Cigars and pipes differ in design from cigarettes, which are made from tobacco wrapped in thin paper. Cigars are wrapped in tobacco leaves, and unlike cigarettes, they don't typically have filters. In pipes, the tobacco sits in a bowl at the end, and a stem connects the bowl to the mouthpiece. Pipes can be equipped with filters. Another type of pipe, the water pipe, consists of a body filled with water, a bowl in which the tobacco is placed, and an attached tube and mouthpiece through which the pipe is smoked.
The main function of dog training leashes is to prevent a dog from escaping and getting into trouble. However, even the best trained dogs are often required to wear a leash due to local leash laws. Leash laws are generally enforced in parks and other protected areas.
It could be a few things-excitement or aniexty about being with other dogs. You may want to take your pup for a really good walk BEFORE you take him to the dog park to release some of the energy or anxiety. The dog park should be used as a means of play/reward and not the place to release his energy (IMO). When dogs come to a dog park full of unreleased energy which could cause problems with other dogs. Give it a try and see if the foaming stops.