As with everything- as items enter our houses, our pets have the potential to get their paws on them shortly after!
We have recently received a few enquiries about pets chewing and ingesting the solution of the COVID-19 rapid test. This is a buffering agent or extraction solution. There is usually only a few millilitres available and- as far as we are aware- they containing no hazardous ingredients. Some testing kits contain a isothiazolinone preservative but the concentration is very low and so not an issue.
We would not expect any toxicological hazard from these tests.