I am uploading a NMU to DELAYED/10 in order to fix this.
The debdiff is included.
diff -Nru animals-201207131226/debian/changelog
animals-201207131226/debian/changelog
--- animals-201207131226/debian/changelog 2018-04-16 19:21:27.000000000
+0200
+++ animals-201207131226/debian/changelog 2023-10-26 00:57:51.000000000
+0200
@@ -1,3 +1,10 @@
+animals (201207131226-2.2) unstable; urgency=medium
+
+ * Non-maintainer upload.
+ * Replace libdb++-dev with libdb5.3++-dev. (Closes: #1042087)
+
+ -- Bastian Germann <b...@debian.org> Thu, 26 Oct 2023 00:57:51 +0200
+
animals (201207131226-2.1) unstable; urgency=medium
* Non-maintainer upload.
diff -Nru animals-201207131226/debian/control
animals-201207131226/debian/control
--- animals-201207131226/debian/control 2018-04-16 19:21:27.000000000 +0200
+++ animals-201207131226/debian/control 2023-10-26 00:57:51.000000000 +0200
@@ -2,7 +2,7 @@
Priority: optional
Maintainer: Alberto Fuentes <paj...@gmail.com>
Build-Depends: debhelper (>= 9),
- libdb++-dev,
+ libdb5.3++-dev,
Standards-Version: 3.9.3
Section: games
Homepage: http://software.keep-cool.org/animals.html
