Economic effect of pneumonia and pleurisy in lambs in New Zealand

AIM: To estimate the cost of pneumonia and pleurisy in lambs to the sheep industry in New Zealand, in order to provide a reference for future cost-benefit calculations for control programmes to reduce the incidence of pneumonia. METHODS: An estimate of the economic cost of pneumonia and pleurisy in lambs was based on: cohort studies of the association between growth rate and the extent of pneumonic lesions at slaughter (n=14 flocks), the prevalence of moderate to severe (MS) pneumonia (> or =10% lung surface area affected) and pleurisy (n=1,719 flocks), the correlation between the prevalence of MS pneumonia and economic loss at the flock level, and data on annual slaughter statistics and carcass value in New Zealand. A stochastic spreadsheet model was developed and run with 1,000 iterations. Input variables represented by probability distributions were growth rate, average cost of loss according to the prevalence of pneumonia per month, carcass value, prevalence of pleurisy, and carcasses downgraded for pleurisy, and annual national slaughter statistics. The output was a posterior distribution of the annual cost of disease. RESULTS: The cost of pneumonia only included the loss associated with reduced growth rate, while mortality due to pneumonia was assumed to be low and was ignored. The cost of pleurisy included the loss associated with downgraded or condemned carcasses. Thus, the simulated annual average cost of pneumonia was NZ$28.1 (95% CI=NZ$15.0-42.0) million, and that of pleurisy NZ$25.1 (95% CI=NZ$10.2-48.1) million. The combined cost of pneumonia and pleurisy averaged NZ$53.2 (95% CI=NZ$32.4-78.9) million. The parameters with the greatest impact on the combined cost of pneumonia and pleurisy were prevalence of pleurisy between March and May, and cost of reduced growth due to pneumonia for lambs slaughtered in June. CONCLUSIONS: The average cost of pneumonia and pleurisy to the sheep industry in New Zealand due to reduced lamb growth and decreased carcass value is likely to be between NZ$32.4 and $78.9 million. This is a conservative estimate, omitting mortalities, indicating that pneumonia and pleurisy have substantial economic impact on sheep farming in New Zealand. Considering that 23,833,000 lambs were slaughtered in 2003/2004 (average value $65.56/lamb), this cost would equate to NZ$1.36-3.31 per lamb. CLINICAL RELEVANCE: Pneumonia and pleurisy are common diseases in lambs in New Zealand, leading to substantial economic loss to producers.     

Antimicrobial resistance in Salmonella enterica subspecies enterica serovar Dublin from dairy source calves in the central San Joaquin Valley, California (1998-2002)

The present study describes antimicrobial resistance patterns of Salmonella enterica subspecies enterica serovar Dublin (S. Dublin) in clinical submissions from calves and temporal and farm-type trends in antimicrobial resistance patterns of the isolates. A total of 300 isolates of S. Dublin were obtained from fecal or internal organs of calves fewer than 120 days of age originating from 84 dairies and 18 calf ranches from July 1998 to December 2002. The isolates were susceptibility tested to a panel of 10 antimicrobials using the disk diffusion assay. Temporal and farm-type trends in individual antimicrobial inhibition zone sizes were assessed and antimicrobial resistance patterns were described using cluster analysis. Isolates obtained from calf ranches compared with dairies exhibited decreased susceptibility to florfenicol, gentamicin, neomycin, sulfisoxazole, sulfamethoxazole/trimethoprim, and tetracycline. During the years 1998-2002, decreasing susceptibility was seen for ceftiofur, enrofloxacin, and sulfamethoxazole/trimethoprim. There were 20 different antimicrobial resistance patterns in the isolate set, indicating that S. Dublin has the ability to transfer and pick up resistance genes with relative ease. The trends seen in antimicrobial resistance in S. Dublin may likely be linked to antimicrobial drug use in young calves.     

Pelvic lymphoma as a cause of urethral compression in a mare

A 6-year-old mare was presented for evaluation of dysuria and pollakiuria. A pelvic mass, which caused obstruction of urinary outflow, was identified. Evidence of renal failure was also present. Due to poor prognosis the mare was euthanized. A postmortem examination revealed a pelvic lymphoma that surrounded and compressed the urethra.     

Inductive expression of the NOD1 signalling pathway in chickens infected with Salmonella pullorum

1. The aim of this study was to describe the role of Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) receptor signalling in chicken.

2. Tissue-specific expression analysis of NOD1, receptor-interacting serine-threonine kinase 2 (RIPK2), nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase 11 (MAPK11 or p38) by quantitative real-time PCR (qRT-PCR) revealed their wide distribution in various organs and tissues.

3. Salmonella pullorum infection activated NOD1 receptor signalling in vivo and in vitro, resulting in significant induction of downstream signalling molecules RIPK2, NF-κB/p65, MAPK11/p38 and the effector molecules IL-1b and IL-8.

4. Activation of NOD1 by its agonist bacterial γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP) in HD11 cells induced the adapter molecular RIPK2 and activated the NF-κB/p65 and MAPK11/p38 pathways, resulting in an increase in IL-8 but not IL-1β. Additionally, inhibition of NOD1 using NOD1-shRNA resulted in downregulation of RIPK2, MAPK11 and IL-8, while NF-κB/p65 and IL-1β were unaltered.

5. These results highlight the important role of NOD1 receptors in eliciting the innate immune response following pathogenic invasion in chicken.     

Effect of body weight on the pharmacokinetics of flunixin meglumine in miniature horses and quarter horses

In most species, large variations in body size necessitate dose adjustments based on an allometric function of body weight. Despite the substantial disparity in body size between miniature horses and light‐breed horses, there are no studies investigating appropriate dosing of any veterinary drug in miniature horses. The purpose of this study was to determine whether miniature horses should receive a different dosage of flunixin meglumine than that used typically in light‐breed horses. A standard dose of flunixin meglumine was administered intravenously to eight horses of each breed, and three‐compartmental analysis was used to compare pharmacokinetic parameters between breed groups. The total body clearance of flunixin was 0.97 ± 0.30 mL/min/kg in miniature horses and 1.04 ± 0.27 mL/min/kg in quarter horses. There were no significant differences between miniature horses and quarter horses in total body clearance, the terminal elimination rate, area under the plasma concentration versus time curve, apparent volume of distribution at steady‐state or the volume of the central compartment for flunixin (P > 0.05). Therefore, flunixin meglumine may be administered to miniature horses at the same dosage as is used in light‐breed horses.