It's hard to know how many animals are on these drugs, but I can tell you that the animal pharmaceutical industry is immense and growing, from seven billion dollars in 2011 to a projected 9.25 billion by the year 2015.
很难知道有多少动物 在服用这些药物， 但我可以告诉你 动物制药业很强大 且还在发展。 从2011年的70忆美金， 到2015年预估的92.5忆