Soft tissue sarcomas and mast cell tumours in dogs; clinical behaviour and response to surgery

OBJECTIVE: To characterise the types of canine soft tissue sarcoma and mast cell tumour treated surgically at the University Veterinary Centre, Sydney. To evaluate the success of surgical treatment of these tumours and identify variables predictive of local recurrence and survival. To establish whether conclusions drawn from previous international studies are applicable to the University Veterinary Centre, Sydney, dog population and vice versa. DESIGN: Clinical presentation and results of surgical excision of 54 soft tissue sarcomas and 70 mast cell tumours affecting the trunk and limbs of dogs at the University Veterinary Centre, Sydney, between 1989 and 2001 were reviewed retrospectively. RESULTS: Cross-bred dogs and Rhodesian Ridgebacks were at significantly greater risk of developing soft tissue sarcomas, and Boxers, Australian Cattle Dogs and Staffordshire Bull Terriers were at significantly greater risk of developing mast cell tumours than other breeds. Fine needle aspiration biopsy yielded a correct diagnosis in 62.5% of soft tissue sarcomas and 96% of mast cell tumours. Local recurrence was encountered after surgical excision in 7.4% of soft tissue sarcomas and 7.3% of mast cell tumours. Metastasis occurred in 6% of soft tissue sarcomas and 12% of mast cell tumours. The most significant risk factors for local recurrence were contaminated surgical margins (soft tissue sarcomas) and histological grade (mast cell tumours). Due to the low number of animals experiencing metastasis, no conclusions could be drawn about significant risk factors. CONCLUSIONS: Aggressive surgical management of soft tissue sarcomas and mast cell tumours is associated with a low incidence of local recurrence. The type, location and behaviour of mast cell tumours and soft tissue sarcomas in the population of dogs presented to the University Veterinary Centre, Sydney are similar to those reported by others.     

Usefulness of serological examinations in the analysis of Salmonella infections in pig herds

The development of the antibody concentration against lipopolysaccharide (LPS) of S. Typhimurium und S. Choleraesuis in rearing pigs during the fattening period and in breeding sows of the corresponding age was recorded. The studies revealed the following results. Antibodies of isotypes IgG1 and IgG2 revealed a more pronounced specificity against the according Salmonella serovar than IgM antibodies. The calculated "antibody percent value" based on the total amount of Salmonella antibodies is mainly determined by the IgM antibodies in sera and meat juice, respectively. In fattening pigs a significant increase of antibodies against IgM and total Ig was observed between week 3 and 10 after beginning of the rearing period. In breeding pigs this increase was detectable already earlier. In only 3 out of 10 groups an increase of IgG1 and IgG2 was also seen. The detected significant increase of total Ig and IgM in the other groups might be the result of a less intensive exposure to salmonellas or it might be due to an increase of unspecific antibodies induced by other antigens. Serological investigations represent a valuable tool to record the intensity and development in time of the Salmonella exposure in pigs farms. Examination of total Ig is an appropriate method to detect pig herds with a high level of Salmonella exposure, for detailed epidemiological studies in pig farms the examination of antibody isotypes will give more comprehensive information.     

Assessing the agreement of Western blot test results for paired serum and cerebrospinal fluid samples from horses tested for antibodies to Sarcocystis neuronaf

Equine protozoal myeloencephalitis (EPM) is a neurological disease of equids that is caused by infection of the central nervous system with Sarcocystis neurona. Veterinarians diagnose EPM by performing a neurological examination and by ordering Western blot tests for antibodies to S. neurona in the blood and/or cerebrospinal fluid (CSF). The negative predictive value of the Western blot test is generally accepted to be high for both serum and CSF. If the agreement between serum and CSF test results is strong, serum tests could be used to substitute for CSF tests in some cases. The purpose of this study was to assess the agreement of the results of 181 paired serum and CSF Western blot antibody tests on equine samples submitted to the Michigan State University Animal Health Diagnostic Laboratory. The agreement of the paired serum and CSF results was assessed for three possible test outcomes--negative, positive or suspect. An additional analysis was performed in which samples reported as suspect were reclassified as negative. The kappa statistic for negative, positive and suspect samples was 0.469. The kappa statistic for the analysis in which the suspect results were reclassified as negative was 0.474. In addition, 29% (33/112) CSF samples from seropositive horses were negative. Our results demonstrate that the level of agreement is only moderate in diagnostic samples. This supports the practice of testing CSF of seropositive horses suspected of having EPM.     

Full pedigree quantitative trait locus analysis in commercial pigs using variance components

In commercial livestock populations, QTL detection methods often use existing half-sib family structures and ignore additional relationships within and between families. We reanalyzed the data from a large QTL confirmation experiment with 10 pig lines and 10 chromosome regions using identity-by-descent (IBD) scores and variance component analyses. The IBD scores were obtained using a Monte Carlo Markov Chain method, as implemented in the LOKI software, and were used to model a putative QTL in a mixed animal model. The analyses revealed 61 QTL at a nominal 5% level (out of 650 tests). Twenty-seven QTL mapped to areas where QTL have been reported, and eight of these exceeded the threshold to claim confirmed linkage (P < 0.01). Forty-two of the putative QTL were detected previously using half-sib analyses, whereas 46 QTL previously identified by half-sib analyses could not be confirmed using the variance component approach. Some of the differences could be traced back to the underlying assumptions between the two methods. Using a deterministic approach to estimate IBD scores on a subset of the data gave very similar results to LOKI. We have demonstrated the feasibility of applying variance component QTL analysis to a large amount of data, equivalent to a genome scan. In many situations, the deterministic IBD approach offers a fast alternative to LOKI.     

