A simple method for the preparation of inflated air-dried Lung specimens

A simple method for the preparation of air-dried lung specimens is described. These specimens have proven valuable as teaching tools in anatomy, radiology, pathology, medicine, and surgery. Specimens have been made from the lungs of the cat, dog, pig, and horse.     

A double-blind,randomized, placebo-controlled study of pimobendan in dogs with dilated cardiomyopathy

A double-blind, randomized, placebo-controlled study was conducted to examine the effect on heart failure class and survival of pimobendan, an oral calcium-sensitizing inodilator, in dogs with dilated cardiomyopathy (DCM). Pimobendan (0.3-0.6 mg/kg body weight/d) or placebo was administered to English Cocker Spaniels (CSs; n = 10) and Doberman Pinschers (DPs: n = 10) that had DCM in addition to background therapy of furosemide, enalapril, and digoxin. Addition of pimobendan to standard triple therapy was associated with a significant improvement in heart failure class, regardless of breed (P < .02, Mann-Whitney rank sum test). Overall, 8 of 10 animals in the pimobendan-treated group, and 1 of 10 animals in the placebo group improved their heart failure status by at least I modified New York Heart Association functional class after initial stabilization (P = .005, Fisher's exact test). Pimobendan had no significant effect on survival in the CSs (P = 0.77, log-rank test), but DPs treated with pimobendan had significantly longer survival times compared with placebo (P < .02, log-rank test), with a median survival time of 329 days in the pimobendan group compared with 50 days in the placebo group, and a hazard ratio of 3.4 (95% confidence interval 1.4-39.8). Pimobendan resulted in significant improvement in heart failure class when added to standard therapy in this group of dogs with DCM, and may have contributed to improved survival in DPs.     

An outbreak of sheep-associated malignant catarrhal fever in bison (Bison bison) after exposure to sheep at a public auction sale.

An outbreak of malignant catarrhal fever (MCF) among bison sold at an auction market was studied for an 18-month period. Forty-five of 163 bison submitted for sale from 8 different bison farms died on 7 other destination farms. The outbreak began on day 50 after the sale, peaked between days 60 and 70, and ended on day 220. Twenty-one dead bison were confirmed to be MCF cases by clinical histories, pathology, and detection of ovine herpesvirus-2 DNA in their tissues with polymerase chain reaction assays. Twenty-four dead bison were classified as suspect MCF cases from clinical histories. No cases of MCF were observed among bison remaining on originating farms or resident bison mixed with sale bison on destination farms. There were no sheep reported within 3 km of originating or destination farms, limiting bison exposure to sheep to the auction facility, where sheep were present for less than 1 day. The outbreak provides an illustration of the temporal distribution of MCF mortality expected in bison and an estimate of the time from exposure until death from MCF after a single short exposure to sheep. The study provides evidence that bison with MCF do not transmit MCF to other bison.     

Farm-level risk factors for the presence of Salmonella in 89 Alberta swine-finishing barns

This study investigated potential risk factors for the presence of Salmonella on 89 Alberta swine-finishing farms with the use of a questionnaire. Salmonella status was regressed on each fixed effect in a logistic mixed regression model, with farm as the random effect. Eleven variables were significant at the 10% level: farm type, number of square feet per pen, number of pigs per pen, source of feed, ration type, dust control measures, cat presence, reported effective mouse-control measures, time required to be away from pigs before visiting the farm, precautions taken when entering or leaving the farm, and reported use of antimicrobials through water. Three factors remained significant at the 5% level in the multivariable analysis: farm type, ration type, and precautions taken when entering or leaving the farm. Finishing barns at multisite operations or individual grow-to-finish farms had a greater risk of the presence of Salmonella at a single visit than did finishing barns at farrow-to-finish farms. The use of pelleted and wet feed was associated with higher odds of the presence of Salmonella than was the use of meal feed. Farms that required their personnel or visitors to shower before entering and before leaving had increased odds of the presence of Salmonella compared with farms that provided boots and coveralls; no significant difference was observed between the latter category and farms that used boot disinfection. Further work is necessary to better understand the effectiveness of all-in/all-out pig management and disinfection practices in reducing the presence of Salmonella in swine and to evaluate the association with certain types of feed.     

