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 Post subject: rattlesnake vaccine
 Post Posted: Tue May 25, 2010 11:40 pm 
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Info from UC Davis, a vet teaching school in CA. I am not sure how old this info is, but it is from their current website.

Canine Rattlesnake Vaccine
The canine rattlesnake vaccine comprises venom components from Crotalus atrox (western diamondback). Although a rattlesnake vaccine may be potentially useful for dogs that frequently encounter rattlesnakes, currently we are unable to recommend this vaccine because of insufficient information regarding the efficacy of the vaccine in dogs. Dogs develop neutralizing antibody titers to C. atrox venom, and may also develop antibody titers to components of other rattlesnake venoms, but research in this area is ongoing. Owners of vaccinated dogs must still seek veterinary care immediately in the event of a bite, because 1) the type of snake is often unknown; 2) antibody titers may be overwhelmed in the face of severe envenomation, and 3) an individual dog may lack sufficient protection depending on its response to the vaccine and the time elapsed since vaccination. According to the manufacturer, to date, rare vaccinated dogs have died following a bite when there were substantial delays (12-24 hours) in seeking treatment. Recommendations for booster vaccination are still under development, but it appears that adequate titers do not persist beyond one year after vaccination. Adverse reactions appear to be low and consistent with those resulting from vaccination with other products available on the market. The product license is currently conditional as efficacy and potency have not been fully demonstrated. Based on existing evidence, the UC Davis VMTH does not currently recommend routine vaccination of dogs for rattlesnake envenomation, and the vaccine is not stocked by our pharmacy.

And, a quote from a vet on a hiking forum. Mar 30 2010 2:32 pm

Sorry for being a behind the scenes lurker and only an occasional poster. I hike, backpack and ride mules on lots of trails and use this website as a great recourse for adventures.

I have to comment on the “Rattlesnake Vaccine” as I am a practicing veterinarian, board certified and acted as the advisor to the veterinarian that has written all the textbooks and articles concerning rattlesnakes.

Vaccination sounds like a simple solution to a very complex problem. It is not.
A snakebite is a very complex problem with lots of variables. Lots of things determine the amount and quality of venom the snake releases with each bite. The size of the snake, the species (Mohave are the worst) whether the snake has recently eaten and used his venom. Is it an early spring bite or a very young snake which makes the venom more potent?. Lastly is it a defensive warning bite or a full on aggressive bite. That said there is no way of knowing if the vaccine worked or it was just the luck of the dog getting a dry bite from a snake that had just eaten. Bottom line there has been no scientific, peer reviewed studies that show that this vaccine works any better than a placebo. The only research that is provided by the manufacturer is all anecdotal stories about how well it worked. Warm and fuzzy, but not science. It is not FDA approved and all the veterinary organizations do not recommend its use.

Even with vaccine. The manufacture recommends seeing a veterinarian after a bite and the administration of anti venom. The best thing you can do for your dog after a bite is use your car keys and get to a veterinarian and allow antivenin use. It’s proven science that the survival rate is much higher, both for you and your dog if anti venom is used. Forget all the tourniquets, cutting and sucking that you learned in Boy Scouts, it does more harm than good.

The worst thing about the vaccine is that it gives a pet owner a false sense of security and delays medical attention.

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 Post subject: Re: rattlesnake vaccine
 Post Posted: Wed May 26, 2010 10:26 am 
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I found this article last night and thought it was very interesting. I wish we could get the opinion of an allergist or immunologist on some of these issues.

Quote:
Stanford Snake Venom Study Shows That Certain Cells May Eliminate Poison

ScienceDaily (July 27, 2006) — Death by snakebite is horrible. The immediate pain of the bite is followed by swelling, bruising and weakness, then sweating or chills, with numbness, nausea, blurred vision and possibly convulsions before it's all over. Such misery is produced by a veritable witches' brew of toxins in snake venom.

It's long been thought that the body's own immune system, rather than reducing the symptoms, may make things worse. But now researchers at the Stanford University School of Medicine have shown that the immune system really does side with the victim, at least in four kinds of venom that were used in their experiments. Their findings will be published in the July 28 issue of Science.

Venom from three species of poisonous snakes and one species of honeybee were studied by a group led by Stephen Galli, MD, professor and chair of the Department of Pathology. Using mice, they analyzed how mast cells, a vital part of the immune system in mammals, reacted to the various venoms. The net effect of the mast cell response to the four venoms "is to enhance resistance to the toxicity and reduce mortality induced by the venom," said Galli, the paper's senior author.

This helpful mast cell response runs contrary to the conventional wisdom - that the immune system only added to the woes of snakebite victims. This assumption arose because of the way mast cells respond to certain other stimuli.

Mast cells synthesize a wide range of biological mediators - compounds that can promote inflammation and other tissue changes - that are selectively unleashed from the cells in response to various triggers, often intruders such as parasites or bacteria. In people who have been sensitized (i.e., made allergic) by prior exposure to substances such as peanuts or certain pollens, mast cells also respond to those stimuli. When mast cells overreact to allergens, they contribute to the effects associated with allergy attacks, such as a runny nose, sneezing, itching and red eyes. When they severely overreact, they can cause anaphylaxis, which can be fatal.

Given that tendency to overreact when stimulated by allergens, it seemed plausible that introducing venom into the body would trigger a similar response. But Galli and Martin Metz, MD, a postdoctoral scholar in pathology and first author of the study, have shown that when mast cells respond to selected venoms, they unleash proteins that break down some of the venoms' most toxic components.

