Luna keeps her eye on the ball at Horseshoe Lake.
Are local lakes making dogs sick?
By Katie Vane
Rumor has it, there’s something in the water at Horseshoe Lake that’s making local and visiting pets sick. But, says Dr. Teslaa of Alpen Veterinary Hospital in Mammoth, that rumor “has been going around for a while now.”
It is true, he adds, that something has been causing multiple, mysterious cases “of dogs having neurological symptoms — including seizures.” However, Dr. Teslaa doesn’t think Horseshoe Lake has anything to do with it. June and Convict Lake are more likely culprits.
In the second weekend of June, Dr. Teslaa saw three cases of dogs that “had seizures for the first time in their lives” — and all three had just come out of June or Convict Lake, or were standing in the waters of those lakes when the seizures happened. Dr. Teslaa does acknowledge that there might only be a “loose association” between these cases and the lake waters.
Yet one of his theories is that there may be a blue green algae bloom in these lakes. Blue green algae produces toxins that can cause sickness in animals and humans. “Usually,” he admits, “blue green algae doesn’t thrive in lakes at this altitude, and has to have still waters to bloom.”
Indeed, the Mono County Health Department recently tested June Lake, and tests for toxins associated with blue green algae came back negative. “There’s really no story here,” says Environmental Health Director Louis Molina. And, he adds, “No further studies are being conducted at this time. Until we know what we’re looking for, we can’t just send off water samples to the lab.”
If it’s not blue green algae blooms causing sickness in dogs, then Dr. Teslaa has another theory. “I do suspect,” he says, “that because we have so much wildlife up here, there are protozoa microorganisms that can be contracted by local and visiting dogs.”
This time he may have hit the nail on the head. Dr. Carl Lind of Bishop Veterinary Hospital confirms multiple cases of pet owners bringing sick pets down to his practice from none other than Horseshoe Lake. These dogs weren’t having seizures, but suffering from diarrhea caused by Giardia, a single cell protozoic parasite that lives in lake and stream water. However, Dr. Lind doesn’t believe Horseshoe has any higher concentration of Giardia than other lakes in the Mammoth area. He believes Horseshoe makes more dogs sick because more dog owners let their dogs off-leash to run there. “We tell clients not to walk dogs loose at Horseshoe,” he says. Off-leash dogs drink the lake water, inadvertently ingesting the Giardia that will make them sick.
Giardia doesn’t explain the seizures Dr. Teslaa alluded to, however, and that mystery might persist. Because so many of these sick pets were visitors to the Town, Dr. Teslaa says, “it’s hard to get follow-up data.”
“It’s a question we field all the time,” he concludes; “‘is there something in the water?’” Perhaps giardia is the answer to that question. But perhaps the mystery of Something in the Water, like any Town legend, will persist long after the mystery has actually been solved.