Adult E. alarioides collected from the intestine of North American river otter (100X magnification)
The North American river otter (Lontra canadensis) is a fur bearing mammal of economic value. Historically they were distributed throughout Canada and United States but their present range is fragmented due to pollution and urbanization. Reintroduction efforts have greatly expanded the distribution of this mammal in the United States and Canada. In spite of these efforts, the North American river otter is considered vulnerable across much of its range. Therefore, it is important to study the diseases and the disease causing agents that this animal is susceptible to. Nonetheless, there have been relatively few studies on parasitic fauna of river otters.
Baptiste Froidefond, an intern from École Nationale Vétérinaire, Toulouse, France in Alberta-CWHC lab working on molecular diagnosis of E. alarioides.
As part of a 6 week wildlife parasitology internship at the Alberta-CWHC, Baptiste Froidefond, a second year DVM student from École Nationale Vétérinaire, Toulouse, France investigated gastro-intestinal parasites of North American river otters (supervised by Dr. Mani Lejeune). Baptiste found the tiny trematode parasite, Enhydridiplostomum alarioides in some of the otters. This parasite belongs to the subfamily: Diplostomatinae (Parasites of birds). The members of this subfamily generally use birds as definitive hosts and aquatic snails as intermediate hosts. The parasitic stages (cercaria) released from the snails encyst (metacercaria) on the eyes of surface and bottom dwelling fresh water fishes and can cause blindness. The life cycle is completed when the definitive hosts feed on the infected, blinded fish.
The specific life cycle for E. alarioides is unknown; however, it is possible that it is transmitted to river otters through burbot or other food fish. A previous Healthy Wildlife blog post reported that 35% of burbot had cataracts associated with parasitic stages (metacercaria) belonging to genus Diplostomum. However it should be noted that parasite species confirmation based only on morphology of metacercaria is difficult and one has to resort to molecular methods for accurate identification. Moreover, burbot are bottom dwellers, and the likelihood of them being fed on by birds is low. These fish are therefore considered to be ‘ecological sinks’ for the parasites if they require bird hosts. Given that E.alarioides appears to be fairly common in river otters, and that burbot are a preferred food source, further DNA-based studies are needed to determine if E.alarioides has a life cycle that includes the predator-prey association between river otter and burbot.
Acknowledgement: Fur Institute of Canada, Vegreville, Alberta for allowing secondary use of tissues collected on necropsy of North American river otter trap assessment project
On September 3, 2014, the Ontario Ministry of Natural Resources and Forestry announced that they are opening five new provincial parks:
Carden Alvar, located near Orillia
Cedar Creek, near Essex
Clear Creek Forest, near Chatham-Kent
Queen Elizabeth The Queen Mother Mnidoo Mnising, located on Manitoulin Island
Strawberry Island, near Manitoulin Island
While each of these new parks will be significant, the Carden Alvar is of special interest to the CWHC. The Carden Alvar provides a unique and vital habitat for the endangered Eastern Loggerhead Shrike. Over the past several years, the CWHC has been assisting Wildlife Preservation Canada and their associated agencies with their Eastern Loggerhead Shrike captive breeding program.
In addition to the new parks, the ministry will also be expanding existing parks:
Dr. Malcolm McAdie has been a key part of the recovery program for the Vancouver Island marmot (Marmota vancouverensis). This video gives us a quick update on what he saw in the field this year in the population of animals that have been re-established in the wild. Malcolm talks about the marmot population declining this year after several years of population increases; likely as a result of drought and predation.
Craig Stephen, executive director of the Canadian Wildlife Health Cooperative, and Zee Leung of the International Development Research Centre recently co-authored an op-ed in response to the current Ebola outbreak. The article argues for investment directed at the basic drivers of emergence and resilience as a way to prepare for the inevitable emergence of a new disease problem.
“To protect ourselves against the next outbreak looming on the horizon, not only do we need emergency responses that work closely with communities, we also need to invest in healthy ecosystems and strong communities: clean and safe environments; nutritious and accessible sources of food; health education; basic sanitation; effective healthcare systems; and strong infection control.”
