Zoetis Inc. ZTS

Key data

The business

Zoetis makes the medicines a veterinarian reaches for. Vaccines, pills, injections, and diagnostic machines, split across pets and farm animals, though pets are now roughly two-thirds of the money and the part that matters. The names an owner would recognize are the ones on the bill: Simparica Trio, the monthly chew that handles fleas, ticks, and heartworm at once, Apoquel and Cytopoint, the pair that stops a dog scratching itself raw, and Librela, the once-a-month injection for the sore joints of an old dog, its fastest riser. A vet writes the prescription, the owner pays whatever it costs because it is the dog, and next month they refill. That is the moat: the medicine is chosen by a professional the owner trusts and bought on a schedule the animal's body sets, so demand barely flinches when wallets tighten. Zoetis has spent the last two years shedding its lower-margin farm business to lean into exactly this.

The numbers

Two things happened at once: earnings kept climbing while the top line quietly stopped.

The spring quarter is the tell. Sales of $2.47B sat within a whisker of the $2.46B a year earlier, up just 0.3%, the weakest growth in years, while operating profit fell about 5%. Earnings per share still rose, to $1.65, but only because the share count keeps shrinking. On the adjusted measure the quarter came in a touch above expectations at $1.87, after the winter quarter had come in below, so the pattern is a business bumping along, not one inflecting up. The itch franchise the last read hung on, the one that had to settle near $400M a quarter rather than fall through $350M, is not broken out in this run, but minimal companywide sales growth says the floor, if it arrived, did not turn into expansion.

Step back and the deceleration is the whole story. Sales compounded about 5% a year from 2021 to 2025, and only 2% in the last year of that stretch, down from better than 8% the year before. Earnings did better, near 9% a year, and free cash flow per share better still at 22% a year over three years, because the company retired about a twentieth of its stock. That gap, minimal sales growth but rising per-share numbers, is what a maturing compounder looks like, and it is what the market re-rated. What this memo believes that the tape does not is that pet-medicine demand is sturdier than a single minimal-growth quarter suggests and the erosion is one product, not the franchise. The print that settles it is two quarters of companion-animal sales growing again.

Management

The people closest to the business are buying it. Three directors, including the chairman, bought about $0.9M of stock on the open market in May near these lows, and no insider sold in the last year. Those are discretionary purchases, not scheduled sales, which is the version that carries a signal. Against that, the capital record has a bruise: the company spent $3.24B on buybacks in 2025 at an average of about $151 a share, and that stock now trades at $76, so last year's repurchase destroyed value in real time. Pay is not the issue, the chief executive made $17.2M, under 1% of profit, and the adjusted-earnings guide has been hit in seven of the last eight quarters. The scorecard reads as a capable operator who mistimed the checkbook badly.

How it fails or surprises you

The itch drug gets copied. Apoquel's protection has thinned and rivals are bringing their own itch treatments. If dermatology keeps sliding the way it did through last year, minimal growth turns into shrinking sales. Watch the companion-animal growth rate: another two quarters near zero says the franchise, not one product, is being competed away.

Librela's safety file. The fastest grower is a newer injection that has drawn adverse-event reports to the FDA, some involving deaths in treated dogs. A stronger label warning or a vet pullback would reset the one product carrying the growth. The print is any change to the Librela label or a sequential drop in its sales.

Demand proves defensive and the multiple snaps back (right tail). If pet-medicine spend holds through a soft economy and Librela and Simparica push companion-animal growth back above 6%, a stock at 12 times earnings that spent a decade near 30 has room to double on re-rating alone, and today's price pays for none of it. Two quarters of mid-single-digit organic growth is the tell.

Closing thoughts

This is an uncertainty a single number resolves, not an exposure you can only survive. The evidence points to a business that has stopped growing meaningfully but not started shrinking, priced as though the second is already underway. If the next two prints show companion-animal sales growing again, 12 times earnings for a franchise this durable was a gift. If they show the top line rolling over, the fall from $150 to $76 was the market getting there first, and there is more to come. The fatter tail, on the insider buying and the durability of prescription refills, is the upside, but the left tail is real enough that the minimal-growth quarter has to become a growing one before you lean on it.

The bet, still, is that people keep spending on their dogs and cats through anything and keep buying Zoetis's medicines to stop the itch, kill the fleas, and ease the joints. What breaks it is the newer drugs failing to outrun the copies of the older one. The pair to watch is companion-animal growth against the dermatology line: if both are still falling two quarters from now, the bet is wrong.