Eiichi Kanai

Partial Anomalous Pulmonary Venous Connection in 2 Miniature Schnauzers

A 3-year-old, 6.0 kg, intact female Miniature Schnauzer was presented to Azabu University for evaluation of right heart enlargement, incidentally noticed on survey thoracic radiographs. The dog was asymptomatic and no abnormalities were identified on physical examination. Radiographic evaluation of the thorax indicated right heart enlargement (vertebral heart score, 12.1). Two-dimensional echocardiography disclosed right atrial and right ventricular dilatation (Fig 1). An abnormal vascular structure connected to the right atrium at the heart base was observed on color Doppler echocardiography (Fig 2). No other structural heart disease or conditions that could result in right heart dilatation (eg, pulmonary hypertension, atrial septal defect [ASD], tricuspid valve regurgitation) were found. A complete blood count (CBC) and serum biochemistry profile were within normal limits. D-dimer concentration (reference range, <0.2 lg/mL) was normal. Computed tomography angiography (CTA) and cardiac catheterization were performed under general anesthesia, maintained by fentanyl constant rate infusion and isoflurane inhalation, to determine a definitive diagnosis. A 4 Fr multipurpose catheter was introduced from the right jugular vein through a catheter introducer placed by the Seldinger technique. Oxygen saturation (SaO2) of each site within the heart was measured while breathing room air. Mean SaO2 of the cranial and caudal vena cava was 55.9%. SaO2 in the right atrium varied from 81.8 to 99.2%, depending on the location of the catheter tip. SaO2 at the right ventricle and pulmonary artery were 77.0 and 83.2%, respectively. Mean right atrial and pulmonary pressures were 1 and 11 mmHg, respectively. The dog was placed in dorsal recumbency on a clinical 16-multi-detector-row computed tomography scanner. Iodinated contrast medium (2 mg/kg) was rapidly injected via the cephalic vein. Repetitive transverse plane cine scans (120 kV, 99 mAs, 0.625 mm slice thickness, 0.6 s tube rotation time, 0.938 helical pitch) were acquired over the heart. Images were transferred to an image software system for further evaluation. Acquired images were analyzed using multiplanar reconstruction and volume rendering, and it was determined that the pulmonary vein of the right cranial lung lobe was connected to the right atrium. Therefore, a definitive diagnosis of partial anomalous pulmonary venous connection (PAPVC) was made (Fig 3).

Ultrasonographic evaluation of depth–width ratio (D/W) of benign and malignant mammary tumors in dogs

Depth-width ratio (D/W) is the only quantitative item in the criteria recommended by the Japanese Ultrasound Society for the evaluation of breast tumors in humans. However, the usefulness of the D/W has not been evaluated in dogs. Eighty-six mammary masses in 34 female dogs underwent ultrasonographic examination to determine the D/W and other characteristics. Results of ultrasonographic and histopathologic examinations were compared. The D/W of malignant tumors was significantly greater than that of benign tumors, and it had a sensitivity of 56.3% and a specificity of 92.9% for the diagnosis of malignancy when the threshold of D/W was 0.7. In addition, irregular margin, polymorphous shape and heterogeneous internal echographic characteristics were correlated with malignancy.

Combining isoflurane anesthesia with midazolam and butorphanol in rats

Representative inhalant anesthetic agent, isoflurane is commonly used during surgery in rats. However, isoflurane mediates relatively strong respiratory depression. In human and veterinary medicine, sedatives and analgesics are co-administered to complement the anesthetic action of inhalant anesthesia. The present study aimed to establish the novel balanced anesthesia that combines midazolam and butorphanol with isoflurane (MBI) in rats. Male Sprague Dawley rats were divided into 2 groups, and administered either isoflurane monoanesthesia or isoflurane with midazolam (2.5 mg/kg, ip) and butorphanol (2.0 mg/kg, ip). The minimum alveolar concentration (MAC) in each group was evaluated. Induction and recovery times were measured in each group. Adverse reactions during induction were also recorded. In each group, vital signs were assessed for 1 h under 1.5×MAC of isoflurane. Instability of vital signs was assessed under each anesthesia by calculating coefficient of variance. Compared with isoflurane monoanesthesia, MBI anesthesia caused 32% MAC reduction (isoflurane monoanesthesia: 1.30 ± 0.09%, MBI 0.87 ± 0.08%, P<0.05). MB premedication mediated smooth sedating action with low incidence of adverse reactions such as urination and defecation. Isoflurane monoanesthsesia remarkably decreased respiratory rate and saturation O2 (SPO2). In contrast, MBI anesthesia resulted in a relatively stable respiratory rate without decreases in SPO2 during the anesthetic period. In summary, MB premedication is effective for attenuating respiratory depression induced by isoflurane, and achieving smooth induction. This anesthetic protocol serves as a novel option for appropriate anesthesia in rats.

Pericardial Conduit for Pulmonary Artery Reconstruction by Surgical Stapling

Pulmonary artery reconstruction in lung cancer surgery is an effective surgical method to avoid pneumonectomy that leads to longer survival times with few adverse effects. The pericardium is often used for the interposition of a prosthetic conduit. A pericardial conduit can be easily and precisely constructed by surgical stapling, which facilitates pulmonary artery reconstruction. In this report, the process and pitfalls of surgical stapling are described.

Transrectal guidance of the ovaries reduces operative time during bovine laparoscopic ovariectomy.

