Ryokichi Ishikawa

Arteriovenous shunts resembling patent ductus arteriosus in dogs: 3 cases

Three dogs presented for the evaluation of cardiac murmurs were diagnosed with aberrant arteriovenous shunts. All cases demonstrated the following findings: 1) relatively soft continuous murmur loudest at the left heart base resembling patent ductus arteriosus (PDA); 2) shunt flow signals in the pulmonary artery on echocardiography; and 3) no PDA on selective angiography, but evidence of anomalous shunting vessels from thoracic aorta to pulmonary vasculature. An aberrant arteriovenous shunt should be considered when a continuous murmur of relatively small intensity is heard.

Comparison of left ventricular contraction profiles among small, medium, and large dogs by use of two-dimensional speckle-tracking echocardiography

OBJECTIVE To assess differences in left ventricular contractile indices among dogs of 3 body sizes via 2-D speckle-tracking echocardiography (STE) and to determine body weight-independent systolic variables. ANIMALS 37 clinically normal adult dogs. PROCEDURES Dogs were allocated into 3 groups on the basis of body weight: small (<7kg), medium (7 to 20kg), and large (>20kg). Right parasternal short-axis echocardiographic views were acquired to measure conventional M-mode variables (left ventricular internal diameter at end diastole, left ventricular internal diameter at end systole, and fractional shortening [FS]) and STE indices (peak systolic strain, peak systolic strain rate, synchrony time index [STI], peak systolic apical rotation, peak systolic basal rotation, peak apical twisting rate, and peak systolic torsion). Values were compared among the 3 groups. RESULTS STE indices, except for peak systolic radial strain (SRad), peak systolic basal rotation, and STI, were significantly decreased in large dogs, compared with values for small and medium dogs. No significant difference was detected in stroke index, peak systolic SRad, and peak systolic basal rotation among the 3 groups. The STI in large dogs was significantly increased, compared with that of medium dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results revealed that decreased systolic indices in large dogs should not be interpreted as signs of decreased systolic function. Increased STI in large dogs may contribute to decreased FS. Because peak systolic SRad was not affected by body weight, peak systolic SRad might be a better variable than FS for assessing systolic function.

Effects of flunitrazepam-ketamine mixed injection for inhalation induction.

Experiments were performed to investigate the effects of inhalation induction in dogs. The combination is preceded by administration of 0.025 mg/kg of atropine sulfate subcutaneously. The dosage is 0.1 mg/kg of flunitrazepam and 5 mg/kg of ketamine, administered intravenously mixed in one syringe. The results were as follows :1. Jaw reflex and auricular reflex were cd not disappear completely but intubation was performed easily. 2. Decrease of arterial blood pressure was controlled in comparison with flunitrazepam administration alone.3. Less obvious changes in electrocardiogram were found in it.4. Immediately after administration, respiration rate and arterial oxygen tension were slightly decrease, therefor using it, in advance anesthesia, great care and inhalation oxygen must be taken.5. The above : It was suggested that flunitrazepam and ketamine administered intravenously mixed injection were useful means.