined to identify lectin(s) that would be useful as coating reagent(s) in a sandwich enzyme-linked immunosorbent assay (ELISA). Of the different lectins studied, the Amaranthus caudatus lectin (ACA), which is specific for the Thomsen-Friedenreich (T)-antigen (Galß1-3GalNAc), was found to react with the CgA from different animals by western blotting. Purified rabbit anti-bovine CgA antibody was also found to cross-react with the crude CgA preparations. On the basis of these findings, a sandwich ELISA was developed with ACA as the coating reagent and anti-bovine CgA antibody as the probing antibody. Using this method, concentration-dependent curves ranging from 0.003 µg/mL to 25 µg/mL and from 0.02 µg/mL to 25 µg/mL were obtained for bovine CgA and canine CgA, respectively. Similarly, concentration-dependent curves were obtained for the equine, swine, and dolphin crude CgA extracts. Thus, ACA is concluded to be a valuable reagent for CgA detection in crude extracts from different animal species, and for CgA isolation/purification.

Use of contrast-enhanced CT in the diagnosis of abscesses in cattle.

We report here the non-contrast and contrast-enhanced computed tomography performed in two calves with brain abscess and multiple pulmonary abscesses with pharyngeal abscess, respectively. Contrast-enhanced computed tomography was useful in the diagnosis of these diseases in both calves. The diseases were confirmed by histopathological examination.

Measurement of canine pancreatic perfusion using dynamic computed tomography: influence of input-output vessels on deconvolution and maximum slope methods.

OBJECTIVE: We investigated whether the prerequisite of the maximum slope and deconvolution methods are satisfied in pancreatic perfusion CT and whether the measured parameters between these algorithms are correlated. METHODS: We examined nine beagles injected with iohexol (200 mgI kg(-1)) at 5.0 ml s(-1). The abdominal aorta and splenic and celiac arteries were selected as the input arteries and the splenic vein, the output veins. For the maximum slope method, we determined the arterial contrast volume of each artery by measuring the area under the curve (AUC) and compared the peak enhancement time in the pancreas with the contrast appearance time in the splenic vein. For the deconvolution method, the artery-to-vein collection rate of contrast medium was calculated. We calculated the pancreatic tissue blood flow (TBF), tissue blood volume (TBV), and mean transit time (MTT) using both algorithms and investigated their correlation based on vessel selection. RESULTS: The artery AUC significantly decreased as it neared the pancreas (P<0.01). In all cases, the peak time of the pancreas (11.5±1.6) was shorter than the appearance time (14.1±1.6) in the splenic vein. The splenic artery-vein combination exhibited the highest collection rate (91.1%) and was the only combination that was significantly correlated between TBF, TBV, and MTT in both algorithms. CONCLUSION: Selection of a vessel nearest to the pancreas is considered as a more appropriate prerequisite. Therefore, vessel selection is important in comparison of the semi-quantitative parameters obtained by different algorithms.

Virtopsy in a red kangaroo with oral osteomyelitis.

This report describes the use of computed tomography (CT) in a nondomestic species. Postmortem CT was performed on a red kangaroo (Macropus rufus) and a diagnosis of oral osteomyelitis was made. CT examination revealed bony remodeling of the right mandible, an intraosseous lesion of the right temporal bone, muscle necrosis around the right mandible, and the absence of the right, first, upper molar tooth. Cardiac and intrahepatic gas and a distended intestine due to postmortem gas accumulation were also seen. All the lesions identified with CT were also identified by conventional necropsy, except the cardiac and intrahepatic gases. Virtopsy may be a useful procedure for the noninvasive identification of cause of death and as a guide for necropsy in animals.

A rhabdomyosarcoma arising in the larynx of a dog.

A neoplastic nodular lesion, 2 × 3 cm in diameter, was found in the larynx of a 6-year-old spayed female dog. The tumor was ill-circumscribed, consisting histologically of large round cells with abundant cytoplasm interspersed with small round cells with less cytoplasm and occasional multinucleated cells (myotubes). Immunohistochemically, tumor cells were positive for myoglobin, desmin and vimentin in varying degrees, but negative for S-100 protein, GFAP or cytokeratin. Cytoplasmic myofilaments/myofibrils with a dense Z-line-like structure were seen, the fine structures of which were complemented by PTAH stain. Based on these findings, the tumor was diagnosed as a rhabdomyosarcoma, a very rare tumor in the larynx of dogs.

