The only real concerns may be chemicals produced due to chemical warfares between corals(toxins). However, if you're not seeing the effects by now, the mutt should be fine(the vast majority of toxins produced are fast-acting vasoconstrictors)... Heart attack-type symptoms would be seen. Another side effect could be bacterial infections... IMO, get a hold of your vet for a possible antibiotic treatment just for preventive reasons.
There's nowhere else I'ld rather be... unless, of course, you're buying