Contribution to the aetiology of synovitis in chickens,with special reference to non‐infective factors. IV

Summary

The comparative study reported in the present paper was undertaken to collect data on the collagen content and collagen quality of tendons showing high (low) tensile strength levels and a compact (loose) histological structure. It was shown that tendon tissues of these two groups do not differ in this regard. The effect of administering a number of nutrients (known to be essential in collagenesis) was tested during this study. Administration of these nutrients did not prevent synovitis and did not increase tensile strength.     

Contribution to the aetiology of synovitis in chickens,with special reference to non‐infective factors. V

Summary

A comparative study was undertaken regarding the extractability of glucosaminoglycans and mucoproteins in the tendon tissue of birds highly susceptible to synovitis, viz. broiler breed cocks (BB cocks), and of birds highly resistant to synovitis, viz. White Leghorn hens (WL hens).

It .was shown that in the case of WL hens this extractability decreased in accordance with ageing. In the case of BB cocks such a decrease was not observed. This observation is in support of a working hypothesis which supposes a relatively high degree of interaction between the several components of tendon tissue (e.g. collagen and glucosaminoglycans/mucoproteins) in the case of WL hens, and a relatively low degree of this interaction in the case of BB cocks.

Moreover the results of this study account for the observation that the tendon tissue of WL hens is more resistant to tensile stress than that of BB cocks, and they indicate that the above interaction is a determinant in the aetiology of synovitis.     

Immunoproteomic analysis of the protective response obtained with subunit and commercial vaccines against Glässer's disease in pigs

An immunoproteomic analysis of the protective response of subunit and commercial vaccines in colostrum-deprived pigs against Glässer's disease was carried out. A mixture of proteins with affinity to porcine transferrin (PAPT) from Haemophilus parasuis Nagasaki strain (serovar 5) was inoculated intramuscularly (PAPT_M) and intratracheally (PAPT_Cp), along with a commercial bacterin. PAPT were separated using 2 dimensional electrophoresis (2DE) gels and with them, 2DE Western blots were carried out. A total of 17 spots were identified as positive with sera of pigs from any of the three vaccinated groups, the highest number of immunoreactive proteins being detected in those having received PAPT_Cp. Among them, six proteins (FKBP-type peptidyl-prolyl cis-trans isomerase, neuraminidase exo-α-sialidase, xanthine-guanine phosphoribosyl transferase, CMP-N-acetylneuraminic acid synthetase, phenylalanyl-tRNA synthetase and glyceraldehyde 3-phosphate dehydrogenase) were found to be novel immunogens in H. parasuis. These proteins showed a high potential as candidates in future subunit vaccines against Glässer's disease. The three experimental groups developed specific systemic total IgG (IgGt), IgG1, IgG2 and IgM antibodies after immunizations. In addition, those receiving PAPT_Cp yielded a serum IgA response.     

Evaluation of the Effects of a Therapeutic Renal Diet to Control Proteinuria in Proteinuric Non‐Azotemic Dogs Treated with Benazepril

Background

Angiotensin‐converting enzyme inhibitors (ACEIs) are currently used to control proteinuria in dogs with chronic kidney disease. Renal diets (RDs) have beneficial effects in the management of azotemic dogs, but its role in proteinuric non‐azotemic (PNAz) dogs has been poorly documented.

Hypothesis

Administration of a RD to PNAz dogs treated with benazepril (Be) improves proteinuria control compared with the administration of a maintenance diet (MD).

Animals

Twenty‐two PNAz (urine protein/creatinine ratio [UPC] >1) dogs.

Methods

Randomized open label clinical trial design. Dogs were assigned to group‐MD (5.5 g protein/100 kcal ME)/Be or to group‐RD (3.7 g protein/100 kcal ME)/Be group during 60 days. Dogs with serum albumin (Alb) <2 g/dL received aspirin (1 mg/kg/12 hours). A physical examination, systolic blood pressure (SBP) measurement, complete blood count (CBC), biochemistry panel, urinalysis, and UPC were performed at day 0 (D0) and day 60 (D60).

