Going for several days without food is not usual for a healthy dog. I would ask, are you sure your dog eats absolutely nothing in this time, as I would be skeptical. Having said this, dogs can go for a number of days without eating, though this is not optimal.
The following is advice for a healthy dog. It is always a good idea to get your dog checked if you are worried. If your dog shows signs of poor health, weight loss, lethargy, any worrying signs, it is a good idea to get her checked professionally.
The best and easiest solution.
The best way to encourage a fussy eater to eat is to introduce competition for the food. Many dogs that eat slowly, are fussy and will not finish their food will eat reasonable helpings in good time when there is another dog present.
This is not always a viable option, especially to own a second dog. If you have any friends, family or neighbors with dogs, it would be worthwhile experimenting by feeding both dogs together, separate bowls, but within reasonably close proximity and see if this makes a difference. If not then there may be an organic cause for your dog's sussy eating behavior. As a general rule, though these things are behavioral and your dog has no reason to gulp her food quickly, and it pays her to be a fussy eater, as she is fussed over, petted, offered a variety of food and hand fed. It is good to remove these rewards if this behavior is a problem.
The harder and more realistic solution.
Consistency is the key word.
You must not feed her, except for what is in her bowl for the following to work. Make sure the family eats their evening meal first. When this is finished, place a set amount in the bowl for 30 minutes, and take it up until the next day and repeat. She needs to learn two things:
- She will not get treats by holding out.
- She is at the bottom of the pack, so needs to be grateful for the food she gets at the end of the meal. Currently, she is ruling the family, by waiting until she is fed the things she wants to eat.
If you give in, she will learn that she just needs to wait it out. She's obviously not starving, or she would eat, and the pay-off of holding out is worth it for her.
Ruling out health problems, you'll find your dog will eat what she needs to maintain a healthy body weight.
The one problem you will have is going to her less favorite foods, try and keep her on her most favorite dog food mixtures, this is something you can worry about changing down the track.