It depends on the breed of dog, but your pet's senior years generally begin at age 7. Louise Murray, DVM, director of the ASPCA's Bergh Memorial Animal Hospital in New York City and author of Vet Confidential (Ballantine, 2008), tells you what you need to know to keep your older dog spry and happy.
At this stage, Murray recommends taking your dog to the vet twice a year. 'So much can happen to an elderly dog,' she says. Your veterinarian can take blood annually to test liver and kidney functions. 'Discovering problems early is extremely important,' she says. Your vet can be on the lookout for conditions that often affect older dogs, such as anemia and arthritis.
Pay attention to what might be subtle changes in your dog's habits: Is she drinking more water or urinating larger amounts? These behaviors might indicate a liver or kidney problem. Have your dog's bowel movements shifted? This could indicate a digestive issue. Diabetes or digestive problems might cause your dog to eat more but still lose weight. Knowing the dog's patterns can help the veterinarian determine a course of treatment.
Continue to use preventive medicines.
Clean your dog's teeth daily. If she has tartar buildup, you might need to have her teeth professionally cleaned at your vet's office, which requires sedating your pet.
Your dog is probably less active, so steady, moderate exercise is best for her now. Don't turn her into a 'weekend warrior' who, after lying around on weekdays, accompanies you on a 10-mile hike on Saturdays. This is especially hard on an older dog's joints.
Your veterinarian might wish to put your dog on a senior diet, such as IAMS™ ProActive Health™ Senior Plus. These formulations contain nutrients specifically geared toward older-dog health.
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.