When dog owners take their pets for annual vaccines, some include a shot to protect against leptospirosis, a bacterial infection that can make dogs fatally ill and can be transferred to humans, veterinarians say.
The Leptospirosa bacterium is shed in the urine of infected wildlife, including skunks, oppossums, rats, coyotes and raccoons. When dogs are infected, they may develop a fever, muscle weakness, vomiting and lethargy, often leading to death by kidney or liver failure, veterinarians said.
Local vets say they recommend the vaccine depending on the dog and its lifestyle.
"We see the occasional case," said vet Craig Zabel of the Sugar Grove Animal Hospital. "Not every dog needs it, and it's difficult to establish which dogs really need a vaccine and which don't."
"Out on the farm – no question," Zabel said. "If your dog is strictly in your backyard and there's no wild animals running through the yard, you might not need it."
The bacterium must be wet for the disease to spread to a dog, he said.
"When [the urine] dries, [the bacteria] dies. It cannot live in a dry environment," Zabel said. "But if a dog eats an infected mouse, and the urine gets into a dog's mouth, he can get it."
Vet Jennie Christakos at Valley Animal Hospital in Geneva said she assesses the risk before recommending the vaccine.
"If I have a dog owner with a Chihuahua that does not go outside much, maybe 2 feet into the yard – maybe not," Christakos said. "If I have a dog that hangs out in a backyard with lots of wildlife, that goes to dog parks, walks around in the river – then I will recommend vaccinating them."
A case can be made to vaccinate every dog, Zabel said.
"You can fail to give a vaccine to a little suburban back yard dog and then that dog may go for a walk in the park and take a drink out of the creek," Zabel said. "When in doubt, go ahead and vaccinate. ... These diseases are very dynamic. All you need are a few coyotes in the neighborhood spreading it all over the place."
Romie Michael of Aurora had her toy poodle, Dash, vaccinated for leptospirosis at the Sugar Grove Animal Hospital.
"We live close to Sugar Grove, and we see wild animals all over – coyotes, raccoons, possums, foxes and squirrels," Michael said. "We live next to a tree line, which is why we see a lot more animals. I have read up on it, and this is something that is recommended. I feel better, absolutely, that Dash has had this vaccine."
The veterinarians added that treating the infection is extremely hard on the dog and is more expensive than vaccinating. The vaccine is given in two doses four weeks apart for the first time, then as part of a yearly booster.
"If we see animals come in for fever, loss of appetite, nausea, vomiting, diarrhea – that is what is so hard about diagnosing it," Christakos said, as other diseases have these same symptoms.
Christakos said she would begin treatment on a dog with these symptoms, using antibiotics and intravenous fluids while waiting for blood work. Zabel said realistically, leptospirosis is hard to pin down because it "can be a chameleon." Diagnosis is more complicated than a simple blood test, though better tests are being developed, he said.
"Have I seen dogs die of it? Yes, over the years," Zabel said. "Leptospirosis is a dangerous disease. By the time we get a diagnosis, too much damage is done. ... From a realistic standpoint, it's tricky to diagnose and most results are not absolute."
People can get leptospirosis from their dogs – called zoonotic transmission – or the same way dogs get it, by exposure to contaminated water or wet soil or from the urine, blood or tissue of an infected animal, according to the Illinois Department of Public Health.
Illinois has about one human case reported per year.
Human symptoms are similar to a dog's. The treatment is similar with antibiotics and IV fluids, possibly renal dialysis, but death is rare, according to the health department.
For information about leptospirosis, visit the following websites:
• American Veterinary Medical Association – www.avma.org.
• Illinois Department of Public Health – www.idph.state.il.us.