As the parent of a 12-year-old Parson Russell Terrier, I've been fortunate to watch Lily age gracefully into her twilight years while maintaining much of her spunk and agility. But each day I encounter clear signals that she's achieved senior citizen status: the onset of cataracts makes her timid around now-blurry strangers, and bathroom breaks are a frequent necessity (or so our carpet has learned the hard way). We remember fondly the tiny creatures we welcomed into our homes years ago, but the reality is that their bodies and minds are changing, and so too must their lifestyles. Here are a few tips to help ensure that your geriatric animal pals stay healthy and happy.

Sit and be fit. You may notice that your furry friend is less active these days. Understand that — just like grandpa — your pet is feeling his age, but this development does not excuse him from exercise. For dogs, daily walks relieve stiffness and limber up arthritic joints, but be prepared to turn for home when he exhibits signs of fatigue. Keep his reflexes sharp with a game of fetch or catch-the-laser-pointer, but tailor sessions to his mobility and energy limits.

Read on for more tips.

Round, round, get around. While certain breeds are prone to joint problems, many dogs and cats will begin to display mobility issues as they age. Arthritis is a common culprit, causing pups to slip on hardwood floors. Keep dog toenails trimmed, lay down nonslip surfaces around the house, and provide your pal with ramps leading to his favorite raised spots.

A cloudy forecast. Many dogs and cats develop cataracts or other vision impairments as they age. Vets can treat your pet's peepers through surgery, but it's probably not necessary until his vision severely affects his quality of life. Until then, a few daily adjustments should make your pal's life happy and safe. Dim lighting accentuates vision problems, so leave a light on in your pet's favorite areas. Avoid major changes to the layout of your home: imagine if someone turned out the lights and rearranged your furniture! Take Fido for walks when it's still bright out and choose paths that are free of obstructions. Keep him away from strangers and children if he acts frightened or aggressive.

Keep an eye on food intake. While your pet would certainly love to indulge in the local diner's senior special, his slowing metabolism may lead to indigestion if he overeats or consumes too much fat. Just like humans, obese pets have shorter life spans than pets who maintain a healthy weight. Your vet may recommend laying off the table scraps, switching to high-quality, low-fat geriatric pet food, and reducing portions.

Hydrate, hydrate, hydrate. Although food intake may decrease, your pet may quickly become dehydrated if he doesn't have access to plenty of water. Consider trading up to a pet fountain (which recirculates water, keeping it fresh all day) or place a few water bowls around the house near his favorite spots.

Don't go chasing waterfalls. Of course, moisture in equals moisture out, and that water needs to go somewhere. The inconvenient truth: your pet will need more frequent potty breaks. Cats will appreciate an extra litter box or two, and dogs will need more access to the great outdoors. You might consider investing in wee-wee pads for his bed and other areas where he likes to lounge in case of . . . er . . . leakage.

Don't be a stranger to your vet. In the end, doctor knows best when it comes to your aging pal's health. When Fluffy turns 7 or 8, request a baseline blood panel so that your vet can spot deviations later on. Your doc may want you to schedule twice yearly geriatric checkups; be sure to mention any changes in your pet's behavior or physical appearance so your vet can diagnose the problems and recommend treatment options. Even common changes noted above are worthy topics of discussion: an extreme or sudden change could be a sign of something serious.

Aging makes the heart grow fonder. Just because your pet is looking a little more rickety than he used to doesn't mean that his love for you has diminished. He's given you years of friendship, a workout buddy, and a furry shoulder to cry on. Reciprocate his devotion with more affection, snuggle sessions, play time, and other favorite activities to make his twilight years the best they can be.

Source: Flickr User chriswsn