Tattooing is a common practice in animals for identification purposes. Intravenous injection of India ink has been reported to cause thromboembolism in rabbits, mice, and rats.1 The toxicity of ink is dependent on the type of ink used, with ink containing shellac being more pathogenic. In June 2000, three, approximately three-month-old, captive, freshwater orange spot stingrays (Potamortrygon motoro) died following routine tattooing as part of an animal identification program. One stingray died post-recovery following anesthesia with MS222, and the other two stingrays were found dead in their tank two days following the tattooing procedure. At necropsy, all three stingrays had gills that were blackened. Histologically, all stingrays had many ink emboli within one or more of the following tissues: gills, kidney, heart, and liver. Complications associated with the leakage of ink into the circulation following tattooing are believed to have caused the death of these three stingrays.
1. Kitamura Y, Taguchi T, Yokoyama M, et al. Higher susceptibility of mast cell deficient W/W mutant mice to brain thromboembolism and mortality caused by intravenous injection of India ink. Am J Pathol. 1986;122(3):469–480.