Synonyms for big (grande), as in volume?

Question

I'm trying to find a proper synonym for "grande", as in the quality of three dimensional objects of occupying space, to use with a regular object, such as a "big dog". I'll explain my specific situation below.

However, when searching, this is what I find:

magnate, noble, prócer, ilustre, egregio, excelso, ínclito, sobresaliente, conspicuo

These have a totally different meaning, using the meaning of "great", as in good at something or respectable.

monumental, considerable, mayúsculo, extraordinario, desmesurado, desmedido, ingente, inusitado, gigantesco, colosal, exorbitante, enorme, tremendo, grandioso

These, while referring to space, all involve the concept of being "too big" for something. While "considerable" does not have that effect, it also does not provide the idea of something being big (as another meaning for "considerable" is also to be acceptable).

vasto, espacioso, extenso, holgado, amplio, ancho, alto, elevado

And finally, these ones are closer to that concept, but it is not completely correct to use them with the exact same meaning as "grande". A "big bed" is not the same as a "vast bed" nor a "wide or tall bed".

---

My specific purpose is to write this sentence. In the context, I have two dogs (one big, and one small), and I want to refer to the bigger one.

Mi perro más grande tiene (...)

I want to avoid the use of "grande" because it could also be understood as older, when I actually want to talk about size.

Answer 1

When talking about animals or objects, "grande" is always about size, it only takes the meaning of age when it is said about a person, so your sentence is completely fine and impossible to be understood as "older". If you want to talk about your older dog, you would use "viejo":

viejo, ja.
1. adj. Se dice de la persona de edad. Comúnmente puede entenderse que es vieja la que cumplió 70 años. U. t. c. s.
2. adj. Se dice de los animales en igual caso, especialmente de los que son del servicio y uso domésticos.

So, you don't need any synonym as the precise word you are looking for is "grande", and there isn't any synonym for that.