There’s no getting around it: Everyone ages. Aging is a gradual biological process that begins at birth and continuously intensifies until death. No matter what the species, aging causes cellular, metabolic and organic changes.
Before becoming old, however, dogs become "mature." Maturity is a time when cellular changes start taking place that are the invisible forerunners of old age.
The changes that appear with age gradually increase the dog's susceptibility to disease and stress. In old dogs, the risk of mortality is considered to double every one or two years. That’s why it’s so important to make sure your older dog visits the veterinarian annually – or twice a year – for checkups. This is the best way of addressing changes before they become problems.
Here are some changes that may occur in an older dog:
- An increase in fat deposits, as the dog is fatter and cannot mobilize lipids as well.
- Reduced hydration, or chronic dehydration, which is harmful to proper functioning of the body.
- Reduction of immunity.
- Reduced resistance to cold and heat.
- Gradual reduction of kidney function.
- Slow demineralization of the skeleton.
- Destruction of cell membranes due to oxidative membrane stress.
- Increase in cases of liver or heart failure.
- Obvious increase in the frequency of both benign and malignant tumors.
- Gray hair and slack skin.
Once old age sets in, the dog’s teeth may suddenly become a problem, with increased tartar formation causing gum inflammations and infections leading to tooth loss. Also, less saliva is produced as soon as the dog becomes fat and adipose tissue invades the salivary glands. The passage of food through the intestinal tract slows, due to a decrease in intestinal muscle tone. This subjects the dog to bouts of constipation, often followed by diarrhea. The old dog’s intestine becomes increasingly less able to adapt to changes in diet. For this reason, the diet must remain the same. Absorption of the food is also less efficient, requiring that the dog be fed a highly digestible food.
Finally, the dog's senses and behavior also change:
- Loss of visual acuity and hearing are common.
- The sense of smell may diminish.
- Being weaker and less hardy, the dog becomes apathetic, requiring a food with a lower energy content.
As disheartening as these changes sound, there is an upside. You can counter many of the effects of the aging process with a high-quality mature diet and regular exercise.