A retrospective clinical study of the fractures and luxations of the mandible in the cat

Twenty-six cases of mandibular fractures and luxations are reviewed. Mandibular trauma was due to car accidents (46%) and falls from great heights (23%). Cardiovascular shocks (40%), thoracic injuries (23%), epistaxis (30%), cleft palates (19%), subconjunctival hemorrhages (15%), broken canines (15%), concussions (15%), maxillary fractures (12%) were the most frequently encountered associated problems. Of the 26 cats, 22 had symphyseal fractures, 6 mandibular body fractures, 4 ramus fractures (3 of which were articular) and 6 had temporo-mandibular luxations. Open reduction and internal fixation was performed in 21 cases, surgery being indicated for unstable symphyseal and body fractures, the rostral body fractures being the most challenging to repair. Conservative therapy and ancillary treatment methods such as external coaptation and pharyngostomy were used for the fractures of the ramus. Six temporo-mandibular luxations associated with mandibular fractures in 5 cases were reduced under anesthesia. Good dental occlusion and mandibular function was obtained in the 24 treated cases.     

A survey for torovirus in New Zealand cats with protruding nictitating membranes

Faecal samples from 51 cats were examined by negative stain electron microscopy to investigate a possible association between the syndrome of bilateral protrusion of the nictitating membranes and torovirus infection. Although toroviruses were not observed in any sample, other viruses or virus-like particles were observed in faeces from one of 15 cats with the syndrome, six of 21 cats which had experienced prior episodes of the syndrome and four of 15 healthy control cats. The findings of this study do not support the hypothesis that the syndrome is associated with torovirus infection.     

Ability of laying hens to negotiate horizontal perches at different heights,separated by different angles

1. This paper describes how birds move between horizontal perches at different heights with different angles separating them, using the time to complete the task and the number of birds failing to indicate ability.

2. For the first experiment, 4 groups of 15 birds (ISA Brown) were subjected to each of the experimental treatments (using three perches with angles of 0° (horizontal control), 30°, 45° or 60° between them). The birds were required to move upward between the perches for each treatment and then to move downward between the perches, as a second part of the experiment.

3. Birds moving up between the perches took significantly longer at 60° than at any other angle. No birds failed to complete the task.

4. For birds moving downward between the perches, the median time to complete the task increased significandy with angle. Furthermore, the number of birds failing to complete the task increased with angle.

5. A second experiment was conducted to test whether the vertical or horizontal component of distance affected birds’ ability to negotiate perches separated by different angles.

6. For the second experiment 4 groups of 10 Lohmann Brown laying hens were subjected to each of the following treatments: two horizontal perches separated by 30° or 60° and either direcdy, horizontally or vertically separated by a set distance of 50 cm. Birds were required to move both up and down between perches.

7. Birds negotiated horizontally‐separated perches more successfully at 30° than at 60°. However, when the vertical distance between the perches was 50 cm there was no significant difference in the ability of birds to move downward at 30° or 60°. For birds moving upward, 60° was easier to negotiate dian 30°.

8. The vertical and horizontal separations, as well as the different angles affected the ability of birds to move between perches. There was a general decreasing trend in ability with increasing vertical separation between perches.

9. The findings are important in terms of arrangements of perches to improve bird welfare. To minimise die risk of injury, the angle between perches at different heights should be no more than 45 degrees, and die horizontal and vertical distances between these perches minimised, to allow the birds to be able to move downwards more easily.     

Comparative pharmacokinetics of acetylsalicylic acid and sodium salicylate in chickens and turkeys

1. Pharmacokinetics of acetylsalicylic acid (ASA) and sodium salicylate (SS) were assessed following single intravenous (i.v.) and oral administration at doses of 50 mg/kg body weight to chickens and turkeys. Plasma drug concentrations were determined using high-performance liquid chromatography with ultraviolet detection and pharmacokinetic variables were calculated using a non-compartmental model.

