CROW Case of the Week: Ruddy Turnstone (#18-4047)

The ruddy turnstone (Arenaria interpres) is a short and stocky shorebird that has only one other relative tied to its surname, the black turnstone. Turnstones are so named due to their ability to overturn stones and similar items when searching for invertebrate prey. 


Ruddy turnstones are known to be opportunistic when it comes to feeding, especially during non-breeding season. They are scavengers and will pick at many food items, even human corpses. Mostly, these waders will strut along the shoreline using their stocky bills and ingenuity to flip over stones and other beach debris in search for insects and small crustaceans. 

Ruddy turnstones are known to be long-distant migrants and need to feed heavily before their journeys to breeding grounds as far south as South America or Australia. These strong fliers average between 27 to 47 miles per hour to shorten their distances when over bodies of water. 

At CROW, a non-breeding, adult ruddy turnstone was admitted to the clinic from South Seas Island Resort on Captiva. The patient was suspected to be affected by brevetoxicosis, commonly known as red tide poisoning. The small bird’s intake exam revealed that it had hind limb paresis and no blink reflex.

“Although hind limb paresis can also occur due to spinal trauma, in this bird’s case, it had no evidence of trauma on its physical exam. It had other neurological deficits – lack of blink/palpebral reflex – which made us suspicious of red tide poisoning, which is a result of a neurotoxin affecting the central and peripheral nervous system,” said Dr. Robin Bast, CROW staff veterinarian. “Brevetoxin is a neurotoxin, and it can inhibit the nerves that control the ability to blink the eyelids closed. Usually, this is temporary and resolves with treatment. Birds that cannot blink their eyes may develop secondary corneal ulcers, or abrasions on the surface of the eye, since it is not protected.” 

The intake exam also disclosed poor cloacal tone that caused staining of its surrounding feathers. 

“The brevetoxin also can inhibit the nerves that affect muscle tone, even the ones around the cloaca resulting in weakness,” explained Dr. Bast. “When this sphincter is weak, the bird will ‘leak’ urates and feces onto the feathers around it, and oftentimes this results in discoloration of those feathers if the bird is unable to stand.” 

The patient’s eyes were checked for ulcers using a fluorescein stain. It was given fluids and artificial tears and a treatment plan, including a feeding schedule and daily neurological checks, was determined by the veterinarians.

“This is a diagnostic tool where a topical eye drop is used. The stain sticks to areas of the eye where the cornea has been abraded or ulcerated,” said Dr. Bast. “If a superficial ulcer is found, then topical antibiotics are used to treat that as well as artificial tears to provide protection to the surface of the eye until the blink reflex has returned.”

The ruddy turnstone had a relatively short stay at CROW and, sadly, succumbed to the effects of brevitoxicosis. “Unfortunately, this patient did not survive red tide poisoning and passed away shortly after being admitted to the hospital,” said Dr. Bast. 

 

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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