Understanding the 5 Domains of Pet Quality of Life: A Guide for Pet Owners

When your pet is diagnosed with a serious illness or entering their senior years, one question becomes increasingly urgent: "How do I know if they're still comfortable?"

You watch them closely. You notice every hesitation, every sigh, every change in routine. But without a framework to guide you, it's hard to know whether what you're seeing adds up to acceptable quality of life or whether it's time to have harder conversations with your vet.

This is where the Five Domains Model comes in.

What is the Five Domains Model?

The Five Domains Model is a scientifically validated framework used in veterinary medicine to assess animal welfare and quality of life. Originally developed for research and zoo animals, it's now widely used in companion animal palliative care, hospice, and end-of-life decision-making.

Unlike older models that focused only on physical health, the Five Domains Model recognises that quality of life includes both physical and mental wellbeing. It assesses five key areas—nutrition, environment, health, behavior, and mental state—to build a complete picture of how your pet is experiencing their life.

Veterinarians use this framework to guide quality-of-life conversations because it moves beyond subjective impressions and provides structure for evaluating comfort over time.

The Five Domains of Quality of Life for Dogs and Cats

Domain 1: Nutrition

What this includes:

• Appetite and interest in food

• Ability to eat and swallow

• Weight maintenance or loss

• Need for appetite stimulants or hand-feeding

• Nausea or vomiting

• Hydration levels

Why it matters

Loss of appetite is one of the most common signs of declining quality of life in both dogs and cats. However, it's important to distinguish between temporary appetite loss (common during illness) and sustained disinterest in food that doesn't respond to intervention.

What to monitor daily

• Did your pet eat their meals?

• Did they show interest in food, or did you need to coax them?

• Are they maintaining weight, or losing it steadily?

• Are they drinking enough water?

• Are they experiencing nausea or vomiting after eating?

If you're struggling to track these patterns, read our guide on how to know when it's time to say goodbye.

Domain 2: Environment

What this includes

• Physical comfort (temperature, bedding, access to favorite spots)

• Ability to move freely within their space

• Access to water, food, and toileting areas

• Hygiene and cleanliness

• Safety from stressors or hazards

Why it matters

As pets age or become ill, they may struggle to access the things they need. A dog who can no longer climb stairs to sleep near you, or a cat who can't jump into the litter box, experiences a reduced quality of life even if pain is well-controlled.

What to monitor daily

• Can your pet access their food, water, and resting areas comfortably?

• Are they able to toilet appropriately, or are accidents increasing?

• Are they isolated from the family, or still integrated into household life?

• Is their bedding clean and comfortable?

• Are they showing signs of distress due to temperature, noise, or household activity?

Domain 3: Health

What this includes

• Disease progression and stability

• Pain levels and pain control

• Response to medications

• Side effects of treatment

• Frequency and severity of symptoms

• Prognosis and likelihood of improvement

Why it matters

This domain assesses whether your pet's condition is stable, improving, or worsening, and whether interventions are supporting comfort or simply prolonging decline. It's not about whether disease is present—it's about whether the disease is manageable.

What to monitor daily

• Is pain well-controlled with medication, or breaking through?

• Are symptoms stable, or worsening despite treatment?

• Is your pet recovering from setbacks, or is each episode leaving them weaker?

• Are medication side effects affecting their quality of life?

Domain 4: Behaviour

What this includes

• Activity levels and mobility

• Interest in play, walks, or exploration

• Social interaction with family and other pets

• Sleeping patterns

• Anxiety, restlessness, or withdrawal

• Ability to perform species-typical behaviors

Why it matters

Behavioral changes often signal declining quality of life before physical symptoms become severe. A dog who no longer greets you at the door, or a cat who stops grooming, is telling you something important about how they're feeling.

What to monitor daily

• Is your pet still interested in activities they used to enjoy?

• Are they interacting with family, or withdrawing?

• Are they able to move around comfortably, or reluctant to stand or walk?

• Are they restless, pacing, or unable to settle?

• Are they showing signs of confusion or disorientation?

Domain 5: Mental state

What this includes

• Contentment vs. distress

• Anxiety, fear, or confusion

• Engagement with surroundings

• Responsiveness to interaction

• Presence of joy or positive experiences

Why it matters

This domain captures your pet's emotional experience of life—the aspect that's hardest to measure but perhaps most important. A pet may have manageable physical symptoms but still experience significant emotional distress, boredom, or loss of interest in life.

What to monitor daily

• Does your pet still experience moments of joy or contentment?

• Are they anxious, fearful, or distressed more often than calm?

• Do they respond to your voice, touch, or presence?

• Is there still a "spark" in their eyes, or have they emotionally withdrawn?