Cleaner fishes and shrimp diversity and a re‐evaluation of cleaning symbioses

Cleaning symbiosis has been documented extensively in the marine environment over the past 50 years. We estimate global cleaner diversity comprises 208 fish species from 106 genera representing 36 families and 51 shrimp species from 11 genera representing six families. Cleaning symbiosis as originally defined is amended to highlight communication between client and cleaner as the catalyst for cooperation and to separate cleaning symbiosis from incidental cleaning, which is a separate mutualism preceded by no communication. Moreover, we propose the term ‘dedicated’ to replace ‘obligate’ to describe a committed cleaning lifestyle. Marine cleaner fishes have dominated the cleaning symbiosis literature, with comparatively little focus given to shrimp. The engagement of shrimp in cleaning activities has been considered contentious because there is little empirical evidence. Plasticity exists in the use of ‘cleaner shrimp’ in the current literature, with the potential to cause significant confusion. Indeed, this term has been used incorrectly for the shrimp Infraorder Stenopodidea, involving three families, Stenopodidae, Palaemonidae and Hippolytidae, and to represent all members of Lysmata and Stenopus. Caution is expressed in the use of grey literature and anecdotal observations to generate data on cleaning interactions, due to the presence of species complexes. Interest in cleaning organisms as biological controls in aquaculture is increasing due to their value as an alternative to various chemical ectoparasite controls. Reports of the importance of cleaner organisms in maintaining a healthy reef ecosystem has also been increasing and we review the current biological knowledge on cleaner organisms, highlighting areas that are understudied.     

Drones detect illegal and derelict crab traps in a shallow water estuary

The issues surrounding illegal, unregulated and unreported fishing, and that of abandoned, lost and discarded fishing gears, leading to ghost fishing, are intensifying. Estuarine crab trapping is likely subject to high levels of illegal and potential ghost fishing, because it also has good economic incentives regarding potential catch, low gear acquisition costs and accessible fishing grounds. To improve the efficiency and effectiveness of fisheries monitoring, control and surveillance operations, the efficacy of small consumer‐grade drones for sighting traps in an estuary in NSW, Australia, was tested. Twelve sets of two flights were undertaken at 20 and 30 m altitude over a 600‐m stretch of estuary for 5 days to quantify the detectability of submerged mesh traps of three different mesh colours. The drone was able to detect the majority of traps efficiently, with depth in relation to water clarity being the main factor affecting detection. In shallow water, detection rates were high for all mesh colours, but in the slightly deeper placements, orange traps were more readily detected. This study demonstrates that drones could be an efficient and reliable tool for rapidly assessing areas for illegal and derelict traps and can be supplemented into land or vessel‐based fisheries operations.     

Genetically-informed population models improve climate change vulnerability assessments

Landscape Ecology - Climate change will cause species extinctions that will be exacerbated by human-caused landscape changes, preventing species from tracking shifting climatic niches. Although...     

Distinct habitat selection by freshwater morays in tropical rainforest streams

Morays occupy unique interstitial habitats and function as key predators in marine ecosystems. Conversely, there is limited understanding of the ecology of Gymnothorax polyuranodon, the lone representative of the family Muraenidae known to reside in freshwater systems. In this study, we used field‐based encounters over a 3‐year period in three short–steep–coastal–streams of the Australian Wet Tropics to find that most G. polyuranodon individuals (74%) occupied pools, with very few individuals observed in run (23%) or riffle (3%) mesohabitats. Moreover, G. polyuranodon positively selected microhabitats of slow flow (<0.05 ms^?1) and deep water (>80 cm), while avoiding high flows (>0.5 ms^?1) and shallow water (<40 cm depth). Morays exhibited strong preferences for boulders (73% of the immediate stream bed area occupied relative to 36% availability) with most individuals resting directly underneath large or very large boulders. Collecting and compiling records of this rare and elusive species over the long‐term helped to reveal such habitat specialisation. Future management plans for G. polyuranodon should focus on preserving boulder interstices year‐round and maintaining stream‐sea connectivity to facilitate a diadromous life cycle.     

Decline of an isolated timber rattlesnake (Crotalus horridus) population: Interactions between climate change, disease, and loss of genetic diversity

Extinction of populations from anthropogenic forces rarely has a single cause. Instead, population declines result from a variety of factors, including habitat loss, inbreeding depression, disease, and climate change. These impacts often have synergistic effects that can lead to rapid decline in isolated populations, but case studies documenting such processes are rare. Here, we describe the recent decline of the last known population of timber rattlesnakes (Crotalus horridus) in the state of New Hampshire. We used polymorphic nuclear DNA markers to compare genetic diversity of this population to other populations in the region that are not isolated. We also compare results from ongoing field monitoring of these populations. Genetic analyses reveal that the New Hampshire population lacks genetic diversity and exhibits signs of a recent bottleneck. New Hampshire snakes also exhibited high levels of morphological abnormalities (unique piebald coloration, amelanistic tongues) indicative of inbreeding depression. Furthermore, after a year with exceptionally high summer rainfall, a skin infection of unknown etiology caused significant mortality in the New Hampshire population, whereas other surveyed non-inbred populations were unaffected. This case study demonstrates how different anthropogenic impacts on natural environments can interact in unexpected ways to drive threatened populations toward extinction.