Here's what I recommend:
* Contact your vet immediately: This is a serious situation. Your vet needs to re-evaluate the wound, especially since it's not healing and continues to drain.
* Follow your vet's instructions: Listen carefully to your vet's recommendations for treatment and follow them diligently.
* Don't delay: Waiting can make the problem worse, potentially leading to infections and complications.
Possible reasons for continued drainage and lack of healing:
* Infection: The wound could be infected, requiring further antibiotics or stronger medications.
* Foreign object: A piece of the spider's fangs or other debris might be lodged in the wound, preventing it from healing.
* Underlying medical condition: Your dog might have a health issue affecting their immune system or wound healing abilities.
Remember, your vet is the best resource for addressing your dog's health concerns. Please contact them immediately to discuss this further.