If you have a dog, there is a fair chance that once a month it eats a small chewable tablet that keeps fleas, ticks and worms away. When it grows old and stiff, the vet may give it an injection that eases the pain in its joints.
Many of these medicines come from Zoetis. So do many of the vaccines that protect cattle, pigs and chickens on farms. Few pet owners give the company a thought as they leave the clinic.
Lately, though, Zoetis has been selling fewer pet medicines in the United States. Cheaper copies of two of its older drugs have reached the market. New rivals have arrived as well. Abroad and on farms, sales are still growing, so the company as a whole is holding steady.
Is this a passing setback, or the start of a lasting change?