Jennifer Saul, “Dogwhistles, Political Manipulation, and Philosophy of Language”, Oxford Scholarship online, August 2018
“Dogwhistles: The Background”, Carl Fox, Joe Saunders, Media Ethics, Free Speech, and the Requirements of Democracy, Routledge, 2019
Tracy Storey, “Dogwhistles and Figleaves: Techniques of Racist Political Manipulation”, Ethical Challenge Lecture, Southampton Ethics Centre, Feb 13, 2017
JJ Lang, “The Anatomy of a Dogwhistle”, The Outline, April 8, 2019
Logan Smith, “Trump campaign continues to use antisemitic dogwhistles”, Bend the Arc Jewish Action, Sep 14, 2020
Just to name a few, quite apart from the text I am currently translating. (I referred to "the Internet” only as a shortcut for saying there's a number of publications out there, not all of them suspected of dyslexia, that use the term in this form.)
For lack of a good translation, here's a pretty good German explanation:
... ein Ausdruck, der zwar nicht justiziabel ist, von der eigenen Gesinnungsgruppe aber so verstanden wird, wie er gemeint war... Ähnlich einer Hundepfeife, die das Haustier hört, der Mensch aber nicht. ("Framing-Check: 'Rassenunruhen' - Übersetzungsfehler mit zersetzender Wirkung", Süddeutsche Zeitung 10.6.2020)