Take your dogs to the Vets and get them tested and treated......... and if you walk your dogs in areas where they could potentially get bitten by ticks then protect them.
I use NEEM bark/leaf powder sprinkled on their meal and NEEM oil used as a 'finisher' once a week after grooming..... your dogs will be safely protected against parasites such as ticks, fleas, worms, mites, so no need to give them chemical medications
Many animals can have Lyme disease and show no signs. In dogs, the most common signs include fever, loss of appetite, painful or swollen joints, lameness that comes and goes, swollen lymph nodes, and lethargy. If Lyme disease is left untreated it can lead to damage in the kidneys, nervous system, and heart.