It's perfectly acceptable to not allow your dog to greet others on-lead, especially if you want to train them to walk without being in a habit of sniffing every dog you see. Then, only let your dogs sniff one another for up to ten seconds, then praise your dog and encourage them to continue walking. If you allow your dog to greet other dogs while on-lead, always ask the owner for permission first. On-lead greetings can actually be more dangerous than off-lead greetings because the dogs may feel trapped, and may snap because they are not able to get away. Only let your dog off-lead if you are able to supervise them closely, and recall them away from dogs with which they cannot safely interact. Take caution around dogs that you do not know, whether your dog is large or small. Give your dogs food and bones in separate crates, or use a puppy pen to give each dog a safe space of their own. Aggression due to resource guarding is especially common when dogs value comfy spaces, edible chews and favourite humans. As with all doggy housemates, it's important that you do not show favouritism, and try to avoid situations that can lead to resource guarding.
Small dogs and big dogs can get along beautifully, and may even snuggle up and share beds.
Big Dogs And Little Dogs Sharing A Household
With such enormous differences in size, the little guys tend to be at a disadvantage, whether they're trying to participate in group play at the park, or sharing a home with a much larger "sibling." With safety precautions in place, bigs and littles can have fun, enriching relationships. Dogs can be as small as 1.5 kilograms, and as large as 75 kgs.