EFFECT OF REGION OF INTEREST SELECTION AND UPTAKE MEASUREMENT ON GLOMERULAR FILTRATION RATE MEASURED BY 99mTc-DTPA SCINTIGRAPHY IN DOGS

Determinations of different methods of measurement of uptake of 99mTc-DTPA using scintigraphy of glomerular filtration rate (GFR) were made from 29 studies on 10 healthy beagle dogs. GFR was measured by calculating the percentage dose uptake (integral method) and rate of uptake (slope method) of 99mTc-DTPA using manual kidney regions of interest (ROI) and automatic kidney and background ROIs at different time periods of the uptake phase. These results were compared using linear regression analysis to the GFR obtained from 99mTc-DTPA plasma clearance using multiple blood samples. The best correlation coefficient between percentage DTPA uptake and GFR by DTPA clearance (r = 0.84, P < 0.001) was derived from time intervals between 30s-120s with a perirenal background ROI at 1 or 2 pixels out from the kidney ROI using automatic kidney ROI at 20% threshold. With the slope method, the best correlation coefficient (r = 0.85, P < 0.001) was obtained from time intervals between 30s-peak with the background ROI at 2 pixels out from the kidney ROI using automatic ROI at 35% threshold. The offset was higher, and the correlation varied more with different ROIs and the method was unreliable at time intervals extending beyond the peak radioactivity. Manual kidney ROIs with automatic background ROIs had slightly lower correlations. With DTPA renography both integral and slope uptake method with automatic kidney and background ROIs are accurate methods to estimate the GFR, but that the integral method is much more stable to variations in ROI size and the duration of the uptake phase of the renogram.     

Transmission of Actinobacillus pleuropneumoniae in pigs under field-like conditions: emphasis on tonsillar colonisation and passively acquired colostral antibodies

The objectives of this study were to elucidate at which age tonsillar colonisation by Actinobacillus pleuropneumoniae occurs in pigs and relate this occurrence to the presence of colostral antibodies to A. pleuropneumoniae. The infection patterns were studied in an isolated cohort of pigs, which consisted of the offspring from five sows originating from a conventional pig herd. The sows were transferred to isolated research facilities before farrowing. A. pleuropneumoniae was detected on the tonsils of all sows. After a nursing period of 3 weeks, the pigs were weaned and reared isolated from other pigs until slaughter. The pigs were examined repeatedly for the presence of A. pleuropneumoniae on the tonsils and for antibodies to A. pleuropneumoniae using bacteriological and serological techniques, respectively.A. pleuropneumoniae was detected in the tonsils of one pig as early as 11 days after birth, showing that A. pleuropneumoniae can be transmitted from sow to offspring during a 3-week nursing period. The cumulative proportion of pigs carrying A. pleuropneumoniae in their tonsils increased significantly between the age of 4-12 weeks. This age period corresponded to the age at which the proportion of pigs with detectable levels of colostral antibodies to the different serotypes of A. pleuropneumoniae was declining. Since these two events take place in the same age period, we expect a possible biological association between the level of the passive immunity and the degree of tonsillar colonisation. The median duration of tonsillar colonisation was estimated to approximately 7-8 weeks.     

Development of furnished cages for laying hens

1. A 3-year trial was carried out of cages for laying hens, occupying a full laying house. The main cage designs used were 5000 cm2 in area, 50 cm high at the rear and furnished with nests and perches. F cages had a front rollaway nest at the side, lined with artificial turf. FD cages also had a dust bath containing sand over the nest. H cages had two nest hollows at the side, one in front of the other. They were compared with conventional cages 2500 cm2 in area and 38 cm high at the rear. 2. Cages were stocked with from 4 to 8 ISA Brown hens per cage, resulting in varied allowances of area, feeder and perch per bird. No birds were beak trimmed. In F and FD cages two further treatments were applied: nests and dust baths were sometimes fitted with gates to exclude birds from dust baths in the morning and from both at night; elevated food troughs, with a lip 33 cm above the cage floor, were compared with standard troughs. 3. Management of the house was generally highly successful, with temperature control achieved by ventilation. Egg production was above breeders' standards and not significantly affected by cage design. More eggs per bird were collected when there were fewer birds per cage but food consumption also then tended to be higher. 4. The number of downgraded eggs was variable, with some tendency for more in furnished cages. Eggs laid in dust baths were often downgraded. Those laid at the back of the cage were frequently dirty because of accumulation of droppings. H nests were unsuccessful, with less than 50% of eggs laid in the nest hollows. However, up to 93% of eggs were laid in front rollaways, and few of these were downgraded. 5. Feather and foot damage were generally less in furnished than in conventional cages, greater where there were more birds per cage. With an elevated food trough there was less feather damage but more overgrowth of claws. In year 2, mortality was greater in cages with more birds. 6. Pre-laying behaviour was mostly settled in front rollaway nests. Dust baths were used more for pecking and scratching than for dust bathing. Comfort behaviour was more frequent in furnished cages than conventional, although still not frequent. Locomotion was strongly affected by number of birds per cage or by space per bird, being reduced by crowding. Most birds perched at night except in one treatment providing only 10.7 cm perch per bird. 7. Behaviour was more unrestricted and varied, and physical condition was better, in furnished than in conventional cages. However, egg production will cost more in furnished cages, partly because more eggs are downgraded. Dust baths must be fitted with gates that the birds cannot open from outside, but gates for nest boxes were found unnecessary. If a low perch is fitted it must be far enough from the back of the cage for birds to walk there. 8. Where there was less space per bird (more birds per cage) than the requirements in the 1999 European Commission Directive on laying hens, there were: fewer eggs per hen, but still above the breeders' target; lower food consumption; more feather and foot damage, but less than in conventional cages; higher mortality in one trial out of three; less freedom of movement. However, the results were still very good even with 8 birds per cage, and support the principle that furnished cages provide an acceptable way of protecting the welfare of laying hens.     