Pharmacodynamic evaluation of a reference and a generic toltrazuril preparation in broilers experimentally infected with Eimeria tenella or E. acervulina

1. The aim of this study was to investigate the effects on pigmentation, faecal oocyst output, immune responsiveness and reactive oxygen species (ROS) generation following treatment with either the reference toltrazuril (Baycox) or a generic preparation (gen-TTZ), during an experimental Eimeria tenella (Et) or E. acervulina (Ea) infection of 210 Ross broiler chickens.

2. Results showed a significant difference on the anticoccidial efficacy 6 d after treating infected animals with Baycox (Et: 99.69% and Ea: 99.52%) or gen-TTZ (Et:85.71% and Ea 81.81%).

3. Gen-TTZ-treated animals were less strongly carotenoid-pigmented than Baycox-treated broilers. Mean plasma carotenoid concentrations were significantly higher in groups treated with Baycox than in broilers given gen-TTZ.

4. Treatment of animals with Baycox led to a significant decrease in ability of the peripheral blood mononuclear cells to produce ROS in contrast to gen-TTZ-treated groups. Baycox, but not generic toltrazuril, increased IL-10 and decreased tumour necrosis factor alpha (TNF-α) concentrations in chickens infected with E. tenella and E. acervulina.

5. It is suggested that differences in anticoccidial efficacy may be observed when using a generic toltrazuril product. Hence, in addition to plasma profiles of drugs, standardised clinical control tests may be necessary for generic formulations, particularly if other parameters are important to achieve a better control of coccidiosis.     

Admixture analysis in relation to pedigree studies of introgression in a minority British cattle breed: the Lincoln Red

Investigation of historic population processes using molecular data has been facilitated by the use of approximate Bayesian computation (ABC), which enables the consideration of multiple alternative demographic scenarios. The Lincoln Red cattle breed provides a relatively simple example of two well‐documented admixture events. Using molecular data for this breed, we found that structure did not resolve very low (<5% levels) of introgression, possibly due to sampling limitations. We evaluated the performance of two ABC approaches (2BAD and DIYABC) against those of two earlier methodologies, ADMIX and LEADMIX, by comparing their interpretations with the conclusions drawn from herdbook analysis. The ABC methods gave credible values for the proportions of the Lincoln Red genotype that are attributable to Aberdeen Angus and Limousin, although estimates of effective population size and event timing were not realistic. We suggest ABC methods are a valuable supplement to pedigree‐based studies but that the accuracy of admixture determination is likely to diminish with increasing complexity of the admixture scenario.     

N‐Terminal Pro‐C‐Natriuretic Peptide and Cytokine Kinetics in Dogs with Endotoxemia

Background

Serum N‐terminal pro‐C‐natriuretic peptide (NT‐proCNP) concentration at hospital admission has sufficient sensitivity and specificity to differentiate naturally occurring sepsis from nonseptic systemic inflammatory response syndrome (SIRS). However, little is known about serum NT‐proCNP concentrations in dogs during the course of sepsis.

Objective

To determine serum NT‐proCNP and cytokine kinetics in dogs with endotoxemia, a model of canine sepsis.

Samples

Eighty canine serum samples.

Methods

Eight healthy adult Beagles were randomized to receive Escherichia coli lipopolysaccharide (LPS, 5 μg/kg) or placebo (0.9% NaCl) as a single IV dose in a randomized crossover study. Serum collected at 0, 1, 2, 4, and 24 hours was stored at −80°C for batch analysis. Serum NT‐proCNP was measured by ELISA and 13 cytokines and chemokines by multiplex magnetic bead‐based assay.

Results

Serum NT‐proCNP concentrations did not differ significantly between LPS‐ and placebo‐treated dogs at any time. When comparing serum cytokine concentrations, LPS‐treated dogs had higher interleukin‐6 (IL‐6), IL‐10, TNF‐α and KC‐like at 1, 2, and 4 hours; higher CCL2 at 1, 2, 4, and 24 hours; and higher IL‐8 and CXCL10 at 4 hours compared to placebo‐treated dogs. There were no differences in serum GM‐CSF, IFN‐γ, IL‐2, IL‐7, IL‐15 or IL‐18 between LPS‐ and placebo‐treated dogs.

Conclusions and Clinical Importance

Serum NT‐proCNP concentration does not change significantly in response to LPS administration in healthy dogs. Certain serum cytokine and chemokine concentrations are significantly increased within 1–4 hours after LPS administration and warrant further investigation as tools for the detection and management of sepsis in dogs.     

向镰刀菌毒素污染的谷物添加葡甘露聚糖对初产母猪生产性能和血液生化指标的影响

研究表明,镰刀菌毒素会导致泌乳母猪的采食量和日增重下降,具有延长母猪从断奶至发情间隔时间的倾向;葡甘露聚糖能够防止由镰刀菌毒素毒性作用引起的血清尿素和总蛋白浓度的下降。