Leiomyosarcoma is malignant mesenchymal tumor of smooth muscle and commonly encountered in the gastrointestinal tract of dogs. However, primary canine leiomyosarcoma in oral cavity is rare due to lack of smooth muscle in the oral tissue. A 13-year-old, neutered male Poodle presented a hard and immobile mass on the left maxilla. Imprinting cytology from the mass as well as fine-needle aspirated cytology from the left scapular lymph node revealed predominant spindle cells met malignancy criteria of the tumors, including coarse chromatin, high N/C ratio, nuclear molding, macro/multi-nucleoli with cigar-shaped nucleus. Radiography of the skull showed lysis of the nasopalatine bone, and mineral radiopacity in the mass. Computed tomography showed soft tissue attenuating mass from the left incisor teeth to the left retrobulbar space with loss of nasopalatine bone and medial wall of orbit. The histopathological examination showed irregularly arranged malignant spindle-shaped cells with oval or elongated nuclei. The nucleolus is distinct and moderate cellular polymorphism is observed. Mitotic figures are occasionally observed. The tumor cells are positive to vimentin, desmin, α-smooth muscle actin when immunohistochemistry was performed, and in Masson’s trichrome stain, tumor cells are stained as red. Overall, histopathologic exam and immunohistochemistry confirmed canine oral leiomyosarcoma. Because of the poor prognosis, the owner did not consent further treatment.

A 2-month-old Turkish Angora cat presented with multiple skin masses after first vaccination and spot-on antiparasitic treatment. There was no hair loss or pruritis, and tests revealed negative for the feline leukemia and immunodeficiency viruses. Biopsy revealed densely packed eosinophils in sparse dermal tissue with a few mast cells. These lesions did not respond promptly to prednisolone treatment, but they regressed without relapse over the following month, despite sequential vaccinations and anti-parasitic treatment. The present case is interesting considering the rarity of multiple eosinophilic granuloma development in a very young cat with a recent history of vaccination and antiparasitic treatment.

This study compares the differences in the gastrointestinal transit time between the conventional capsule endoscope and a minimized capsule endoscope model in normal dogs to verify whether the minimization of capsule endoscope can help relief retention in the gastrointestinal tract, especially in the pyloric passage. Three male beagles were used as the experimental group for which the minimized capsule endoscope model was orally administered and the control group consisted of three beagle dogs for which the conventional capsule endoscope was orally administered. Nine experiments were conducted with three experiments for each dog in each group. The results showed a significant difference in the gastric transit time (GTT) by the minimization of the capsule endoscope between the two groups (control group: 123.3 ± 80 min, experimental group: 63.3 ± 40.9 min, p=0.019). In contrast, the difference in the small bowel transit time (SBTT) by the minimization of the capsule endoscope between the two groups (control group: 86.6 ± 58.9 min, experimental group: 80 ± 33.5 min, p=0.863) was not significant. In this study, the capsule endoscopes reached the large intestine without retention in the small intestine in all subjects. The significant difference in the GTT between the control group using the conventional capsule endoscope and the experimental group using the minimized capsule endoscope model suggests that the smaller size of the capsule endoscope is helpful in resolving retention in the gastrointestinal tract, thus shorting the GTT.