Clinical parameters for assessment of udder health in Danish dairy herds

This study examined the possibilities of using clinical parameters related to the bovine udder for characterisation of udder health. Five clinicians performed systematic clinical recordings of udder health at 3 visits to 4 dairy herds. Several of the clinical parameters were scored on an ordinal scale. The agreement between clinicians was compared using kappa statistics. Factor analysis was used to identify udder types. The clinical evaluations showed substantial variation among clinicians. Parameters that were not directly related to pathological conditions showed the highest variation e.g. length of the claws, teat shape and hardness of the udder parenchyma. On the other hand, evaluation of pathological parameters such as nodes in the udder, skin lesions and oedema showed good agreement between clinicians. Udder types identified by means of factor analysis were found to be suitable for characterisation of udder health. Especially one factor related to dry quarters and udder asymmetry showed a more consistent relationship to milk yield than traditionally applied udder health parameters such as treatment rate and cell count. It is concluded that there is a considerable need for increased efforts among clinicians in order to standardise clinical recordings. It is further concluded that certain combinations of extended clinical recordings have significant perspectives for future characterisation of udder health.     

ULTRASONOGRAPHIC INTESTINAL HYPERECHOIC MUCOSAL STRIATIONS IN DOGS ARE ASSOCIATED WITH LACTEAL DILATION

In this retrospective study, the medical records of 23 dogs with the sonographic feature of small intestinal hyperechoic mucosal striations and an endoscopic or surgical intestinal biopsy were reviewed. Histopathologic lacteal dilation was present in 96% of dogs with mucosal striations. Sonographic findings associated with mucosal striations included: mild jejunal wall thickening (96%), mild duodenal wall thickening (78%), mucosal speckles (70%), and abdominal effusion (87%). The mucosal striations were diffuse (70%) or multifocal (30%) and did not cause loss of wall layering, except in one dog with a severe mural lipogranuloma. Mesenteric lymphadenopathy was identified in 9% of dogs. Thirteen dogs with endoscopic biopsies had mild to moderate villus lacteal dilation and the nine dogs with surgical biopsies had moderate to severe dilation. Inflammatory infiltrates were mild (61%) or moderate (30%) with variable numbers and combinations of cells, including eosinophils (65%), plasma cells (61%), lymphocytes (57%), and neutrophils (30%); one dog had disseminated villus histiocytic sarcoma. The biochemistry changes and clinical signs were consistent with protein-losing enteropathy in 78% of dogs. Hyperechoic mucosal striations in dogs are associated with lacteal dilation and are frequently associated with mucosal inflammation and protein losing enteropathy.     

Repair of Complete Dorsal Fracture of the Proximal Phalanx in Two Horses

Simple complete dorsal fractures of the proximal phalanx were repaired in 2 mature pleasure horses with cortical bone screws placed in lag fashion. Healing occurred within 12 weeks and both horses returned to their previous performance level of light pleasure riding within 6 months of injury.     

Reactivity of workshop monoclonal antibodies on paraformaldehyde-fixed porcine blood mononuclear cells

One hundred sixty-four monoclonal antibodies (mAbs) of the second international swine CD workshop were tested for their reactivity with porcine blood mononuclear cells before and after fixing the cells with varying concentrations of paraformaldehyde (PFA) (1, 5 and 10 g l⁻¹). A total of 38 (out of 134) positive reacting mAbs were significantly affected in their binding behavior on fixed cells. Modulation was seen as reduction in binding (staining intensity and/or % positive cells, n=18) or in elevated values (n=20). Modified mAb binding occurred after fixing cells with 5 to 10 g l⁻¹ PFA.