Hosts: Horse, donkey.
Location: Mouth, around gums and teeth.
Geographic Distribution: This species has apparently been reported only from Jugoslavia.
Prevalence: Simitch (1939) found T. equibuccalis by culture in 7 out of 22 horses and 2 out of 4 donkeys in Jugoslavia.
Morphology: The body is piriform or ovoid, 7 to 10 u long. It has a single blepharoplast and 4 anterior flagella 10 to 15 u long. The undulating membrane is relatively short, rarely reaching the posterior end. There is no free posterior flagellum. The costa is slender and not always visible. The axostyle is apparently slender and extends beyond the body.
Remarks: Simitch (1939) transmitted T. equibuccalis readily from the horse to the donkey and vice versa, but was unable to infect cattle, sheep and goats with it.