When Behaviour Change Is Really Pain

A group of veterinary behaviour specialists reviewed 100 recent dog cases from their own referral clinics. They estimated that “a conservative estimate of around a third of referred cases involve some form of painful condition, and in some instances, the figure may be nearly 80%” (Mills et al., Animals 2020).

Those dogs were referred for behaviour problems. In many of them, the problem was pain.

While training and behaviour therapy help many dogs, a dog in pain may not improve with them, and the pain goes untreated meanwhile. The specialists’ advice to vets is blunt: “it is better for veterinarians to treat suspected pain first rather than consider its significance only when the animal does not respond to behavior therapy.” This page sets out what they found, and what to look for.

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1. What the specialists found

The paper is a commentary, not a controlled study. The authors are open about that. They write that “It is difficult to present definitive evidence concerning the breadth of the problem given the individuality of problem behavior.” They drew on cases from clinics in the UK, the US and Spain.

The figures varied widely between clinics. In the six caseloads they tabled, the proportion of behaviour cases where pain was suspected ranged from 23% to 82%. Musculoskeletal pain was the most common, especially the hip, the knee (stifle) and the spine. Gut and skin pain also featured.

Four ways pain and behaviour connect. The authors suggest pain can:

1. be the problem, as when a dog snaps when touched in a sore spot
2. sit underneath it unrecognised, driving a fear or anxiety
3. make an existing problem worse
4. show up as extra behaviours alongside it

Our note: The paper’s summary gives the range as 28–82%, but its own table shows one clinic at 23%. We give the table’s range. The examples in the list are our illustrations.

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2. Signs that pain may be involved

Behaviour signs. Mills and colleagues list signs vets will recognise as pain: “shifting between limbs when standing, an abnormal gait, propping oneself up against convenient objects, interruptions to gait/and sudden freezing, an unusual approach to lying and sitting”. They also list unusual or hesitant toileting, and “nibbling or scratching of a specific area, especially if sudden and accompanied by a skin flinch or yelp.”

Aggression that seems to come from nowhere. The authors explain that a dog in pain may skip the usual warnings, “This could make the behavior appear sudden and without warning.”

Reluctance. They cite findings in dogs with spinal problems: “unwilling or reluctant to jump up onto objects/into vehicles”, reluctance to sit, increased anxiety, and “sudden onset of aggressive behaviors”.

A change in an older dog. A sudden new problem in a dog who has been settled for years is worth a vet visit before a trainer.

Our note: The “older dog” line is our advice, based on the late onset found in the noise study and the paper’s case reports.

→ Reading Pain in an Old or Sick Dog

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3. Fear of noises, and pain

A 2018 study at the University of Lincoln compared 10 noise-sensitive dogs with musculoskeletal pain and 10 without (Lopes Fagundes et al., Frontiers in Veterinary Science 2018). In the dogs with pain, “the age of onset of the noise sensitivity was on average nearly 4 years later”.

They also showed “widespread generalisation to associated environments and avoidance of other dogs”. A noise on a walk could make the dog avoid a whole area. And they “responded well to treatment once the involvement of pain had been identified.”

That is 20 dogs from one clinic. But it supports the specialists’ point: a dog that develops a new fear later in life should be checked for pain.

→ Separation Anxiety: Training, Medication, and What the Trials Show

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4. What to do

• See your vet before, or alongside, a trainer or behaviourist. Say what has changed and when it started.
• Video the behaviour, and also how your dog walks, sits, lies down and gets up. Your vet sees your dog for a few minutes, in an unfamiliar place.
• Ask whether a trial of pain relief makes sense. In the paper’s case reports, some dogs improved markedly once pain was treated. Your vet decides whether, and what.
• Don’t punish growling or snapping. It may be the only warning a dog in pain can give.

Our note: The video advice and the “don’t punish growling” line are ours, not quoted from the paper.

→ Reward-Based or Aversive Training: What the Studies Found · → Arthritis Treatment: What Works, From Weight to Medication · → Cruciate Ligament Rupture: Surgery, Conservative Care, and the Evidence Gap

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5. What we could not verify

Commonly said	What we found
“He’s just grumpy in his old age”	Maybe, but check. Specialists estimate pain is involved in around a third or more of referred behaviour cases.
“A dog in pain will limp or cry”	Not always. Signs can be subtle: shifting weight, sitting oddly, reluctance to jump.
“Aggression without warning means a bad temperament”	Not necessarily. Pain can make aggression appear sudden and without warning.
“Pain causes a third of behaviour problems in all dogs”	Not shown. The estimate comes from specialist referral caseloads, not from dogs in general.
“Training will fix it”	Not if pain is driving it. Specialists advise treating suspected pain first.

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Sources

• Mills DS, Demontigny-Bédard I, Gruen M, Klinck MP, McPeake KJ, Barcelos AM, et al. Pain and Problem Behavior in Cats and Dogs. Animals (Basel) 2020: commentary drawing on specialist caseloads; not a controlled study
• Lopes Fagundes AL, Hewison L, McPeake KJ, Zulch H, Mills DS. Noise Sensitivities in Dogs: An Exploration of Signs in Dogs with and without Musculoskeletal Pain Using Qualitative Content Analysis. Front Vet Sci 2018: qualitative study, 20 dogs

Always confirm with your vet before acting on anything on this page.