Initial evaluation of a canine stifle arthrotomy post-operative pain model.

Most models of acute post-operative orthopedic pain involve the injection of a clinically irrelevant pro-inflammatory agent. The ideal model should, however, be clinically relevant and allow full functional recovery of enrolled animals after research is completed. This study explored the validity of a model employing arthrotomy and objectively measured limb use. Six purpose-bred Beagles underwent arthrotomies on each stifle with a washout period in between. Using a randomized crossover design, each dog received placebo and an extended-release buprenorphine (ER-Bup) preparation. Static and dynamic ground reaction forces (GRFs) were measured prior to and for 72 h following surgery using a pressure sensitive walkway (PSW). GRFs for each hind limb were compared using difference (delta), and symmetry indices (SI). The effects of surgery and of treatment were analyzed using repeated measures ANCOVA. The results indicated significantly decreased limb use compared to baseline for placebo, and significantly increased limb use in the ER-Bup group over placebo at all times for % bodyweight distribution (%BWdistrib), peak vertical force (PVF) and vertical impulse (VI). There was a significant treatment by time interaction for velocity (P = 0.03) and %BWdistrib (P = 0.01, 0.003). Overall, the data show that reduced limb use was present for at least 72 h following arthrotomy. In addition, the use of the ER-Bup analgesic decreased lameness, confirming the validity of this approach as a model of post-operative pain. Subjective assessments did not detect the pain-inducing effects of arthrotomy or pain-alleviating effects of treatment, and subjective measures of procedural pain in research dogs need to be developed.

Molecular phylogeny of isolates of Ctenocephalides felis and related species based on analysis of ITS1, ITS2 and mitochondrial 16S rDNA sequences and random binding primers.

The phylogenetic relationships among 31 different flea isolates representing seven different species were studied by nucleotide sequence comparison of the internal transcribed spacer 1 (ITS1), internal transcribed spacer 2 (ITS2) and/or mitochondrial 16S ribosomal RNA gene (mt16S-rDNA) to examine the patterns of variation. Results show that all regions are useful in discriminating among flea species. In Ctenocephalides felis and Tunga penetrans, some differences in these gene regions occurred among different isolates within the same species. In the latter case, the differences are in the mt16S-rDNA region, with one isolate showing 48% divergence in nucleotide sequence. The taxonomic implications of this result are unclear at present. The gene regions revealed differences between C. felis isolates only after DNA sequencing the PCR products. Further differentiation among C. felis isolates was obtained using four different random binding primers (decamers) and primers for mammalian aldolase to amplify narrow differences in the genome. Using these primers we were able to discriminate between different C. felis isolates and determine that some of the genetic variation coincided with minor differences in response to the control agent imidacloprid. However, overall findings do not support the existence of subspecies of C. felis.

Development of a larval bioassay for susceptibility of cat fleas (Siphonaptera: Pulicidae) to imidacloprid.

Strategies for controlling cat fleas, Ctenocephalidesfelisfelis (Bouché), have undergone dramatic changes in the past 5 yr. With the advent of on-animal treatments with residual activity the potential for the development of insecticide resistance increases. A larval bioassay was developed to determine the baseline susceptibility of field-collected strains of cat fleas to imidacloprid. All four laboratory strains tested showed a similar level of susceptibility to imidacloprid. Advantages of this bioassay are that smaller numbers of fleas are required because flea eggs are collected for the test. Insect growth regulators and other novel insecticides can also be evaluated. Using a discriminating dose, the detection of reduced susceptibility in field strains can be determined with as few as 40 eggs.

Comparative evaluation of the speed of flea kill of imidacloprid and selamectin on dogs.

Imidacloprid (Advantage, Bayer Corporation, Shawnee Mission, KS) and selamectin (Revolution [United States], Pfizer Animal Health, Exton, PA 19341; Stronghold [European Union], Pfizer Animal Health Ltd, Sandwich, Kent CT 13 9NJ, UK) were tested to assess the speed of flea kill achieved against existing flea infestations and subsequent reinfestations. Thirty-six dogs were infested with 100 unfed adult fleas on day-1. On day 0, 12 dogs (group 1) were treated with imidacloprid at the minimum label dose of 10 mg/kg body weight. Twelve dogs (group 2) were treated with selamectin at the minimum label dose of 6 mg/kg body weight. Twelve dogs (group 3) remained as untreated controls. Four sub-groups (A through D) of three dogs each were designated within each group. All dogs were subsequently reinfested with fleas on days 6, 13, 20, 27, 34, and 41. Live flea counts were performed for subgroups A through D at 6, 12, 24, and 36 hours after treatment/reinfestation. Imidacloprid provided significantly and consistently greater flea kill than selamectin at 6, 12, and 24 hours after treatment and at 6 and 12 hours after each reinfestation. Although both products are commercially labeled for monthly topical use, imidacloprid provided significantly greater 36-hour flea kill at 34 and 41 days after treatment.

Tying physician incentive pay to performance.

Physician compensation costs in healthcare organizations continue to increase as organizations hire physician employees or acquire them through mergers with group practices and pay them salaries plus substantial benefits. In an effort to obtain the greatest possible return on their investments in physician employees, many healthcare organizations are linking physician pay and benefits to improved performance, according to two recent benefit and compensation surveys.