Hoping for the best could cost owners dear, with vets' fees rising by an estimated 12% a year, according to a survey for Debenhams Pet Insurance.
It says almost one in five pet owners report that they have made financial sacrifices in order to continue paying for the care of their animals.
The average annual spend by a dog owner is nearly £100 a month, while for cat owners it's £85, yet treating a dog at the vet could cost £800 or more.
Meanwhile, cold weather and over-indulgence at this time of year can cause significant health problems – and that's just for pets. According to pet insurers certain types of claims tend to go up in the winter months.
One insurer saw a 79% increase in claims for poisoning in December last year as a result of dogs eating the wrong things.
John Ellenger, at insurer More Than, said: "Most owners know that chocolate is toxic to dogs and in some cases as little as 2g of dark chocolate can cause dogs to vomit and suffer from muscle tremors. Sadly, in some instances it can also be fatal.
"To help prevent this happening, remember to avoid low hanging chocolate tree decorations or tempting edible presents wrapped under the tree."
Poultry skin, fat trimmings, rich gravies and buttery sauces can also upset dogs' digestive systems, while onions, chives, leeks and sage and onion stuffing can be poisonous to them.
Other insurance claims are weather-related.
Stephen Ebbett, director of specialist insurer Protect Your Bubble, said: "In the cold winter months we see ailments that can be linked to cold weather – such as cut pads on the feet caused by ice or frozen ground, coughing and respiratory problems, and arthritis – increase quite dramatically."
One problem owners face is choosing from the large number of insurance policies available.
In the case of dog insurance, around 70 companies offer more than 280 product variants, according to financial researchers Defaqto.
Comparison websites such as Gocompare.com or Confused.com. do offer pet insurance, but the danger is that you may be tempted to choose the cheapest option, which may not always be the best.
Mike Powell, general insurance specialist at Defaqto, said: "The problem with pet insurance is that it is not like car or home insurance. You can't switch the cover around each year. You have to get it right at the start of your pet's life.
"Comparison sites are getting a bit better (at giving qualitative information), but price should never be your main focus."
The main costs pet owners want covered are vets' bills, so it is important to be aware that there are three main different types of policies.
There are per condition policies, which will pay for the treatment of your pet's condition up to a certain maximum amount, say £5000, but with no time limit.
There are time-limited policies which also pay a maximum amount per condition, but with a 12-month limit on the treatment period. Once either limit has been reached no further pay-outs will be made. So even if you renew the policy, the condition will then be excluded. These policies are the cheapest.
The best pet insurance policies are the lifetime products. The amount that can be claimed for vets' bills in any one year is limited, but each time you renew your policy the limit is reinstated. This means that if your pet has a recurring problem, it will still be covered.
If you have a special breed of animal which may be prone to certain types of hereditary conditions, it is advisable to choose this type of policy.
The problem is that you can't switch to this type of policy later, because once you have made a claim for a certain condition, insurers will generally exclude any pre-existing conditions that your pet has suffered.
Besides the type of policy, the premium will also be affected by a pet's breed and gender. The location can also affect premiums because vets are more expensive in some areas than in others. As a pet gets older, the cost is likely to increase and there could also be a change in the excess which you have to pay when you make a claim.
Most policies apply a "flat rate" excess, for example £50, but as a pet gets older, some insurers may ask you to pay a percentage of the treatment costs, say 10%.
According to Defaqto, pet insurance premiums can even be influenced by the owner's gender, age, and marital status.
It suggests that ways of keeping costs down include having your pet neutered and having it microchipped, as it will be easier to locate it if it is lost or stolen.
Alastair Thomson, 44, from Edinburgh is the proud owner of two labradors, two and four years old – the same age as his children.
He pays £18 per month for pet insurance from Sainsbury's Bank and says: "I had grown up with dogs and I know my father never insured his animals but I think people have different expectations nowadays."
He has good reason to be thankful as he has already claimed three times on his policies.
"The older dog broke a toenail at about six months old and had to have an operation to have it removed.
"The younger ate a child's sock when it was a puppy and also had to have an operation – then it did the same thing again a few months later."
Mr Thomson says the main reason he chose the policy is because the labradors will sometimes act as gun dogs for friends – and not all insurers will cover that type of activity.