There are many articles showing that this is connected to Lyme disease, and one article citing that it's from Ehrlichia. Here are a few:
/www.ncbi.nlm.nih.gov/pubmed/16059573/www.researchgate.net/publication/274724293_Unilateral_mydriasis_in_Lyme_neuroborreliosis(but you have to pay to read this one)
and this one is the one that talks about
it being from Ehrlichia. They won't allow us to copy and paste the link to the article, so here is the information. it's from cliniciansbrief.com:
Ehrlichia ewingii - Main Clinical/Clinicopathologic Findings -
Lameness (polyarthritis)
Fever, neurologic abnormalities (ataxia, paresis, conscious proprioceptive deficits,
anisocoria, vestibular dysfunction)
Mild thrombocyt
openia and anemia
Neutrophils in joint fluid and CSF
I did underline the word anisocoria.