Computed tomographic morphology of the synovial invaginations of the distal sesamoid bone of the horse

The morphological features of the distal border synovial invaginations (SI) of the distal sesamoid bone (DSB) in horses were described by the use of computed tomography (CT). Transverse CT images were obtained on 50 cadaver forefeet from 25 Warmblood horses. Dorsal and sagittal planes were reformatted. The CT images allowed the evaluation of the number, shape, depth of penetration and direction of the SI into the bone. The total number of SI was 295 (mean 5.9). The number of invaginations in a particular DSB ranged from 3 (n = 3), 4 (n = 6), 5 (n = 11), 6 (n = 12), 7 (n = 13), 8 (n = 3), 9 (n = 1) to 11 (n = 1). The shape of the SI was 'conical' (n = 118), 'linear' (n = 109), 'lollipop' (n = 38) or 'branched' (n = 30). Penetration of the SI into the DSB was 'mild' in 195 cases, 'moderate' in 67 cases and 'deep' in 33 cases. The SI ran in a 'straight', 'dorsoproximal' and 'palmaroproximal' direction in 187, 28 and 80 cases, respectively. In only six DSBs, all SI ran in the same direction. The images obtained in this study may serve as reference for the radiographic evaluation of these SI.     

Clinicopathological findings associated with feline infectious peritonitis in Sydney, Australia: 42 cases (1990-2002)

Objectives To review the clinicopathological findings in naturally-occurring, histopathologically confirmed cases of feline infectious peritonitis in client-owned cats in Sydney, Australia, with the purpose of identifying factors assisting in the diagnosis of this complex disease syndrome and to characterise the disease as it occurs in this region.
Design Retrospective clinical study: the clinical records of all cats with histopathologically confirmed feline infectious peritonitis at the University Veterinary Centre Sydney and a private cat hospital in Sydney between 1990 and 2002 were reviewed for signalment, history, physical findings, diagnostic test results and the distribution of histological lesions throughout the body at necropsy.
Results Forty-two cats met the inclusion criteria. Significant features of this study that unique to the contemporary literature are i) the over-representation of certain breeds (Burmese, Australian Mist, British Shorthaired, and Cornish Rex) and the under-representation of other breeds (Domestic Shorthaired, Persian); ii) the overrepresentation of males; iii) the tendency for effusive disease in Australian Mist cats and non-effusive disease in Burmese; iv) the even age distribution of disease seen in cats older than 2 years-of-age; and v) the presence of fulminant immune-mediated haemolytic anaemia in two cats in this study.
Conclusion The study highlights the diverse range of clinical manifestations and the complexities experienced by clinicians in diagnosing this fatal disease. Some aspects of the epidemiology and clinical manifestations of feline infectious peritonitis appear different to the disease encountered in Europe and North America, most notably the over-representation of specific breeds and the presence of immune-mediated haemolytic anaemia.     

Discrete time survival analysis of lamb mortality in a terminal sire composite population

Mortality records of 8,642 lambs from a composite population at the U.S. Meat Animal Research Center during the first year of life were studied using discrete survival analyses. Lamb mortality was studied across periods from birth to weaning, birth to 365 d of age, and weaning to 365 d of age. Animal-time data sets were created for each period using different time intervals: daily, weekly, fortnightly, and monthly. Each data set was analyzed using logistic and complementary log-log sire, animal, and maternal effects models. Explanatory variables included in the models were duration of time interval, sex, type of birth, contemporary group, age of dam, and type of upbringing (nursery or not). Similar estimates of explanatory variables were obtained within the same period across models and different time intervals. Heritability estimates from the complementary log-log models were greater than those from the comparable logistic models because of the difference in variance of the respective link functions. Heritability estimates from the complementary log-log sire model ranged from 0.13 to 0.21 for all periods. These estimates were greater than the complementary log-log animal model estimates that ranged from 0.04 to 0.12. Maternal effects were important early in life, with the maternal heritability slightly greater than the direct additive heritability. Negative correlations (-0.72 to -0.65) between direct additive and maternal effects was estimated. The similarity of results among survival analysis methods demonstrates that the discrete methodology is a viable alternative to estimate variance components in livestock survival data.     

