Ocular and oral lesions caused by Tacinga inamoena in sheep and goats in Northeast Brazil

Abstract

Two outbreaks of traumatic injuries in goats and sheep associated with grazing and ingestion of the cactus Tacinga inamoena have recently been reported in the state of Paraíba, Brazil. In the first of these, which was detected in 2019 during a preliminary inspection of a herd of 70 animals, it was found that 15 showed certain ocular complications, and these animals were subjected to general physical and ophthalmic examinations. The clinical findings included excessive lacrimation, blepharitis, photophobia, corneal opacity, hyphema, corneal neovascularization, corneal ulcers, and adherence of gloquids to the bulbar conjunctiva and cornea. Large amounts of T. inamoena were found to be present in several areas in which these animals had been grazed and had been observed consuming the fruits of this plant. In the second outbreak during the following year, two sheep from a total of 100 animals were identified as having oral lesions associated with grazing in areas within which T. inamoena was growing. One of these animals was referred to a veterinary hospital, and on physical examination was found to show apathy, anorexia, a body score of 1.5, and the presence of gloquids within the fur. With respect to the oral cavity, halitosis, severe sialorrhea, extensive hemorrhagic ulcers, and painful tenderness on palpation were detected. Given the unfavorable prognosis, the sheep was subsequently euthanized. At necropsy, multifocal to coalescent plaques were detected on the upper and lower lips, oral mucosa, tongue, and hard and soft palates. These were generally elevated and firm and characterized by an irregular, ulcerated surface, sometimes crusty, with a yellow to light brown center and erythematous edges. The findings of this study highlight that the consumption of T. inamoena can cause serious oral and ophthalmic lesions in small ruminants in the northeastern semi-arid regions of Brazil, and can potentially contribute to substantial large economic losses. This problem tends to be exacerbated by the invasive behavior of T. Inamoena, particularly in areas in the process of environmental degradation.