Charlie Dog (Mel Blanc) talks about needing to live in the rural/country instead of the stifling big city. America has been continuously urbanizing: In 1908 when Blanc was born 45% of Americans lived in cities; 64% lived in cities when this cartoon was released in 1949; and by 2010 80% were in cities/urban areas.
Charlie Dog recounts the horrors of city life and begs to experience the fresh air and good food of a farm. Although Americans had begun moving to cities, organizations such as the Fresh Air Fund in NYC were working to bring city children to the more healthful country environment for a break. Even TV's Adventures of Superman extolled these virtues as he supported such a local charity supported by the Daily Planet.
Porky ends up in what appears to be the American southwest, as seen by the background depictions of colorful red rock formations and stately Saguaro cactus plants.
Although Charlie dog claims ancestry from many of the popular dog breeds of the era, he is more likely a Heinz special, as in 57 varieties. A good old fashioned mutt.
In a particularly prescient line, Charlie goes into his rant, in a New York accent, about the horrors of the city, and says before he faints, "Look! It's the towers! They're falling!" 52 years later, they actually did.