How Veterinarians Use the Five Domains Model to Assess Quality of Life

When you bring your pet to the vet for a quality-of-life consultation, they'll likely ask detailed questions about each of these domains. They're trying to understand not just whether symptoms are present, but how those symptoms are affecting your pet's overall experience of life.

For example:

• A dog with arthritis who still enjoys short walks, eats well, and greets family members may have good quality of life despite limited mobility.

• A cat with kidney disease who is eating, drinking, and grooming normally may still have acceptable quality of life even though the disease is progressing.

• A pet with well-controlled pain but increasing confusion, isolation, and loss of interest may have poor quality of life despite medical stability.

The Five Domains Model helps vets—and you—see the whole picture rather than focusing on isolated symptoms.

Scoring Quality of Life Using the Five Domains

Many pet owners and veterinarians use a simple scoring system to track quality of life over time:

5 = Good/Normal: Your pet is comfortable, engaged, and functioning well in this area

3 = Fair/Acceptable: There are mild or intermittent challenges, but they're manageable

1 = Poor/Concerning: Significant distress, discomfort, or loss of function

By scoring each domain daily, you can track whether quality of life is stable, improving, or declining. This is far more reliable than trying to remember how things were last week or last month.

More Good Days was created to help you track these domains easily at home, so you and your vet can see patterns clearly.

Special Consideration for Cats

For cats, veterinarians often add a sixth domain: Grooming and Self-Care.

Cats are fastidious groomers, and a cat who stops grooming is often signaling significant distress or illness. Changes in coat condition—matting, greasiness, or unkempt appearance—are sensitive early indicators of declining quality of life in cats, even before appetite or mobility changes become obvious.

What to monitor in cats:

• Is your cat still grooming themselves?

• Is their coat clean and well-maintained?

• Are they over-grooming (indicating stress or pain) or under-grooming (indicating lethargy or illness)?

Why Tracking the Five Domains Daily Matters

When you're caring for a senior or terminally ill pet, days blur together. You might think you remember how yesterday went, but stress, exhaustion, and anticipatory grief make memory unreliable.

Tracking each domain daily creates an objective record. Instead of relying on impressions, you can see actual patterns:

• Are mobility scores declining week over week?

• Is appetite becoming more unpredictable?

• Are good days becoming less frequent?

This data supports clearer conversations with your vet and helps you make end-of-life decisions based on evidence rather than fear or hope.

One Bad Day Doesn't Define Quality of Life

It's important to remember that one bad day in one domain doesn't mean quality of life is poor.

Pets with chronic illness will have fluctuations. Your dog might sleep more one day, then be more active the next. Your cat might skip breakfast but eat dinner enthusiastically.

What matters is the overall pattern across all five domains over time. If most domains are scoring 3–5 consistently, quality of life is likely acceptable. If multiple domains are consistently scoring 1–2, or if scores are trending downward week after week, it may be time to have a serious conversation with your vet.

How To Use the Five Domains at Home

You don't need to be a veterinarian to use this framework. Here's how to apply it:

1. Observe your pet daily across all five domains

2. Score each domain using a simple 1–3–5 scale

3. Record your observations so you can track trends

4. Review weekly to see whether quality of life is stable or changing

5. Bring your records to vet appointments to support clearer discussions

Many pet owners find that using a structured quality-of-life tracker helps them stay grounded during an emotionally overwhelming time. It's not about turning care into a checklist—it's about giving yourself a tool to see clearly when your heart is breaking.

When Quality of Life Declines: What to Do Next

If your tracking shows that quality of life is declining across multiple domains, or if scores are consistently low despite treatment adjustments, it's time to talk to your vet about your options.

This might mean:

• Adjusting medications or adding palliative care

• Considering hospice support at home

• Discussing euthanasia timing

These conversations are never easy. But decisions grounded in quality-of-life assessment over time are consistently associated with greater confidence and less regret.

How More Good Days Supports Quality of Life Assessment

We created More Good Days while caring for our Great Dane, Luca, through terminal cancer. We needed a way to track his quality of life that was structured but not overwhelming, evidence-based but compassionate.

More Good Days reflects the Five Domains Model in a format designed for daily use at home. It helps you track mobility, appetite, pain, hydration, and engagement, then automatically generates weekly summaries so you can see patterns clearly.

The goal isn't to tell you when it's time—that's a decision only you and your vet can make. The goal is to give you the clarity and confidence you need to make that decision when the time comes.

Final Thoughts

The Five Domains Model gives you a language for something that feels impossible to articulate: whether your beloved pet is still experiencing a life worth living.

It doesn't make the decision easier emotionally. But it does make it clearer.

And when you're facing the hardest goodbye you'll ever make, clarity is a gift.