Quebec is conducting an active surveillance program for rabies, particularly the raccoon strain that is present across the border in the United States. Here is an update on this program as of August 22, 2014. The map shows the locations where animals tested for rabies were found as well as cases in the USA up to July 21, 2014. As you will see in the chart, the collection of specimens for testing in 2014 so far has been very similar to 2013.
No cases of raccoon rabies have been detected in Quebec since 2009.
Locations of animals collected for surveillance of raccoon rabies in Quebec and across the border in the United States in 2014. Animals that tested negative are shown in green; results pending are shown in yellow; animals not tested are shown in blue.
Number of citizen reports and animals collected for surveillance of raccoon rabies – comparison by week for 2013 and 2014
Last week, an episode of CBC Radio’s “The Current” featured the issue of urban wildlife. This topic is full of controversy, as many people enjoy living closely with wildlife, while others complain of animals destroying their gardens and shrubs and becoming too bold and aggressive in their expectation for food.
Regardless of which stance they choose to take on the issue, homeowners should consider the possible consequences before feeding wildlife in their backyards. Feeding wildlife can have unintended effects such as increased disease spread within animal populations, and individuals becoming overly habituated to the presence of humans. In some cases, there are also risks of disease spread from wild populations to humans or domestic animals.
The radio show asked listeners to call in with their stories of living with urban wildlife, and also featured a debate on the issue of whether or not to carry out a planned deer cull in an area where urban deer have become a problem.
In celebration of World Elephant Day (August 12, 2014), we’re sharing our collection of elephant photos taken during former CWHC director, Ted Leighton’s travels to Sri Lanka as part of a partnership between the CWHC and the Sri Lanka Wildlife Health Centre (SLWHC). The SLWHC was developed in 2011 in a plan to improve Sri Lanka’s capacity for wildlife health management. The partnership between SLWHC and CWHC was officially renewed in March, 2013. The two organizations collaborate in research and training with the goal of developing a national program for wildlife health in Sri Lanka and providing people with the training to operate the program.
Some of these photos were taken at the Elephant Transit Home at Udawalawe National Park, where orphaned elephants are raised, trained and re-introduced to the wild, and the Elephant Orphanage at Pinnawala where many elephants reside after being salvaged from injuries in the wild.
See more photos and read about the collaboration here:
CWHC director, Craig Stephen, interviewed graduate students Diana Sinclair (University of Guelph) and María Fernanda Mejía-Salazar (University of Saskatchewan) at the 2014 Wildlife Disease Association (WDA) meeting in Albuquerque, New Mexico.
An article in WCVM Today – the newsletter of the Western College of Veterinary Medicine, University of Saskatchewan, talks about Craig Stephen, the new executive director of the Canadian Wildlife Health Cooperative (CWHC), and his commitment to wildlife health.
On July 3, 2014, a dead, 17 m, juvenile fin whale drifted from the west side onto the Canso Causeway, between Cape Breton Island and mainland Nova Scotia. The causeway’s gates were opened to allow the whale to drift through, but on July 5 it was blown onshore on the east side of the causeway by post-tropical storm Arthur.
It is always a challenge, logistically and financially, to dispose properly of such a large carcass, let alone to perform a necropsy to try to determine the cause of death. Depending on the location and circumstances, different Departments (federal, provincial, municipal) may inherit the responsibility to dispose of the carcass, and special arrangements (assembling a team of prosectors, securing access to heavy equipment) need to be made if there is agreement to do a necropsy.
In the end, after having undergone substantial decomposition, the carcass was towed for 25 km to a burial site, and on July 12, thanks to the Marine Animal Response Society (MARS) of Nova Scotia, and with the cooperation of Nova Scotia Department of Natural Resources and of Fisheries and Oceans Canada, a complete necropsy was performed, involving 10 volunteers and a heavy equipment operator. There was no evidence that this whale had become entangled in fishing gear, and the complete absence of traumatic injuries such as broken bones ruled out the possibility of a ship strike. However, there was some suggestion, based on the blubber thickness of this animal, that it was in poor body condition and that it may have died from emaciation/starvation.