Cactus‐induced keratoconjunctivitis in Texas: A case series of three dogs and one cat

Abstract

Objective To describe the historical, clinical, and diagnostic features of small animal patients affected by cactus‐induced keratoconjunctivitis and their response to therapy. Animals studied Three dogs and one cat. Procedures Ophthalmic examination directed subsequent selected diagnostic tests in each case including light microscopy of extracted foreign bodies, in vivo confocal microscopy (IVCM), corneal histopathology, and corneal bacterial culture. Treatments consisted of foreign body surgical extraction with concurrent medical therapy (three cases), or medical therapy alone (one case). Results Clinical histories obtained supported acute cactus injury in all cases. Ophthalmic abnormalities were unilateral in each case and included ulcerative keratoconjunctivitis associated with linear, microscopic conjunctival and/or corneal penetrating cactus spines, known as glochids. Light microscopy and IVCM showed glochids to be heavily barbed, consistent with the spine morphology Prickly Pear (Opuntia) cactus species. Bacterial culture yielded Proprionicimonas sp. in one case with keratomalacia. Surgical extraction of spines was challenging, and residual conjunctival and/or corneal glochids were present in all cases. Patient discomfort resolved at a median of 21 days (range 10‐51 days). Vision‐threatening complications were not observed in any case at the time of last follow‐up examination. Epithelial downgrowth, demonstrated by IVCM and histopathology, was present in one case at 108‐day follow‐up. Conclusions Cactus‐induced keratoconjunctivitis should be considered as a differential in regions in which Opuntia cacti are prevalent, and microscopic ocular foreign bodies are observed. Although glochids are difficult to extract, positive clinical outcomes can occur in small animal patients despite the presence of residual organic corneal foreign material.

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

“…Cacti have a widespread global distribution and can cause lesions similar to those detected in the cases described herein, and are generally associated with the spines and gloquids produced by these plants. In companion animals, such as cats and dogs, cacti have been found to cause ocular lesions compatible with keratoconjunctivitis after these animals had accessed areas colonized by large amounts of cacti (Dowler et al 2019). In Kenya, the cactus Opuntia stricta has been found to cause ocular and severe gastrointestinal tract lesions in goats following contact and ingestion, leading to progressive weight loss.…”

Applications of in vivo confocal microscopy in the management of infectious keratitis in veterinary ophthalmology

“…Corneal microscopic foreign bodies can also be confused with fungal keratitis by IVCM. Examples include ophthalmia nodosa associated with insect hairs, cactus spines, and burdock pappus bristles 49–52 . Except in the most extreme cases, the number and distribution of corneal microscopic foreign bodies are expected to be less than hyphae in cases of infectious keratitis.…”

“…Examples include ophthalmia nodosa associated with insect hairs, cactus spines, and burdock pappus bristles. [49][50][51][52] Except in the most extreme cases, the number and distribution of corneal microscopic foreign bodies are expected to be less than hyphae in cases of infectious keratitis. In addition, careful evaluation of the shape, length, and other unique distinguishing features can often assist in differentiating fungal hyphae from many foreign bodies.…”