Squealer is a well-known and essential character in the plot development of Animal Farm. It is Squealer's smooth- talking and manipulative personality that calms the animals and makes them believe that the pigs are working for the good of all. Whenever any of the animals are unsure of new developments and changing Commandments, it is Squealer who can "turn black into white."
In the story of Kalila and Dimna - working only from a (basic) translation, as the original is part of a collection of ancient animal fables known as "The Panchatantra"- Dimna is a jackal,subservient only to the 'king of the jungle,' the (inevitable) lion.
A very real difference between Squealer and Dimna's roles is that Squealer is purposely employed by Napoleon who relies on Squealer as his best propagandist. Dimna is an individual who acts alone out of his own interests only. Both Squealer and Dimna are self-serving but Squealer is protecting (supposedly) the pigs whereas Dimna only himself.
In Animal Farm, the pigs gain more and more power as Squealer spins stories of Snowball's treason and tells the animals that the pigs "need" milk and apples for their "brain" work whereas in Kalila and Dimna, Dimna's initial actions (when he believes the lion will eat the bull of which he is afraid) do not bring any benefit to Dimna who then schemes to get rid of the bull that is causing his jealousy.
Squealer has a very specific task and position in Animal Farm
now they were free, and that made all the difference, as Squealer did not fail to point out.
The mantra of "All animals are created equal but some are more equal than others" reverberates throughout Animal Farm and Squealer ensures this . Dimna has a similar belief in the hierachy of animals but again it is personal and not shared by others. He tricks the lion by using the lion's ignorance of a bull's characteristics and the lion's initial fear of the bull and makes the lion believe that the bull wants to take over as king.
However, Dimna's actions backfire on him and he is revealed as a liar so the lion has him imprisoned where he dies.
So, while both Squealer and Dimna are liars and cheats, their motives differ and the stories have quite different endings. Bith stories serve as warnings to those who read them.