\ProvidesAnimalsLang{german}

\providecommand*{\germananimals}{%
  \renewcommand*{\catname}{Katze}%
  \renewcommand*{\dogname}{Hund}%
  \renewcommand*{\ladybirdname}{Marienk\"afer}%
}

\germananimals

\@ifundefined{captionsgerman}%
{%
  \@ifundefined{captions\CurrentTrackedDialect}{}%
  {%
    \expandafter\g@addto@macro
      \csname captions\CurrentTrackedDialect\endcsname{\germananimals}%
  }
}%
{%
  \g@addto@macro\captionsgerman{\germananimals}%
}