Partitioning of pulmonary resistance in calves

in Journal of Applied Physiology (Bethesda, Md. : 1985) (1987), 62(5), 1826-1831

Nine right apical lobes of healthy Friesian calves and 10 right apical lobes of double-muscled calves of Belgian White and Blue (BWB) breed were suspended in an airtight box, inflated at a constant ... [more ▼]

Nine right apical lobes of healthy Friesian calves and 10 right apical lobes of double-muscled calves of Belgian White and Blue (BWB) breed were suspended in an airtight box, inflated at a constant transpulmonary pressure (Ptp), and subjected to quasi-sinusoidal pressure changes (amplitude: 0.5 kPa) at a frequency of 30 cycles/min. Lobar resistance (RL) was partitioned at six different lung volumes into three components: central airway resistance (Rc), small airway resistance (Rp), and tissue resistance (Rt). Pressure in small airways (2-3 mm ID) was measured with a retrograde catheter. Alveolar pressure was sampled in capsules glued onto the punctured pleural surface. RL was minimal at values of Ptp comprised between 0.5 and 0.7 kPa and increased at higher and lower values of Ptp. At a Ptp of 0.5 kPa, Rc, Rp, and Rt represented 30, 15, and 55% of RL, respectively, in Friesian calves and 25, 25, and 50% in BWB calves. Rp increased markedly at low lung volumes. Rt was responsible for the increase of RL at high Ptp. Rc tended to decrease at high Ptp. The significantly higher values of Rp in BWB calves (P less than 0.05) might explain the sensitivity of this breed to severe bronchopneumonia [less ▲]

Partitioning of pulmonary resistance in Friesian calves

in Research in Veterinary Science (1987), 42(3), 313-317

Eight right cranial lobes of healthy Friesian calves were suspended in an airtight box. They were inflated at a constant transpulmonary pressure (Ptp) and ventilated from the outside by modifying ... [more ▼]

Eight right cranial lobes of healthy Friesian calves were suspended in an airtight box. They were inflated at a constant transpulmonary pressure (Ptp) and ventilated from the outside by modifying pressures in the box with a quasi-sinusoidal pump at a frequency of 30 counts per minute. Peak-to-peak changes were 0.5 kPa. Lobar resistance (Rl) was partitioned into three components: central airway resistance (Rc), small airway resistance (Rp) and tissue resistance (Rt). Partitioning of R1 was realised at six different lung volumes. Minimal R1 was observed for a value of Ptp between 0.5 and 0.7 kPa. At a Ptp of 0.5 kPa, Rc, Rp, Rt represent 30, 15 and 55 per cent of R1, respectively. Lobar resistance increases at high and low lung volumes. Small airway resistance is small and independent of the level of lung inflation, except at low lung volumes where a marked increase is observed. Tissue resistance is relatively high and responsible for the increase of R1 at high lung volumes. Central airway resistance does not change significantly with lung volumes [less ▲]

Partitioning of upper airway resistance in Friesian and double-muscled calves.

in Respiration Physiology (1987), 69(3), 299-306

Respiratory resistance in calves was partitioned in two components: upper airway resistance and pulmonary resistance. The former one was divided into naso-pharyngeal and laryngeal resistance. A comparison ... [more ▼]

Respiratory resistance in calves was partitioned in two components: upper airway resistance and pulmonary resistance. The former one was divided into naso-pharyngeal and laryngeal resistance. A comparison between seven healthy unsedated double-muscled calves of the Belgian White and Blue breed (BWB) and five healthy unsedated Friesian (F) calves was performed. Respiratory resistance was significantly greater in the BWB calves, due to the significantly higher values of the naso-pharyngeal and the laryngeal resistances. This finding might be related to the higher prevalence of laryngitis in this breed [less ▲]

Efficacy of ivermectin and levamisole against immature Dictyocaulus viviparus in cattle

in Veterinary Record : Journal of the British Veterinary Association (1986), 118

Eighteen calves aged approximately three months were each infected with Dictyocaulus viviparus larvae at a rate of 30/kg bodyweight. Seven days later they were randomly allocated to three groups of six ... [more ▼]

Eighteen calves aged approximately three months were each infected with Dictyocaulus viviparus larvae at a rate of 30/kg bodyweight. Seven days later they were randomly allocated to three groups of six animals. Calves of group 1 were controls. Calves of group 2 were given levamisole at a dose rate of 10 mg/kg and calves of group 3 were given ivermectin at a dose rate of 200 micrograms/kg. The anthelmintic activity of these two drugs was compared using clinical, functional, parasitological and pathological parameters. The results showed that the efficacy of ivermectin, given at a therapeutic dose, against immature D viviparus was higher than that of levamisole, given at double the recommended dose [less ▲]

