“Moose bit us often, but we could see his good nature”

Researchers at the Behaviour Clinic of the faculty of Veterinary Medicine are investigating a link between behavioural problems in dogs and the bacteria, fungi and parasites in their intestines. They hope this will lead to a better understanding of behavioural problems and expand the range of treatment options.

Labradoodle Moose greets us enthusiastically as we enter the home of his owners, Dominique Rijshouwer and Caspar Schoevaars. Moose appears to be a cheerful and energetic puppy, but a small sign on the wall bearing the number two hints at a problem. Rijshouwer and Schoevaars use it to keep track of when Moose last bit one of his owners. Two days ago now. The record stands at three.

Sleepless nights

Moose, now ten months old, began showing behavioural problems soon after he came to live with his owners in the centre of Utrecht as a young puppy. “He bit us often and was restless and hyper-alert,” Rijshouwer says. “His behaviour was also unpredictable. Sometimes everything seemed fine, but then he would suddenly attack us.” Schoevaars: “It was tough. The uncertainty was particularly hard. Was it our fault? Were we doing something wrong? It led to sleepless nights.”

The uncertainty was particularly hard. Was it our fault? Were we doing something wrong?

Rijshouwer and Schoevaars set out to find help. “Despite the problems, we could see his good nature. He just didn’t always have his impulses under control,” Rijshouwer says. Through their vet and several behaviour trainers, they ended up in the consultation room of Daniëlle Hartman, a researcher and veterinarian at the Behaviour Clinic of the Faculty of Veterinary Medicine.

Bacteria, fungi and parasites 

Hartman researches the link between behaviour and gastrointestinal problems. In the clinic she regularly sees dogs that struggle with impulsivity, like Moose. “We noticed that these dogs often also have gastrointestinal issues,” she explains. “We are therefore investigating the microbiome, the collection of bacteria, fungi and parasites in the gut. A disruption of this microbiome, for example due to a parasitic infection, may influence behaviour.”

So how do those bacteria, fungi and parasites in the gut affect behaviour? “We have some ideas about that,” Hartman says. “The microbiome produces the building blocks needed to create neurotransmitters. These are substances the nervous system uses to send signals throughout the body. A well known example is serotonin, which helps regulate sleep, appetite and mood. In theory, a disrupted microbiome could produce fewer of these essential building blocks, resulting in lower serotonin production. That may have an impact on behaviour.”

Gastrointestinal problems may also be a factor in Moose’s case. Rijshouwer: "He has been infected with the Giardia parasite on several occasions and he doesn’t like it when we stroke his belly." Moose is therefore one of the participants in the Behaviour Clinic’s study.

In this study, Hartman will collect faeces from around two hundred patients to map their microbiome. "We are looking for links between these dogs’ behavioural problems and the composition of their microbiome. We are working together with colleagues in internal medicine and parasitology, and we are taking inspiration from human medicine. Scientists there already have more experience with methods to unravel the microbiome."

In the cargo bike 

Hartman hopes that her research will make a difference for dogs like Moose and their owners. "We can help dogs better if we understand their behavioural problems better. In the clinic we already look at the whole picture: the dog, its behaviour, its body, the owner and nutrition. The microbiome may well belong on that list too. If, for example, we discover that the microbiome of many patients is lacking certain elements, we might be able to add these through probiotics or a faecal transplant from a healthy dog. That would give us an extra tool in our current treatment arsenal."

We can help dogs better if we understand their behavioural problems better.

Moose is doing better and better thanks to his treatment at the Behaviour Clinic. As his owners talk about this, Moose settles himself on the sofa and calmly chews on a toy. "that would have been unthinkable a few month ago," Rijshouwer says. "He finds it easier to relax, he bites far less and he is more comfortable in himself." Schoevaars adds: "We can now cuddle and play with him without it ending in biting. And it’s easier to take him out and about. Yesterday he sat with Dominique up front in the cargo bike on the way to the woods. It is wonderful that we can finally do fun things with Moose."

Text: Jordy van Asten | Image: Bas Niemans

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