What can I give my dog for a cold?

I would not recommend giving your dog human medication bought over the counter, without consulting with a vet regarding proper dosage and type, as they can review the dog's medical history and ask probing questions to help determine if further care and a check up is needed. Sometimes, dogs cough and sneeze and can get a cold, just like us and it doesn't always require seeing a doctor. The protocol for healing relief would be similar fresh clear liquids, healthy food, warmth, humidified environment. However, it sounds like you're seeing a change in activity energy level and maybe there are more things to consider to rule out the possibility of a virus or infection.

The best thing you can do for your dog is to take her to a veterinarian. There are different types of colds and viruses animals can get. They can even get a canine version of the flu. Or different parasites could cause cold like problems. Keep her away from other dogs until you can get her seen by a veterinarian.