Earlier this year, my husband and I noticed that our nearly twelve-year-old greyhound was limping. Obie is a retired racer, and suffered a broken leg back in his racing days, so we're used to seeing a slight shuffle to his gait. But this limp was worrisome, particularly since we know that greyhounds are prone to bone cancer.

We took Obie to the vet, who thankfully, assured us that his limp was nothing to worry about — but the scare did get me wondering about pet insurance. Considering our dog's age, we're probably going to see some expensive vet bills over the next couple of years.

If you have an older dog or cat, you may be thinking about pet insurance, too. Here's what you need to know about pet health insurance, and whether your four-legged friends will need coverage.

Is it worth the investment?

When looking at pet insurance think of it as an investment so if you intend to spend less on premiums than you receive in payouts, it may not be a worth the money. According to Robert Krughoff, president of checkbook.org, "it's common to pay $300 a year or more for pet insurance. Over the life of a dog or cat that might be $5,000 or more. Most people are not going to have a big expense like that."

For that reason, many consumer advocates recommend that pet owners set aside the amount of the premiums each year into a savings account, so if your dog or cat never has a serious health issue, you get to keep the money, rather than giving it to the insurance company.

How will your finances be affected?

However, that plan overlooks a couple of important issues: First, many people struggle with that kind of financial discipline. And second, even if you have no trouble setting the money aside, if your pet has a serious health emergency within the first couple of months after you start your savings account, you won't have enough in savings to cover the bill.

For this reason, it's a good idea to take your overall financial health into consideration when deciding on whether or not to purchase pet insurance.

Do you know how pet insurance works?

Another issue to remember is the fact that pet insurance does not work like health insurance, where a medical provider is paid directly by the insurer. Instead, the pet owner must pay the vet for the procedure and file a claim for reimbursement.

So even if you carry pet insurance, you still have to pay for your cats kidney stone removal. (This is yet another reason why a robust emergency fund is always a good idea.)

Does your pet have pre-existing conditions?

Unfortunately, my husband and I are probably too late in considering pet insurance for Obie. Though most policies claim to be for pets of any age (although some policies deny coverage for pets over the age of ten), policies often exclude pre-existing conditions — like Obie's old racing injury.

The older your pet is, the more likely it is there will already be a condition listed in their medical history. In addition, most insurance companies also exclude breed-related diseases, such as the bone cancer that is common to greyhounds.

Should you get pet insurance coverage?

Ultimately, pet insurance is, at least in part, an emotional decision. It helps protect pet owners from the agonizing choice between their beloved family member and money they cannot afford to part with.

In our case, my husband and I have had the difficult discussion about the dollar limit we're able to spend on any one pet health issue, and have earmarked a portion of our emergency fund for Obie's potential vet bills.

We just hope we are never in a position to have to revisit that dollar limit conversation.

Written by Emily Guy Birken for MoneyNing and legally licensed through the Matcha publisher network. Please direct all licensing questions to legal@getmatcha.com.