Choosy pet owners like Mr. Chen are a small minority in China, but their pain could presage broader tensions as the trade war deepens. China’s retaliatory tariffs have made imported soybeans and meat more expensive in a country that depends on imports for many of its food needs. Attitudes in China could harden if a lengthy trade war leads to higher prices, but it could also put pressure on Beijing to win concessions or cave — and both options carry big risks for China’s leaders.

Pet food may seem an unlikely target in a trade war, but it shows how creative Chinese officials must become if they want to hit back at President Trump. China doesn’t import enough to match, dollar for dollar, Washington’s tariffs on more than $250 billion in Chinese goods. Instead, Beijing has taken a series of unorthodox moves, such as blocking a huge corporate takeover and tying up imported cars in administrative knots at China’s docks.

Pets in China have become big business. Soaring real estate prices and other costs have made it prohibitively expensive for many city dwellers to start families. Many have chosen to buy animals instead.

According to China Securities, a Beijing brokerage, pet spending in China has surged more than eightfold since 2010, to about $25 billion a year, mostly on cats and dogs. The market is still growing. China has four times as many people as the United States but roughly half the number of household pets, with 51 million dogs and 41 million cats.