UNH researchers discover previously undiagnosed parasite, virus infecting Canada lynx

April 22. 2018 5:39PM
Recently, Canada lynx have been observed in New Hampshire and Vermont, including female lynx with kittens, which suggests an expansion of their current habitat range. (Dorothy Fesche Photo)
DURHAM - Scientists with the New Hampshire Veterinary Diagnostic Laboratory at the University of New Hampshire say they have discovered a previously undiagnosed parasite and virus in the Canada lynx.

The parasite, transmitted by ticks, is known to infect domestic dogs, a UNH press release states. The virus is similar to the Epstein-Barr virus, which causes mononucleosis in humans and is related to a virus that infects domestic cats.

“Lynx in New Hampshire and Maine are on the southern edge of their natural range and are amongst the largest and most majestic predators in these states. The health of these apex predators can function as an indicator of the health of their varied prey species, and health of their wild environments,” said Dr. David Needle, senior veterinary pathologist and assistant clinical professor with New Hampshire Veterinary Diagnostic Laboratory.

Needle and Dr. Brian Stevens, also a senior veterinary pathologist and assistant clinical professor with New Hampshire Veterinary Diagnostic Laboratory, are leading the project to establish a baseline of diseases affecting a seemingly healthy wildlife population.

Seen in New Hampshire

Canada lynx have been federally listed as threatened since 2000, and the only state in the Northeast with a resident breeding population is Maine. Recently, lynx have been observed in New Hampshire and Vermont, including female lynx with kittens, which suggests an expansion of their current habitat range.

Scientists primarily with the NH Veterinary Diagnostic Lab performed postmortem examinations on 38 Canada lynx from the state of Maine Department of Inland Fisheries and Wildlife.

The frozen carcasses of the animals were retained over 10 years and had been collected by wildlife biologists after having been found dead, with the most common cause of death being hit by a car, the news release states.

Data were collected during postmortems, and tissues were collected and examined microscopically. Additionally, other tissues were sent to collaborators for further infectious agent and nutritional testing. Scientists found lungworm infection in 22 of 32 animals where the lung was examined.

According to Stevens, it is unclear how much of an effect the presence of these parasites had on the health of the lynx, though some cases had more severe inflammation associated with the parasites.

“However, scientists also found inflammation in the heart and skeletal muscle of multiple Canada lynx, and in two animals noted a microscopic protozoal organism suggestive of Hepatazoon sp. Additional diagnostic tests are being performed at the University of Georgia to definitively identify the protozoal species in these lynx. Protozoa are unicellular organisms, which occasionally lead to parasitic disease in different animal species.

“To our knowledge, the parasite we believe this to be has not been diagnosed this far north as it tends to infect animals in the southern states and has not been diagnosed in Canada lynx, although they are often diagnosed in bobcats in southern states. This parasite is transmitted by tick vectors and to this point, the range of these tick vectors is not described to be in Maine so it is unclear if the tick range has expanded into Maine or if the Hepatazoon-like organism in these lynx is one not normally found in North America,” Stevens said.

Virus discovery

In collaboration with investigators at Western University in London, Ontario, Stevens and Needle also discovered a previously unknown virus in a subset of animals. This virus is similar to a gamma herpes virus recently identified in domestic cats, and is in the same family as Epstein-Barr virus, which causes mononucleosis and other diseases in humans. Stevens said it is unclear whether the virus is a causative agent of the disease in lynx.

“We are identifying infectious agents of importance to the wild lynx population, which could have impact throughout their range, and could impact other wild animals, and potentially domesticated animals. The finding of Hepatozoon-like organism was a surprise, as it has not been described previously this far north, or in this species. Hepatozoon is a known parasite of domestic dogs and is rarely a cause of disease in this geographic region, but if it is endemic in wild carnivores, then it may only be a matter of time before veterinarians start to seeing it affecting our own dogs,” Stevens said.

Going forward, Maine wildlife biologists will continue to collect tissues from Canada lynx so that scientists can continue to monitor the overall health of the population and survey for new and emerging diseases.

Stevens presented the initial findings of this study at the 74th Northeast Fish and Wildlife Conference in Burlington, Vt., on April 17.

This project was funded by the Maine Department of Inland Fisheries and Wildlife and supported by the New Hampshire Agricultural Experiment Station and the State of New Hampshire.

General NewsManchester

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