Tox- Small ani. Tox part 3- envenomations

drraythe's version from 2016-04-29 15:43


Question Answer
3 types of poisonous snakes in US?(1) pit vipers*(largest group) (2) coral snake (3) Elapidae subspecies
Crotalidae (pit vipers) main 3 types of snakes in this most common group? (most to least dangerous)Rattlesnakes > Cottonmouths/water moccasins > Copperheads
is there a seasonality to snake bites?during WARM WEATHER Snakes show increased aggression, and have higher venom yield.
if a person swears their dog was bit by a rattler, but no CSs are developing, so you assume they are lying?NO. pit vipers can control the amount of venom they put in a bite- Offensive bite vs. defensive bite. (injecting no venom= "Dry Bite"). An agonal bite makes you agonal (if the snake is dying it will release everything its got)
2 big factors which can determine severity of bite? (1) volume & toxicity of venom (consider dry bites) (2) Location of bite (uptake)-- neck/head more severe than leg/tail.
rattlesnakes can have what kinda venom?9 species & 12 subspecies contain protein similar to Mojave neurotoxin (coagulopathies, swelling, AND neurosigns) or can just have neurotoxins
pit viper venom composition? (dont have to memorize super harD)Enzymatic proteins, non-enzymatic proteins. Goal of venom is immobilization and partial liquifying to be more digestible! Mostly hemotoxic, some neurotoxic. 90% water and 10% killing fraction (Phospholipase A2, Hyaluronidase, Collagenase, Bradykinins, Mojave toxin)
whats a dry bite?bite without venom
would you generally be more worried about getting bit by an adult or juvenile viper?juvenile- they can't control their venom release as well so might give way more
CSs post snake bite? (2 most common?)COAGULOPATHY, thrombocytopenia, Local tissue injury , Vascular permeability, hypotension, Cardiovascular instability, Neurologic, Respiratory (depression), Necrosis (tissue, muscles)
what will you see on blood smear of snake bite victim?Ecchinocytosis!!
how might elyte levels be affected by snake venom?hypokalmia and hypoMg ca be seen.
how can you monitor any progression of toxic effects of snake envenomation?use marker-- outline where you see bruising/hge.... over time only know if tx works if whether or not bruising/ heg is progressing or not. if tx working, hge will not progress outside of sharpie area.
what is edema from snake bite like?very intense swelling. not pitting edema- its hard and thick bc leaking of fluid in interstitial fluids but leak so much gets hard and full. if lift lip- ecchymotic hge.
what SHOULD you do for bite first aid? what SHOULDNT you do for bite first aid.DO NOT DO: Ice area, incision suction, tourniquet (not proven to work, might cause more harm than good.) DO: Keep the patient calm, Lower bite sight below level of heart, Emergency care ASAP
TOC for snake bite is antivenin- what is the major risk factor with any antivenin?THEY ARE BIOLOGICAL PRODUCTS-- can cause anaphylaxis. ACP equine (equine hyperimmune serum), CroFab ovine (great but SUPER expensive)...also, not every bite needs antivenom. dont need if only local swelling and not coagulopathic
what do you think about giving plasma for a snake bite?hey are coagulopathic... why not give them this? not appropriate- all it does is temporarily give some clotting factors- but does not neutralize toxin or stop 1* process, and inc risk of anaphylactic reaction. So if theyre bleeding, just give more antivenom!! This is what neutralizes the toxin.
what does she think about the vx for snake venom?Vx is made for Mojave rattlesnake, Eastern Diamondback rattlesnake, cottonmouths or coral not protective against all envenomations. but you can make a vx for anything- what is it doing? right now- will not prevent animal from showing signs of envenomation- but might lessen clinical course.
what analgesia should you NOT provide for snake bites?NO NSAIDs- they can already barely clot (use opioids). NO PLASMA- just inc risk of anaphylaxis. Can consider packed RBCs if anemic tho. Give fluids to counteract hypotension/tx shock
how are cats affected compared to dogs with snake bites?Signs are worse when cat gets bit, but we dont see cases often (prolly bc they run off to die)
Coral snake bite: CSs?Signs w/in 1 – 18hrs. Not usually painful (Can have minimal swelling). Systemic effects: Vomiting, lethargy, Hemolysis (hematuria), Cardiac arrhythmias (uncommon). Neurologic effects: Postsynaptic acetylcholine receptor blockade, Death secondary to respiratory paralysis
tx of coral snake bites?IV fluids, don't recc abx or steroids. consider blood products if severe hemolysis. Consier mechanical ventilation is severe resp failure. Antivenoms: Coralmyn (discontinued), BioVeteria

Black widow and spiders

Question Answer
fancy name for black widowlatrodectus
bh of latrodectus/BW?NON-AGGRESSIVE
where does BW live?Found in every state except Alaska
what do BW webs look like Spin funnel-shaped webs in dry, dimly lit secluded places, especially corners. Web often looks like cobwebs, disorganized, “messy”
who is most susceptible to BW venom?Cats, horses and guinea pigs very susceptible to venom-- dogs less affected
main toxin in BW venom?Alpha-latrotoxin—potent mammalian neurotoxin. NOTE: No locally acting toxins, No inflammation at site of bite. Puncture wounds and mild erythema can rarely be found
explain diff between bite and envenomation with BWsFemale spiders control amount of envenomation. Bite ≠ envenomation (can have dry bite).
when is BW venom most toxic? Increased toxicity in warmer environmental temps. Toxicity highest in autumn, lowest in spring. Single bite can be fatal! Latrodectus venom often exceeds toxicity of most snakes
spider vs victim dependant variablesSPIDER: size, reason for bite, time of year (fall). VICTIM: Species and size, Location of bite, health status, age
general CSs of BW biteUsually present in severe distress. Loss of up to 20% of body weight in first 24 hours (fluid shifting), Regional numbness in dogs, Regional lymph node tenderness precedes hyperesthesia, muscle pain, fasciculation in affected region (remember: neurotoxin)
what are CSs of cats?remember: particularly susceptible. Paralytic signs appear early in course (Body becomes atonic), Severe pain: Howling, pytalism, restlessness, V+ (often vomit spider) and D+
tx of BW bite?support, there IS antivenon, Available as lyophilized. Administer via slow IV infusion (Dilute in 100mls saline and give over 30 minutes ) LOOK OUT FOR ALLERGIC REACTIONS. consider Diphenhydramine, Decrease rate of administration. (true anaphylaxis rare). the antivenom Provides permanent and quickest relief of signs, Signs abate within 30 minutes of administration. Usually 1 vial sufficient. Full Recovery can take weeks.