I moved to New England from the Midwest and quickly became familiar with Lyme disease (borreliosis) shortly thereafter. First, a few quick facts: Lyme disease is a tick borne illness carried by the deer tick (Ixodes genus). I don't know a lot about the disease in people, but early symptoms include a "bull's eye" lesion at the site of the bite, fever, headache and feeling tired. Longer term symptoms can include loss of the ability to move one or both sides of the face, joint pains, severe headaches with neck stiffness, or heart palpitations, among others (https://en.wikipedia.org/wiki/Lyme_disease). The interesting things is, Lyme disease acts quite different in dogs compared to people. Perhaps the most striking difference is that whereas 90% of people infected with Lyme disease develop clinical symptoms of disease, most dogs infected with Lyme disease never show any clinical signs of being infected, or they will be subtle enough that the owner will fail to recognize them. We don't know the exact number of dogs that develop clinical disease after being exposed to the borrelia bacteria, but in one study, 95% of dogs that were experimentally infected showed no clinical signs. The remainder developed vague arthropathy weeks to months after exposure (Littman et al 2006). A very small percentage can develop Lyme nephropathy (kidney disease).
Next up: testing for lyme disease.
Littman MP, Goldstein RE, Labato MA, Lappin MR, Moore GE. ACVIM small animal consensus statement on Lyme disease in dogs: diagnosis, treatment, and prevention. J Vet Intern Med. 2006;20(2):422-34.