Why Logging Your Dog's Behaviour Changes Matters

There's a particular pattern in how owners describe the onset of illness in their dogs. It nearly always involves behaviour first. "He'd been quieter than usual for about two weeks." "She stopped meeting me at the door." "He wasn't interested in his ball, which is unusual."

These observations get noted mentally, filed under "probably nothing", and then mostly forgotten. When the dog is eventually diagnosed with something, the owner often says - in hindsight - that they'd noticed something was different for a while.

This gap between noticing and acting, and between noticing and recording, is where health journals do some of their most useful work.

Why behaviour changes matter medically

Behaviour changes are often the first sign of a specific condition. See the monitoring guides for arthritis, anxiety, dental disease, obesity, and UTI.

Dogs are stoic. They don't complain about pain the way humans do. What they do is change their behaviour: move more carefully, engage less, avoid things that hurt, become less patient, sleep more. These changes are often subtle enough to miss in isolation but significant in aggregate.

Pain expresses itself behaviourally before physically in many dogs. A dog with developing arthritis may start avoiding the stairs before they're visibly limping. A dog with dental pain may eat more slowly, prefer soft food, or drop pieces from their mouth before they refuse food entirely. According to veterinary professionals surveyed for the PDSA PAW Mini Report 2025, 25% of vets ranked obesity among the top five welfare concerns for dogs - and obesity itself is a leading cause of painful conditions like arthritis that present as behaviour change before they present as visible symptoms.

Urinary tract infections often present as house-training accidents - a previously reliable dog starts having accidents indoors. This is a medical problem, not a behavioural regression.

Neurological conditions including early cognitive dysfunction, vestibular disease, and spinal cord changes can present as confusion, apparent forgetfulness, changes in gait, or loss of previously reliable skills.

Hormonal conditions - hypothyroidism, Cushing's syndrome - can alter temperament, energy levels, and mental sharpness.

Pain from internal sources - abdominal pain, referred pain from organ disease - often makes dogs quieter, less tolerant of handling, or reluctant to move in ways that exacerbate the pain.

The adaptation problem

When behaviour changes gradually, we adapt to the new normal without registering the change. This is how you end up not noticing that your dog hasn't initiated play in three weeks, or that they've been sleeping through your morning routine when they used to be your alarm clock. The PDSA PAW Mini Report 2025 found that 82% of UK dog owners reported their dog had never shown problematic behaviours - suggesting that when behaviour does change significantly, owners may be particularly likely to normalise it rather than treat it as a signal.

A log entry from three weeks ago that says "seemed really keen for the walk, brought his lead before I'd even put my shoes on" creates a reference point. When you write today's entry - "seemed reluctant to leave the house, shorter walk than usual" - you can see the contrast.

Without the earlier entry, you might not have noticed there was a contrast.

What to write

The bar for an entry is lower than most people set it. You don't need to know what something means. You just need to describe what you observed:

• What was different from usual
• When you first noticed it
• Whether it's isolated or part of a pattern
• Any accompanying physical changes - appetite, water intake, mobility

"Seemed less interested in his toys than usual tonight. Has been the same for the last few days. Still eating fine. Not sure if I'm imagining it." That's a complete, useful entry.

If you're not sure whether something is worth writing down, write it down. You can always decide later that it was nothing. You can't go back and create a record of something you didn't note.

Video as a supplement to written notes

For behavioural concerns, brief video clips are often more useful than descriptions. A clip of your dog's gait, their greeting behaviour, or them getting up from rest gives a vet far more information than "she seems to be moving differently."

Most smartphones record usable footage easily. File it alongside written notes with a date.

When to act rather than just record

Some behaviour changes warrant a vet visit rather than a log entry and a wait-and-see approach. Call your vet if:

• The change is sudden and severe
• There's apparent pain or distress
• The behaviour change is accompanied by physical symptoms - vomiting, not eating, urinating more
• A previously friendly dog becomes aggressive or snaps without warning
• Your dog is a puppy, senior, or has an existing health condition

For gradual changes without obvious acute symptoms, logging and monitoring for a week is usually reasonable. If it's still present after a week, book an appointment.

Frequently Asked Questions

What if I write it down and it turns out to be nothing? That's the best outcome. A vet who reviews your notes and says "this is all normal" is giving you reassurance with evidence, not just reassurance. And the habit of noting things means the genuinely important changes get recorded too.

How specific do entries need to be? Specific enough that you'd understand it in six months. "Seemed off" is less useful than "reluctant to go for the evening walk, sat by the door instead of running ahead. Has happened three times this week." The more detail you can capture at the time, the more useful it is later.

My dog has always been lazy. How do I know if the behaviour is actually different? Compare to your own baseline for that dog, not a general expectation of what dogs should do. A greyhound who sleeps 18 hours a day being slightly slower than usual isn't meaningful. The same greyhound who used to spring up for their evening walk now needing to be encouraged - that's a change from their baseline, and it matters.

Does logging behaviour changes help with behavioural issues as well as health? Yes. Understanding the pattern of a behavioural problem - when it happens, what precedes it, how severe each episode is - is exactly what a clinical animal behaviourist needs to build an effective plan. The log is the same whether you're tracking for medical or behavioural purposes.