Snakebite in Dogs


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Snake bites

Question: Dr. Richards,

Even though rattle snakes are very rarely fatal in humans in the Northwest, I am not sure about dogs. In the event an animal is bitten? In human we generally elevate the affected extremity to be level with the heart. Unsure of what is most effective in critters. Dale G.

Answer: D-

The potential for death in pets depends a lot on the species of poisonous snake in your area. I am not familiar enough with the distribution of snakes to know which ones are in your area but the snakes that are most likely to be able to kill a dog or cat are rattlesnakes. Copperhead and water moccasin bites are less likely to be fatal. In our area we only have copperheads and we usually do not use antivenin since the mortality rate so far has been 0 for copperhead bites. We usually see three or four dogs a year with snake bites. I can only remember seeing one cat. I'm not sure why that it is, though.

My friends who practice in areas in which rattlesnakes do occur say that they do see fatalities in untreated dogs and they are a lot more likely to use antivenin routinely. I think that there is some variation among the species of rattlesnake in the risk of bites but I am not sure how significant those differences are.

From a first aid standpoint the best advice seems to be to transport the dog or cat to the veterinarian's or emergency veterinary clinic as quickly as possible. It is supposed to be best to keep exercise to a minimum on the way to the clinic, so a slow walk out of the woods is probably better than a forced march. Snake bites are really really painful and even very mild tempered dogs will sometimes bite, or threaten to bite, when the area around the snake bite is touched so be careful not to get bitten by the dog or cat. There doesn't seem to be much benefit to direct treatment of the bite, so there isn't a big reason to touch it or manipulate it, anyway. If it is necessary to pick the pet up and carry it, you might consider a muzzle if you can't avoid putting pressure on the painful area. You might want to ask your vet is there is any advice specifically for the snakes found in your area since he or she would be more familiar with what species of snakes are found and the severity of their bites.

Mike Richards, DVM 7/2/2001

Rattlesnake bites..any poisonous snake bites

Question: first of all, let me apologize if the answer to this question is already out there and i haven't seen it.... i am quite concerned about what, and all, i can do to help out my dogs if they get bitten by a rattlesnake. i have 4 labs- 14 yrs, 12 yrs, 7 months, 5 months old. the 12 year old (70 lbs) has been bitten before (i assume a western diamondback). i was not there and the situation was handled by the doggie sitter, so i'm not sure exactly how long it took to get the dog to the vet. however i know it must have been at the very least an hour. i paid quite a bit for the anti venom shot. i remember thinking that i couldn't imagine the effects being much worse and wondering if i wasted my money. i was told it was a one fang hit under the eye.

what, of course, i would really like is to be able to carry an anti-venom shot with me but i'm assuming that won't be possible. (please address this subject anyway). the state of california won't even let emt's carry epinephrine for heavens sake so........ i live in southern california and take my dogs out to a field with grass and medium brush. i saw a teenage rattler the other day. it was a bad situation (snake coiled between me and the pups) but we all survived.

if my dogs got bit, i would be again, about an hour away from an emergency room. also i would be perhaps 20 minutes away from a vehicle. i typically do not use leashes because no one gets enough exercise with them on. (so please, do not offer leashes as the only solution, what i am looking for is the best i can do without leashes) if course, i am more worried about the pups. i have considered training them to be afraid of the rattle sound. do have any info on anyone who has tried this?

what i would like to know is, if my dogs got bitten, - how important would it be to carry them to a vehicle vs walk - is there something on the market to help the effects until i got to the vet (i am especially interested in this) - how quickly will i be able to tell if they have been bitten (please address this) - in general, suggestions on the best thing to do

i understand it depends on the age of the snake and the actual strike. i have heard alot of strikes are dry? if the snake is coiled to strike and i poke it with a long stick, will it strike and then move on? or do you suggest doing this? thanks for any info, pam Pam- The seriousness of snake bites varies due to several factors. The type of snake that causes the bite is one factor. Copperhead bites, with represent 100% of the bites I have treated, do not pose much threat of death and we do not use anti-venin. All of the rattlesnake bites are considered to be such more toxic (by a factor of 5 to 10X) and almost all vets that I have spoken to who treat these bites feel that anti-venin at least cuts down on the rate of serious complications and probably saves the life of some patients. Even rattlesnake bites vary in their toxicity based on how recently the rattlesnake bit someone else, whether one or both fangs entered the dog's body, whether the venom was successfully injected, the size of the snake and probably some other factors I'm not thinking of right now.

