Can animals attain Moksha or do that have to take human birth to attain Moksha ?
There is this story of Gajendra Moksha where an elephant gets Moksha. Is it just a special case or is it possible by animals to attain Moksha.
No, animals don't attain moksha. Because the natural order is as below:
sthāvarāḥ krimayo'vjāśca pakṣiṇaḥ paśavo narāḥ
dārmmakāstridaśāstadūnamokṣiṇaśca yathākramam [VP - 2.6.34]
After experiencing the sufferings of hell, the sinners go through the various stages of existence in the following order: immovable trees, worms, birds, animals, men, pious men, gods and liberated souls.
Moreover, if by moksha you mean, the advaita one, then by no means animals can attain that because they cannot cultivate the knowledge to ward away ignorance.
However, due to the grace of the Lord an animal certainly can attain mukti, just like Gajendra did [SB - 8.4.6]. But these are special cases when they were devotees of Lord in their previous births. For example, Gajendra was a devotee of the Lord:
This Gajendra had formerly been a Vaiṣṇava and the king of the country known as Pāṇḍya, which is in the province of Draviḍa [South India]. In his previous life, he was known as Indradyumna Mahārāja. [SB - 8.4.7]
Other than that, I have also heard that god-realized saints can also liberate animals if they want. But in anyway, animals can't attain moksha naturally by their own, because unlike humans, those are bhoga yonis (where one only experiences the deeds of his actions, doesn't accumulate newer ones).
Well,they probably can get Moksha too.Its all upto Parameswara to decide.
Manu Smriti says that even insects & plants can attain higher worlds(i.e heavens) by austerities!.So,if they can attain higher worlds they can probably attain moksha too.Because,even attaining heavens is an equally impossible task(seemingly of course) for all those beings.
Manu Smriti 11.240. Insects, snakes, moths, bees, birds and beings, bereft of motion, reach heaven by the power of austerities.
From the significance of Rudrakshas and Bhasmas chapter of the Devi Bhagawata Purana:
However, Sage Narayana quoted Maha Deva telling Kartikeya that any human being irrespective of caste or even animals or other species carrying Rudrakshas would be immune from sins as an ass carrying a load of the beads died on way but had salvation!
So,yes animals possibly can get moksha too.
Our Guruji's dog always refuses to eat on ekadsahi tithis!
Now,what can be the rational reason for this?How does it know which day is ekadashi ?& how does it know that one is not supposed to eat on that day?
May be this is how the dog is doing it's share of austerities and making itself fit for salvation.So,you never know actually.
I agree with @Mr_Green's answer in the comment.
Srikalahasti is the place where The Spider (SRI), Cobra (KALA) and Elephant (HASTI) rendered service with devotion to lord shiva and attained moksha (wiki).
Second as again pointed by @Mr_Green, Gajendra_Moksha is a good example. Elders say this is when the makara/crocodile got boon to turn into makara torana (as decoration behind lord vishnu in all His temples).
Most of the hindu gods have animals or birds as vehicles like hen, peacock by lord Subrahmanya, cow by lord Dattatreya, rat by lord Ganapathy, lion by mother goddess, owl by lord Lakshmi, camel by lord Hanuman, kite by lord vishnu, nandhi by lord Shiva, swan by mother saraswathi .. the list is endless. Snake is worn by lord Shiva as ornament in His neck and hands, lord Vishnu as His bed, lord Ganapathy as His yagnopaveetham, those snakes attained moksha in this way. Behind every of these there is a story on how they attained moksha! There are good no of wiki articles on this!
Yes , animals can attain moksha. Sri vaishnavas take sharanagathi from a guru. The guru can also give sharanagati to a cow in the house of a vaishnava.
From Padma Purana Uttara Kanda Chapter 224
Those devotees of Visnu, having stuck to (i.e. round) their necks the garland of Tulasi or lotuses or a rosary, having the marks of conch or disc at the roots of their arms, or those having the Urdhvapundra (the vertical lines) on their foreheads, quickly purify the world. Beings are not sorry for those who pre-serve (but) do not properly carry (the mark of) the extensive disc of the lord of heaven. Those who carry the disc very firm(-lymarked) with (the proper) rite on their arm(s), quickly occupy, by means of their lustre, a high place in the sky. He who has at the root(s) of his arms the disc mark of Visnu, the highest soul (made) by heating (the disc) in the sacrificial fire, crosses the great ocean of the mundane existence, and goes to the pure world of the highest lord. A man should make at the roots of his arms the marks with the heated discs etc. He should also get such marks put on (the bodies of) his wife, children, servants and beasts etc.