Distribution of immunoglobulin-bearing cells in the gut-associated lymphoid tissues of the turkey: effect of antibiotics

Distribution of immunoglobulin (Ig)-bearing cells in the gut-associated lymphoid tissues of antibiotic treated and untreated control turkeys (Meleagris gallopavo) was compared. Antibiotic treatment was similar to a regimen used in commercial turkey production, which included preincubation dipping of fertile eggs in gentamicin solution, injection of turkeys with gentamicin at hatching, and inclusion of chlortetracycline in the diet. Tissues were examined from turkeys at 3, 7, 14, and 21 days of age with a direct immunofluorescence procedure. Cell distribution in control turkeys was as follows: In the bursa of Fabricius, IgA-carrying cells predominated at 3 days of age, but at later intervals, the 3 classes of Ig-bearing cells were in equal numbers. In the cecal tonsils, IgM- and IgA-bearing cells were in larger numbers at 3 days of age, whereas, the IgG-bearing cells were sparsely distributed. By 7 days of age, IgM cells became more numerous in the cecal tonsils and remained numerous until 21 days of age. At 3 days of age, IgA cells predominated in the small intestines and IgM cells predominated in the large intestine. At 7 and 14 days of age, IgM cells were more numerous in the small and large intestines, but by 21 days of age, IgA cell population equaled that of IgM. The IgG cells were generally sparse in the intestines. Antibiotic treatment often resulted in lower numbers of Ig-positive cells, especially those bearing IgM and IgA. Normal development of the bursa of Fabricius was also retarded in this group.     

Usefulness, completeness, and accuracy of Web sites providing information on osteoarthritis in dogs

OBJECTIVE: To evaluate the quality of information regarding osteoarthritis (OA) in dogs currently available on the World Wide Web. DESIGN: Survey study. PROCEDURE: 5 search engines were searched with the keywords "dog," "degenerative joint disease," "canine," and "osteoarthritis," and the first 50 sites listed by each search engine were analyzed. Unique Web site addresses were distributed to 3 diplomates of the American College of Veterinary Surgeons, who provided a standardized evaluation of each site. RESULTS: 30 unique Web sites were evaluated. Twenty (66%) provided information consistent with conventional knowledge as outlined in textbooks and peer-reviewed literature, 8 (27%) provided experimental or anecdotal information in addition to conventional knowledge, and 2 (7%) provided misleading information. Mean scores for overall usefulness of the information provided in regard to clinical features of and treatment for OA were 1.3 and 1.5, respectively (1 = information of minimal use; 5 = very useful information). Twenty-three (77%) sites encouraged pet owners to seek the advice of a veterinarian. Twenty-three (77%) sites were given overall quality scores < 2, and 7 (23%) were given scores between 2 and 3 (1 = site was counterproductive; 5 = site was very valuable). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the quality of information currently available on the Web that addresses OA in dogs is questionable. Although most of the sites conveyed some conventional information with reasonable accuracy, the information was incomplete, of minimal use, and often considered counterproductive.     

Neuronal ceroid lipofuscinosis in Merino sheep

OBJECTIVE: To characterise neuronal ceroid lipofuscinosis (NCL) in Merino sheep. DESIGN: A prospective clinical, pathological, biochemical and genetic study. PROCEDURE: NCL cases were studied from a medium-wool Merino flock, the stud of origin of its replacement rams, and an experimental flock established at the University of Sydney. RESULTS: Behavioural changes and visual impairment were first detected at 7 to 12 months of age and progressed, with associated motor disturbances and at later stages seizures, to premature death by 27 months of age. At necropsy there was severe cerebrocortical atrophy associated with neuronal loss, astrocytosis and the presence in neurons of eosinophilic intracytoplasmic storage bodies with the characteristics of a lipopigment. In the retina there was progressive loss of photoreceptor cells. Storage bodies isolated from fresh brain, liver and pancreas formed electron-dense aggregates and coarse multilamellar and fine fingerprint profiles ultrastructurally, and consisted mainly of the hydrophobic protein, subunit c of mitochondrial ATP synthase. A homozygosity mapping approach localised the gene causing the disease in Merino sheep to the chromosomal region (OAR7q13-15) associated with NCL in South Hampshire sheep. CONCLUSION: NCL in Merino sheep is a subunit c-storing disease, clinically and pathologically similar to NCL in South Hampshire sheep. We propose that the disease in both breeds represents mutation at the same gene locus in chromosomal region OAR7q13-15.     