I think that it is best to be cautious about rattlesnake bites. Treatment for shock using intravenous fluid therapy may be necessary, swelling may be treated with antihistamines and some vets use corticosteroids (this is controversial and vets feel pretty strongly both ways in some cases), antibiotics are a good idea and pain relief medications can be very useful.

It is best to take the dog directly to your vet, or an emergency veterinary clinic, rather than attempting first aid, if it is possible to get there within a reasonable time. I don't think I would attempt first aid, especially avoiding the application of tourniquets and/or cutting and attempting to suck venom from the bites. It is better to use the time that might be spent on these things getting to the veterinary hospital. An hour is not too bad as a delay in treatment but longer than four hours probably does start to limit the beneficial effects of the anti-venin, although I know that some vets give it up to 24 hours later and still believe that it has beneficial effect in many patients.

I am not familiar enough with rattlesnake bites to know how severe the effects are in untreated dogs or to know what the expected fatality rate is from untreated bites. I suspect many dogs would live through the bites but that it is probably really hard to tell in advance which ones they are.

I have not ever had to figure out whether or not anti-venin was reasonable to prescribe. There is a possibility of anaphylactic shock reactions to this product so I suspect that is best to use it in a clinical situation whenever possible, though.

I am under the impression that the sound of a rattlesnake is an imprinted fear in most creatures. I was rock climbing in New Jersey once and put may hand on a ledge over my head and withdrew it with an alacrity that could only be instinct when I heard the sound of a rattlesnake for the first time. On the other hand, I'm pretty sure that you could reinforce that fear in some manner, too.

I think it is OK to let your dog walk to the car unless there is some disability induced by the bite. The recommendations that I have seen say it is best to walk a normal pace rather than to run or hurry and cause wider spread of the venom.

I can't speak for rattlesnake bites but it is unmistakable when a dog gets bitten by a copperhead in most cases. These bites REALLY hurt. Even really nice dogs will try to bite me when I attempt to touch the injured area. In many instances the fang marks continue to ooze blood and are obvious due to this. Swelling occurs very rapidly, usually within 15 minutes and almost always within a half-hour or so. If you have questions about whether the dog was bitten, it probably wasn't --- but it is still a good idea to be cautious and head for the vets (or at least for home) until it can be determined that clinical signs such as those above are not going to occur.

I suspect that diphenhydramine (Benedryl tm) would be beneficial to give, at a dose rate of about 1mg per pound of body weight.

I don't know about rattlesnakes but copperheads can be very aggressive in some cases when you get close to them. I would try to just avoid any confrontation, personally. There is no point in making the snake feel it must defend itself aggressively, rather than opting for retreat.

I am glad that I can't provide personal experience information about rattlesnake bites but sorry that it limits the value of this answer somewhat.

Mike Richards, DVM 5/22/2001

Rattlesnake bites and Cancer

Question: Quick followup to my post. We are talking about cancer a lot. Do you have any personal thoughts what may be causing so much cancer in dogs? Do you think it related to chemicals/constituents/perservatives in the commercial foods? Also, have you ever heard of a connection between rattlesnake bites and cancer in dogs? Living in the southwest, I see a lot of dogs bitten by rattlesnakes and almost all of the ones I know personally have subsequently have died of cancers....connection or just coincidence? Just curious. I have had three dogs bitten by rattlesnakes and two of the three have died from cancer.