Results

At D0, there were no significant differences between groups in the evaluated variables. During the study, logUPC (geometric mean (95% CI) and SBP (mean±SD mmHg) significantly decreased (paired t‐test, P = 0.001) in Group‐RD (logUPC_D0 = 3.16[1.9–5.25]; UPC_D60 = 1.20 [0.59–2.45]; SBP_D0 = 160 ± 17.2; SBP_D60 = 151 ± 15.8), but not in Group‐MD (UPC_D0 = 3.63[2.69–4.9]; UPC_D60 = 2.14 [0.76–6.17]; SBP_D0 = 158 ± 14.7; SBP_D60 = 153 ± 11.5). However, RM‐ANOVA test did not confirm that changes were consequence of dietary modification. Weight and Alb concentration did not change significantly in any group.

Conclusion and Clinical Relevance

The administration of a RD to PNAz dogs treated with Be might help to control proteinuria and SBP compared with the administration of a MD, without inducing clinically detectable malnutrition, but more studies are warranted.     

Serological detection of chicken flocks naturally infected with salmonella enteritidis,using an enzyme‐linked immunosorbent assay based on monoclonal antibodies against the flagellar antigen

Summary

The Dutch Salmonella enteritidis monitoring and eradication programme for poultry prescribes a periodic examination of all breeding flocks for the presence of S. enteritidis. For the first years of the programme this was done by bacteriological examination of 50 faecal samples per visit per flock.

In this study we compare the results of bacteriological examination of faecal samples taken at 1580 visits from 545 flocks with those of a S. enteritidis enzyme‐linked immunosorbent assay (ELISA) applied on 24 serum samples per visit per flock. Two flocks were found positive for S. enteritidis by bacteriological examination; both flocks were also detected by ELISA. Ten flocks, bacteriologically negative for S. enteritidis were found positive by ELISA. S. enteritidis was isolated from three of these flocks by repeated and extensive bacteriological examination for verification. Verification was not possible in the fourth EL1SA positive flock. S. enteritidis infections were likely in three other flocks because of the farm histories.

On the basis of the results of this study it was decided to use this ELISA, starting from April 1992, as screening technique in the Dutch S. enteritidis programme instead of bacteriological examination of faecal samples. The ELISA is regarded as a flock test; an extensive, confirmatory bacteriological investigation for S. enteritidis is carried out in ELISA positive flocks to decide whether the flocks are truly infected.     

Omega‐3 Fatty Acid Supplementation Provides an Additional Benefit to a Low‐Dust Diet in the Management of Horses with Chronic Lower Airway Inflammatory Disease

Background

Omega‐3 polyunsaturated fatty acid (PUFA) may benefit humans and animals with chronic inflammatory diseases.

Hypothesis

Omega‐3 PUFA supplementation improves clinical signs, lung function, and airway inflammation in horses with recurrent airway obstruction (RAO) and inflammatory airway disease (IAD).

Animals

Eight research horses and 35 client‐owned horses.

Methods

A pilot study examined the dose of PUFA that can alter plasma PUFA composition. Then, a randomized, controlled clinical trial was performed in horses with RAO and IAD. Horses were fed a complete pelleted diet with no hay and randomly assigned to 1 of 3 daily treatments for 2 months: 30 or 60 g of the supplement or 30 g of placebo. Clinical signs, lung function, plasma PUFA composition, and bronchoalveolar lavage fluid (BALF) cytology were evaluated. Data were expressed as median (25–75th percentiles). P < .05 was considered significant.

Results

Polyunsaturated fatty acid supplementation resulted in increased plasma docosahexaenoic acid (DHA) that peaked at 4 weeks. Clinical improvement was noted in all horses involved in the clinical trial, but the group that received PUFA had greater improvement in clinical signs (cough score improved 60%), lung function (respiratory effort decreased 48%), and BALF (neutrophils decreased from 23 to 9%) when compared to placebo (cough score improved 33%, respiratory effort decreased 27%, BALF neutrophils increased from 11 to 17%; P < .05).

Conclusions and Clinical Importance

Feeding horses with RAO and IAD a PUFA supplement containing 1.5–3 g DHA for 2 months provides an additional benefit to low‐dust diet.     

