My dog is lethargic with a dry nose. When should I see a vet?

Thank you for contacting PetCoach with your question about Winston. The good news is that a dry, warm nose isn't considered a sign of illness. This is because a dog's nose can go from wet and cold to warm and dry just by laying in the sun or next to the heat source. The lethargy is a little more concerning. It's a very general sign of illness, and can be caused by systemic illness, infection, inflammation, or injury. If Winston is eating and drinking, and his only symptom is lethargy, you can watch him for now. Keep him warm and comfortable. Should this lethargy continue over the next 48 hours, or he develops other signs such as coughing, vomiting, diarrhea, sneezing, nasal discharge, or anorexia, he will have to see a vet. If paying for a vet is an issue, you can see if your vet accepts payment plans, if there is a low cost clinic in your area, or you can apply for Care Credit online. There is also an organization called Red Rover that give grants for treatment of sick animals, and you can see if you qualify for one of their grants. Best Friends also has a list of resources that offer financial assistance on their website.
http://www.humanesociety.org/animals/resources/tips/trouble_affording_pet.html?credit=web_id91754962
https://www.redrover.org
https://www.carecredit.com
http://bestfriends.org/resources/financial-aid-pets
http://lessonsfromaparalyzeddog.com/when-pet-owners-cant-afford-veterinary-bills/
http://www.dogheirs.com/resources-affordable-veterinary-care/

Check out these resources to see if one can help you. Best of luck.