Usage of preposition 'a'

Vamos a rescatar a este perro. Deseo entender el uso de la preposición 'a' antes de la frase este perro en esta sentencia (oración o frase; sentencia es más legal, as in a court sentence). ¿Alguien puede/podría ayudarme?
Could someone correct the mistakes and explain to me, the usage of 'a' preceding este perro. Would that be the personal a?

Think of it this way: If there wasn't an A before "este perro", who would we be rescuing? "Vamos a rescatar este perro" isn't completely wrong. People will still understand you, but it flows better when you add the A. It indicates the object receiving the action.

Voy a llamar a Maria. (I'm going to call Maria.)

Voy a visitar a Juan. (I'm going to visit Juan.)

Vamos a jugar al campo. (We're going to play in the country.) Here "campo" is masculine, and the masc. form of A + EL = AL. We don't say "a el campo." We contract this two prepositions. 

Espero que te ayude! Saludos!

Usage of preposition 'a'

Vamos a rescatar a este perro. Deseo entender el uso de la preposición 'a' antes de la frase este perro en esta sentencia frase. ¿Alguien puede ayudarme?
Could someone correct the mistakes and explain to me, the usage of 'a' preceding este perro. Would that be the personal a?

Colocamos la preposición "a" para señalar a qué perro te refieres. Cuando pones "a" estas contestando la pregunta ¿A qué perro te refieres? respuesta: me refiero a este perro.

I´m going to try explainning this question in english. When you want say "We are going save save to this dog" you are answering to the question: Which dog do you want save? answer: I want to save to "a, in spanish" this dog.

Usage of preposition 'a'

Vamos a rescatar a este perro. Deseo entender el uso de la preposición 'a' antes de la frase este perro en esta oración (we say frase or oración not sentencia) sentencia. ¿Alguien puede ayudarme?
Could someone correct the mistakes and explain to me, the usage of 'a' preceding este perro. Would that be the personal a? (ir+a+wherever)

Hola Deepica, I leave you some resources I've created to learn Spanish, you have a lot of explanations. Take a look, I think they are quite interesting.

https://www.facebook.com/pages/Spanish-from-Spain-SFS/292630590862141

https://www.youtube.com/channel/UCeseHPP6FLZppw-oz9GGeYA

https://www.pinterest.com/reyes137/