The yellowthroated warbler (Setophaga dominica) is a colorful creature with a bright yellow throat, a black face mask, a white eyebrow and white underparts with black streaking. In summer, male yellowthroated warblers flaunt grey upperparts and wings, with double white wing bars.

This species of warbler, while relatively small with a pointed bill, is more heavybodied compared to others. It is also considered to be more confident and cooler than its cousins.

While you may find them at bird feeders, yellow-throated warblers tend to forage along tree branches, checking out cracks and crevices for insects such as beetles, caterpillars and flies. They like to rummage high above at the top of canopies, so if you are looking hard for one, you may get a case of what birdwatchers call “warbler neck.”

The woodland species of songbird is known for its clear voice. Its breeding range extends from southern Pennsylvania and northern Missouri to the Gulf of Mexico.

At CROW, an adult male yellowthroated warbler was admitted from Fort Myers Beach after the finder witnessed the patient-to-be involved in a window strike incident. Veterinarians noted he had a corneal ulcer – an open sore in the eye.

“A corneal ulcer is a scratch on the very outer layer of the eye, the clear part called the cornea. You can’t always see these scratches with the naked eye, so we have a special type of eye solution called fluorescein stain, which we use to diagnose ulcers,” said Dr. Melanie Pearson, CROW veterinary medicine intern. “We put a drop in each eye and then flushed the eye with normal eye wash solution. Finally, we shined a special light on the eye – called the cobalt blue setting on our ophthalmoscope. The stain only stays on the part of the cornea with a scratch/ulcer. In this patient’s case, we saw stain uptake in the left eye, which was already squinting, but not the right eye.”

The injury was determined to be non-life threatening. CROW medical staff stated the size of the corneal ulcer was basically microscopic and that it would clear up on its own.

“This corneal ulcer was small, about the size of the tip of a pen. Yes, corneal ulcers do heal over time,” Dr. Pearson confirmed. “Birds in particular heal their corneal ulcers very quickly, sometimes even within a few days.”

The warbler was given supportive medications and was closely monitored.

“We prescribed an antibiotic eye drop called ‘ofloxacin’ to make sure the eye didn’t get infected,” said Dr. Pearson. “Additionally, corneal ulcers are quite painful, so we also prescribed an oral pain medication – an NSAID (nonsteroidal anti-inflammatory drug) called meloxicam.

The eye drops appeared to work quickly, and there was no infection reported.

“We checked the warbler’s eye the next day, and they were already squinting less,” said Dr. Pearson. “Then, three days after the diagnosis, we repeated the eye stain procedure to see if the ulcer had healed.

“The ulcer was completely gone when we rechecked the eye, and the warbler was released on Sanibel Island that same day.”

CROW Case of the Week stories are written by Bob Petcher and appear weekly in the Island Sun and River Weekly Newspapers.

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