2. The mean residence time (MRT) of salicylate (SA) after i.v. administration of SS was 6.08 ± 0.59 and 3.32 ± 0.27 h and after oral administration was 6.95 ± 0.72 and 4.55 ± 0.71 h in chickens and turkeys, respectively. The elimination half-life (T _{1/2 e}) was shorter in turkeys compared with chickens. The value of body clearance (Cl_B) was higher in turkeys than in chickens, but the apparent volume of distribution (V _ss) was similarly low in both species. The bioavailability of SS was complete and the maximal plasma concentration of SA (C _max) after oral administration was 96.93 ± 8.06 and 91.76 ± 9.64 µg/ml, respectively, in chickens and turkeys.

3. The MRT of ASA after iv administration was 0.24 ± 0.08 and 0.24 ± 0.02 h and after oral administration was 0.78 ± 0.25 and 0.59 ± 0.13 h, respectively, in chickens and turkeys. In both species, T _{1/2 e} was very short, Cl_B and V _ss were similar and markedly higher than those of salicylate. The bioavailability of unchanged ASA was low and C _max after oral administration was 6.9 ± 3.6 µg/ml in chickens and 8.6 ± 1.3 µg/ml in turkeys.     

Divergent selection for shape of growth curve in Japanese quail. 7. Effect of egg storage at high temperature on embryo development and hatchability

1. Hatching time, hatchability of fertile eggs and embryo mortality in relation to (1) physical quality of fresh eggs and (2) embryonic development during storage and incubation periods were analysed after egg storage for 1, 5 or 10 d at 30°C in the meat-type lines of Japanese quail, HG and LG, divergently selected for high and low relative weight gain between 11 and 28 d of age, respectively, and constant body weight at 49 d of age.

2. In both lines, the increase of egg storage temperature from 12°C (standard level) to 30°C increased the egg weight loss during storage, shortened the incubation period and reduced the hatching success.

3. Similar to standard egg storage temperature, LG quail hatched earlier than HG quail after egg storage at 30°C and early and late mortality of both lines increased with a prolonged period of egg storage. In contrast to the standard egg storage conditions, no line differences in hatchability were observed.

4. The results did not identify a relationship between the decrease in hatchability or embryo viability and line differences in external egg parameters as well as any important role of undesirable changes induced by a high storage temperature on albumen viscosity.

5. The pattern of embryonic death, low developmental rate of embryos and a dichotomy between the development of the extra-embryonic vascular system and the embryo itself during egg storage at high temperature implied that an insufficient nutrient supply in consequence of developmental delay could represent a key factor in increasing early and late embryo mortality.     

Role of genetically engineered animals in future food production

Genetically engineered (GE) animals are likely to have an important role in the future in meeting the food demand of a burgeoning global population. There have already been many notable achievements using this technology in livestock, poultry and aquatic species. In particular, the use of RNA interference (RNAi) to produce virus‐resistant animals is a rapidly‐developing area of research. However, despite the promise of this technology, very few GE animals have been commercialised. This review aims to provide information so that veterinarians and animal health scientists are better able to participate in the debate on GE animals.     

Morphological Characterization of the Ovarian Preantral Follicle Population of Collared Peccaries (Tayassu tajacu Linnaeus, 1758)

The aim of this research was to characterize the preantral ovarian follicular population in collared peccaries (Tayassu tajacu) using light and electron microscopy. Ovaries from six mature females were collected and further fixed for histological and ultrastructural analysis. A total of 33273.45 ± 5789.99 preantral follicles (PFs) were estimated for the population in each ovary. Most preantral follicles were primordial (91.56%), followed by primary (6.29%) and secondary (2.15%) ones. Most PFs were morphologically normal (94.4%), and only a few were atretic (5.6%). At histology assessment, amounts of lipid droplets were observed into the oocyte cytoplasm, which was confirmed through ultrastructural analysis. This work characterizes for the first time the ovarian population of preantral follicles, total and per category, in collared peccaries (Tayassu tajacu). The general follicles featured at primordial, primary and secondary categories are very similar to those described for other species.