NOT a symbiotic relation. It is a parasitic relation. In symbiosis, each thing gives some benefit to the other. A tick provides no benefit to the dog, it just drinks their blood. It gives them nothing but disease.

No. Ssymbiosis is a term for the relation between species, not a species and it's environment. See http://en.wikipedia.org/wiki/Symbiosis

it is a parasitic symbiotic relationship

There is no symbiosis because there is no benefit to us. It's not a symbiotic relationship - they are parasites.

Competition, symbiosis, & prey.