Dog behaviour: is it normal, or time to see a vet?

Every threshold in the checker and on these pages comes from a veterinary source we read on the day the page was built. We use only these: the Merck Veterinary Manual, the AVMA, the ASPCA, AAHA, the American Veterinary Society of Animal Behavior (AVSAB), the Cornell Feline and Riney Canine Health Centers, International Cat Care, the RSPCA, VCA Animal Hospitals, and peer-reviewed papers. We do not cite other pet websites.

The rules are written as data, one small file per behaviour, and each rule points at the source it rests on. Where no source gives a cut-off, such as how many days of a symptom is too many, we do not invent one. The rule says “Call your vet to be safe” instead.

Every result is one of four verdicts:

• Usually normal: common, expected behaviour in a dog that is otherwise well.
• Worth watching: not urgent, but keep notes and book a check if it carries on or gets worse.
• See a vet today: call your vet and be seen today.
• Emergency: go now: go to your vet or the nearest emergency clinic now, and phone on the way.

Each source, the claims it supports and the date we read it are logged in a data review file for every page, and listed under “Where this comes from” at the foot of the page.

More often than most owners expect. The Merck Veterinary Manual says medical causes must be ruled out before a behaviour problem is diagnosed, and that pain is an important risk factor. In one study of dogs seen by veterinary behaviourists, signs of pain were found in 28% to 82% of cases. (Merck)

Medical problems that can change behaviour include:

• Pain, which can turn a gentle dog defensive when touched or moved. Merck calls this pain aggression. (Merck)
• Kidney or liver disease, nerve disease and hormone disorders, which can all cause aggression. (Merck)
• Arthritis, which can stop a dog getting up to greet you, and kidney disease, which can cause accidents indoors. (VCA)
• Pain showing as fast breathing and restless, unsettled behaviour. (AAHA)

The pattern to look for is change: a dog that starts doing something new, or stops doing something it always did. Merck advises seeking veterinary help as soon as any sign of aggression appears. (Merck)

It can be. Cognitive dysfunction syndrome is a slowly progressive, age-related decline in thinking and behaviour, and VCA says experts recommend yearly screening for it in dogs from 7 years of age. (VCA) Your vet will also check for arthritis, kidney disease and other problems that can look the same. Our dog age calculator shows where your dog sits.

Vets group the signs under the letters DISHAA:

VCA advises a physical and behavioural check for any dog showing more than one of these signs. (VCA)

Dogs talk with their whole body: posture, face, tail and ears, raised hackles, voice, scent and touch. Our dog body language chart shows how to read them. (Merck) Breed is a weak guide on its own, because dogs within one breed vary as much as dogs of different breeds. (Merck)

Age shapes behaviour more. The Merck Veterinary Manual describes these stages:

Puppy chewing, mouthing and testing limits are expected. The same behaviour appearing suddenly in an adult or senior dog is the kind of change worth a check. Our puppy weight calculator covers the growth side of the same months.

The ASPCA lists aggression as the most common and most serious problem, and stresses finding the reason for a behaviour before trying to treat it. (ASPCA)

• Aggression, including growling or snapping when touched: rule out pain first and see your vet early. (Merck)
• Barking and howling: work out what sets it off. Our barking cause finder builds a plan. (ASPCA)
• Distress when left alone, often with chewing or noise: see separation anxiety. (ASPCA)
• Chewing, mouthing, mounting and food guarding: common, and each has its own cause. (ASPCA)

Vets diagnose behaviour from a careful history and from seeing the behaviour itself, so what you bring matters. (Merck)

1. When it started, and whether it came on suddenly or slowly.
2. When and where it happens, and what seems to set it off.
3. Whether it is getting better, worse or staying the same.
4. Any change in eating, drinking, toileting, sleep or energy.
5. A short video on your phone. Merck calls video of the behaviour an invaluable diagnostic tool. (Merck)
6. Any medicines, past illness, or anything your dog may have eaten. (Merck, AVMA)

For breathing, keep it simple: say you are worried about the way your dog is breathing, and that it started at home, since many dogs breathe faster at the clinic anyway. (AAHA)

No. The American Veterinary Society of Animal Behavior recommends only reward-based methods for all dog training, including the treatment of behaviour problems. (AVSAB)

• Avoid aversive tools such as shock collars, prong collars and choke chains. (AVSAB)
• Techniques that cause pain or fear can lead to lasting fear, anxiety and aggression. (Merck)
• Physical punishment can make an aggressive dog worse. (Merck)
• Reward the behaviour you want, and change the setting that triggers the one you do not.

Today, if any emergency sign is present, or your dog may have been poisoned. (Merck, ASPCA) As soon as you can, if your dog has shown any aggression. (Merck)

For a new behaviour without those signs, the veterinary sources give no fixed number of days to wait, so call your vet to be safe and book a check. For an older dog with more than one of the DISHAA signs, ask for a physical and behavioural check. (VCA)

Every figure and threshold on this page comes from the veterinary sources below, and each one is linked where it is used. Where no source gives a cut-off, we say call your vet rather than invent one.