After a PET scan, most patients are told to avoid contact with babies and anyone up through  the age of 18.  Patients are also told to keep their distance from pregnant women.  This prohibition is generally for 6 hours.  Physicians provide this warning because the radioactive material used in the scan, 2-fluorodeoxy-D-glucose (2FDG), may damage growth in immature individuals. 

Unfortunately in the discharge instructions from the scan facility, pets are often overlooked.  I recommend avoiding contact with any growing or pregnant animal. Since growth plates remain open in horses for up to 3 years, avoid contact with any colts or fillies under 3 years of age or any pregnant mare or filly.  For small dogs and cats, most growth plates are closed by a year.  In large breed dogs, growth plates remain open much longer.  I once radiographed a Great Dane who still had open growth plates in his shoulder at two years of age.  Therefore, I recommend avoiding large and giant breeds of dogs who are pregnant or under the age of two.  Just to be safe, I stay away from my pets for 6 hours after a PET scan just as I do for the young and pregnant people we are all instructed to avoid.  Once it is safe, I highly recommend hugging your animals.  PET scans are stressful and the love of animals is great for the soul, mind and body!