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Snake envenomation in a dog. Elizabeth G. Welles* Merrilee Holland** Auburn University, *Department of Pathobiology, **Department of Clinical Sciences. Signalment and history. 7 yr old, F/S, mixed breed dog, 39 kg Bitten by a venomous snake evening of 5-29-07
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Snake envenomation in a dog Elizabeth G. Welles* Merrilee Holland** Auburn University, *Department of Pathobiology, **Department of Clinical Sciences Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only
Signalment and history • 7 yr old, F/S, mixed breed dog, 39 kg • Bitten by a venomous snake evening of 5-29-07 • Owner, a veterinarian, administered cephalexin, sucralfate, and dexamethasone • Next morning – hematuria • Admitted to AUSAC on 5-30-07 Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only
Southeastern venomous snakes copperhead, rattlesnakes, cotton mouth, coral snakeCrotalid venom • Enzymatic and non-enzymatic proteins • Hyaluronidases, collagenases – facilitate venom entry into blood and tissues • Phospholipases – injure endothelium inflammation, pain, vasculitis loss of fluid hemoconcentration, hypovolemia • Fbrinolytics, anticoagulants, procoagulants defibrination prolonged APTT, PT, TT, impaired platelet function, increased FDPs Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only
Patient was treated with antivenom, fresh frozen plasma, IV fluids, antibiotics, hydromorphone Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only
Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only
Blood smear 6-5-07 Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only
Outer leaflet Inner leaflet • Severity of envenomation estimated from fresh blood smears • Echinocytes echinospherocytes spherocytes • Echinocyte formation (I, II, III) self-limiting (48 hours) • Lecithin lysolecithin (via phospholipase A2) – outer membrane leaflet • Progression to echinospherocyte stage or beyond is irreversible • Cells sphere and lyse or removed by macrophages normal discocytes echinocytes echinospherocytes spherocytes Vet Path 1987;24:471-476 Vet Path1997;34:442-449 Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only
2 1 Discocyte (normal biconcave) Echinocytes 3 4 Echinospherocytes Spherocytes Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only Vet Path1997;34:442-449
Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only Blood smear 6-5-07