Antivenom

An antivenom is an antidote made of antibodies – not a synthetic agent, but a biological product. It is obtained from the blood serum of horses or sheep that have been immunised with the respective venom in a controlled manner. If snake venom enters the dog’s body, these antibodies bind directly to the venom molecules and render them harmless. The result: Further spread is stopped, organ damage can thus be prevented.

In short – the serum gives the body the tools it cannot build quickly enough itself.

Which venomous snakes are relevant in Germany?

Anyone out and about with their dog in Germany needs to know mainly one snake: the adder. It is the only truly native venomous snake here – and its bite can be life-threatening for dogs, especially smaller breeds.

In addition, the asp viper occasionally appears in the Alpine region, as do escaped exotic species. Such cases are rare, but medically they must still be taken seriously.

Adder bites occur almost exclusively between April and October, when the animals are active. Typical meeting places: heathlands, forest edges, boggy areas in northern and southern Germany. Anyone walking their dog through bushes there should keep this in mind.

How do I recognise a snake bite in a dog?

The first thing that stands out is usually two small puncture wounds – about 1 cm apart. Immediately afterwards, the area begins to swell, sometimes within minutes.

In the first 2 to 6 hours, further symptoms develop:

• A massive swelling that can spread over the entire leg
• Severe pain – the dog whines, pants unusually heavily
• Apathy and obvious weakness
• Pale mucous membranes
• In severe cases: shortness of breath, collapse

How intense it becomes depends on how much venom the snake actually injected during the bite – this varies greatly.

What do I do as first aid before seeing the vet?

The most important thing first: go to the vet immediately. But on the way there, there are a few things that can make the difference.

Keep the dog calm: Movement distributes the venom faster in the body. Carry the dog – do not let it walk, even if it wants to.

Cool the bite site: Cold compresses slow down the spread. Do not put ice directly on the skin.

Do not tie off: Pressure bandages or tourniquets are counterproductive with adder venom. Keep your fingers away from them.

Do not suck out: This only spreads the venom further and simply does nothing.

How available is antivenom in German veterinary clinics?

Most veterinary clinics in areas with many adders have the antidote in stock – but not all. Smaller practices often only order it when needed, which can cost valuable time.

The catch: A dose of antivenom against adder venom costs between 300 and 800 euros. Many clinics do not store it permanently because it is rarely needed – and expires. A classic dilemma.

In emergencies, the vet contacts the nearest university clinic or regional poison information centre. Access to various antiserums is usually available there.

The total treatment – antivenom plus intensive care over several days – often costs between 1,000 and 3,000 euros.

How does the antivenom work in treatment?

The vet administers the antivenom intravenously, usually diluted via a drip. The antibodies bind to the venom in the blood within minutes – this happens faster than many would expect.

At the same time, fluid therapy runs to support circulation and kidneys. Painkillers are added, as the pain is often considerable.

After a few hours, the swelling subsides and the dog becomes more alert again. Full recovery usually takes 5 to 10 days.

With timely treatment, almost all dogs survive. Without antivenom, however, a noticeable proportion of bitten dogs die – which underscores the urgency.

What side effects does antivenom have?

Because the serum is derived from horses, the dog’s body may react to it. A small proportion of treated animals show mild symptoms such as a rash or fever.

Severe reactions – shortness of breath or anaphylactic shock – occur in less than 1 per cent of cases. Therefore, the vet closely monitors the dog during administration.

Late reactions are also possible after 1 to 2 weeks: joint pain or renewed fever. In most cases, this resolves on its own, but should be reported to the vet.