The relationship between the size of caudolateral curvilinear osteophyte of the canine femoral neck and the radiographic view.

Caudolateral curvilinear osteophyte (CCO), an osteophyte at the site of joint capsule attachment on the caudal aspect of the femoral neck, has been advocated as a radiographic criterion for coxofemoral subluxation. The correlation between the presence of CCO on radiographs (radiographic-CCO), the size of the CCO (CCO index) on three-dimensional computed tomographic (CT) images, and hip evaluation using transverse CT images was assessed in 22 Border Collies. CCOs were detected on the radiographs and CT images of 32% and 100% femurs, respectively. The CCO index correlated significantly with radiographic-CCO, but a large CCO index did not necessarily imply that the CCO was visible on radiographs. Hence, radiographic-CCO findings should be used cautiously in hip evaluation of Border Collies.

Computed tomographic evaluation of cerebral ventricular size in clinically normal calves.

OBJECTIVE: To evaluate lateral ventricular size in clinically normal calves by use of computed tomography and to examine the relationships between ventricular height (Vh), ventricular area (VA), and ventricular volume (VV). ANIMALS: 14 Holstein calves. Procedures-14 calves underwent computed tomography of the head with transverse images acquired from the rostral aspect of the frontal lobe continuing caudally to the level of the foramen magnum. Hemispheric height, Vh, VA, and hemispheric area were measured on images obtained at the level of the interventricular foramen. Ventricular volume was calculated by multiplying the sum of VAs measured on each transverse image by the total slice thickness. The left Vh-to-right Vh ratio was calculated to determine the degree of ventricular asymmetry, which was categorized as normal (ie, symmetric) to minimally asymmetric, mildly asymmetric, or severely asymmetric. RESULTS: Mean +/- SD values for Vh and the Vh-to-hemispheric height ratio were 4.96 +/- 1.56 mm and 7.47%, respectively. The mean VA was 114.29 +/- 47.68 mm(2), and the mean VV was 2,443.50 +/- 1,351.50 mm3. Normal to minimally asymmetric ventricles were identified in 13 calves, and mildly asymmetric ventricles were identified in 1 calf. Significant correlations were found between Vh and VA and between Vh and VV. CONCLUSIONS AND CLINICAL RELEVANCE: These results establish reference values for ventricular size in clinically normal calves and suggest that Vh measurement may be a simple and useful technique for examining size of the cerebral ventricles in calves.

Inflammatory reaction in the herniated degenerative disc materials in miniature dachshunds.

Histological and immunohistochemical studies were conducted using herniated intervertebral disc materials obtained surgically from 39 miniature dachshunds. Infiltration of inflammatory cells, such as macrophages, neutrophils, T or B lymphocytes, and multinucleated giant cells, were identified in intervertebral disc materials in 23 cases. Furthermore, proliferations of connective tissue, including neovascularization, were also observed in 17 cases. These results suggest that spontaneous regression of herniated intervertebral disc material could occur in affected dogs.

Influence of osmolarity of contrast medium and saline flush on computed tomography angiography: comparison of monomeric and dimeric iodinated contrast media with different iodine concentrations at an identical iodine delivery rate.

PURPOSE: To evaluate the influence of osmolarity of iodinated contrast media and saline flush on the contrast effect in thoracic computed tomography angiography (CTA) at an identical iodine delivery rate (IDR). MATERIALS AND METHODS: Seven beagles were used in a cross-over experiment. The contrast media used were iohexol 350 mgI/ml (IOH350; osmolarity 844 mmol/kg) and iodixanol 320 mgI/ml (IDX320; osmolarity 290 mmol/kg). Each contrast medium was administered to groups with and without saline flush at 40.0 mgI/kg/s for all experiments. Dynamic CT scanning was performed at the ninth thoracic vertebra level. The peak value, area under the curve (AUC), and time to peak (TTP) were calculated from the time attenuation curves of the pulmonary artery and aorta. RESULTS: There was no significant difference between IOH350 and IDX320 with or without saline flush in the peak values for the pulmonary artery and aorta. AUC was significantly higher in groups with saline flush for both contrast media and arteries (p<0.05) with no significant difference between contrast media. TTP was significantly longer in groups with saline flush than without saline flush for both contrast media and arteries (p<0.05), with no significant difference between contrast media. CONCLUSIONS: There were no significant differences in the contrast effects of monomeric IOH350 and dimeric IDX320 in thoracic CTA when used at an identical IDR. Moreover, saline flush prolonged the peak duration at 600 mgI/kg.