Reticular contraction attributes and passage of digesta from the ruminoreticulum in cattle fed roughage diets.

Four nonlactating Holstein dairy cows (BW = 692 +/- 49 kg) were used in a 4 x 4 Latin square design experiment to determine how changes in attributes of reticular contractions were related to changes in passage of digesta from the ruminoreticulum in cattle fed a forage-based diet. Frequencies of reticular contraction during eating, ruminating, and resting phases of the feeding cycle were not affected (P = .09; P = .07; P = .09, respectively) by feeding level. Duration and amplitude of reticular contractions both increased linearly during eating (P = .03; P = .01), ruminating (P = .01; P = .02), and resting (P = .04; P = .02), respectively, as feed intake level increased. After removing the effects of intake, squared partial correlations computed within analyses of covariance indicated that NDF flow was not related to frequency (r2 = .15, P = .20) but was positively correlated with duration (r2 = .76, P = .0001) and amplitude (r2 = .56, P = .003) of contraction, indicating that duration and amplitude of reticular contraction were more associated with duodenal NDF flow than frequency. However, duration of reticular contraction (r2 = .47, P = .014) explained a greater variation in duodenal NDF flow than amplitude (r2 = .011, P = .74). Stepwise multiple regression also indicated that duration of reticular contraction was the attribute most associated (r2 = .76, P = .0001) with duodenal NDF flow. It was concluded that the changes in digesta passage from the ruminoreticulum were associated primarily with changes in the duration of reticular contraction.     

Diabetes mellitus induced in a dog after administration of corticosteroids and methylprednisolone pulse therapy

An 8-year-old ovariohysterectomized Chow Chow was referred because of dermatologic lesions diagnosed as pemphigus foliaceus. Intolerance to orally administered corticosteroids necessitated the use of methylprednisolone pulse therapy. One week after treatment, diabetes mellitus was diagnosed on the basis of blood and urine test results. For 3 years after treatment, the dog has remained a well-regulated diabetic. Complete remission of pemphigus foliaceus is maintained by alternate-day, orally administered prednisone (0.5 mg/kg of body weight).     

Resistance of Pasteurella multocida A:3,4 to phagocytosis by turkey macrophages and heterophils

A virulent field isolate and 2 vaccine strains of Pasteurella multocida A:3,4 were compared for resistance to phagocytosis by turkey macrophages and heterophils, using in vitro assays. The least virulent vaccine strain (M-9) was phagocytosed to a greater degree than was the field isolate or the other vaccine strain (Clemson University). All 3 bacteria differed significantly from each other in the amount of capsular material present as measured by polycationic ferritin labeling and electron microscopy. Removal of the capsule with hyaluronidase resulted in a significant increase in phagocytosis of the field isolate.     

Detection of genomic DNA of the crayfish plague fungus Aphanomyces astaci (Oomycete) in clinical samples by PCR

A diagnostic procedure, based on a polymerase chain reaction method (PCR) was developed to detect infection of crayfish with the Oomycete Aphanomyces astaci. A set of oligonucleotide primers was designed to specifically amplify A. astaci DNA in the ITS region surrounding the 5.8S rDNA gene. The PCR amplifies a 115 bp amplicon. The specificity of the primers was demonstrated by testing on 27 A. astaci strains and against 20 non-A. astaci Oomycetes and 5 fungal species. Most of the non-A. astaci Oomycete or fungal species included in the study are either known parasites of freshwater crayfish cuticle or can be found in their natural environment. Specificity was also tested against crayfish tissue and some known parasites and bacteria infecting crayfish.

A protocol for the extraction of A. astaci DNA from infected crayfish tissue was developed. The optimised method allows the detection of two genome equivalents of purified A. astaci genomic DNA.

The method was tested on noble crayfish (Astacus astacus), artificially infected with A. astaci. Detection of A. astaci was possible at the very first time of sampling, which was 2 days after the beginning of spore exposure.