Electrocardiography, heart rates, and heart weights of free-living birds.

To examine the waveforms of electrocardiograms, cardiac rhythm, heart rates at rest and during excitement, and the rate of increase of heart rate, electrocardiograms were recorded with standard bipolar limb leads from 79 free-living birds, including 19 species. The heart weights and heart-to-body weight ratios were obtained from an additional 96 free-living birds, including 20 species. In the majority of the electrocardiograms, lead I was of low amplitudes for all waves except the P wave, and leads II and II were very similar to each other with a predominant S wave and a very short or elevated ST segment. The P wave was often superimposed on the T wave when the heart rate increased to 330 beats/min. Four types of arrhythmia were observed in 50 of the 79 birds (63.3%): 48 sinus arrhythmias, four sinus arrests, two atrial premature contractions, and one ventricular premature contraction. The resting heart rate was negatively associated with the rate of increase, suggesting that a bird with a low resting rate might be able to maintain a greater capacity to increase its heart rate than one with a high resting rate. A negative correlation on a bilogarithmic scale was obtained between the heart weight and the resting heart rate, indicating that a bird with a high heart weight had lower resting heart rate than a bird with a low heart weight. When the heart-to-body weight ratios of free-living birds were compared according to their motility, the ratios of more active birds were greater than those of less active ones.

Clinostomum complanatum (Trematoda) infection in freshwater fish from fish dealers in Tottori, Japan.

During the period January 1989 through February 1991, 327 freshwater fish of 3 different species (Carassius cuvieri, Cobitis anguillicaudatus and Hypomesus transpacificus) purchased from 7 fish dealers in Tottori City were investigated for the metacercarial infection of Clinostomum complanatum. Among them, 20.5% (16/78) of C. cuvieri were infected with this fluke. Each infected fish harbored 1 to 30 metacercariae. The sites and rates of parasitization of metacercariae in the infected fish were 42.4% in the body muscles, 30.3% in the muscles at the pectoral fin, 21.2% in the tissues around the gills and 6.1% in the cheek muscles.

Clinostomum complanatum (Trematoda: Clinostomatidae) in five new fish hosts in Japan.

Metacercariae of Clinostomum complanatum were found in six species of natural freshwater fishes collected at Koyama Pond in Tottori City of Tottori Prefecture, Japan. Five of these fish species are reported here as new records for second intermediate hosts of C. complanatum in Japan: the silver crucian carp (Carassius gibelio langsdorfi), the deepbodied crucian carp (Carassius cuvieri), the carp (Cyprinus carpio), the topmouth gudgeon (Pseudorasbora parva) and the rose bitterling (Rhodeus ocelatus).

Natural infections of Clinostomum complanatum (Trematoda: Clinostomatidae) in wild herons and egrets, Tottori Prefecture, Japan.

Nycticorax nycticorax, Ardea cinerea, Egretta garzetta, and Egretta intermedia were naturally infected with Clinostomum complanatum (Trematoda: Clinostomatidae) among fourteen wild herons, seven wild egrets and one wild bittern evaluated at the Veterinary Hospital of Tottori University, Tottori, Japan. The latter three species of heron and egrets are reported for the first time as definitive hosts of this parasite in Japan.

Myocardial infarction secondary to a disseminated coagulopathy in a cow.

A 3-year-old Holstein cow was presented with a history of high fever, jaundice and subsequent recumbency. The animal died 3 hours after arrival at our department; continuous electrocardiographic examination was performed during those last 3 hours. There were ventricular premature beats (VPBs) with high frequency and complex patterns (bigeminal, trigeminal, repetitive or early cycle VPBs) and paroxysms of ventricular tachycardia (VT). Serum CK-MB was markedly elevated. On histopathological examination, large areas of myocardial necrosis were found in the anterior aspects of the left ventricle. Large, partially organized thrombi occluded the intramural coronary arteries within and adjacent to the lesion. From the histopathological findings, it appeared that a disseminated coagulopathy caused the thromboembolism in the intramural coronary arteries, resulting in acute myocardial infarction (AMI). Various clinical findings, such as arrhythmias, were similar to those in man.