The effect of a homologous bacterin given to sows prefarrowing on the development of Glässer's disease in postweaning pigs after i.v. challenge with Haemophilus parasuis serotype 5

The trial was carried out to evaluate the impact of maternal antibodies on the development of Gl?sser's disease after i.v. exposure of weaned pigs with a homologous serovar of Haemophilus parasuis (HPS). Two groups of weaned pigs were formed. Group one VI (n = 10): born to vaccinated sows, weaners i.v. challenged one week postweaning and euthanatized 14 days postweaning. Group two NVI (n = 10 wearners): born to non vaccinated sows, i.v. challenged one week postweaning euthanatized 14 days postweaning. One week postweaning all weaners were i.v. inoculated with HPS serovar 5. The following parameters were evaluated: clinical signs (depression, centralnervous signs, fever, lameness), macroscopic lung, pleura, peritoneum, liver and joint changes, and mortality. All trial sows were HPS seronegative prior to vaccination. The HPS vaccinated sows were proven seropositive on day 3 p.p. (values > 0.24), the non vaccinated ones were tested seronegative (values < 0.23). The progeny of sows vaccinated prefarrowing with two doses of HPS serovar 5 bacterin were partially protected against HPS caused clinical and pathological signs. The majority of clinical signs as fever, depression, recumbency, lack of response to verbal stimuli and lameness showed significant (P < 0.05) milder clinical symptoms in VI than in NVI animals. Respiratory signs (P = .169) and involvement of the central nervous system as ataxia, muscular tremor, incoordination of hind legs and convulsions (P = 1) showed no significant differences between the groups. Except lesions of pericard (VI vs. NVI, P = .14) and pleura (VI vs. NVI, P = .14) there were significant (P < 0.05) macroscopic differences at necropsy in lung, liver, joints and cerebrospinal fluid between the offspring of vaccinated sows and the ones of non vaccinated dams. No HPS were isolated from the nasal mucosa of the pigs prior to inoculation. HPS serovar 5 was recovered at necropsy from the nasal mucosa of all pigs in both groups. One pig from group VI presented in all examined organs the presence of HPS serovar 5. The remaining animals in group VI revealed in lung, pericard, pleura, liver, joints and cerebrospinal fluid no presence of HPS. The rate of isolation between VI and NVI groups revealed a significant (P < 0.05) difference. All the survived piglets of group NVI showed positive ELISA titres against HPS serovar 5 (values > .24). The piglets that died or were euthanatized before the end of the study have not been subjected to ELISA serological testing. One piglet died in group VI before the end of the study. Non of the remaining animals in group VI showed seroconversion to HPS serovar 5. Implications: Vaccination of sows did not influence the colonisation of nasal mucosa, but progeny of sows vaccinated prefarrowing with two doses of HPS serovar 5 bacterin were partially protected against HPS caused diseases.     

Sero‐epidemiological screening of pig sera collected at the slaughterhouse to detect herds infected with Aujeszky's disease virus,porcine influenza virus and Actinobacillus (Haemophilus) pleuropneumoniae in the framework of an Integrated Quality Control (IQC) system

Summary

Over a period of six months, approximately 4700 blood samples were collected from 97 pig‐finishing farms in the provinces of Noord‐Brabant and Gelderland and screened for antibodies with respect to Aujeszky's disease virus (ADV), porcine influenza virus (PI) and Actinobacillus (Haemophilus) pleuropneumoniae (App). There were significant differences in the percentages of seropositive pigs between the two provinces, which may be related to the difference in the density of the pig population in the two provinces.

In practice, it was possible to perform a reliable sera collecting procedure at the slaughterhouse. No farms remained seronegative with respect to most of the disease agents during the sampling period. There was a high degree of variation in the percentages of seropositive pigs per farm as to most of the disease agents. Evidence was found that animals that were seropositive with respect to ADV were significantly more susceptible to becoming seropositive with respect to App. serotype 2, and vice versa. The same connection was observed for PI serotype H₁N₁ and PI serotype H₃N₂. Furthermore, evidence was found that pigs seropositive with respect to PI serotype H₁N_i only, or to PI serotype H₁N₁ and ADV or PI serotype H₃N₂ show a significant decrease in average daily weight gain compared to pigs that were seronegative.