Survey of equine castration techniques,preferences and outcomes among Australian veterinarians

Objectives

(1) To collect the perceptions of veterinarians performing equine castrations in Australia on techniques, preferences and outcomes, (2) to investigate veterinarian use and experience with the Henderson castrating instrument and (3) to investigate potential associations between demographics, castration methods and techniques, and complications.

Design

Online survey of members of the Australian Veterinary Association’s Special Interest Group, Equine Veterinarians Australia (EVA).

Methods

A link to the survey was included in the EVA e‐newsletter and practices on the EVA website were contacted by telephone and follow‐up email. Fisher’s exact test was used to determine associations between ligation and complications. A generalised linear model with a negative binomial family was used to determine associations between count response variables and categorical independent variables.

Results

Responses were obtained from 138 veterinarians (response rate, 13.1%) who performed 5330 castrations over 12 months. Castrations were most commonly performed in the field, on anaesthetised horses, using emasculators, via an open approach and without ligation of the spermatic cord. Estimated complications after use of emasculators were swelling (25%), haemorrhage (5%) and infection (5%). The Henderson instrument was used by approximately 10% of respondents and its use for castration was associated with fewer reports of postoperative swelling compared with emasculators (P = 0.002). Rates of evisceration with the Henderson and emasculator methods were comparable (0.43% and 0.9%, respectively).

Conclusion

Castration preferences varied widely among survey participants. Reported complication types and rates were comparable to those reported previously in other countries. Perceptions that the Henderson instrument was associated with less swelling should be investigated further via a prospective controlled investigation.     

Determination of potassium guaiacolsulfonate by ion-pairing partition chromatography.

Potassium guaiacolsulfonate, a highly polar, acidic substance, is readily eluted by chloroform from a pH 4.5 Celite column in the form of its ion-pair with trihexylamine, thereby effecting facile separation from other pharmaceuticals. The sulfonic acid is then back-extracted into aqueous alkali and determined spectrophotometrically. Assay of standard solutions by this procedre averaged 100.44 plus or minus 0.81%. The method was applied successfully to 4 commercial cough preparations containing a variety of other drugs.     

Plasma lipopolysaccharide elevations in cattle associated with early-stage infection by Fasciola hepatica

Fasciolosis is an endemic zoonotic parasitic disease with significant impacts on human health and both animal health and production. Early post-infection impacts on the host remain unclear. The objective of this study was to determine the changes, if any, to levels of endotoxin in cattle plasma in response to early-stage infection with Fasciola hepatica. Thirty-six (36) commercial bred cattle were experimentally infected with approximately 400 viable metacercariae. Plasma lipopolysaccharide (endotoxin) levels were examined on 24 occasions from 0 h before infection to 336 h after infection using the Limulus Amoebocyte Lysate chromogenic end point assay and compared with that of six (6) uninfected control animals. Peak lipopolysaccharide levels in infected animals were reached at 52 h after infection and returned to pre-infection levels at time 144 h after infection. Infected animals had significantly elevated lipopolysaccharide levels between 24 and 120 h after infection when compared to uninfected animals. The mean change in endotoxin units (EU)/mL over time after infection was statistically significant in infected animals. Elevations of lipopolysaccharide occurred in all infected animals suggesting a possible repeatable and titratable endotoxemia conducive to therapeutic agent model development.     

“Indirect selection” for genetic change: A quantitative analysis illustrated with Macrobrachium rosenbergii

“Indirect selection” is exerted on a trait indirectly, by means other than artificial selection for the trait itself. Expressions are derived for calculating the intensity of indirect selection in aquaculture environments. The calculations are illustrated with growth-rate data on M. rosenbergii from farm ponds in Thailand, and with computer-generated data which simulate measurements made during a multiple mark-recapture experiment. Indirect selection for growth is probably negligible in Thai prawn farms and hatcheries at present, but small changes in management practice could exert strong indirect selection on growth rate. One very effective change appears to be collecting broodstock as early in the production cycle as possible. Control of indirect selection may be useful for the genetic improvement of aquaculture stock, especially in developing countries and other situations where an intensive artificial selection program is not economically or biologically desirable. Like all selection programs, the probability of success is critically dependent on the genetics of the traits being selected.     

Stifle joint luxation in the dog and cat: the use of temporary intraoperative transarticular pinning to facilitate joint reconstruction.

Multiple ligament injuries of the canine and feline stifle joint which result in luxation are uncommon. Two cats and one dog, that had sustained such a joint injury were surgically treated. A rupture of the cranial and caudal cruciate ligaments, and at least one collateral ligament was observed in all of the three animals. Prosthetic reconstruction was used, as previously described, in combination with a novel technique of intraoperative placement of a temporary trans-articular pin (TTP) to maintain intra-operative anatomical reduction. TTP placement facilitated maintenance of joint alignment during surgical reconstruction and aided appropriate tensioning of the prosthetic sutures, preventing collapse of femorotibial joint compartments. The TTP was removed prior to closure of the joint allowing immediate post-operative joint mobilisation. Based on assessment by their owners, all the animals made a complete recovery. TTP was considered a relatively simple and effective adjunctive aid for surgical treatment of traumatic luxation of the stifle joint.     

Low-voltage organic transistors on plastic comprising high-dielectric constant gate insulators

The gate bias dependence of the field-effect mobility in pentacene-based insulated gate field-effect transistors (IGFETs) was interpreted on the basis of the interaction of charge carriers with localized trap levels in the band gap. This understanding was used to design and fabricate IGFETs with mobility of more than 0.3 square centimeter per volt per second and current modulation of 10(5), with the use of amorphous metal oxide gate insulators. These values were obtained at operating voltage ranges as low as 5 volts, which are much smaller than previously reported results. An all-room-temperature fabrication process sequence was used, which enabled the demonstration of high-performance organic IGFETs on transparent plastic substrates, at low operating voltages for organic devices.