Spirulina: A Supplement in Search of an Indication for Dogs
Spirulina is a dietary supplement with a history that keeps rolling over us in waves. Back in the 1970s, it captured the popular imagination with its use on moon missions by NASA. Its hard to imagine a better way to conjure hype for a dietary supplement. But now this venerable supplement is making its way into diets for dogs. A new paper in Scientific Reports offers up an RCT of spirulina for overweight dogs in hopes of finding an effect on their cholesterol.
The authors of this report did their best to put a good face forward, but they had a null result. The difference in serum triglycerides for their treatment and control groups was “non-significant.”
Nonetheless, they conclude:
“The results of this study suggest that spirulina may manifest a hypotriglyceridemic effect in dogs, even if further research is needed to infer causation.”
In other words, we didn’t find that it works, but maybe someone else can.
Perspective
Since we have no expertise in small animal medicine, we turned to Professor Alex German, who told us:
“It is encouraging to see a randomised controlled trial in veterinary nutrition and obesity. Such trials are all too rare. Although it is a small study (as most veterinary RCTs are), the authors did a pretty good job with the design, with admirable attempts at randomisation and blinding.
“However, in their analysis, there was no significant between-group effect. This, coupled with the fact that a per protocol (rather than intention to treat) analysis was conducted, mean that the null hypothesis cannot be rejected. All in all, therefore, it would have been better to report this as a negative outcome.”
Commerce Rolls On
Remember, though, spirulina lives in the world of dietary supplements, where imagination is more important than boring old data. Research articles tell us that data on the effectiveness of spirulina for any health benefit in dogs is “scarce.” No matter. The web is ready to sell us spirulina for our pups with vague claims about “the potential to enhance immune function.” Plus “it’s generally considered safe for dogs” and “it’s full of macro and micro nutrients.”
So click around and Amazon will sell you some spirulina dog treats for under ten dollars. Bezos needs your money.
To read the study report, click here. For perspective on spirulina, click here and here.
Spirulina Farm in Argagnon, photograph by Peter Potrowl, licensed under CC BY-SA 4.0
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November 30, 2024
