The striking thing about the great brouhaha over the billing practices of General Dynamics is that it was so suddenly triggered by the sound of a dog -- yes, a dog -- lapping at the public trough.

That General Dynamics, which as the nation's biggest defense contractor takes in some $7 billion from the public till every year, is a highhanded servant is certainly not news. Soon after becoming secretary of the Navy four years ago, John Lehman challenged the submarine-building division of General Dynamics (as well as other firms) for producing slack workmanship and then seeking public indemnity when it had to be made good at extra cost.

Lehman's assault on such practices as bad welding and phony "cost overruns" did not go unnoticed, indeed was generously reported. But for all its impact on the level of public indignation, Lehman might have saved breath and ink.

Nor are cynicism and laxity in defense procurement limited to submarine building, or General Dynamics. Almost daily, test embarrassments haunt costly weapons systems: the DIVAD antitank vehicle, for instance, or the new Jeep substitute, or the Pershing 2 ballistics missile, which is supposed to be in deployment in Europe but has been plagued by repeated test failures. Yet one rarely if ever sees any effective demand in Congress or by the public that such contracts be renegotiated, canceled or otherwise adjusted when costly systems flop.

Yet now, in what may be history's most spectacular exercise in loud barn-door slamming after fled horses, Defense Secretary Caspar Weinberger has "suspended" the Pentagon's payment of "overhead" billings by General Dynamics, a small pinch of the huge monthly cash flow to that contractor.

And the offense? A mouse has escaped. It was one thing, you see, to put bad welding seams in submarines. But it wasn't until a General Dynamics executive boarded his dog and sent the bill to the Pentagon that a howl went up from coast to coast. A dog? What, it was thundered, did boarding a dog have to do with national defense?

Nothing, strictly speaking. Yet were we wholly rational about such matters it might be argued that boarding a dog has as much to do with defense as building a high-tech weapons system that won't work; perhaps even a bit more. Suppose, perversely, that a defense-contractor executive freed from a weekend of dog-sitting made an intelligent decision that saved the taxpayers some millions of dollars. From what we know of General Dynamics, that may seem implausible; but it could happen.

It seems obvious, then, that the great huffing and puffing triggered by the dog-boarding bill reflects less skepticism about defense procurement habits than that eternal puritanism that lurks in the American soul. Throw away billions on a gun that won't shoot straight, if you will; but never, never indulge at public expense in so flagrant a symbol of the cushy life as boarding a dog.

This may be the ultimate in gagging at gnats while swallowing camels by the carload, but it is such trivialities that get the public's and the Pentagon's attention.

Meanwhile, serious abuses in defense procurement slip by unpenalized. They include buying weapons that won't work; committing excess because so many state and local economies depend on defense contracts; winking while retired military officers exploit their experience and contacts to the public's detriment.

No president since Dwight Eisenhower, who as an old soldier was hard to bamboozle, has seriously tried to discipline the procurement system. Certainly not Ronald Reagan or Caspar Weinberger, who exhibit a touching faith that the more and bigger (and more expensive) weapons you buy, the stronger you grow.

Meanwhile, the procurement process weaves itself inextricably into the fabric of economy and politics, so that to yank at any dangling string risks an incalculable unraveling of local economies from Bangor to Point Barrow.

Is there no consolation? Yes. Contrary to another ancient American superstition, professional military people are not, with occasional exceptions, very warlike; nor is the defense contracting system, corrupt as it is, an instrument of war-mongering per se. No beneficiary of so golden a goose would risk its neck in warfare when the rewards of peaceful nesting are so great.