The Pack Leader April's Paws & Read Blog

A place for anyone who enjoys learning everything about dogs, go ahead dig in!

My Dog Was Normal Now He’s a Monster, Who Are You Gonna Call?

dog-900215_1920 Malinois Dog

I often get calls that are quite scary to the regular person: ‘My dog just attacked my other dog. Serious injuries occurred.’ The common call ‘My dog just nipped someone and we are now scared to have him’.

We often realize that most people have no idea why these behaviours occurred. The scariest of calls ‘My dog has suddenly become absolutely unpredictable’.

When you know that this dog’s life is potentially in your hands the importance of having a helping hand from your vet is priceless.


So let’s say we had an issue between two dogs.

They got along fine and now have had a conflict which has caused some stress in the household. What happened?!

Well first I like to know there is nothing medically wrong with this dog because really I could take your money and work really hard with you but if this is a medical problem, how far will we get?

How will this affect the dog and his family? The risk is high for a rehome or euthanasia.


Have you ever thought that Hypothyroidism could cause your dog to act out?

Sure wasn’t my first thought when I entered into the world of training over 10 years ago. Noted by one of my favourite veterinarians Dr. Jean Dodds.

The mechanism whereby diminished thyroid function affects behaviour is unclear. Hypothyroid patients have reduced cortisol clearance, as well as suppressed TSH output and lowered production of thyroid hormones.

Constantly elevated levels of circulating cortisol mimic the condition of an animal in a constant state of stress. In people and seemingly in dogs, mental function is impaired and the animal is likely to respond to stress in a stereotypical rather than reasoned fashion.

Chronic stress in humans has been implicated in the pathogenesis of affective disorders such as depression. Major depression has been shown in imaging studies to produce changes in neural activity or volume in areas of the brain which regulate aggressive and other behaviours.

Dopamine and serotonin receptors have been clearly demonstrated to be involved in aggressive pathways in the CNS. Hypothyroid rats have increased turnover of serotonin and dopamine receptors and an increased sensitivity to ambient neurotransmitter levels.


Investigators in recent years have noted the sudden onset of behavioural changes in dogs around the time of puberty or as young adults.

Most of the dogs have been purebreds or crossbreeds, with an apparent predilection for certain breeds. For a significant proportion of these animals, neutering does not alter the symptoms and in some cases, the behaviours intensify.

The seasonal effects of allergies to inhalants and ectoparasites such as fleas and ticks, followed by the onset of skin and coat disorders including pyoderma, allergic dermatitis, alopecia, and intense itching, have also been linked to changes in behaviour.


At the onset of puberty or thereafter, however, sudden changes in personality are observed.

The typical history starts out with a quiet, well-mannered and sweet-natured puppy or young adult dog. The animal was outgoing, attended training classes for obedience, working, or dog show events, and came from a reputable breeder whose kennel has had no prior history of producing animals with behavioural problems.

At the onset of puberty or thereafter, however, sudden changes in personality are observed. Typical signs can be incessant whining, nervousness, schizoid behaviour, fear in the presence of strangers, hyperventilating and undue sweating, disorientation, and failure to be attentive.

These changes can progress to sudden unprovoked aggressiveness in unfamiliar situations with other animals, people and especially with children.’


Interestingly enough your dog’s diet can also play a factor in his/her attitude.

This became apparent to me after seeing a puppy in class with extreme stress symptoms. While I knew his handler was doing her homework and even getting additional assistance was not achieving the results we wished for. In the end, he was seen by Dr. Cindy Lizotte and placed on Royal Canin ‘Calming food’ with absolutely astounding results.

Cases like this make me truly irritated when other professionals say that ‘Vet exclusive’ food is not of reasonable quality for dogs. Please trust the doctor that went to school and studied hard to achieve a degree and the ability to come up with a proper diagnosis.

Another hot topic we often see is the level of protein in your dog's food. During my research, I was surprised to find this study.

In the 2000 study completed by Nicholas H. Dodman, BVMS; Ilana Reisner, DVM; Louis Shuster, Ph.D.; William Rand, Ph.D.; U. Andrew Luescher, DVM; Ian Robinson, Ph.D.; Katherine A Houpt, VMD, Ph.D. They discovered this:

Excerpt of the Study on the effects of High & Low-Protein Diets on the Behaviour of Dogs


To evaluate the effect of high– and low-protein diets with or without tryptophan supplementation on the behaviour of dogs with dominance aggression, territorial aggression, and hyperactivity.


For dominance aggression, behavioural scores were highest in dogs fed unsupplemented high–protein rations. For territorial aggression, [corrected] tryptophan-supplemented low-protein diets were associated with significantly lower behavioural scores than low-protein diets without tryptophan supplements.


For dogs with dominance aggression, the addition of tryptophan to high–protein diets or change to a low-protein diet may reduce aggression. For dogs with territorial aggression, tryptophan supplementation of a low-protein diet may be helpful in reducing aggression.


Did anyone think maybe she is in pain?

What about that older dog that just can’t keep up well anymore, you go a nice leisurely hike and head home for a nice cup of hot chocolate and cookies. All of a sudden she has unleashed her fury on her mom for trying to brush out those pesky snowballs stuck on her bum and hocks.

Did anyone think maybe she is in pain? Perhaps it’s time to slow down for this girl and ask your vet about some Cartophen shots.

Pain is not always easy to detect in dogs. Their tolerance is outstanding and sometimes I wish that stamina existed in me when I have a migraine entering a kennel in the morning.


In Conclusion

Please before you:

  • truck your faithful companion over for a lethal injection
  • call your dog trainer and expect miraculous results immediately
  • expect your vet to have answers without any testing

Know that we are here to help and getting the right help is very important.

While I don’t obviously recommend every client I see to seek veterinary help, I’ve been experienced enough to see when there could be an issue that might be medically related and that’s when I’m going to ask for your help so I can help your dog.

Should you have questions about dog behaviour – never hesitate to contact April!


* A special thank you to Dr. Cindy Lizotte for her expertise and guidance while I researched for this article.


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Tuesday, 16 July 2024