What you need to check for if you think your dog might be sick:
I don't know about you, but I like to afford an expensive trip to the vets if at all possible. I mean we have to take our dogs for their shots, worming, neutering and stuff like that anyway. This video explains some of the basic checks you can do yourself to determine whether or not your dog is sick. THEN, you can decide whether it's important to take him or her to the vet.
Two of the checks are the same type of test you would do on a human, but the first one is different. She shows you how to check the color on a dog's gums and whether or not they are a healthy color. I remember taking my sheltie to the vet when she wouldn't eat and sure enough the first thing the vet checked was the color of her gums. Unfortunately they were not a nice, healthy pink and she was very sick.
Next is a demonstration of how to check a pup's heartbeat. I'm not sure that I would have known to check the heart-rate on my pup or the best way to go about it would be. So, knowing how to do this could be very helpful.
Lastly, the video shows how to take the temperature of your dog, cause again, just like with people, temperature is an indication of how sick someone is. Of course if the signs indicate your dog is not well you shouldn't hesitate to take him or her to the veternarian. I just like that there is some method of deciding whether or not my dog might be really sick or not. After all, those vet bills can really pile up fast!