Surgical correction of pectus excavatum, using external splintage in two dogs and a cat

Two 4-week-old pups and a 7-week-old kitten with respiratory distress and pectus excavatum were treated by external application of a coaptation splint to the ventral aspect of the thorax. Sutures were placed percutaneously around the sternum and through predrilled holes in a piece of moldable splint material that had been contoured to fit a normal-shaped thorax. Correction of the sternal deformity and alleviation of respiratory distress were achieved in all 3 animals. Frontosagittal index and vertebral index were assessed before and after surgery. In all 3 animals, both indices were abnormal before surgery, but were within the normal range after surgery.     

Udder health in dairy cattle infected with Neospora caninum

Blood samples were collected from 3449 cows on 57 representative Ontario dairy herds during the summer of 1998 and analysed for antibody to Neospora caninum using an ELISA. Forty-eight herds (2742 cattle) contained at least one N. caninum-seropositive animal. Two composite milk samples were collected from all cattle: the first on the day of blood collection and the second 68 to 365 days later. All milk samples were submitted for bacteriological culture. Ontario Dairy Herd Improvement Corporation (DHI) data were available for 3162 cattle in the 57 herds at the time of bleeding. Furthermore, complete DHI data were available for 1658 cattle that were culled between 12 and 24 months following blood collection. Using a standardised ELISA sample-to-positive (S/P) cut-off of ≥0.45, the corrected seroprevalence was 8.2% overall and 10.1% within seropositive herds. At blood collection the odds of N. caninum-seropositive cows having a high linear score (≥4.0; equivalent to a somatic cell count ≥200,000 cells/ml) was 27% less than for seronegative animals. Similarly, at the time of culling, the odds of having a high linear score was 22% less in N. caninum-seropositive cattle. Overall, linear score was lower in N. caninum-seropositive cattle at culling. After controlling for herd, parity, days in milk, and the interval between collection of milk samples, the odds of N. caninum-seropositive cattle testing positive for an environmental pathogen (i.e. environmental Streptococcus species and coliforms) on the second milk sample was 56% less than for seronegative animals. The odds were 83% less at a higher ELISA S/P cut-off of ≥0.70. Finally, the odds of N. caninum-seropositive cattle developing a new infection with a major pathogen (environmental or contagious) were 60% less than seronegative cows using the higher ELISA S/P cut-off.     

Neospora caninum serostatus and culling of Holstein cattle

OBJECTIVE: To determine whether time until culling or risk of culling was associated with Neospora caninum serostatus among Holstein cattle in dairy herds in Ontario. DESIGN: Retrospective cohort study. ANIMALS: 3,412 cows in 56 herds. PROCEDURE: Blood samples were collected, and serum was tested for antibodies against N. caninum. Information on cows that were culled was collected during the 1- to 2-year period that producers were unaware of serostatus of individual cows in their herds. RESULTS: Herd prevalence of N. caninum-seropositive cows ranged from 0 to 68.3% (median, 7.0%). During the time of the study, 184 of 359 (51.3%) N. caninum-seropositive cows were culled, compared with 1,388 of 3,053 (45.5%) seronegative cows. Mean time from blood sample collection to culling for seronegative cows (289 days; 95% confidence interval, 280 to 299 days) was not significantly different from mean time for seropositive cows (296 days; 95% confidence interval, 269 to 323 days). Survival analysis indicated that N. caninum serostatus was not associated with time to culling or risk of culling. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that N. caninum serostatus of Holstein cows in Ontario was not significantly associated with either time to culling or risk of culling. Thus, N. caninum serostatus alone should not be used to determine whether cows should be culled.     

Single neuron activity in cat gigantocellular tegmental field: selectivity of discharge in desynchronized sleep

Ratios of discharge rates in desynchronized sleep to those in waking and synchronized sleep of gigantocellular neurons are five to ten times higher than are those of neurons in adjacent tegmental fields and 25 to 30 times higher than in other brain sites. This marked concentration of activity in desynchronized sleep is compatible with an active roie of gigantocellular neurons in the generation of this sleep phase.     

Optimising land and fertiliser N usage in grassland systems where grazing and conservation areas are separate

In grassland systems where grazing and conservation areas are separate, the farmer must decide on the N rates to use in the two areas and on the proportion of the total area to devote to conservation. Quantified relationships between N supply and herbage yields, and estimates of DM requirements, were used to determine the optimum split of total area for cutting and grazing and the N rates to be used to maximise stocking rate for a fixed total fertiliser N usage, or to minimise N usage for a fixed stocking rate. Results indicated that the optimum split of area was around 70% grazed, 30% cut for conservation, with higher N rates on the cut area than on the grazed area. The method also allowed estimates to be made of the economic optimum fertiliser N usage and stocking rate.