Yes, I would avoid most meat and dairy products, but it isn't necessarily so...

What is harmful is injecting cattle and chickens with hormones and antibiotics, feeding them crap, penning them up, and then slaughtering them and expecting their meat to be nutricious.

What is harmful is leading a sedentary life and not breathing properly/breathing fume-filled air.

What is harmful is taking asprin every time you fill a bit under the weather, eating a lot of preprocessed food and refined sugars, and growing crops sprayed with pesticides and grown in dead soil.

Meat itself is not harmful in reasonable quantities, but in our usual agro-business, couch-potato, city-dewlling lives, it tends to be a very poor source of nourishment and can be a health risk... not everyone lives this sort of life though.

I agree with that, and would go further: in many areas, raising animals for meat or milk is necessary for subsistence. It's how people store food for the winter, or over the dry season.