It was just like any other day fishing at the lake. By Mark’s side, his dog Bear waited anxiously for his owner to reel in a catch. Bear, a 10-year-old male Chow, has earned the title of being Mark’s trusty fishing partner over the last five years since the family moved to Crestline and living a stone’s throw away from a nearby lake.
“I’ll catch fish and Bear will pull them out of the water and play with them,” Mark said. “Once I clean the fish, I sometimes give him a fish head every once in a while, and he’ll eat it.”
This fishing adventure was different – a couple of days later Mark noticed Bear wasn’t quite himself.
“Bear didn’t eat dinner. I first kind of thought it was normal since he’s a finicky guy,” he said.
Bear then started becoming incredibly lethargic. Mark began to wonder if maybe Bear had food poisoning from the meals he had earlier that week. Bear had some samplings of Mark’s pastrami sandwich and a burger. Mark followed his instincts by calling the vet and bringing in a fecal sample. It wasn’t food poisoning.
Instead, the pathologist identified fluke eggs which are consistent with salmon poisoning. The lake was stocked with fish from the Pacific Northwest which had this parasite that Mark’s dog contracted.
Once the diagnosis was clear, Mark drove Bear to California Veterinary Specialists in Ontario. “The care my dog got was great,” Mark said.
One of the attending veterinarians who treated Bear was Dr. Tim Concannon whose area of medical specialty is in emergency and critical care. According to Dr. Concannon, there is a family of parasites called flukes which are a naturally-occurring parasite found in fish from the Pacific Northwest. Inside these flukes are additional microscopic parasites called rickettsial agents.
“When a dog eats the fish, it liberates this fluke from the fish into the dog. The parasite attaches to the intestine,” Dr. Concannon said. “Inside the fluke is another microscopic parasite named rickettsial which migrates into the bloodstream. It’s distributed throughout multiple organs in the body, and it’s that rickettsial organism which makes the dog sick.”
While each patient reacts differently, generally the incubation period is five to seven days.
When Bear arrived at CVS, the medical team started him on supportive treatment for dehydration. Bear was administered fluids and then started on two different types of antimicrobial drugs.
Doxycycline targeted the rickettsial agent and an anthelmintic drug called Praziquantel destroyed the fluke.
Bear stayed at CVS for three nights. While patient dependent, most dogs feel better five days following treatment. However, recovery may last up to two weeks in more advanced cases of the illness.
Like any illness or disease, early intervention is key. Dr. Concannon went on to say how in his career in Southern California, this parasitic illness occurs every five years or so. Fish native to this area do not carry fluke.
“When fluke pops up, the reason it happens is that some local fishery decided that they’re going to import fish from someplace else for those who are fishing. Periodically, they may receive an inventory of fish that carry fluke,” he said. “I’m sure the lake, in this case, was recently stocked with fish from the Pacific Northwest.”
Frequently, it takes one “season cycle” for the fluke to disappear. However, to keep lakes clear of a fluke the goal is to not repopulate the lake with another stock of fish with this parasite.
“But for right now, whichever lake this is that was stocked, it almost certainly has other fish in it that have this fluke, and this is a problem,” he said. “Normally, we notify the lake that has the problem, and they put warning signs up all over not to let dogs eat any of the fish out of the lake.”
Because there is a propensity for parasitic contamination, Dr. Concannon highly recommends that pet parents be cognizant regarding this disease process. Again, this means fishing at a lake which was stocked with Pacific Northwest inventory.
Be on the lookout for signage warnings.
“If people want to be extra cautious, I would suggest stopping and asking whoever the ranger is at the lake whether they’ve stocked the lake recently. And if the answer is yes, find out where the fish came from,” he said.