/* package whatever; // don't place package name! */
 
import java.util.regex.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String str = 
		"I found a street animal. It was a dog. \r\nThen the dog found another dog. \r\nIt was kind of fun to see the two dogs barking to each other."; 
 
		Pattern pattern = Pattern.compile("(?<=dog\\.(?!\\s*\\n))\\s*");
		Matcher matcher = pattern.matcher(str);
		System.out.println( matcher.replaceAll("\r\n") );
 
		System.out.println( "============================" );
 
		str = 
		"I found a street animal. It was a dog. Then the dog found another dog. It was kind of fun to see the two dogs barking to each other.";
		pattern = Pattern.compile("(?<=dog\\.(?!\\s*\\n))\\s*");
		matcher = pattern.matcher(str);
		System.out.println( matcher.replaceAll("\r\n") );
 
	}
}

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