The effects of 1.0, 1.5, and 2.0 minimum alveolar concentration (MAC) of sevoflurane on hemodynamic, pulmonary and blood chemistry variables were measured during spontaneous and controlled ventilation in healthy horses. Sevoflurane was the only anesthetic drug administered to the horses. In a dose-dependent manner, sevoflurane significantly decreased (P < .05) mean arterial blood pressure, cardiac output, and stroke volume. There was a progressive decrease in peripheral vascular resistance and an increase in heart rate as the concentration of sevoflurane was increased, but the differences were not significant. During spontaneous ventilation there was a dose-dependent decrease in respiratory rate that caused a decrease in the minute volume. As the dose of sevoflurane increased, the arterial carbon dioxide tension also increased (P < .05). All blood chemistries remained within normal limits. Recovery from anesthesia was without incident. In conclusion, sevoflurane induces a dose-dependent decrease in hemodynamic variables and pulmonary function in horses that is not greatly different from that of other approved inhalant anesthetics.

Ulcerative keratitis is the most frequent corneal and ocular disease of the racehorse in Japan. Careful observation of the eyes after racing is necessary as early diagnosis and treatment of corneal ulcers speeds healing. Many antibiotic have efficacy against the bacterial isolates, however, potent antibiotics should be reserved for the most severe corneal ulcers.

No abstract

ABSTRACT. In the present study, the concentrations of serum amyloid A and surfactant protein D in sera were measured to evaluate them for identification of the clinical condition of horses with bacterial pneumonia. The study utilized 185 clinically healthy control thoroughbreds and 9 thoroughbreds for experimental infectious study with S. zooepidemicus. Blood samples were collected from the 185 healthy control thoroughbreds. The 9 thoroughbreds were experimentally infected S. zooepidemicus using an endoscopic injection to a lung lobe and were then observed of clinical conditions. Blood samples were collected before inoculation and on the 1-15th, 22nd, and 29th days after inoculation (follow-up group). The levels of SAA and SP-D in the healthy control thoroughbreds were very low. In the follow-up group, the levels of SAA and SP-D changed in parallel with the horses' clinical condition. The pyrexia observed after bacterial inoculation faded by the 11th day, and the changes in SAA and SP-D occurred simultaneous to disappearance of the clinical signs. Measurement of SAA and SP-D proved useful for monitoring the clinical condition of the horses with bacterial pneumonia. Changes in the SP-D value were preceded by changes in the SAA value. Since the changes in SP-D occurred approximately simultaneous to the changes in the horses' clinical signs, we believe that they reflect the condition of the alveolar membranes. We conclude that measurement of SAA and SP-D in sera is useful for identification of the clinical condition of horses with bacterial pneumonia. KEY WORDS: bacterial pneumonia, clinical condition, equine, serum amyloid A, surfactant protein D.

No abstract

No abstract

No abstract

ABSTRACT. Equine respiratory patterns during swimming were examined in five normal horses. The experiment included a preliminary warming-up stage and 6 circuits of swimming around an annular pool of a 50-meter-circumference. The horses were examined for respiratory rates, intratracheal pressures, inspiratory time (T I ), expiratory time (T E ), respiratory cycle (T; T I +T E ), heart rates, blood lactate concentrations, hematocrit and blood gases. The respiratory rates were maintained around 25/min. Blood gas values changed significantly during swimming. The intratracheal pressures during expiration and inspiration increased significantly with exercise duration compared to the immediately after the warming-up stage. The duty ratio (T I /T) averaged 0.33, which implied that the expiratory time was roughly doubled the inspiratory time. We considered that a longer expiratory time may limit sudden collapse of airways by water pressure during swimming and prevent a radical decrease of air space volume, thus maintains buoyancy. -KEY WORDS: blood characteristic, duty ratio, equine, respiratory function, swimming.J. Vet. Med. Sci. 60(6): 687-689, 1998 Measured items and measuring method: Intratracheal pressures, heart rates and pulmonary arterial temperature were measured. Venous and arterial blood samples were collected in parallel. The blood was taken during the resting period, immediately after the warming-up (just before entry into the annular pool), after the second, fourth and sixth round of swimming and at 3, 6 and 10 min after starting the cooling down.The intratracheal pressures were measured based on the method used by Williams et al. [9]. The signals were detected as varied intratracheal pressure through a thermodilution catheter (Criti Cath, Ohmeda, Tokyo) and recorded (Bioview E, Nihondenki Sanei, Tokyo) to output its respiratory waves through a recorder (Bioview printer, Nihondenki Sanei, Tokyo). Obtained respiratory waves were analyzed for a 20-sec run prior to each blood collection to calculate the respiratory rates, inspiratory pressure, expiratory pressure and duty ratio (T I /T; T I =inspiratory time, T=inspiratory time + expiratory time).The heart rates were calculated based on cardiogram (A-B lead) using the same setting of equipment. The data for the heart rates were analyzed for a 20-sec run prior to each blood collection.Venous blood samples, drawn from the thermodilution catheter inside the pulmonary artery, were used to measure blood lactate concentrations and hematocrit. The blood lactate concentrations were measured with a lactate analyzer (YSI-1500 sports, Yellow Spring Instruments, Ohio, U.S.A.) after sodium fluoride was added to the blood, while the hematocrit was determined using the conventional method after heparin sodium was added to the blood. Pulmonary arterial blood temperature was measured by a thermistor fixed to the end of the thermodilution catheter and monitored by a cardiac output computer (MTC-6210, Nihon Koden, Tokyo) .The arterial blood was obtained anaerobically through...