Pulmonary function changes induced by experimental dichlorvos toxicosis in calves

in Research in Veterinary Science (1986), 40(3), 318-321

Clinical and pulmonary function changes induced by intravenous dichlorvos (2,2-dichlorvinyldimethyl phosphate) (DDVP) toxicosis, and reversibility of these changes after atropine treatment were ... [more ▼]

Clinical and pulmonary function changes induced by intravenous dichlorvos (2,2-dichlorvinyldimethyl phosphate) (DDVP) toxicosis, and reversibility of these changes after atropine treatment were investigated in six Friesian calves one to three months old. From one minute after dosage, all animals showed severe respiratory distress, excitation, weakness, muscle fasciculation and cholinesterase inhibition. Decrease in dynamic lung compliance and arterial oxygen tension and increase in total pulmonary resistance, viscous work of breathing and alveolar arterial oxygen gradient were highly significant (P less than 0.01). On the other hand, body secretions, heart rate, respiratory rate, tidal volume and arterial carbon dioxide tension were not significantly affected by DDVP injection. Atropine promptly and completely reversed these changes, except for muscle fasciculations, central depression and cholinesterase inhibition which disappeared progressively within 24 hours. [less ▲]

High-frequency ventilation in cats: technical data

in 4th Comparative Respiratory Society meeting - Anaheim California - USA (1985)

Longitudinal study of the effects of lungworm infection on bovine pulmonary function

in American Journal of Veterinary Research (1985), 46(6), 1392-1395

Clinical and physiologic investigations were done weekly in 5 nonsedated Friesian calves before, during, and after an induced infection with Dictyocaulus viviparus infective larvae. Clinical, hematologic ... [more ▼]

Clinical and physiologic investigations were done weekly in 5 nonsedated Friesian calves before, during, and after an induced infection with Dictyocaulus viviparus infective larvae. Clinical, hematologic, serologic, and parasitologic findings were all compatible with the classic picture of moderate subacute verminous bronchitis. Most pulmonary function values revealed significant (P less than or equal to 0.05) changes in the 2nd or 3rd week after inoculation and maximal changes at 5 weeks after inoculation. Most marked changes included a decrease in tidal volume, dynamic lung compliance, and arterial oxygen tension, and an increase in minute ventilation, minute viscous work of breathing, and alveolar-arterial oxygen difference. Minute ventilation, dynamic lung compliance, minute viscous work of breathing, and PaO2 revealed the most homogeneous change. Conversely, maximal change of intrapleural pressure, total pulmonary resistance, and viscous work of breathing had higher variability from week to week [less ▲]

Upper airway resistance in healthy Friesian cattle

in Research in Veterinary Science (1985), 38(1), 77-79

Total pulmonary resistance (RL) and upper airway resistance (Ruaw) were measured in nine healthy unsedated Friesian cattle divided into three age groups. Mean values for these three groups of animals aged ... [more ▼]

Total pulmonary resistance (RL) and upper airway resistance (Ruaw) were measured in nine healthy unsedated Friesian cattle divided into three age groups. Mean values for these three groups of animals aged four, 188 and 1157 days were 0.32, 0.13 and 0.06 kPa litre-1 s for RL; 0.14, 0.09 and 0.05 kPa litre-1 s for Ruaw; and 0.45, 0.68 and 0.79 for the ratio Ruaw/RL respectively. Ruaw, measured with the head in the normal position, did not significantly differ from values obtained with the head in the horizontal position. Ruaw, measured with the head in the vertical position, was approximately three times greater than when measured in the two other positions. [less ▲]

A computerized method adapted for pulmonary function testing in unsedated horses

in Deegen, E.; Beadle, R. E. (Eds.) Lung Function and Respiratory Diseases in the Horse (1985)

Elastic properties of the oesophageal wall in the dynamic measurement of intrathoracic pressure in cattle

in Research in Veterinary Science (1984), 37(3), 366-367

The elastance of the midthoracic portion of the oesophagus was measured in 14 healthy Dutch Friesians. These were divided into three groups with mean ages of six, 126 and 1636 days, respectively. Mean ... [more ▼]

The elastance of the midthoracic portion of the oesophagus was measured in 14 healthy Dutch Friesians. These were divided into three groups with mean ages of six, 126 and 1636 days, respectively. Mean elastance was 0.17, 0.10 and 0.06 kPa ml-1, respectively. The calculated percentage of error, in relating the endoesophageal pressure with that in the thorax, was found to be smaller than 1 per cent for each animal. [less ▲]