Can a supplement improve a dog's response to training?

Ah, the sharp focus of a German shepherd.

When I was in veterinary school, my roommate had a dog nicknamed Mr. C who had some focus issues. (She still has him, but is sadly no longer my roommate.) We used to joke that C had attention deficit hyperactivity disorder (ADHD); he just had an extreme case of not being able to keep his mind on one thing for any length of time. Training him was challenging. He’d get excited and then seemed to be unable to absorb new ideas.

I thought of C when a former student of mine, Melissa Hartley, pointed me at this article:

Kano, Masaaki, et al. "Oral tyrosine changed the responses to commands in German Shepherds and Labrador Retrievers but not in Toy Poodles." Journal of Veterinary Behavior: Clinical Applications and Research (2015). http://dx.doi.org/10.1016/j.jveb.2014.12.009

Background

Although ADHD isn’t a formal diagnosis in dogs currently, the authors of this paper hypothesized that a dog’s focus during training may affect their learning just as a human child’s focus can affect their learning. Human children with ADHD seem to have differences in levels of adrenaline and noradrenaline in their bodies, and their learning abilities appear to improve when they are given medication to modify those levels. The authors hypothesized further that giving dogs a supplement which is a building block of adrenaline and noradrenaline could improve their response to training by improving their ability to respond to the task at hand.

Adrenaline (also known as epinephrine) is the hormone that you can feel shooting through your body when you’re startled, during the fight-or-flight response. Noradrenaline (norepinephrine) is a close cousin with similar effects. It seems counter-intuitive that giving a hyperactive child (or dog) a supplement to increase this hormone which is associated with being overly excited should help them focus, and yet this is the pathway that Ritalin (methylphenidate) uses quite successfully to help children with ADHD improve their focus. The brain is a complicated organ, and the effects of moderating particular substances in different areas are unfortunately not always intuitive.

This study looked at the effects of supplementing dogs with tyrosine, an amino acid which is known to increase the levels of adrenaline and noradrenaline in the brain. The question asked in this study was: would supplementing dogs with tyrosine improve their response to training?

The study methods

Three breeds of dogs were tested in the study: German shepherds, Labrador retrievers, and toy poodles. The GSDs and labs were at a training facility for police dogs, while the toy poodles were at a different type of facility. All dogs received three training sessions to learn to sit. Then some of them received a daily tyrosine supplement for three days, and a control group did not. At the end of the three days, both groups were trained again. Urine samples were taken both before and after each training session to test for levels of adrenaline and noradrenaline in the urine.

The training approach appears to have been based on operant conditioning: capturing the sit behavior via a food reward and associating it with a verbal cue.

The results

Dogs were divided into high achievement versus low achievement groups based on the number of times the dog sat after being given the cue. High achievement dogs sat frequently after receiving the cue, suggesting a better response to training in this group.

The urine of all dogs was tested before tyrosine supplementation. Levels in the urine of the toy poodles were significantly lower than the levels in the urine of the GSDs and labs. The poodles also appear to have responded correctly to the sit cue less often than the GSDs and labs in the initial training sessions, though this data isn’t clearly represented.

After three days of tyrosine supplementation, dogs were trained again and compared to control dogs who did not receive supplementation. Did dogs given tyrosine improve in their response to training, compared to dogs who were not?

• German shepherds: yes
• Labrador retrievers: yes
• Toy poodles: no

And they really did improve: the tyrosine-supplemented GSDs and labs responded to the sit command correctly about twice as many times as did the control dogs. The poodles’ performance actually improved a little as well, but the difference was not statistically significant.

Why the breed differences in response?

Why did the GSDs and the labs seem to respond so well to the tyrosine supplementation, and the poodles did not?

Now, with caveats that looking at urinary levels of adrenaline is not the same thing as looking at brain levels of adrenaline (it’s just a lot less invasive to do), it’s very interesting that the toy poodles had lower levels of adrenaline before supplementation than the GSDs and labs did, and that their response to supplementation was different. If we take as a given that toy poodles are harder to train than German shepherds (and I’m pretty comfortable saying that, just from what I know about the two breeds), could part of the reason be a difference in brain levels of adrenaline making it harder for the toy poodles to focus?

Why wouldn’t the toy poodles respond better to the supplementation, then? It’s hard to say. Perhaps the adrenaline pathways in toy poodles function so differently from those of the other two breeds that the supplementation was just insufficient. It’s also possible, of course, that there were confounding factors in this study — for example, the fact that the toy poodles were being raised in a very different environment from the police dogs in training.

Will tyrosine supplementation help my dog focus better?

Who knows? This was an initial study. If you think that your dog is difficult to train because of focus issues, my first suggestion to you would be to make sure you’re making training fun and providing sufficient incentive (treats, opportunities to play).

I would have loved to have seen video of the training techniques used in this study. Were they good techniques, or perhaps could have different techniques been just as effective as tyrosine supplementation?

Was tyrosine supplementation actually effective in these dogs? I’d want to see another study or two looking at more breeds before I was comfortable with the results of this one. Again, it’s hard to trust just a single study; there could be factors at play that don’t come out until the hypothesis has been tested in more situations.

If you really want to pursue this supplementation, be sure to do so with your veterinarian’s approval so you don’t jeopardize your dog’s health.