At 16 weeks, I'd get her in pretty dang quick for a stool sample! It could be giardia, coccidia and other things that could cause her to go downhill pretty quickly if untreated. It may be nothing, but I wouldn't chance it.
I'd suggest you be quite careful with the Metro - if you give this intermittently for ONLY short periods, you may be creating a resistant bug bc the offending bug doesn't ever really go away. If giving Metro, do the full regimen - as recommened by the vet. (No offense SadiesAmie
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