PENSACOLA, Fla. (AP) _ A dog track had to cancel some of its races this weekend after more than 100 dogs were infected with ''kennel cough,'' a viral ailment veterinary officials say is striking various parts of the nation.

About 30 dogs have died of the disease in Florida in the past month, state officials said. Dog owners across the state are having their animals vaccinated.

An outbreak also has been reported in New England.

In Florida, six greyhounds have died and 20 others have been put to death in Pensacola in the past month, said Mary Booker, a spokeswoman for the state Business Regulation Department.

The Pensacola Greyhound Track announced it would cancel its Friday and Saturday matinee races this weekend after 116 dogs became infected.

The track has about 700 healthy dogs, and almost all have been vaccinated, said general manager Craig Holtz. But he said the dogs, which normally run every three to five days, need time to rest and recover.

At Ebro Greyhound Park, about 100 miles east of Pensacola, four or five dogs have died of kennel cough, but no races have been canceled, general manager Stockton Hess said.

The illness apparently was transmitted to the Florida dogs from a group of greyhounds that arrived from the Midwest, Holtz said.

Pensacola and several other Florida tracks are operating under quarantines, meaning dogs are restricted to the track and others can't be brought in from the outside, said John Rush, a regional manager for the state's Pari-Mutuel Wagering Division.

Elsewhere, a New England dog track has also had to restrict racing because of a kennel cough outbreak, said Dr. J.W. Seanor, the Pari-Mutuel Wagering Division's veterinarian.

Kennel cough comes from two viruses, Adnovirus Type-2 and Parainfluenza, which dogs can be vaccinated against. Symptoms include a dry, hacking cough, sinus trouble and watery eyes.