Answer: Ro-

I am not aware of a connection between rattlesnake bites and later cancers but couldn't rule out the possibility. I searched the PubMed web site for information on this and did find one article by Bode, et al, the summary of which indicated that the venom of the Eastern diamondback rattlesnake had proteins that resembled proteins linked with human breast cancers. I don't think there is any inference that their is any sort of cause and effect thing, just that the proteins are similar in appearance. That was the only article I could find with an abstract, but there was at least on article that mentioned the effects of rattlesnake (Crotalus) venom on malignant and normal cells in the title. There may be some connection but if so, it isn't clearly delineated in any of the studies I could find that had abstracts or summaries.

I think that cancer is common in dogs, especially if you count all the benign and malignant forms of neoplasia and lump them under the general term "cancer". I think that this tendency has probably always been present but that several things have changed that make it more of a pressing issue now than it was twenty years ago.

Dogs live longer now than they did even a decade ago. More dogs live predominantly inside lives where they are safer and where they are a closer family member, making their problems more noticeable. Treatment for cancer has improved to the point that veterinarians are willing to recommend it much more frequently than in the past. This makes it necessary to identify the type of cancer to plan chemotherapy, making people aware of names like lymphoma, hemangiosarcoma and mast cell tumors.

Someday, it may be possible to link things like food preservatives, medications, toxins and other potential carcinogens directly to cancer that occurs in an individual dog. At the present time, the best that can be done is to link broad increases in cancer in a population to specific potential carcinogens that population is exposed to. Since there isn't a ton of money for research of cancers in dogs and there isn't any real central reporting body that vets are required to send data to and since most dogs that die are not examined for cause of death --- it is not possible at the present time to say much about what might be causing cancer in dogs. This is extremely frustrating but it is just fact. I hope this situation changes in the future. So many advances have been made in veterinary medicine just in the time I have been in practice that I am hopeful this information really will be available in the future.

Since you asked for my opinion, though, this is what I really think. I think that there will be few things in veterinary medicine that will be identified as significant risks for specific types of cancers. I just have no clue what they are going to be.

What I really worry about is that one of the things that really benefits most dogs will be identified as a cause of cancer in a small number of dogs and that a lot of dogs will suffer because of the fear of cancer will make people stop using a valuable medication or food preservative that prevents many more deaths than it causes. This situation already occurs with medications. One example is fear of anesthesia leading to people putting off surgeries or dental procedures that would be very valuable for their pet's quality of life or even the length of their life.

I guess this was an overly long answer, since the bottom line is that I don't know of a connection between cancer and rattlesnake bites and I don't know if any of the commonly used food preservatives or medications in veterinary medicine have any significant carcinogen effect!

Mike Richards, DVM 3/8/2000

Snake Bite

Q: my dog got bitten by a rattle snake at lake mead - the vet gave us pills for her...bite was on nose...occured on 5/11... she seems happy, wags her tail, has a semi difficult time eating...bite was on nose..her mouth is all swollen so is her neck looks like she has a tennis ball in her this normal? any pictures i can look at? i will take her to our vet tomorrow but appreciate any info...thanks skb

A: skb- I do not practice in an area with rattlesnakes, but their bites are supposed to be more toxic than the copperheads we have. Since it has been a couple of weeks since she was bitten it seems likely that the current problem is either an infection or possibly a ruptured salivary duct associated with the bite or possibly even coincidental to it. I think that infection of the damaged tissue is a bigger danger than the venom from copperhead bites. That might not be true of rattlesnake bites but infection is probably still a major concern.

When a salivary duct ruptures, swelling occurs under the jaw, first on the side that the duct is ruptured on, then becoming a generalized swelling. An aspirate from the swelling usually contains saliva if this is the problem. In many (most?) cases it is necessary to remove the salivary gland since repair of the duct is not usually possible.

Taking your dog to your vet was definitely the right thing to do and I hope this worked out well for her

Mike Richards, DVM


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...