Dog Flu
I wish this was an urban legend.
But, according to Snopes.com, my source for urban legend veracity testing, it is real. Apparently, there is a fairly dangerous flu moving through the domestic dog population. It started as an avian flu, jumped to horses and then to dogs via horse meat being fed to greyhounds. The flu can be transmitted via dog-to-dog contact as well as via shared objects. According to the article, it made the jump to domestic dogs, as opposed to the racing greyhounds, via workers who,unknowingly, brought it home on their hands and clothes. As this is the first of its kind in the dog world, there is no vaccine and little or no resistance in the dog population.
So, watch your dogs and pray.