Factors affecting tests for differential pathogenicity in populations of Plasmodiophora brassicae

Factors affecting the use of the European Clubroot Differential (ECD) series for determining the differential pathogenicity of Plasmodiophora brassicae were studied. Replicate tests made with one collection of P. brassicae did not give consistent results. Collections were shown to be heterogeneous for differential pathogenicity. Selection of components of a collection occurred during passage through a range of differential host cultivars. ECD host 06 was shown not to be uniform. There was a linear relationship between the logarithm of spore concentration in the inoculum used in tests and the incidence of disease, and some ECD hosts required a higher concentration of spores than others to give the same incidence of disease. The implications of these findings for the future use of the ECD series are discussed.     

The Effects of Plaster of Paris and Autogenous Cancellous Bone on the Healing of Cortical Defects in the Femurs of Dogs

Four one quarter inch evenly spaced circular defects were created bilaterally in the lateral femoral diaphysis of 12 clinically normal adult dogs. The defects were left unfilled (control), or were filled with one of the following: (1) plaster of Paris, (2) an equal-volume mixture of plaster of Paris and autogenous cancellous bone, and (3) autogenous cancellous bone. The degree of bone healing was evaluated radiographically and histologically at 2, 4, 6, 8, 10, and 12 weeks. Radiographically, no objective conclusions could be drawn due to the small size of the defects and limited amount of plaster of Paris implanted. Histologically, there was no inflammatory reaction to the plaster of Paris. No differences were determined in the degree of bone healing between autogenous cancellous bone, plaster of Paris, and a mixture of plaster of Paris and autogenous cancellous bone. All implants were superior to the control defect in degree of bone healing.     

Investigations into the effect of two sedatives on the stress response in cattle

The effects of the sedatives acepromazine (an alpha-adrenergic antagonist) and xylazine (an alpha 2-adrenergic agonist) on plasma indicators of stress in cows were assessed after intramuscular injection and transport. After blood samples had been taken for baseline values, nine cows were given an intramuscular injection of saline (2.5 ml), acepromazine (0.05 mg/kg in 2.5 ml) or xylazine (0.05 mg/kg in 2.5 ml) on different occasions at least 1 week apart. The animals were then transported for 5 min by truck to a different environment and blood sampled for a further 1-3 h. There was a significant increase in plasma cortisol concentration (3.29 +/- 1.59 x baseline) after the injection of saline and transport. The injection of acepromazine also resulted in a significant increase in cortisol concentration (2.84 +/- 0.84 x baseline). There was no similar increase after injection of xylazine. This suggests that alpha 2-adrenergic receptors are involved in the response of plasma cortisol concentrations to stressors. An hyperglycaemic response occurred after xylazine (1.66 +/- 0.49 x baseline) and saline (1.20 +/- 0.1 x baseline) but not after acepromazine. Both sedatives produced a metabolic alkalosis (1.13 +/- 0.01 x baseline pH after xylazine and 1.034 +/- 0.02 x baseline pH after acepromazine). A greater decrease in haematocrit was seen after both sedatives (0.88 +/- 0.04 x baseline after xylazine, 0.81 +/- 0.08 x baseline after acepromazine) than after the injection of saline (0.97 +/- 0.06 x baseline).     

Metrizamide myelography in sixty-eight dogs

The results of 68 metrizamide myelograms in the dog are recorded, involving both cisternal and lumbar punctures. The technical considerations are described together with interpretation of the normal myelogram and the diagnostic signs. Failure to obtain a good contrast column occurred in 14 dogs, and post myelographic signs were observed in eight.     

Use of Papain for the detection of incomplete erythrocyte autoantibodies in autoimmune haemolytic anaemia of the dog and cat

A simple technique, employing a papain test in place of the Coombs Test, can be used routinely to detect incomplete erythrocyte autoantibodies in the dog and cat.