Disease of geese caused by a new herpesvirus

A goose flock farmed outdoors in south-eastern Queensland suffered an outbreak of peracute disease with high death rate (97%). Small button ulcers and large plaques overlying lymphocyte aggregates were present on the mucosa of the small intestine of affected birds. Small white foci of necrosis and focal haemorrhages were seen in the livers. Numerous intranuclear inclusion bodies were observed microscopically in hepatocytes and a herpesvirus which grew rapidly in chicken kidney cells was isolated from tissues. Duck virus enteritis (DVE) was suspected but DVE antiserums failed to neutralise the virus. Further serological studies with a limited range of known avian herpesviruses have failed to identify the virus. Experimental transmission resulted in high mortality in geese (100%), lower mortality in ducklings and nil mortality in chickens. Surveillance studies showed no evidence of infection in domestic and wild birds beyond the original farm and the infection appears not to have been established in the area. Wild ducks, which were frequent visitors to the farm dam, were considered the most likely source of the infection.     

Blood supply of the ovine adrenal gland and its relevance in adrenal autotransplantation

SUMMARY The arterial supply and venous drainage of 62 left and 5 right ovine adrenal glands is described, and the contribution of individual arteries to successful adrenal gland autotransplantation was evaluated. Arterial flow was measured by direct collection from the draining adrenal vein. Assessment of function of the transplanted adrenal gland was made from survival of the sheep and by the cortisol response to infusion of ACTH and the aldosterone secretory response to infusion of angiotensin II or potassium. For the left adrenal, the principal arterial supply was from the renal artery in 21 (34%), a lumbar artery in 32 (52%), and the anterior mesenteric artery in 3. The total blood flow was 5.0 ± SEM 0.4 mL/min, the flow from the renal branch 2.3 ± 0.3 mL/min, and the principal lumbar branch 2.6 ± 0.3 mL/min. Venous drainage from the left adrenal was via a major adrenal vein to the left renal vein, but additional tributaries to the renal vein were present in 26% . The arterial supply to the adrenal is regional and omission of a branch at transplantation could result in infarction of portion of the gland. By defining arterial supply and measuring blood flow, selection of the appropriate artery or multiple arteries can achieve an adrenal gland autotransplant survival of 90% .     

Evaluation of shock waveform configuration on the defibrillation capacity of implantable cardioverter defibrillators in dogs

BackgroundImplantable cardioverter defibrillators (ICD) are programmed to detect ventricular arrhythmias and terminate them by delivering an electrical shock. A defibrillation threshold (DFT) at least 10 J below the maximum device output is recommended for successful therapy. Shock waveform configuration is a programmable parameter used to achieve a low DFT. It is hypothesized that a fixed-pulse configuration results in lower defibrillation energy requirements than a fixed-tilt configuration.Animals10 mongrel dogs.Materials and methodsICD generator and transvenous lead were surgically implanted. Defibrillation threshold was determined using a protocol guided by the upper limit of vulnerability. Fixed-pulse and fixed-tilt (50%/50%) waveform configurations were tested in a random order. Plasma cardiac troponin I (cTnI) was measured for signs of myocardial injury.ResultsThe experiment was completed in 9 dogs. Overall mean DFT value was 424 ± 88 V (9.2 ± 3.9 J). Mean differences among voltage, energy and impedance at the DFT for fixed-pulse (422 ± 97 V, 9.1 ± 4.2 J, 62.6 ± 13.8 Ω) and fixed-tilt (426 ± 83 V, 9.3 ± 3.8 J, 62.8 ± 18.5 Ω) configurations were not statistically significant (All P > 0.21). Cardiac TnI concentration changed from 0.03 ng/mL (95% CI: 0.02–0.04) at baseline to 0.11 ng/mL (95 CI: 0.08–0.16) after DFT was obtained with the first waveform configuration and 0.19 ng/mL (95% CI: 0.13–0.28) at the end of the study period. There were no significant changes in heart rate, end-tidal CO2 and blood pressure over time (all P > 0.09).ConclusionThe tested ICD device and lead placement reliably produced acceptable DFT values, based on a 10-J safety margin below the maximum device output. A benefit of fixed-pulse configuration could not be demonstrated over the standard fixed-tilt waveform. Signs of acute myocardial damage from repeated high-voltage shocks and episodes of ventricular fibrillation seemed of limited clinical significance.     

