Provided you like the dog you have, you probably want it to live a long, full life in good health. You can't make them live forever, but here are some life-shortening risks that you CAN control.

1. Inferior Diet

You saw that one coming, didn't you? Low-quality and even outright toxic ingredients in commercial dog foods and treats will erode your dog's health. Cheap kibble may look like a bargain but you'll end up paying for it in other ways. Did you know that loose stools, gas, runny eyes, ear infections, greasy fur, itchiness, attention deficit, lethargy, and liver and kidney damage can all be related to poor diet? Chose a food that is grain-free and sourced in the US. Check on how your current food measures up at Dog Food Advisor

2. Lack of exercise

News flash: exercise releases endorphins, improves muscle tone, circulation and organ function, and reduces obesity. Active dogs are healthier than sedentary dogs. They are also less destructive and nervous because their energy has a happy outlet in the exercise you choose for them.

Obesity negatively affects blood sugar regulation, blood pressure, kidney health, and heart health, and contributes to crippling joint conditions. Dogs who are overweight typically lose about 2 years of their lives compared to their fit counterparts. If you can't easily feel your dog's ribs with your hand, you should consider making changes to your current exercise and feeding plan.

3. Not Vaccinating Puppies

Infectious diseases are the leading cause of death in puppies, mostly from parvo. The immunization known as DHPP (distemper, hepatitis, parvovirus, parainfluenza), given as a series of shots between 8 and 18 weeks, will protect young dogs from the most dangerous canine diseases. Oh yeah, and remember Old Yeller? Rabies is still alive and well all over the US in skunks, bats, feral cats, foxes, coyotes and raccoons. If your dog gets scratched or even drooled on by an animal that is acting odd, he had best have his rabies vaccines up to date. Otherwise, it's an early trip to the Rainbow Bridge, possibly by way of being seized by Animal Control.

4. Not Training

Yes, you can actually contribute to your dog's untimely demise by not training him or her. The leading cause of euthanasia in the US is "behavioral problems" (i.e., the dog acts like a normal dog instead of like Lassie). Here's how to create an aggressive, fearful, difficult to manage, destructive and at-risk dog:
1. Fail to socialize your puppy during the critical period of 12-16 weeks.
Many people are concerned about taking their pup out before the final set of shots. However, taking partially-vaccinated puppies to low-risk public areas is not as dangerous as under-socializing the dog.
2. Recklessly give your young dog as few restrictions and instructions as possible. When there is a void of leadership regarding house rules, dogs do what comes natural. Train early and often to prevent rather than just cope with common problem behaviors as they develop.
3. Fail to rigorously practice teaching your dog to come when called. This is a great way to let your dog get mauled, run over, or lost some day.
It takes a lot of consistent, deliberate work to mold a crazy little canid pup into a pleasant, domesticated companion. Well-socialized dogs who engage with their owners in positive training activities are more relaxed and happy at home and in public.

5. Slow Access to Care

"A stitch in time saves nine." Since dogs can't tell us how they're feeling, the alert owner must note and be prepared to act on any behavior out of the ordinary. Signs like change in stool texture, increased water drinking, salivation, lethargy, increase in self-licking, restlessness, panting, and anxiety all point to invisible health issues.

Make an effort to find a vet you can trust and develop a client-history with them. A good private-practice vet will be available after hours for true client emergencies. Be aware of common, fast-acting killers like bloat, salmon poisoning, GI blockage, and foxtails.

6. Not Treating For Heartworms

Seriously, these things are nasty and fairly common in California. They literally live in the dog's heart, enjoying a warm, constant meal of blood. As you might expect, having a parasite infestation can negatively impact a dog's heart-health. Fortunately, a simple dose of ivermectin every 30-60 days will prevent heartworms from developing. Read more about heartworms

7. Inadequate Management

Fences, leashes, crates, and gates will all increase your dog's life-span. Management is about not letting a dog "do what comes natural", getting into dangerous things. There are countless canine risks in our modern world, from cars to fishbones to other dogs to rat poison to open canals to that pack of sugar-free (Xylitol-containing) gum on your nightstand. You can't save your dog from everything. But you can sure try your best not to be careless. Use common sense; be aware; be the Responsible One. Dogs should not be expected to "know" how to behave in our strange modern world. Train, manage, and look after your pet so that he or she can share a long and happy life with you!