10 month old puppy suddenly barking at other dogs

[Jasminejoy]

She's a small dog (9 pounds at almost fully grown) and she is normally very friendly towards humans and other dogs but in the last month will growl and bark at another dog say, if we're in a cafe.

She doesn't do it in the park. Just indoor areas. I'm not sure if it's a protective or territorial thing?

Can anyone please advise about this?

Many thanks

I'm not sure if it's a protective or territorial thing?
Probably neither.
Feeling a bit anxious and uncomfortable would be my guess.
Shes restrained on a lead, in a loud, busy, potentially stressful environment, she’s got unfamiliar dogs approaching probably at quite close range.
I bet she’s feeling quite stressed.

you need to take the lead and show her how to manage these interactions. She’s barking because she is anxious but isn’t getting guidance from you on how to behave. This video is quite good, particularly at the start for explaining this reaction you are seeing m.youtube.com/watch?v=5_xVxOitu8I

Thank you both!!