Читать книгу Blackwell's Five-Minute Veterinary Consult Clinical Companion - Группа авторов - Страница 46

 Intravenous antivenom can be used in horses to prevent paralysis, coagulopathies, and thrombocytopenia from snake and black widow spider bites. They have little to no effect on tissue necrosis. Early administration is preferred as it not only lessens the severity of signs but attenuates the need for a large number of doses at a later date.

 Anaphylactoid, anaphylactic, and serum sickness reactions can occur, especially if the animal has received antivenom at a prior time.

 Sensitivity testing for antivenom reactions is frequently unreliable with false‐positive and ‐negative results.

 Elapid antivenin (coral snakes):North American Coral Snake Antivenin (LLC [subsidiary of Pfizer Inc.] has a new product, Lot Y 03625 [3‐year shelf life]) available. Product is prescription only. Contact for new in‐date antivenin: +1 (844) 646‐4398. However, cost is considerable, and as such veterinary use may be difficult.Mexican, Costa Rican, and Australian antivenoms have been shown to be effective in neutralizing North American coral snake venoms (Coralmyn™, Instituto Bioclon, Mexico; Anticoral antivenom, Instituto Clodomiro Picado, Costa Rica; Australian ANG Polyvalent Snake Antivenom, CSL Limited, Australia). These antivenoms may be available through some zoos or by contacting a regional poison center with Antivenom Index access.Neostigmine (AChE inhibitor) has been used in animals and humans to successfully reverse Micrurus venom‐induced cholinesterase actions (Vital Brazil, 1996). In the absence of antivenom this may be considered for rescue and short‐term use.

 Crotalid antivenin (pit vipers; rattlesnakes, copperheads, and cottonmouths):Antivenin (Crotalidae) polyvalent (equine origin) (ACP); lyophilized IgG preparation; (Antivenin™; Boehringer Ingelheim Vetmedica, Inc., St Joseph, MO – +1 866‐638‐2226); canine indication. Administration of one vial (reconstituted in 10–50 mL normal saline) diluted to 100–250 mL (volume depends on animal size) administered IV may be adequate for many cases, but three or more vials may be required in more severe envenomations.Antivenin Crotalidae polyvalent equine origin; liquid plasma preparation (Rattler Antivenin™; Mg Biologics, Ames, IA – +1 877‐769‐2340); canine and equine indication. Product is a whole IgG preparation. The product comes in 50 mL bags for use with an IV filtration administration set. A unique feature is that it contains all the clotting factors in addition to venom antigen antibodies. Typically, one or two 50 mL doses are adequate.Antivenin polyvalent Crotalidae (F(ab′)2 equine origin; liquid injectable preparation; (VenomVet™; MT Venom, LLC, Canoga Park, CA – +1 800‐385‐6914). Product is an F(ab′)2 preparation (two‐thirds molecular size of whole IgG). Slow IV administration over first 10 minutes. If no adverse effects entire dose should be given with 60 minutes.Additionally, there are two human FDA‐approved antivenin products for treating North American pit viper envenomation; however, implementation of use must be carefully considered as they may be difficult to obtain and are significantly more costly:Antivenin (Crotalidae) Polyvalent Immune Fab (ovine origin); lyophilized preparation; (CroFab®; BTG International, West Conshohocken, PA).Crotalidae Immune F(ab′)2 (equine); lyophilized preparation; (Anavip®; Rare Disease Therapeutics, Inc., Franklin, TN).

 Black widow (Latrodectus spp.) spider:Antivenin (Latrodectus mactans) (Black Widow Spider Antivenin, Equine Origin) (Merck & Co., Inc., Whitehouse Station, NJ 08889 – +1 800‐444‐2080) – this is a biologic drug, whole IgG antibodies, for use in humans; there is no scientific information on the use in horses. A single 2.5‐mL vial diluted to 100 mL administered IV may be successful in reversing signs (in humans, signs begin to subside in 1–2 h).