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

There are not many common communicable diseases, but pets like dogs and cats can be carriers for things, and we can even be carriers for them. At the end of the day though, I would never worry much about it unless someone in the house is immunocompromised.

Often diseases will survive symptom-free in one species and affect another species.

I'm sure there are some diseases that can affect both pets and owners but probably it's less common (eg I haven't heard of a cold going from pet to owner or vice versa)

Also Psittacosis - an infectious disease in humans caused by bacteria contracted from infected birds, ie parrots, budgies, pigeons, hens

Actually no, if we are around sick animals (same as them) we can actually be a carrier and give it to our pet.

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.

There are many diseases that only humans get, or that only dogs or cats get, but there are diseases which can be spread between humans and their pets as well....and definitely humans can be carriers of diseases that affect their pets, and pets can be carriers of diseases that affect humans.

Toxocariasis is an infection caused by contact with roundworm from the poop of dog or cats, which causes disease of the liver, heart, lungs, muscle, eyes & brain.

You can get breathing problems from inhaling dust from them, especially some people develop coughs from inhaling the dust from their birds feathers

It depends what each party is suffering from really. A lot of illnesses cannot jump species, but there are certainly some that can.

Dog flu and ppl flu are different. You can’t catch a disease from your pet

The only thing I can think of that you can get from your pet is things like ringworm.

in some pretty specific cases, generally no.

I've heard of it happening

Dogs can carry streptococcus

I seriously doubt that.

That is wrong.

Yes you can