Here's what you need to know about your dog’s health as he matures from 1 to 8 years:
Your dog is growing up. Louise Murray, DVM, director of the ASPCA's Bergh Memorial Animal Hospital in New York City and author of Vet Confidential (Ballantine, 2008), gives advice on how to keep your dog in tip-top shape.
Adult Dog Health: Preventive Health. Even if your dog appears fit, see your veterinarian once a year for a checkup. 'Most health problems are more readily and less expensively addressed if you catch them early,' Murray says. What's more, your vet can detect problems that you might miss. You can also stay up to date on vaccination boosters.
Adult Dog Health: Flea, Tick, and Heartworm Medicines. Continue to use preventive medicines. Talk to your veterinarian if you've moved or if your lifestyle has changed to make sure you are using the products best suited for your dog.
Adult Dog Health: Diet. Your pet needs the right food for optimal health. Check with your vet about adjusting the type and amount of food that your dog eats.
Adult Dog Health: Dental Health. If you haven't done so already, get in the habit of cleaning your dog's teeth daily. 'Animals who get gingivitis or inflammation of the gums can end up with problems of the kidneys and the heart,' Murray explains. Get your dog accustomed to having your fingers and hands around her mouth. At the pet store, you'll find dog toothbrushes and finger brushes as well as dog toothpaste.
Adult Dog Health: Weight Gain/Loss. When your dog steps on the scale at her annual visit, weight gain (rather than loss) is more likely to be the problem. Meals usually are not the culprit. It's the things, such as biscuits and human food, she gets in between. 'It all adds up,' Murray says. As your pet gets older, she becomes less active, which can contribute to weight gain and a host of other problems (diabetes, arthritis, and breathing trouble, for instance). But there's another reason to keep an eye on the scale: Weight loss might signal an underlying health problem.
Pregnancy and nursing are not only responsible for many changes in a dog's body, but for changes in her lifestyle as well. If your dog is pregnant or nursing, pay special attention to her changing nutritional needs as she carries, delivers and nurses her puppies.
If you're planning to breed your female dog, it’s important to assess her body condition well in advance of breeding. Because of the physical demands of pregnancy and nursing, a dog with less-than-ideal health can experience problems:
Be sure to feed the proper amounts of a complete and balanced diet. This will support the mother's healthy weight and body condition before breeding and help maintain her health and that of her babies throughout pregnancy and lactation.
The gestation period for dogs is nine weeks. Pregnant dogs gain weight only slightly until about the sixth week, and then gain weight rapidly.
The energy requirements of pregnant dogs are reflected in the pattern of weight gain. Pregnant dogs will need to consume 25% to 50% more than their normal food intake by the end of pregnancy, but energy requirements do not increase until about the sixth week.
The best diet for pregnant and nursing dogs is a high-quality, nutrient-dense pet food formulated for all life stages or for growth. Although puppy diets are generally recommended for pregnant or nursing dogs, large-breed puppy formulas may not be appropriate for this use due to their adjusted energy and mineral content.
Pregnant dogs lose weight after giving birth, but their nutritional needs increase dramatically. Depending on litter size, nursing dogs might need two to three times their normal food requirement to nourish their pups. Be sure your nursing mom has plenty of water so she can generate the milk volume she needs to feed the litter.
To help your nursing dog get enough nutrition, you can try several tactics:

By four to five weeks after birth, most puppies are showing an interest in their mother’s food. Gradually, the puppies will begin eating more solid food and nursing less. At the same time, the nursing mother will usually begin eating less. Most puppies are completely weaned around age 7 to 8 weeks. By this time, the mother's energy requirement is back to normal, and she should be eating her normal pre-pregnancy diet.