Why do my rose bushes leaves turn spotted - light colored spots?

Hi, it could be a fungi but treatable, see the attached link, https://www.growinginmygarden.com/white-spots-on-my-rose-bush-leaves/

Here is an article that might help - http://homeguides.sfgate.com/yellow-leaves-brown-spots-roses-50357.html

Maybe black spotted Disease. Gently remove spotted leaves put them in a bag and discard. They can spread it. Get something to treat black spot. Water only the base, no the leaves. Make sure there is enough air circulation around them.

Roses planted to close to a structure, such as the house, or to one another, may develop these spots. You may prune to give them more room. They need room to breathe. Spray the foliage with a mixture of 1 T. baking soda per 1 gallon of water and a few drops of dish detergent and wipe on leaves.

it is a fungus.treat with a systemic fungus control from Bayer