Islam's message of love and kindness extends to animals as well. Muhammad (صلى الله عليه وسلم) said: 

ما من مسلم يغرس غرسا أو يزرع زرعا فيأكل منه إنسان أو طير أو بهيمة إلا كانت له صدقة

(مشكوة - باب فصل الصدقة - ص 168 - يخاري و مسلم)

If from a Muslim's crops, a human being, a bird or an animal eats some, it becomes charitable donation on (the owner) Muslim's behalf.) This means that benefiting both the humans and the animals is a source of reward for a Muslim. In a Hadith, the Prophet (صلى الله عليه وسلم) said: 

غفر لإمرأة مومسة مرت بكلب علي رأس ركي يلهث كاد يقتله العطش فنزعت خفها فأوثقته بخمارها فنزعت له من الماء فغفر له بذالك قيل إن لنا في البهائم أجرا قال في كل ذات كبد رطبة أجر 

(مشكوة- ص 168 - صحيحين)

A sinful woman was forgiven; she once passed by a well besides which a dog was about to die of thirst. She took off her sock; used her head covering to hang it down the well; and soaked the sock. She then squeezed it to put water in the dog's mouth. Solely due to this act of kindness, she was blessed with forgiveness (from sins.)

A similar story of saving a dying dog's life is mentioned in another Hadith.

(بخاري - ص318 - باب فصل سقي الماء)

When the Prophet (صلى الله عليه وسلم) was asked whether treating the animals also carried some reward, they were told that serving every living creature earned rewards. In another Hadith, the Prophet (صلى الله عليه وسلم) said:

من أحيا أرضا ميتة فله فيها أجر و ما أكلت العافية منه فهو له صدقة.

(مشكوة- ص169- درامي)

 Whosoever gives life to a dead piece of land (by growing plants in it) gets reward for doing so. And if someone hungry eats from the produce, it is charity on the grower's behalf. The hungry include people, birds and animals. Prophet Muhammad (صلى الله عليه وسلم) said: 

عذبت غمرأة في هرة أمسكتها حتي ماتت من الجوع فلم تكن تطعمها و لا ترسلها فتأكل من خشاش الأرض.

(مشكوة - ص168 - بخاري، مسلم )

Punishment (in the Hereafter will be) was given to a woman who kept her cat confined until she died of hunger; she was neither fed by the woman, nor was she allowed to find the bugs to eat herself. In a Hadith, it is said the Prophet (صلى الله عليه وسلم) once went to the orchard of an ansari (a Muslim sponsoring/helping the migrants of Makkah). The Prophet (صلى الله عليه وسلم) there saw a tearful camel. He (صلى الله عليه وسلم) patted the camel's forehead and asked who the owner of the camel was. One of the young ansaris who claimed the ownership was told by the Prophet (صلى الله عليه وسلم), "Aren't you fearful of God who created you? This animal has complained to me that you starved it and you were cruel to it." It is the Mercy of Allah (جل جلاله) that the Prophet (صلى الله عليه وسلم) was able to perceive the animal's pain. The heart of a true Muslim is soft and is full of empathy. The rights of the animals are that they are not burdened beyond their capabilities and that they are properly fed. Prophet Muhammad (صلى الله عليه وسلم) said:

إن لله مائة رحمة أنزل منها رحمة واحدة بين الجن و الإنس و البهائم الهوام فبها يتعاطفون و بها يتراحمون و بها تعطف الوحش علي ولدها و أخر الله تسعا و تسعين رحمة  يرحم بها عباده يوم القيامة

(مشكوة -  باب الإستغفار و التوبة و ما بعده - ص207 - بخاري، مسلم)

Allah (جل جلاله) has 100 blessings; one of which He has bestowed upon the jinns, humans and animals (cattle, beasts, etc.) Due to this single blessing, the living creatures love 14 each other; even the wild animals love their offspring. Allah (جل جلاله) has reserved the other 99 blessings of His until the Hereafter; these blessings, He (جل جلاله) will bestow upon the human beings on the Judgment Day. The universe is limited in time and measure so it gets1% share of Allah's blessings whereas the Hereafter is limitless; that's where Allah's (جل جلاله) infinite blessings will appear. Note that the 99% figure is just to explain the concept; actually Allah's (جل جلاله) mercy and blessings are immeasurable. There is a Hadith Qudsi about Allah's (جل جلاله) blessings in the Hereafter:

أعددت لعبادي الصالحين ما لا عين رأت و لا أذن سمعت و لا خطر علي قلب بشر 

(مشكوة - باب صفة الجنة - 495 - بخاري و مسلم )

I (Allah (جل جلاله)) have prepared for my pious people the blessings that no eye has (fully) seen, no ear has heard of and no heart (mind) has come across. A Hadith of the Prophet (صلى الله عليه وسلم) says: If a woman of the Paradise were to appear on this Earth, all of it would be filled with her fragrance.

(مشكوة - ص 496 - صحيحين)

A Paradise-dweller of the lowest rank will get the Paradise ten times the size of this Earth.

(مشكوة - باب الحوض و الشفاعة - ص 492 - بخاري، مسلم )

According to another Hadith:

أدني أهل الجنة الذي له ثمانون ألف خادم 

(مشكوة - صفحة 499 - باب صفة الجنة - ترمذي )

A Paradise-dweller of the lowest rank will get 80,000 servants.

Link : http://www.scholaris.com/islam/learning/PDF/Islam-TheReligionOfMercy.pdf