Nutrition is the first pillar of your pet health.
Understanding needs
Dogs and cats are carnivores: their protein needs are high. Industrial kibble generally covers the necessary intake.
Read labels
Prioritize foods where meat is the first ingredient. Beware of excess grains.
Adapt to age
Puppy, adult, senior: needs vary. Adapt the formula.
Hydration
Fresh clean water must be available at all times. Cats tend to drink little: consider fountains.