Clinical diagnosis and therapeutic management of ulcerative keratitis in a Shih Tzu dog using conventional therapy and platelet-rich plasma: A case report

Introduction

Ulcerative keratitis is one of the most frequently encountered ophthalmic disorders in dogs and is characterized by disruption of the corneal epithelium with varying degrees of stromal inflammation. The condition is associated with ocular pain, conjunctival hyperemia, lacrimation, corneal edema and visual impairment. If left untreated, corneal ulceration may progress to stromal melting, descemetocele formation, corneal perforation and blindness (Gelatt 2021; Gilger and Kern, 2019) [3,4] . Brachycephalic breeds such as Shih Tzus are particularly predisposed to corneal ulceration because of prominent globes, shallow orbits, lagophthalmos and decreased corneal sensitivity, which increase corneal exposure and susceptibility to trauma (Packer et al., 2015; Williams, 2017) [6,7] . The present report describes the diagnosis and successful management of ulcerative keratitis in a Shih Tzu dog using conventional medical therapy and adjunctive platelet-rich plasma.

Materials and Methods

A seven-year-old intact male Shih Tzu dog weighing 7.8 kg was presented to the Veterinary Clinical Complex, College of Veterinary Science, Rajendranagar, Hyderabad, with ocular discomfort and corneal opacity of the right eye. Detailed ophthalmic examination was performed, including Schirmer tear testing, fluorescein staining and slit-lamp biomicroscopy. Tear production was measured using standard Schirmer tear test strips. Fluorescein staining was performed using sterile ophthalmic fluorescein strips to detect corneal epithelial defects. Slit-lamp biomicroscopy was used to assess ulcer depth, stromal involvement, vascularization and associated inflammatory changes. Platelet-rich plasma eye drops were prepared aseptically from autologous blood and incorporated into the treatment protocol. Clinical response was evaluated through serial ophthalmic examinations and repeat fluorescein staining during follow-up.

Case History and Clinical Examination

A seven-year-old intact male Shih Tzu dog weighing 7.8 kg was presented to the Veterinary Clinical Complex, College of Veterinary Science, Rajendranagar, Hyderabad, with a history of redness, excessive tearing, ocular discharge and cloudiness of the right eye of one-day duration. The owner reported sudden onset of signs accompanied by ocular discomfort. The dog had been treated for tick infestation approximately one month before presentation. Appetite, water intake, urination and defecation were normal. General clinical examination revealed an alert and responsive animal with a rectal temperature of 102.6°F. Mucous membranes were pink and moist, and capillary refill time was less than two seconds. No systemic abnormalities were detected.

Diagnosis

A Schirmer tear test was performed and tear production was found to be within normal physiological limits, thereby ruling out keratoconjunctivitis sicca as an underlying cause (Gelatt et al., 2021) [3] . Fluorescein dye staining using sterile ophthalmic strips showed intense retention of dye over the affected corneal region, confirming disruption of the corneal epithelium and exposure of the underlying stroma (Maggs et al., 2013) [5] . The lesion was characterized by epithelial loss, stromal edema, corneal haze and localized inflammatory infiltration. Superficial corneal vascularization extending from the limbal region toward the ulcer bed was evident. No evidence of stromal melting, descemetocele formation, corneal perforation, hypopyon, anterior chamber involvement or other intraocular abnormalities was observed. Further evaluation by slit-lamp biomicroscopy revealed a superficial to mid-stromal corneal ulcer involving the central cornea. The lesion was characterized by epithelial loss, stromal edema, corneal haze and localized inflammatory infiltration. Superficial corneal vascularization extending from the limbal region toward the ulcer bed was evident (Gilger and Kern, 2019) [4] . Based on the history, clinical signs, Schirmer tear test findings, positive fluorescein dye staining and slit-lamp biomicroscopic examination, the case was diagnosed as:

Unilateral Ulcerative Keratitis with Superficial Corneal Neovascularization of the Right Eye in a Shih Tzu Dog

Discussion

Ulcerative keratitis is a common ophthalmic emergency in dogs and is particularly prevalent in brachycephalic breeds owing to their anatomical predisposition to corneal trauma and exposure-related injury (Packer et al., 2015; Williams, 2017) [6,7] [5,3,4] . [2,1] . Progressive reduction in fluorescein uptake and restoration of corneal integrity during follow-up supported the effectiveness of the therapeutic regimen.

Conclusion

A case of unilateral ulcerative keratitis in a seven-year-old Shih Tzu dog was successfully diagnosed using clinical ophthalmic examination, Schirmer tear testing, fluorescein dye staining and slit-lamp biomicroscopy. Early therapeutic intervention comprising topical atropine, antimicrobial medication, ocular lubricants, systemic supportive therapy and adjunctive platelet-rich plasma resulted in complete corneal healing and preservation of vision. The case highlights the importance of prompt diagnosis and comprehensive therapeutic management in achieving favorable clinical outcomes in canine corneal ulceration.

Acknowledgement

AcknowledgementThe authors are grateful to the Head, Department of Veterinary Clinical Complex and the Associate Dean, College of Veterinary Science, Rajendra nagar for providing all facilities to complete this work.

References

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