Morphometric Study of the Equine Navicular Bone: Comparisons between Fore and Rear Limbs

in Zentralblatt für Veterinarmedizin. Reihe A (1997), 44(9-10), 579-94

Navicular bones collected from the four limbs of 95 sound horses were studied. The anatomic bases have been laid down about morphometry of the navicular bones and their variations according to limbs ... [more ▼]

Navicular bones collected from the four limbs of 95 sound horses were studied. The anatomic bases have been laid down about morphometry of the navicular bones and their variations according to limbs, after corrections have been made for morphologic type, gender, weight, size and age. All the dimensions of the navicular bone (except for the thickness) were larger in the fore limb. This phenomenon probably reflects an attempt to compensate for the greater forces exerted upon the fore limbs during exercise and at rest. Navicular bones collected from the four limbs of 61 sound horses were studied and the anatomic bases were described for histomorphometry of the fore and rear navicular bones. Fore navicular bones possess less cortical bone at the level of the articular surface, as well as at the level of the flexor surface and proximal border, but larger amounts of cancellous bone. Articular and flexor surface cortical bone show a larger porosity in the fore navicular bones and a larger amount of mineralized cartilage. The mineralized portion for distal impar- and collateral sesamoidean ligaments are also larger for the fore navicular bones. Two distinct zones are observed for the flexor surface cortex that have never been reported in the literature before: an external zone, which is mainly composed of poorly remodelled lamellar bone, arranged in a disto-proximal oblique direction, and an internal zone, which is mainly composed of secondary bone, with a latero-medial direction of Haversian canals. Bone architecture is discussed with regard to the mechanic load, encountered by the bone during locomotion. [less ▲]

Pulmonary Ventilation, Mechanics, Gas Exchange and Haemodynamics in Calves Following Intratracheal Inoculation of Pasteurella Haemolytica

in Zentralblatt für Veterinarmedizin. Reihe A (1995), 42(8), 531-544

A Pasteurella haemolytica A1 broth was injected intratracheally in eight calves and measurements of pulmonary function values (PFV) were made once before and hourly post inoculation (p.i.). Changes in ... [more ▼]

A Pasteurella haemolytica A1 broth was injected intratracheally in eight calves and measurements of pulmonary function values (PFV) were made once before and hourly post inoculation (p.i.). Changes in PFVs, included increased respiratory rate and minute ventilation (up to 158% of baseline 2 h p.i.) and decreased tidal volume and lung dynamic compliance (up to 33% of baseline 3 h p.i.). Total pulmonary resistance was not affected. At and after 3 h p.i. there was a progressive impairement of gas exchange, as judged from arterial O2 tension which decreased up to 65% of baseline. In contrast, arterial CO2 tension was not affected. Pulmonary hypertension was observed during the 3 last h of the study and was attributable to an increased pulmonary vascular resistance. Severe neutropenia was observed at 3 h p.i. and post-mortem histological findings were consistent with an acute fibrinohemorragic bronchopneumonia. In conclusion, P. haemolytica airway challenge unequiovocally resulted in acute pneumonia, providing a reproducible pathophysiological model for investigations regarding new therapeutic strategies. [less ▲]

Induction of a Serotonin-S2 Receptor Blockade During Early or Late Stage of Acute Respiratory Distress Syndrome in Double-Muscled Calves: A Comparative Study

in Zentralblatt für Veterinarmedizin. Reihe A (1993), 40(4), 241-8

Ninety-four Belgian White and Blue double-muscled calves were involved in this study which aimed to compare the efficacy of a serotonin-S2 receptor blockade at two different stages of an acute respiratory ... [more ▼]

Ninety-four Belgian White and Blue double-muscled calves were involved in this study which aimed to compare the efficacy of a serotonin-S2 receptor blockade at two different stages of an acute respiratory distress syndrome (ARDS), i.e. at the occurrence of first clinical signs or when another anti-inflammatory compound was clinically shown to be ineffective. Metrenperone, a 5-hydroxytryptamine (5-HT2) blocker, was injected (intramuscularly, 5 times, at 12 hourly intervals, dose rate: 0.1 mg/kg) to (1) 58 calves referred to our laboratory after a treatment (group I) which lasted from 3 to 5 days and which did not improve the clinical status of the animals and (2) 36 calves investigated as soon as first clinical signs occurred (group II). Following the severity of the ARDS, the animals from group I needed to be classified into 2 groups: group IA (moderate ARDS - n = 45) and group IB (severe ARDS - n = 13). For animals in group I, the antibacterial compound previously used was maintained and administered during 4 more days whilst the previous anti-inflammatory drug was suppressed and replaced by metrenperone administered as mentioned above. In group II, each animal was treated with ceftiofur sodium as an antibacterial agent. A clinical score and a breathing score were calculated at each step of the investigation period, i.e. before (T0) and 1 hour (T1) after the first treatment, during the interval 12H-48H (T2) which followed this treatment and 168 H (T3) after this treatment. Four clinical parameters were also taken into account separately: rectal and cutaneous temperatures, respiratory and heart rates.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

Quantitative Buffy Coat Analysis Related to Adrenocortical Function in Horses During a Three-Day Event Competition

in Zentralblatt für Veterinarmedizin. Reihe A (1991), 38(5), 376-82

This study was carried out to investigate stress induced in a cross-country by measuring plasma cortisol and to compare the changes in cortisol level with the leucocytic changes measured with the ... [more ▼]

This study was carried out to investigate stress induced in a cross-country by measuring plasma cortisol and to compare the changes in cortisol level with the leucocytic changes measured with the quantitative buffy coat (QBC) analysis, which is a new method applicable in field conditions for the evaluation of haematological parameters in horses. Seven healthy horses competing in a national three-day event were investigated. Venous blood was sampled under resting condition, 2 min and 180 min after the completion of the cross-country and analysed for haematological parameters, plasma cortisol, protein and lactate levels. Immediately after the event, there was a significant increase in all values except in the granulocytes (Gr) to lymphocytes-monocytes (LM) ratio. 180 min after the event, all the parameters returned to their resting levels while white blood cells (WBC), Gr and Gr/LM ratio were significantly higher with respect to their resting values. A high correlation (r = 0.82) was found between the relative increase in plasma cortisol levels 2 min after exercise and the relative increase in Gr/LM 180 min after exercise. Therefore it was concluded that the Gr/LM ratio measured 180 min after exercise with the QBC analysis is a reliable index to estimate the plasma cortisol levels measured 2 min after exercise. This new technique could consequently be used in order to evaluate, in field conditions, the exercise-induced stress. [less ▲]