ULTRASONOGRAPHIC CHARACTERISTICS OF THE CISTERNA CHYLI IN EIGHT DOGS AND FOUR CATS

Ultrasonography of the cisterna chyli has been used in humans to diagnose increased lymphatic flow or lymph flow obstruction and to guide percutaneous embolization of the thoracic duct via the cisterna chyli. The aim of this study was to describe the ultrasonographic characteristics of the dorsal portion of cisterna chyli in dogs and cats with chylous ascites or chylothorax and in a group of healthy dogs and cats. The aorta and the cranial mesenteric artery were used as anatomic landmarks. Ultrasonography was performed before and 2 h after a fatty meal in healthy dogs and cats. The visualized structure was confirmed to be a dilated cisterna chyli at necropsy in a dog with chylous ascites. The confirmed or presumed cisterna chyli was consistently detected using ultrasonography in nonfasted healthy animals and clinically affected animals and appeared as an anechoic tubular structure, without detectable flow, at the right dorsolateral aspect of the aorta. It had a similar ultrasonographic appearance in patients with chyloabdomen and in nonfasted healthy dogs and cats. There was considerable overlap in diameters of the cisterna chyli for affected and healthy animals. The shape and size of the cisterna chyli in an individual animal were variable during the same ultrasound examination and between different examinations. This study demonstrated the appearance of the presumed dorsal portion of the cisterna chyli by ultrasonography and might provide useful preliminary data for further studies into the feasibility of ultrasound‐guided injections or aspirations of the cisterna chyli in dogs and cats.     

Plant and spider communities benefit differently from the presence of planted hedgerows in highway verges

Road verges should play a crucial role as a refuge for native flora and fauna in human dominated landscapes. However, the influence of construction choices, such as plantation of woody species, on the biodiversity supported by roadsides has received little attention, although the presence of hedgerows in roadsides is likely to enhance their role as a refuge, notably for woodland species. Using standardised methods, we assessed the impact of planted hedgerows on two taxonomic groups (plants and spiders) inhabiting highway verges within an intensive agricultural landscape. We examined community richness, taxonomic and functional composition in sites with and without planted hedgerows. At the site level, the response of plant and spider communities to the presence of planted hedgerows differed markedly: hedgerows were associated with significantly higher plant richness (higher α-diversity), but similar spider richness. Plant communities in sites without hedgerows appeared as a subset of communities in sites with hedgerows, whereas spider communities in non-planted sites were complementary to that of planted sites (increased β-diversity). The presence of planted hedgerows was also associated with increased taxonomic and functional trait diversity at the landscape level (γ-diversity), through an increased β-diversity in both plants and spiders. Our results thus suggest that a mosaic of planted hedgerows and grassland habitats is crucial for the maintenance of biodiversity at a landscape scale. By providing information for road practitioners and policy makers regarding their potential impact on biodiversity, these results have important direct implications for the management of road networks.     

Protection, systemic IFNgamma, and antibody responses induced by an ISCOM-based vaccine against a recent equine influenza virus in its natural host

In the horse, conventional inactivated or subunit vaccines against equine influenza virus (EIV) induce a short-lived antibody-based immunity to infection. Alternative strategies of vaccination have been subsequently developed to mimic the long-term protection induced by natural infection with the virus. One of these approaches is the use of immune-stimulating complex (ISCOM)-based vaccines. ISCOM vaccines induce a strong antibody response and protection against influenza in horses, humans, and a mouse model. Cell-mediated immunity (CMI) has been demonstrated in humans and mice after ISCOM vaccination, but rarely investigated in the horse. The aim of this study was to evaluate EIV-specific immune responses after intra-muscular vaccination with an ISCOM-EIV vaccine (EQUIP F) containing both equine influenza H7N7 (A/eq/Newmarket/77) and H3N8 (A/eq/Borl?nge/91 and A/eq/Kentucky/98) strains. The antibody response was measured by single radial haemolysis (SRH) assay using different H3N8 EIV strains. Stimulation of type-1 immunity was evaluated with a recently developed method that measures EIV-specific IFNgamma synthesis by peripheral blood lymphocytes (PBL). The protective efficacy of this ISCOM-based vaccine against challenge infection with a recent equine influenza (H3N8; A/eq/South Africa/4/03) strain was also evaluated. Vaccinated ponies developed elevated levels of EIV-specific SRH antibody and increased percentage of EIV-specific IFNgamma(+) PBL, whereas these responses were only detected after challenge infection in unvaccinated control ponies. Vaccinates showed minimal signs of disease and did not shed virus when challenged shortly after the second immunisation. In conclusion, evidence of type-1 immunity induced by an ISCOM-based vaccine is described for the first time in horses.