1.) Consider death, before life. The hardest time it will ever be to consider the passing of a pet is after the animal has integrated into your family and become a beloved staple. Unfortunately, young or old, a new furry family member means that it's passing is inevitable. While the modern house cat enjoys a hearty 12-15 years of life, and the modern dog (breeds vary) 10-13, animals, like people, can suffer from unexpected illness and injury.
We are fortunate to have the power and resources to prevent extended suffering of an animal in old age or terminal illness, but even those decisions require prior consideration. Much like a human family member it is best to discuss and look into the proper handling of a deceased or severally ill pet far in advance of the situation arising. Considering these circumstances before you adopt or bring a pet into your family will make you more aware of the options during the difficult time, even 10+ years down the line.
2.) Understand what to expect and how to handle it. While you can never be prepared to let go of a family member, knowing more about your pets breed and size will better equip you to handle their passing. Large breed dogs will prove the hardest to handle in situations that are sudden and unexpected. As unpleasant as the topic is, the animal's body will begin to stiffen and become hard to mange in as little as 10 minutes after it's passing. It may be hard to handle your beloved pet in such a manner but steps will need to immediately be taken to avoid further unpleasantness. Educate yourself on safe handling of a passed pet and have the proper supplies packaged in a sort of emergency kit (medical gloves, heavy duty trash bags (x2 or 3), a bog or container, etc).
Be prepared to store your pet's body in a manner that will postpone decomposition, such as in a deep freezer, or have a local veterinarian or pet crematory's number on hand. Much like human handlers, pet crematories will often have an after hours number and can pick up your pet's body in as short as an hour. Expect these services to be additional- if the costs are outside your family's financial budget, the pet may often be brought to a veterinarian for storage up to 3 days. Plan ahead of time and ask these questions long before the services are needed so the process is smoother and you are informed.
4. Enlist a friend. It is always a good idea, even at adoption, to have someone outside the family in mind to help handle a pet's passing. Think of this as a furry godparent- anticipate it to be someone near enough to be there in a time of need, but ideally not someone who be connecting directly with your pet throughout the years. It is never easy to cope with and handle the passing of an animal, but having someone there who has pet sit and developed a bond with your animal can be as equally emotionally rough for you and your family. If your animal is a large breed consider someone who will be able to help handle the body in difficult circumstances, while remaining respectful and consoling.
5. Plan a memorial. Especially if you have children who may not be able to comprehend the passing of an animal, but in general a good idea. In most cases your pet will be cremated and you will be give access or the option to obtain your pet's ashes. This may be of note for families with pets 15+ years, though others will wish to hold onto more physical trinkets that represent good memories within the pet's life. You may feel the urge to hold onto everything your pet touched at first but it is always best to cleanse your home of the majority of these items, save those tiny trinkets sooner than later. Having in an in home gathering of your immediate house family members and saying a few words over a good meal can substantially help in the healing of this difficult period.