This study investigated the prokinetic effect of metoclopramide and mirtazapine on gastric transit time (GTT), small bowel transit time (SBTT) and gastrointestinal transit time (GITT) during capsule endoscopy in four healthy beagle dogs. Four beagle dogs participated in the experiment as four groups at intervals of more than three days as the following: Control group 1 (capsule alone), Control group 2 (capsule alone), Metoclopramide administered group (metoclopramide + capsule) and Mirtazapine administered group (mirtazapine + capsule). The results of this study demonstrated there was no significant difference in GTT ([min] control group 1: 105 ± 90, control group 2: 172.5 ± 102 vs metoclopramide administered group: 247.5 ± 93, p = 0.07, 0.10) and SBTT ([min] control group 1: 120 ± 88, control group 2: 75 ± 39 vs metoclopramide administered group: 37.5 ± 15, p = 0.20, 0.18) for capsule only administered groups (control group 1 & 2) compared to metoclopramide administered group. In addition, there was no significant difference in GTT ([min] control group 1: 105 ± 90, control group 2: 172.5 ± 102 vs mirtazapine administered group: 127.5 ± 45, p = 0.56, 0.36) and SBTT ([min] control group 1: 120 ± 88, control group 2: 75 ± 39 vs mirtazapine administered group: 157.5 ± 38, p = 0.29, 0.07) between capsule only administered groups (control group 1 & 2) and mirtazapine administered group. In this study, the fact that metoclopramide might be ineffective and administration of mirtazapine might be inadequate in dogs were confirmed.

A saccular aneurysm is a localized, pouch arterial abnormality, Varous kinds of experimental saccular aneurysm models have been developed to treat aneurysms, and more effective ways to create aneurysm model is also needed. This study aims to compare aneurysm models induced by either porcine pancreatic elastase or papain from papaya latex. Eleven New Zealand white rabbits were divided into three treatment groups: normal saline (n=3), papain (n=4), and elastase (n=4). The right common carotid artery was selected as the aneurysmal site, and the respective substance was incubated for 20 minutes. No neurological signs occurred after operation. Hematoxylin-eosin (H&E) staining and modified elastic trichrome stain were performed 2 weeks after the procedure for pathological analysis. Histological findings for the control group showed normal vascular wall structure, normal elastic fiber, and no signs of inflammation. In samples of the papain group, the vascular walls were damaged and the endothelium was detached. Most of the elastic fibers were destructed. All samples of the papain group showed elastic fragmentation. In the elastase group, all samples showed severe inflammation and destruction of the vascular structure. There was also an elastase-induced sterile abscess. These findings indicate that elastase does not induce stable aneurysms at a dose of 1 mg because of excessive inflammation and destruction of the vascular structure. Elastase induces inflammation and apoptosis which results in the vascular wall to weaken before an aneurysm is formed. Papain at the dose of 1 mg, in contrast, seems to be a suitable candidate for enzymatic aneurysm models in the rabbit.

Ischemic stroke is the most common type of stroke in humans. The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI) in a canine model of stroke. Ischemic stroke was induced by using prepared autologous thrombus. The dogs were placed in lateral recumbency on the operation table and the cervical area of each dog was sterilized by using alcohol. After making a cervical incision, the common carotid artery and internal carotid artery (a branch of the common carotid artery that supplies an anterior part of the brain) were exposed. A 200 μL injection of the autologous thrombus prepared 24 hr prior to surgery was delivered with a 20 gauge venous catheter through an internal carotid artery. After successful delivery of the autologous thrombus, the venous catheter was removed, and the cervical incision was sutured. Neurologic signs including generalized seizures, tetraparesis, and altered mental status, were observed in all 3 dogs after induction of ischemic stroke and the signs manifested immediately after awakening from anesthesia. T1- and T2-weighted images and fluid-attenuated inversion recovery (FLAIR) images of the brain were acquired 1 day before and 1 day after surgery. On the day following ischemic stroke induction, MRI revealed multifocal lesions in the cerebral cortex and subcortex such as T1 hypointensity, T2 hyperintensity, FLAIR hyperintensity, and diffusion-weighted hyperintensity in all 3 dogs. Upon postmortem examination, ischemic lesions were found to be consistent with the MRI findings and they were unstained with 2% triphenyltetrazolium chloride. Histologic features of the earliest neuronal changes such as cytoplasmic eosinophilia with pyknotic nuclei were identified. Neuropil spongiosis and perivascular cuffing were also prominently observed at the infarcted area. The present study demonstrated the features of MRI and histopathologic findings in canine ischemic stroke models.