Effects of human recombinant interleukin-1beta on canine articular chondrocytes in three-dimensional culture

OBJECTIVE: To determine the effects of interleukin (IL)-1beta on matrix synthesis and degradation by chondrocytes cultured in a 3-dimensional (3-D) gel medium. SAMPLE POPULATION: Chondrocytes from 7 dogs. PROCEDURE: Articular chondrocytes were harvested and cultured in 3-D gel medium alone or with 10 or 20 ng IL-1beta/ml that was added beginning on day 0, 3, 6, or 9. On days 3, 6, 12, and 20 of 3-D culture, samples of the liquid medium were evaluated for glycosaminoglycan (GAG), prostaglandin E2 (PGE2), and matrix metalloprotease (MMP)-3 content. The 3-D plug in each well was evaluated for histologic characteristics of viability, cell morphology, and proteoglycan staining, immunohistochemically stained for collagen type II, and spectrophotometrically analyzed for GAG content. RESULTS: Significant differences for all variables were detected between controls and each IL-1beta group, among groups with different IL-1beta concentrations, and among groups with IL-1beta added at various time points. Chondrocytes exposed to IL-1beta had loss of GAG, increased PGE2 and MMP-3 concentrations, and lack of collagen type-II synthesis. These IL-1beta effects appeared to be time and concentration dependent. CONCLUSIONS: Addition of IL-1beta to chondrocytes in 3-D gel medium results in time- and concentration-dependent effects on matrix synthesis and degradation and provides an appropriate in vitro model for many of the pathophysiologic events associated with osteoarthritis.     

Seroprevalence of Neospora caninum infection following an abortion outbreak in a dairy cattle herd

OBJECTIVE: To investigate the seroprevalence of Neospora caninum infection in a commercial dairy cattle herd, 15 months after detection of an abortion outbreak. PROCEDURE: Sera from the whole herd (n = 266) were examined for N caninum antibodies by indirect fluorescent antibody test (IFAT) and immunoblot analysis. Herd records were reviewed to collate serological results with abortion history, proximity to calving, and pedigree data. RESULTS: The seroprevalence of N caninum infection was 24% (63/266) for IFAT titre > or = 160, 29% (78/266) for immunoblot positive (+ve), and 31% (82/266) for IFAT > or = 160 and/or immunoblot +ve; 94% (59/63) of animals with IFAT > or = 160 were immunoblot +ve. The association between seropositivity (IFAT > or = 160 and/or immunoblot +ve) and history of abortion was highly significant (P < 0.001); the seroprevalence was 86% (18/21) in aborting cows, compared with 30% (50/164) in non-aborting animals. The abortion rate for seropositive cows was 26% (18/68) compared with 3% (3/117) for seronegative animals. IFAT titres of infected cows were higher within 2 months of calving than at other times (P < 0.001). The association between seropositivity in dams and daughters was highly significant (P = 0.009). CONCLUSIONS: The abortions were associated with N caninum infection and there was evidence of reactivation of latent infection close to calving and congenital transmission of infection. Immunodominant antigens identified by immunoblots may prove useful for improved diagnostic tests.     

Feeding value of an enzymatically digested protein for early-weaned pigs

Weanling pigs were used in a series of studies to determine the feeding value of an enzymatically digested protein product developed from a blend of swine and poultry abattoir by-products. The initial study used 156 pigs weaned at approximately 22 d of age to compare the product with menhaden fish meal in Phase II diets. The product supported equal growth rate, and there was no preference for diet exhibited based on inclusion level of the enzymatically digested protein product. The second study used 100 pigs weaned at approximately 21 d of age to compare the product with spray-dried animal blood cells in Phase II diets. The product supported a growth rate equal to that with the blood cells, and the combination of products enhanced growth rate (P<.05). The third study used 265 pigs to compare the product with spray-dried porcine plasma in a slope ratio growth assay. Results demonstrated a relative feeding value of 91% for the product over a 4-wk feeding period. The fourth study used 290 pigs to compare the product with spray-dried porcine plasma in Phase II diets; results demonstrated comparable growth performance. The final study used 180 pigs to compare the product with spray-dried porcine plasma in Phase I diets; results demonstrated comparable growth performance. These data indicate that the enzymatically digested abattoir by-product is a high-quality protein source for weanling pigs.     

Retrospective study of the relationships between age, inflammation and the isolation of bacteria from the lower respiratory tract of thoroughbred horses

A total of 1235 tracheal aspirates taken from 724 thoroughbreds in race training, aged from two to 10 years, were examined cytologically and bacteriologically. An inflammation scoring system on a scale of 0 to 9 was devised to allow the severity of lower airway disease to be assessed from the cytological results. The inflammation scores were closely related to the isolation of bacteria (P<0.001), and the most common bacterial isolates were Streptococcus zooepidemicus, Streptococcus pneumoniae and Pasteurella/Actinobacillus-like species. Lower airway disease was less common in older horses (P = 0.031), and the groups at highest risk were the two- and four-year-olds. Lower airway inflammation was more common in the four-year-olds at National Hunt yards than in the four-year-olds at flat racing yards (P = 0.040, odds ratio = 3.80).