The European adder (Vipera berus) is Finland's only venomous snake. Adder bites are most common from May to September, especially in spring when the snakes have just woken from hibernation and are sluggish. Dogs are at greatest risk due to their curiosity — most bites occur on the snout or front paws. An adder bite is always a veterinary emergency.
Symptoms
Symptoms appear from minutes to hours after the bite. Local symptoms: severe swelling at the bite area, pain, two puncture wounds. Systemic symptoms: drooling, vomiting, rapid breathing, weakness, collapse. In severe cases: allergic reaction (facial swelling, breathing difficulties), blood clotting disorders, shock and collapse. A bite to the snout can cause life-threatening airway swelling. Symptoms may worsen over 24–48 hours.
First Aid
Keep your pet calm and still — movement spreads the venom faster. Do not try to suck out the venom, apply a tourniquet or ice the bite area. Carry the dog if possible. Seek veterinary care as quickly as possible — time is crucial. Photograph the snake if it can be done safely.
Veterinary Treatment
Treatment includes pain relief, anti-inflammatory medication or corticosteroids, intravenous fluid therapy and antihistamines when needed. In severe cases, antivenom is used. The patient is monitored for clotting factors, kidney and liver function. Most dogs recover within 2–5 days, but in severe cases hospitalization may take longer. Mortality with treatment is under 5%, but without treatment the bite can be fatal, especially for small dogs.
Prevention
Keep your dog on a leash in areas where adders are found (rocky areas, open terrain, forest edges). Adders are most active on warm mornings and afternoons. Check the terrain before letting your dog off the leash. If your dog has previously been bitten by an adder, the risk of a severe reaction is greater next time.