Remembering Owls Head

Fahr's Disease

Written by Sydnie Ellis and Lisa Becker

Historically harbor seal pup season has always been the busiest, most demanding season for the NMLC animal care team both physically and emotionally. It requires our team to be here round the clock, to serve as surrogates as these abandoned pups must now learn all of their critical survival skills from us without becoming habituated, and due to the fragility of these animals, the team has to be ready for anything- including death.

     Owls Head a few days after admit to NMLC

The 2020 harbor seal pup season started earlier than ever before as we admitted our first premature pup, Owls Head (affectionately known as Owl), on April 10, almost a month and a half before most full term pups are born. After 5 months in rehabilitation, Owl lost the battle for his life, and the team had to say goodbye. We have been quiet about the loss of Owl as his case was something the NMLC team had never seen before, but now that we have all the details we are ready to tell his story.

Found on Minots Beach in Scituate, Mass. Owl was rescued by the New England Aquarium and the Scituate Animal Control team after being monitored for over 24 hours to ensure mom truly was gone. Over the next few weeks in our care we were able to determine a multitude of problems his little body was fighting, including hypoglycemia, respiratory acidosis (when the lungs cannot get rid of all the carbon dioxide the body creates), hyponatremia, jaundice, anemia, pneumonia, and a few symptoms often associated with Phocine Herpes Virus 1.

Owl in an incubator that allowed for a controlled environment during the intensive care he was receiving.

Through rigorous fluid, supplement and oxygen therapy, the team was able to stabilize Owl and he began to rebound, but there was one additional concern that had presented itself very early on.

Within the first 48 hours of his care, Owl started to show some slight head twitching and minor mobility issues. Often linked to neurological issues, the team was on high alert, but the symptoms seemed to subside after a few weeks. Owl was moved from the intensive care unit to one of our larger enclosures with other pups and water access.

Owls Head in Kiddie Pool
                   Owls Head in Kiddie Pool

Together, these pups graduated from tube feeds to eating fish, but that is where Owl’s progress ends. On June 9th Owl developed shaking and tremors in his front flippers- these tremors started out gradually, and over time became frequent, and were often accompanied by immobility and increased body heat to his dorsum. Soon Owl’s immobility became more evident and detrimental as he was no longer able to get himself in and out of a kiddie pool on his own, and spent most of his time laying on his back. This immobility didn’t just impact his activity level, but hindered his eating capabilities. Owl developed dysphagia, or the inability to swallow, requiring staff assistance to help him slowly place and advance his fish. While other patients were being prepped for release, Owl was being screened for natural behaviors through a set of tests. During his screening, Owl was moved into the pre-release pool and showed no signs of aggression towards the other animals, and his vision, olfactory and auditory organs showed nothing of concern. Moreover, the tremors seemed to subside during free swim, but it also confirmed that Owl could not catch and consume fish underwater. His inability to hunt alongside his neurological complications concluded that Owl was not fit for wild release. In order to better understand the tremors and build a case for potential placement, an MRI scan was conducted with a partner organization under general anesthesia.

On September 1st, Owl was fasted in the morning, given his routine medications, and loaded into the NMLC truck to be transported for his MRI study. During his transport to the partner facility, Owl began to have intense tremors. On arrival he was given premedication via muscular injection to reduce further stress that would be associated with an IV catheter prior to sedation. Once he was anesthetized, Owl was intubated and continuously monitored to ensure his dive reflex did not kick in. Forty five minutes into his anesthesia, Owl’s heart rate began to drop, and emergency medication had to be administered.  Additional medications were given prior to extubation to aid Owl in coming out of sedation, but an hour after waking up he started to regress back into a sedated state resulting in a second course of medications to prevent what was suspected as renarcotization (opioid induced respiratory depression)

Owl laying on his back, a behavior displayed often as his immobility increased.

prior to his transport back to NMLC. Throughout the rest of the evening at NMLC, Owl remained very sedate with a low respiratory and heart rate. Staff remained with him and administered emergency medications as needed. On the morning of September 2nd Owl appeared more alert, but things started to take a turn at 5:00 pm that evening.

Owl had developed a fever, respiratory distress and severe diarrhea. At this time he also became less responsive, and the team began cooling measures, fluid therapy and emergency medication administration. Owl was later moved to an oxygen cage, and his blood work showed dehydration, respiratory acidosis, hypoxia and a slight increase in his white blood cell count. Despite countless efforts from the staff members present, Owl continued to steadily deteriorate, and was humanely euthanized early in the morning on September 3rd – these two staff members never leaving his side. 

The MRI imaging as well as histopathology from his post mortem exam taught us a great deal about Owl, and just how unique his case was. Owl is the first known instance of idiopathic Fahr’s disease in a marine mammal. Fahr’s disease, as described in humans, is characterized by many of the same clinical signs exhibited by Owls Head, including motor impairment, tremors, and dysphagia. It is a rare neurological disorder characterized by abnormal calcium deposits on the brain that control movement, including the basal ganglia and the cerebral cortex. The MRI imaging confirmed that Owls Head had bilateral calcification in the basal ganglia. While a genetic mutation is suspected in this disease, the exact pathogenesis of the lesions has not been determined. Further research is needed to understand whether calcification is due to metastatic deposition secondary to local disruption of the blood brain barrier or localized ischemia, due to a disorder of neuronal calcium metabolism, due to metabolic disturbances of glial cells and pericytes injury, or a rare consequence of hypoparathyroidism. 

Death is always a reality when it comes to wildlife rehabilitation, but the loss of Owls Head hit the NMLC community in an unexplainable way. From his admit when he was likely only 24 hours old, to his final hours, our team never hesitated to stay late, come in early, and adjust his care to suit his very specific, never before seen needs. To say that through all of this the team grew immensely attached to Owl is an understatement, and those feelings only intensified as the truth about his condition unfolded.

Thank you to all of our supporters who showed love and care for Owls Head during his time with us.

     Owl after a few weeks at NMLC