Low levels of tryptophan, a necessary brain chemical, have been linked to attention deficit/hyperactivity disorder (ADHD) in children. A new study suggests a similar link in canines with behavioral problems.

Researchers from the University of Helsinki and the Folkhälsan Research Centre and the University of Eastern Finland in Finland studied the blood count of hyperactive and impulsive dogs and concluded that the metabolites of phospholipids, tryptophan in particular, differ from the blood counts of the control dogs, similar to previous research done on ADHD patients.

The study was published in Behavioral and Brain Functions on Sept. 29.

The researchers studied the blood metabolites in hyperactive and normally behaved German shepherds and noted a significant link between hyperactivity and lower blood phospholipid levels.

The researchers also identified the negative correlation between hyperactive behavior and the levels of the metabolites of tryptophan, a vital amino acid. This metabolite is only produced when intestinal bacteria process the tryptophan received in food. The discovery suggests differences in the gut bacteria of hyperactive and normally behaved dogs.

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