If the dog has demodex you shouldn't be running the dog . Her immune system is already depressed allowing the mange mite to gain hold .
an 11 month old dog should have no difficulty running on pavement .
what matters is did you condition the dog prior to starting this exercise. you can't start cold turkey idle to running beside a bike.
when on that bike the speed should be even , no spurts , and be at around 7 miles an hour
back to the demodex , you can't have a dog running around the house with a cone to prevent scratching.
I recommend DEFENDEX shampoo VETiONX® Defendex? - Skin Soothing Pet Shampoo
then you need to address diet . Add some MSM , sulfur to the diet .
NONE of these will affect the demodex "We give her some allergy support pills, benadryl, medicated shampoo, and advantage multi. We have switched to blue buffalo grain free."
the immune system needs to be built up
stop the exercise for the time being