My S/O says our pets cant get sick from us and we cant get them sick. Is this true?

there are probably exception to this but we don't have many compatible diseases, we rarely exchange diseases with our pets. other humans have way more probability of making us sick. also in the case of dogs their saliva has a much lower bacteria count then humans and you usually have a e-coli culture more similar to your own dog than other humans because of constant close contact so they cant make you sick in that way either while other humans can.