The study was inspired by a 2004 paper in Nature, by Galli and a team of researchers including Metz, showing that mast cells reduced the mortality rate of mice suffering from bacterial peritonitis, a severe bacterial infection in the abdominal cavity that can also be fatal to humans. They found that mast cells released proteins that broke down a molecule called endothelin-1, one of the major toxins produced by the body during bacterial peritonitis or sepsis (bacterial infection in the blood).

In perusing the scientific literature, Metz noticed that endothelin-1 bore a striking similarity to sarafotoxin 6b, the most toxic component in the venom of the burrowing asp, or Israeli mole viper. Knowing also that mammalian mast cells had been shown to respond to many snake venoms by secreting some potent biologically active mediators, they hypothesized that mast cells might also act to degrade sarafotoxins and reduce the toxicity of the Israeli mole viper venom.

Galli and Metz first did experiments in vitro using isolated sarafotoxin 6b with mast cells from mice. "It worked as we thought it would," said Metz. The mast cells were activated, they released the expected proteins and the proteins degraded the sarafotoxin 6b. Mast cells also enhanced resistance of mice to sarafotoxin 6b when it was injected in vivo.

Next, Galli and Metz did experiments using the whole venom, not just the isolated toxin. Some of the mice they worked with were genetically deficient in mast cells, while others, called wild-type mice, had normal mast cells. "We saw the same results in the wild-type mice that we saw before with just the one component, sarafotoxin 6b," said Metz. The mast cells were activated via a particular receptor they had on the cell surface and released the appropriate proteins, which, Metz said, went on to "degrade and thus eliminate the venom, or at least make it less toxic."

The wild-type mice were able to withstand 10 times the dosage of this venom than the mast cell deficient mice could, further indicating that the mast cells were reducing the impact of the venom. To test whether mast cells could also reduce the toxicity of venom from snakes that didn't contain toxins comparable to sarafotoxin 6b, Galli and Metz tested the venom of the western diamondback rattlesnake and the southern copperhead. Again, the mast cells conferred a distinct protective edge.

Testing the mast cell response even further, they also experimented with the venom from honeybees, with the same positive result. "The mast cells significantly limit not only the toxicity, but also the mortality associated with the venom," said Galli.

But Galli called the battle between predators with venom and their prey "a kind of evolutionary arms race." He and Metz suspect that, given the broad range of venoms that have been developed by snakes and other creatures, mast cells probably won't perform as well against every type of venom.

"We expect that there will be some snake venoms that either are not affected by mast cells at all or perhaps even elicit more pathology due to their ability to activate mast cells. It all depends on the balance between the positive and negative effects of the mediators released by mast cells in response to a particular venom," said Galli.

Galli and Metz are embarking on a systematic survey of animal venoms. As more is learned about the natural defenses the mammalian immune system has against venom, it may someday even lead to better antivenins, though it will first have to be shown that human mast cells respond in the same way mouse mast cells do. The group has begun in vitro studies using human mast cells to evaluate this possibility.

The other Stanford authors of the paper are postdoctoral scholars Adrian Piliponsky, PhD, and Ching-Cheng Chen, PhD, and senior research scientist Mindy Tsai, DMSc. The National Institutes of Health funded the study.

See Also:
Health & Medicine

* Immune System
* Stem Cells
* Lymphoma

Plants & Animals

* Biology
* Frogs and Reptiles
* Mice

Reference

* Histamine
* Inflammation
* Urticaria
* Natural killer cell


Story Source:

Adapted from materials provided by Stanford University Medical Center, via EurekAlert!, a service of AAAS.

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 Post subject: Re: rattlesnake vaccine
 Post Posted: Wed May 26, 2010 12:40 pm 
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This article is really, really interesting! Glad that you found it and posted it, Court. I, too, would like to be able to talk to a knowledgeable person about it.

The thing that I find about humans and scientist particularly is that they always underestimate the ability of the healthy body to deal with stress and strife. Whether you call it God's way, or Mother Nature's way, the make up of the flora and fauna of our planet is amazing. The more that people study it and research it, the more things that they find that tell us that all of this has been preplanned and accounted for.

I find it interesting also that the wild-mice did better at the mast cells responding to the venom. Perhaps that is telling us something too. That wild, or animals that eat naturally and are not treated with all kinds of human interference have a healthier body that functions more like the body should. I may be reading that into the results, but that is what I get from that. I have always said that Larry responded so good to his snake bite because he is so healthy.

I would also be interested in finding out how the mast cells respond to the bacteria that are in the snakes fangs. I read where the rattlesnake has 52 different bacterias on its fangs. Thats a lot of bacteria. So, not only is the immune system being attacked by the powerful venom, it has to react and respond to bacteria, so the immune system is receiving a double whammy, altho I'm sure that the bacteria infection takes a while to get bad.

I'm just glad that rattlesnakes are all that I have to deal with. I was reading about some of the snakes that other countries, like Australia has and I'll take the rattlesnake any day!!

Betty

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"You did then what you knew how to do, and when you knew better, you did
better."
Maya Angelou

"You have enemies? Good, that means you stood up for something in your life!"
Winston Churchill

http://www.flickr.com/photos/bjleek/


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 Post subject: Re: rattlesnake vaccine
 Post Posted: Wed May 26, 2010 4:21 pm 
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Quote:
The thing that I find about humans and scientist particularly is that they always underestimate the ability of the healthy body to deal with stress and strife.


Lucky me...my immune system takes every mold spore as a personal challenge to spawn lung disease. lol!

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