No abstract

1. Four randomised block experiments were conducted to determine the role of litter moisture, excreta and alternative bedding materials on the development of footpad dermatitis in growing turkeys. 2. Adding water to the litter increased external and histopathological scores independently of the presence of excreta. Fully developed lesions were induced by the application of water to dry litter in 2 to 4 d. 3. Footpad lesions were associated with discomfort during walking in one experiment and body weight was lower in birds on wet compared with dry litter. 4. Footpad lesions had virtually healed 15 d after transfer of the turkeys from wet to dry litter although histopathology assessment showed some residual tissue repair. 5. Long barley straw was associated with high footpad scores on wet and dry treatments. The footpad scores for turkeys on reprocessed cardboard chips were similarly high whereas scores were similar on paper litter and wood shavings whether dry or wet. 6. It was concluded that high litter moisture alone was sufficient to cause footpad dermatitis in young turkeys and that footpad dermatitis should be minimised by the maintenance of dry litter.

Further studies are indicated to establish the pathogenesis of this disease complication as well as therapeutic strategies to reverse this state.

Background: The quality of histopathology slides of endoscopic biopsies from different laboratories varies, but the effect of biopsy quality on outcome is unknown.Hypothesis: The ability to demonstrate a histologic lesion in the stomach or duodenum of a dog or cat is affected by the quality of endoscopic biopsy samples submitted. More endoscopic samples are needed to find a lesion in poor-quality tissue specimens.Animals: Tissues from 99 dogs and 51 cats were examined as clinical cases at 8 veterinary institutions or practices in 5 countries.Methods: Histopathology slides from sequential cases that underwent endoscopic biopsy were submitted by participating institutions. Quality of the histologic section of tissue (inadequate, marginal, adequate), type of lesion (lymphangiectasia, crypt lesion, villus blunting, cellular infiltrate), and severity of lesion (normal, mild, moderate, severe) were determined. Sensitivity of different quality tissue samples for finding different lesions was determined.Results: Fewer samples were required from dogs for diagnosis as the quality of the sample improved from inadequate to marginal to adequate. Duodenal lesions in cats displayed the same trend except for moderate duodenal infiltrates for which quality of tissue sample made no difference. Gastric lesions in dogs and mild gastric lesions in cats had the same trend, whereas the number of tissue samples needed to diagnose moderately severe gastric lesions in cats was not affected by the quality of tissue sample.Conclusions and Clinical Importance: The quality of endoscopically obtained tissue samples has a profound effect on their sensitivity for identifying certain lesions, and there are differences between biopsies of canine and feline tissues.

Activated-myofibroblasts (alpha-SMA-positive cells) were increased and inactive-myofibroblasts (vimentin-positive cells) were reduced in mitral valve leaflets of dogs with MMVD, compared with that of clinically normal dogs. Impact on Human Medicine-This is the first description of spatial and temporal alterations in mitral valve cells of any species with MMVD and has clinical importance in the understanding of disease development in dogs and humans.