I ask because I never had cluster headaches until I was around some barn cats. Particulary a feral cat. These cats are well known for harboring the parasite "toxoplasmo gondii" and this parasite is known for causing headaches. This parasite is also found in soil, cows, sheep,etc.
Forutunately most patients infected with T. Gondii are asymptomatic. Links below are to the suspected pathogen and various research efforts.
https://en.wikipedia.org/wiki/Toxoplasma_gondii
https://www.researchgate.net/publication/263441459_Idiopathic_intracranial_hypertension_may_be_caused_by_reactivation_of_latent_cerebral_toxoplasmosis_Effect_of_various_diseases_and_clinical_states