Effect of an autogenous free fat graft on hemilaminectomy defects in dogs.

The purpose of this study was to evaluate the effect of an autogenous free fat graft (FFG) on hemilaminectomy defects. Hemilaminectomy was performed at three levels in three beagles, and each defect was designated as a control site or a site treated with one of two different sizes of FFG. Subsequently, longitudinal computed tomography scanning and histopathological examination were performed. As a result, no postoperative dural adhesion was recognized at the sites where FFGs were placed regardless of the size of the FFG. Moreover, there was no compression of the spinal cord by the FFG. Therefore, it appears that postoperative dural adhesion was controlled by the FFG and that the possibility of FFG migration into the spinal canal is low in hemilaminectomy. In conclusion, placement of an FFG over the defect was considered useful for preventing complications in hemilaminectomy.

Significance of imaging features of alveolar echinococcosis in studies on nonhuman primates.

In this study, we report the imaging findings in two Japanese monkeys (Macaca fuscata) diagnosed with alveolar echinococcosis. Both monkeys were treated with albendazole for 10 years, without surgery. Radiography, computed tomography, and contrast-enhanced ultrasonography were performed under general anesthesia. This is the first report on contrast-enhanced ultrasonographic imaging for alveolar echinococcosis wherein perflubutane was used as the contrast medium. The findings of the imaging analyses were similar to those reported for alveolar echinococcosis in humans, such as snowflake sign and worm-eaten sign. In addition, the serology correlated well with the imaging data in these two monkeys. Therefore, we propose that the imaging findings of alveolar echinococcosis in nonhuman primates may be used to accumulate data on this condition in human alveolar echinococcosis.

Quantitative evaluation of hip joint laxity in 22 Border Collies using computed tomography.

The purpose of this study was to obtain the computed tomography (CT) data for the hip joints of 22 Border Collies. The dorsolateral subluxation (DLS) score, lateral center edge angle (LCEA), dorsal acetabular rim angle (DARA) and center distance (CD) index were measured on the CT images in a weight-bearing position. Radiographic Norberg angle (NA) was also measured. The mean values were 45.7 +/- 10.2% for DLS score, 85.9 degrees +/- 10.3 degrees for LCEA, 18.5 degrees +/- 7.3 degrees for DARA, 0.40 +/- 0.17 for CD index and 102.7 degrees +/- 6.9 degrees for NA. Since the DLS score and LCEA showed strong correlation, combined use of these parameters might improve diagnostic accuracy. We consider CT evaluation in a weight-bearing position to be a useful method for multidirectional evaluation of hips.

Providing an intelligible explanation to pet owners by using three-dimensional CT images: use of clinical imaging for better informed consent.

The purpose of the study reported here was to discuss the level of intelligibility of three-dimensional computed tomography (3D-CT) images of clinical patients for persons who are lacking veterinary knowledge. 143 undergraduate students were participated in this study. They were entirely unfamiliar with veterinary anatomy. A survey was conducted using the visual analog scale method with a focus on the level of intelligibility of the 3D-CT images compared to that of the two-dimensional CT images or radiographs. As a result, the mean value of the intelligibility of the 3D-CT image was 88.4 +/- 17.8 points out of 100 points. In clinical cases, it is very difficult for pet owners lacking veterinary knowledge to understand the clinical status of their pets even with explanations using illustrations, radiographs, and transverse CT images. It is considered that better informed consent and patient satisfaction will be obtained provided veterinarians make an effort towards intelligible patient education by using 3D-CT images.