Earlier this year, we shared the story of Whiffen, a Canadian sea otter whose rescue captured hearts on social media. The 'second-chance sea otter' had been fighting for his life at the Vancouver Aquarium Marine Mammal Rescue Center. Sadly, after an 11-week battle, Whiffen died this past Saturday – but despite the unhappy ending, his story is having a positive impact … it’s helping scientists develop new ways of diagnosing and treating a disease that plagues many species, including humans.
When Whiffen was found near a popular hiking trail near Sooke, British Columbia, he was cold, starving and very sick – but it seemed like any other rescue. "Our group is very used to trying to stabilise animals in critical condition," staff veterinarian Dr Martin Haulena says. "Although he was worse than many, the group did a remarkable job of stabilising him and keeping him comfortable for the past 2.5 months."
Though his seizures and hypoglycemia stabilised over time, Whiffen's poor body condition wasn't getting any better. During a routine MRI scan, Whiffen lost the ability to breathe.
"He was still not gaining weight, had progressive muscle loss, head tremors, [and] weakness,” aquarium staff said in a recent statement. "But of greater concern were progressively increasing [concentrations] of Toxoplasma gondii on repeated blood tests."
Toxoplasma gondii is a single-celled protozoan (a parasite that is so tiny it only has one cell) that causes a disease known as systemic toxoplasmosis. In otters the parasite causes severe brain disease and it’s a common culprit for otter deaths along the California coast. If test results confirm T. gondii as the cause of Whiffen's death, this would suggest the disease is migrating north. That makes Whiffen’s case important: understanding where and how he picked up the parasite could yield a better understanding of how toxoplasmosis spreads.
"If we do have some kind of protozoan disease going on (and I am pretty sure we do) then we need to identify which one," Haulena says.
Though T. gondii is most commonly transmitted between rodent and feline hosts (which is why it's sometimes called the 'cat parasite'), it can spread to humans if they eat meat from infected animals – a fact that troubled scientists when they discovered the protozoans had made their way into beluga whale meat earlier this year.
A human with a healthy immune system will not usually show symptoms if infected, but toxoplasmosis can lead to a slew of serious health problems in sick or pregnant hosts – most commonly infectious blindness and foetal abortion.
For other animals, the parasite is even more devastating, and Haulena hopes that information gleaned from Whiffen's case will help protect animals in northern waters.
“Some of these diseases are now found in the Arctic and other so-called 'pristine' environments," he notes. "The identification and spread to those areas is very important to document … these diseases require a terrestrial host [like cats] for completion of their life cycle. So [understanding] how a disease normally associated with the terrestrial environment spreads to the marine environment is a very important ecological aspect,” he explains.
Molecular parasitologist Michael Grigg has been studying another ecological aspect of T. gondii's evolution: the link between parasite outbreaks in new environments and the thinning Arctic ice.
"What's now happening with the big thaw is that there is this disappearing ecological barrier," he says. "And so you've got liberation of parasites from the north that come south in a new susceptible range of animals." Grigg adds that, similarly, pathogens that normally reside in warmer climates are now emerging to cause disease in populations in the Arctic. This suggests that the parasites are capitalising on shifting global temperatures.
Grigg and his team discovered that a new strain of Sarcocystis (another group of protozoan parasites), Sarcocystis pinnipedi, was responsible for the mysterious deaths of 406 grey seals in the North Atlantic in 2012. Since the seal die-off, the parasite has killed a Steller sea lion, Hawaiian monk seals, walruses, and polar and grizzly bears from Alaska to British Columbia.
While the team at Vancouver Aquarium anxiously awaits various test results of Whiffen's samples, his MRI and CT scans will be forwarded to a veterinary radiologist who will be looking for evidence of subtle lesions that may help diagnose the disease earlier in the future.
"The goal is always to make the best decision possible, as soon as possible, for the individual animals in addition to adding to our understanding of the bigger picture," Haulena says.
Whiffen's supporters continue to tweet about his story using the hashtag #GoWhiffen.
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