Lyme is a scary disease. Boo tested positive, but has not been symptomatic since we treated her with doxy. My old dog also had Lyme disease (and Erlichiosis and Rocky Mountain Spotted Fever) - and would chronically be symptomatic.
For Belle, it manifested itself in stiff, achy joints. She would limp, but not in an acute "this foot hurts" kind of way, but rather in a way that made her seem arthritic and much older than her years. Treatment worked, but she needed recurring treatment with every new batch of symptoms.
I also have family who has suffered with chronic Lyme. My brother had it and has not been symptomatic since treatment, my dad spotted the bullseye rash and is undergoing treatment, and several of my aunts, uncles, and cousins has dealt with or are still dealing with the disease. It used to be a big issue that (human) doctors and insurance companies didn't want to recognize that Lyme could be chronic and so would refuse treatment to patients with recurring symptoms. It has caused some of my relatives serious neurological issues as well as physical.
One big issue with borelia burgdorferi (the bacteria that causes Lyme disease) is that it has 3 distinct forms that researchers know of and it able to transition in and out of these forms to "hide" from stressors.
I've pulled excerpts from a paper that I wrote for a microbio class in college. The words are copied and pasted from my paper, although I've pulled out sections and taken out citations for ease of reading. It's a pretty interesting, albeit very scary little organism.
"The most commonly referenced form is that of a spirochete with rotating flagella on either end. These 7-11 periplasmic flagella have coordinated rotation in opposite directions, creating a serpentine-like motion that allows this organism to drill itself into tissue. Because of the location of the flagella, B. burgdorferi is able to â€œhideâ€ the flagella when needed in order to prevent its detection by the host. The cell wall of the spirochete form of B. burgdorferi stains gram negative although the organism is able to change into various forms including a cell wall deficient form to evade destruction by its hostâ€™s immune system. The cell wall deficient form, also known as the â€˜L Formâ€™ allows the bacteria to better â€œhideâ€ from an active immune system. This form of the bacteria tends to increase the longer the bacterium is inside its host. The third form of B. burgdorferi is known as the cyst form. This form of the bacteria is a â€˜dormantâ€™ form of the bacteria in which many organisms clump together and surround themselves with a thicker membrane. This form of the organism is particularly useful for lying dormant inside the host while avoiding destruction (Table 1). In one study, when the spirochete form of cultured B. burgdorferi were transferred to distilled water, 95% of the bacteria converted themselves into cysts within 1 minute. When placed back into a growth medium, the cysts eventually began to regrow as spirochetes demonstrating that the cyst form of the bacteria may be utilized under stressful conditions.
The outer membrane of the organism contains several proteins called Osps. These proteins interact with the tissue of the host organism, whether that is the tick or mammal. They adjust via up or down regulation depending upon the current host for the organism. One protein, referred to as OspA, assists in the attachment of the spirochete to the gut of a tick that has yet to feed. During feeding, down-regulation of OspA is thought to allow the bacteria to then detach itself from the tickâ€™s gut. Other proteins, such as OspC on the outer membrane of B. burgdorferi upregulate as the tick feeds. OspC is thought to play a role in assisting the movement of the spirochete from the gut of the tick to the salivary glands.
Along with assisting in the transmission of the bacterium, some proteins embedded in the outer membrane of B. burgdorferi fight against the immune response of the host animal, some allow for the bacteria to colonize, and some help the bacterium to adapt to its environmental surroundings. For example, five different proteins (CRASP 1-5) act to repress the immune system of the host by binding to the complement activation centers. Without the ability to â€œturn onâ€ the immune response, the host is less able to fight the bacteria. B. burgdorferi also employs a tactic of â€œhidingâ€ from the host organismâ€™s immune response system by using their ability of motility to bind to fibrocytes within the host and implant themselves in intussusceptions, or fold-like areas formed during the creation of new cell-wall material, on the cellâ€™s surface. Likewise, many other proteins exist within the membrane of B. burgdorferi to contribute to its survival in varying environments."