My 4 Month Old Lab Puppy Has Diarrhea, What Can I Give Her?

I can not advise any treatment of diarrhea in your puppy because treatment of diarrhea depends upon underlying cause. There are many reasons of diarrhea in dogs. These can be

1. Changes in diet
2. Food allergy
3. Garbage eating
4. Gastrointestinal infection caused by bacteria, fungus, virus and parasites
5. Stress and anxiety
6. Side effects of medicines
   
7. Symptom of other diseases

So, take your dog to vet for diagnosis and advice.