DAILY REPORTER-HERALD (Loveland, Colorado) 20 April 06 Barks and bites - Dogs can be vaccinated against rattlesnakes, but effectiveness debated (Ann Depperschmidt)
Pam Howard and her family had hiked more than a mile up Hewlett Gulch trail last July when it happened.
Their 60-pound standard poodle, Thud, was leading them around a corner when the dog suddenly jumped and yelped in pain.
A rattlesnake had struck her front right leg.
“I was keeping my fingers crossed that she’d be able to make it back down,” the Loveland woman said. “But within three minutes, she was unable to walk.”
Thud had to stay at the animal hospital for two days, and the Howards had to spend hundreds of dollars for antivenim and follow-up treatment for the dog.
So this year, Howard decided to give Thud a relatively new rattlesnake vaccine to help protect the dog from the painful — and costly — effects of a rattlesnake bite.
“I certainly don’t mind sharing the land with rattlesnakes,” she said. “But I want my dogs to be protected.”
Red Rocks Biologics, a California-based company, developed the rattlesnake vaccine — Crotalus Atrox Toxoid — and made it commercially available in 2003.
The vaccine works by creating an immunity in dogs that makes the venom’s painful effects less severe and the chances of the dog needing costly treatment less likely, according to information provided by the company.
But Tim Hackett, an associate professor of emergency and critical care at Colorado State University’s College of Veterinary Medicine and Biomedical Sciences, said the university’s veterinary hospital doesn’t provide the vaccine and doesn’t recommend dogs get it.
“It hasn’t been shown to be effective,” he said.
The staff treats about 30 to 40 dogs that have been bitten by rattlesnakes each summer, he said. The vaccinated dogs the staff has seen have not had less-severe symptoms than those that had been vaccinated, he said.
And in some cases, Hackett said, dog owners who have vaccinated their dogs waited too long to get proper medical care because they thought the vaccination was enough.
“People maybe have a false sense of security,” he said.
The company maintains that every rattlesnake bite needs to be treated as an emergency, and dogs should get medical treatment as soon as possible — even if the dog has been vaccinated.
Paula Ibsen, a veterinarian with Red Rocks, said lab tests have shown the vaccine is safe and works well. At veterinarian conventions she has attended since the vaccine’s introduction, she has received “overwhelming positive feedback from veterinarians using the product,” Ibsen said.
Veterinarians have reported seeing less swelling and less pain, and the dogs have required less treatment, Ibsen said.
But Hackett said another reason the university veterinary staff doesn’t use the vaccine is because it wasn’t developed to protect against the prairie rattlesnake — the only species of rattlers that exists in this part of Colorado, he said.
Information from the company says that although the vaccine was developed to protect against western diamondback rattlesnake venom, the similarities between that and the prairie rattlesnake are enough to make it effective against both species.
Barb Roberts, a veterinarian with Blue Sky Animal Clinic in west Loveland, said the clinic has vaccinated more than 100 dogs since last spring.
The staff keeps a log of any side effects dogs have had from the rattlesnake vaccine. So far, the only side effect the staff has seen is dogs that develop a small bump at the vaccination site a small percentage of the time, she said.
Though the staff hasn’t treated a vaccinated dog that has been bitten, she said “a lot of veterinarians across the country feel like it does help.”
Each vaccine costs $25 — two are recommended the first year, and one as a booster each year after — but a vial of antivenin (and some dogs may need more than one vial) can cost about $600, she said.
“Many people aren’t in the financial position to do that,” Roberts said.
So a less-expensive vaccine that may reduce the chance of the dog needing antivenin and follow-up care may be a good option for dogs that spend time in rattlesnake country, she said.
“We felt like we live in such an area where we get lots of rattlesnake bites,” Roberts said.
“So if we can do something to help decrease the chances that the dogs will die from a rattlesnake bite or require extended care, then we wanted to offer it.”
Vaccine Guidelines
The 2006 American Animal Hospital Association Canine Vaccine Guidelines provide information about new vaccines and developments in vaccines to make recommendations on whether veterinarians should use them.
For the rattlesnake vaccine, the guidelines do not take a position because of the lack of evidence on its effectiveness.
But the report goes on to say that “a reasonable expectation of (effectiveness) does exist.”
Dogs can be vaccinated against rattlesnakes