Be aware that 'Gaelic' is actually two separate languages: Scottish Gaelic (called 'Gaelic' in Scotland) and Irish Gaelic (called 'Irish' in Ireland).
In Irish: gadhar rua or madra rua (the latter can also mean 'fox')
In (Scottish) Gaelic: cu ruadh.
The Scottish Gaelic word for 'little' is beag, pronounced beg.
Irish Gaelic would be bocairín.In Scottish Gaelic it is foileag.
In Chinese, "little black dog" is translated as "小黑狗" (xiǎo hēi gǒu). In this translation, "小" (xiǎo) means "little," "黑" (hēi) means "black," and "狗" (gǒu) means "dog." When combined, these characters form the phrase "小黑狗" to represent a little black dog in Chinese.
beag
madra álainn
Bláithín Éireannach in IRISH Gaelic.
In Irish: garpháiste beag In Scottish Gaelic: ogha beag
Mo stoirín.
You would say "īlio ʻeleʻele" in Hawaiian to refer to a black dog.
Cailín beag Éireannach
coileáinín faolchú / coileáinín mactíre
In Irish it's "A Aodhán, mo lasóg"