The fewer and more time between dates means that things are going OK and are pretty much under control. My Vet has also written an article on LP and it is included here. It can happen to any breed dog, but is especially common in the large breeds. It can be a terrible condition to watch any dog suffer through. They can collapse and even die from this condition.
Clinical signs can really vary based on the severity of each dog's problem.
They may just have a voice change in the very early stages, which may progress over time to excessive panting, especially during any exercise or excitement, or even just coughing. These are common signs with other throat infections and some relatively minor problems. When this sign starts to develop, most people realize something real is happening. Their dogs may go further to develop exercise intolerance, collapse, and cyanosis. The condition is caused by some condition affecting the recurrent laryngeal nerves leading to a loss of their function.