[header] How to introduce an older cat to a new dog [title] Start by keeping the animals apart. [step] When you're introducing a new dog to an older cat, you'll want to plan their introduction carefully. Though they're sharing your home, male sure that they're confined to their own spaces at first. 
Allowing them time to adjust to each others' scents within your home will help them get used to each other. [substeps] You'll want to prevent any direct contact until your new dog has had his vet checkup and is cleared of any contagious diseases or infections.