My Cavalier weighs 17.7 lbs. Is she overweight? What's a healthy diet?

From looking at the picture, Chloe looks like an ideal weight right now. I can appreciate a good waist yet I can't see her ribs. You can certainly decrease her food a little to help prevent her from continuing to gain weight but watch closely to ensure she doesn't lose too much weight. I hope this helps!

Yes, provided that Chloe is at a healthy body weight, 18% fat on a dry matter basis is fairly average for most dog foods and should be perfectly fine. I can't comment as to the volume of food that she is being fed because the caloric density of foods can vary widely. However, if you have further questions about feeding Chloe an appropriate amount, feel free to request a consultation or post additional questions.

Weight loss will definitely help with back trouble - sounds like you're already on the right track. I think that a prescription diet sounds like a great idea - talk to your veterinarian about options available through them. Hill's makes a Metabolic diet for weight loss that might be a good option. The other option might be to decrease the amount of food you are offering and eliminating all treats, chews and table foods. You could talk to your veterinarian about what R's estimated ideal weight would be, and formulate a diet plan based on how many calories are in her current diet.

Right now she looks OK but I would not want her to gain anymore weight. I recommend rechecking her weight in 2 to four weeks and if she's continuing to gain weight then you will need to decrease her food.

Before cutting down on her food, I would try limiting her treats. They are loaded with fat and have relatively few nutrients. From this photo, it is apparent that she has a "waistline." which is good. If when you run your hands down her sides you can't feel her ribs, she is too heavy. (If you can see her ribs, she is too thin.) Calories are not the only factors in a dog's weight gain or loss. Remember fat, too! Spayed females may be less active and more prone to weight gain, but it doesn't have to be this way. How about throwing a ball or Frisbee for her to chase? Finding another dog for her to play with? Perhaps a dog park (well-supervised!)? Good luck with trimming Chloe down a bit!

The recommended level for an adult, spayed dog is about 18% protein and 9-15% fat. If she is active as in a working dog, doing agility trials several times per week, or other high-intensity activities, then a higher fat/protein combination is needed as the body uses up more energy and the muscles need to be continually supplied with protein. However, for a typical house pet with regular exercise, sticking to the recommended amount is best. Overfeeding leads to excess calories which turn into fat and weight gain and are not used.

A Havenese should weigh between 7-13 pounds fully grown, so based on that, it could be that Kiba is a bit bigger. Now, he's a puppy, and because he's still growing, I don't recommend introducing any diets as they may interfere with his growth. To keep him from getting overweight, I would cut out all treats. Kiba shouldn't be getting treats every day, as a treat should only be an occasional thing. For now, however, no more treats, cheese, or chews. Just his dog food twice a day, feed according to the package instructions, and make sure that he gets exercise twice a day for at least 20-30 minutes :-)