When your pet receives a diagnosis of a life-limiting illness, or demonstrates signs that their life is winding down, good information can guide you to make good care decisions. A Quality-of-Life consultation can provide insight into your pet’s experience of their life, the things that still make life worthwhile, the things that add to their burden or make them vulnerable to suffering, and the options available to make them feel better. It can help you gain clarity about your priorities for caring for them, recognize and respond to their changing needs and make good choices.

An important part of being prepared to respond is an understanding of the disease process itself, and how things are likely to change over time. That is where an understanding of the disease trajectory can help.

There are three main disease trajectories and knowing which one applies to the condition with which your pet is dealing can help you plan accordingly.

I have attached a picture from the human literature below demonstrating the three disease trajectories. (BMJ. 2005 Apr 30; 330(7498): 1007–1011.)

1. The top picture shows a trajectory where there is a short period of evident decline preceding death. This trajectory is common for many cancers.
2. The middle picture shows a trajectory where there are long-term limitations and intermittent serious episodes prior to death. This trajectory is characteristic of heart or lung failure.
3. The bottom picture shows a trajectory of prolonged dwindling. Decline towards death through frailty or dementia usually follows such a trajectory.

Knowledge is power. Knowing what to expect when you are expecting your pet to die can help you recognize where you have the power to make the dying better than it otherwise might be.

If your pet has cancer you will want to be alert to a sudden change indicating that quality-of-life is beginning to tilt in the wrong direction. Time is of the essence and now is the time to intensively palliate symptoms or to arrange veterinary aid-in-dying.

If your pet has congestive heart failure you will want to recognize when your pet’s steady decline is allowing them to slip below an acceptable quality-of-life, or when they are not able to rebound to an acceptable level during a serious episode.

If your pet’s quality-of-life is deteriorating due to frailty or dementia, pain and mobility issues, or a disease like degenerative myelopathy, then you are less likely to witness a sharp decline however, it is important to recognize at what point your pet’s quality-of-life starts to slip into the unacceptable range. You are less likely to find yourself in a crisis situation but you need to pay attention to where things are going. You will likely have a bit more warning of when it is time to act to ensure your pet stays comfortable and safe.