If your dog is limping then his/her problem of not able to walk is related with injury, fracture, hip dysplasia, etc. If he/she is not able to walk due to weakness or lethargy then diarrhea is the cause because diarrhea can cause dehydration leading to lethargic symptoms. Diarrhea in dogs can be due to
- Stress or anxiety
- Bacterial, viral, fungal and parasitic infections of gastrointestinal tract
- Allergy to foods
- Food intolerance
- Side effects of medicines
- Eating of garbage
- Cancer of GI tract
- Lymphoma
- Diarrhea due to other diseases