The main objective of this study was to evaluate the effects of transrectal guidance of the ovaries by an assistant on operative time during bovine laparoscopic ovariectomy. Twenty four clinically healthy Holstein dairy cows were divided randomly into two groups. In the transrectal guidance group, an assistant grasped the ovaries via the transrectal route and pulled them to a position where they could be visualized with a camera. On the other hand, the control group was operated without guidance. The time required to remove both ovaries in the guidance group was shorter than that in the control group (P<0.01). We concluded that laparoscopic ovariectomy with transrectal guidance of the ovaries can substantially shorten operative time, thereby greatly contributing to animal welfare and to reducing the burden on the operator.

A nasal osteoma with an acute course in a Japanese Black heifer

A 14-month-old Japanese Black heifer presented with unilateral epistaxis and mild swelling of the right face. Radiography revealed a mass with increased radiopacity on the right side of the nasal bridge, extending to the left side. Intranasal endoscopy confirmed a large tumor-like structure protruding into the nasal cavity. Following euthanasia, cranial computed tomography (CT) was performed, revealing a tumor 24.3 × 17.5 × 14.8 cm in size. The tumor occupied the entire right nasal cavity and the frontal and sphenoid sinuses. Histopathological examination revealed that the tumor consisted of well-differentiated trabecular bones and loose connective tissue. Based on these findings, a diagnosis of osteoma was established. This report describes a case of osteoma with an acute course in a Japanese Black heifer.

Pharmacological properties of various anesthetic protocols in 10-day-old neonatal rats

In general, the anesthesia in neonates involves high risk. Although hypothermic anesthesia is recommended in rats up to the age of 7 days, neonatal anesthesia for later periods has not been standardized. The present study investigated the pharmacological properties of conventional anesthetic protocols in 10-day-old SD rats. The rats were anesthetized with four anesthetics: a combination of ketamine and xylazine (K/X); a combination of medetomidine, midazolam, and butorphanol (M/M/B); isoflurane; and sevoflurane. Anesthetic depth was scored by reflex response to noxious stimuli. Induction and recovery times were recorded. Vital signs and mortality rate were evaluated for safety assessment. All rats died after administration of K/X at a dose of 60/6 mg/kg, whereas K/X at 40/4 mg/kg resulted in insufficient anesthetic depth, indicating inappropriate for neonatal anesthesia. Although M/M/B at the adult rat dose (0.15/2/2.5 mg/kg) did not provide surgical anesthetic depth, the mouse dose (0.3/4/5 mg/kg) showed sufficient anesthetic depth with relatively stable vital signs. Isoflurane required a long induction period, and caused remarkable respiratory depression and hypothermia, resulted in a 25% mortality rate. In contrast, sevoflurane provided consistent surgical anesthetic depth with rapid induction. Although respiratory rate decrease was markedly observed, all rats survived. Among the anesthetic protocols investigated in the present study, sevoflurane and M/M/B at the mouse dose were recommended for the neonatal anesthesia. Compared with adult rats, the required dose of both anesthetics in neonates was higher, possibly associated with their lower anesthetic sensitivity.

Infective endocarditis of the aortic valve in a Border collie dog with patent ductus arteriosus

Infective endocarditis (IE) in dogs with cardiac shunts has not been reported previously. However, we encountered a dog with concurrent patent ductus arteriosus (PDA) and IE. The dog was a 1-year-old, 13.9-kg female Border collie and presented with anorexia, weight loss, pyrexia (40.4°C) and lameness. A continuous murmur with maximal intensity over the left heart base (Levine 5/6) was detected on auscultation. Echocardiography revealed a PDA and severe aortic stenosis (AS) caused by aortic-valve vegetative lesions. Corynebacterium spp. and Bacillus subtilis were isolated from blood cultures. The dog responded to aggressive antibiotic therapy, and the PDA was subsequently surgically corrected. After a series of treatments, the dog showed long-term improvement in clinical status.

Dynamic left ventricular outflow tract obstruction secondary to hypovolemia in a German Shepard dog with splenic hemangiosarcoma

Dynamic left ventricular outflow tract obstruction (DLVOTO) is a common condition in cats and humans. In this case report, a dog is described with DLVOTO secondary to severe intra-abdominal hemorrhage caused by a hemangiosarcoma. The dog was a 9-year-old, 35.7-kg, spayed female German Shepard dog that presented with a history of tachypnea and collapse. A Levine II/VI systolic murmur was present at the heart base. Abdominal ultrasonography revealed a splenic mass and a large amount of ascites. Echocardiography showed a reduced left ventricular diameter and an increased aortic velocity caused by systolic anterior motion (SAM) of the mitral valve apparatus. The heart murmur and the SAM were resolved after treatment including a splenectomy and a blood transfusion.

Peripheral pulmonary artery stenosis in three cats

Case 1 involved a 4-month-old intact male Somali cat in which peripheral pulmonary artery stenosis (PPS) was recognized after a cardiac murmur remained following patent ductus arteriosus ligation. Case 2, which involved a 1-year-old neutered male Norwegian Forest cat, and Case 3, which involved a 6-month-old intact female American Curl cat, were referred, because of cardiac murmurs. Grades III to IV/VI systolic heart murmurs were auscultated at the left heart base in all 3 cats. All cases showed bilateral pulmonary artery stenosis, although there were no associated clinical signs. In Cases 1 and 2, the pressure gradient through the stenosis decreased after treatment with atenolol.