Page 10 - Clinical Connections - Autumn 2023

RVC RESEARCH STUDY VETERINARY SERVICES RVC.AC.UK
Ophthalmology

SNOWFLAKE THE RED-EYED REINDEER

Maria-Christine Fischer, Lecturer in Ophthalmology, Sara Lawrence-Mills, Senior Clinical Training
Fellow in Anaesthesia, and Carolina Palacios Jimenez, Lecturer in Anaesthesia
N ine-year-old reindeer Snowflake nonpigmented and displayed a not well canthal pocket syndrome (resulting in
The margin of her left third eyelid was
from
the
treatment
accumulation of mucoid ocular discharge
received
Service
Ophthalmology
neoplastic lesion of the third eyelid. for a defined mass-like lesion, with an irregular in the conjunctival sac), reduced tear
surface on the leading edge, appearing
production and prolapse of orbital fat.
The Ophthalmology Service is primarily consistent with a squamous cell carcinoma. Snowflake in surgery
based at RVC Small Animal Referrals, The remainder of the ocular structures
but the clinicians also collaborate with the presented without abnormalities.
equine, farm animal and exotics teams to The examination of the back of the eye,
support patients with eye problems. the fundus, was a highlight. It revealed
Snowflake previously had a squamous a yellow-green tapetum with prominent
cell carcinoma mass of the right lower vasculature and dark optic nerve heads.
eyelid, which was completely removed in The tapetum is the reflective part of the back
2018. Her owner brought her back in this of the eye that creates the ‘eye shine’ which
year because they noticed an irregular third changes colour depending on the season.
eyelid margin in the left eye. The ophthalmology team and observing
Snowflake lives in a herd of about 20 students found it fascinating to see
reindeer and is kept outdoors on grass. Snowflake’s tapetum colour in transition
As she is only very lightly pigmented, she from winter to summer. The new fundus
requires protection from UV light in body camera, purchased thanks to support from
area with no or little hair growth. To protect the Holliday Foundation and funds raised Standing sedation was performed
her eyes she wears a fly mask in the by the RVC Animal Care Trust, enabled using medetomidine and butorphanol via
summer. Her food is supplemented with everyone to become part of this unique intramuscular injection prior to catheter
moss and lichen, imported from Finland. experience. placement. Snowflake was maintained
with variable rate infusion of medetomidine.
Examination Positioning Snowflake with her head upright
On presentation Snowflake was bright and helped to prevent any aspiration of saliva.
in good body condition, weighing 71kg. Both Monitoring included assessment of the
eyes were open and appeared comfortable heart rate, respiratory rate and non-invasive
and visual. Ocular reflexes and responses blood pressure as well as capnography
were present and as expected. (carbon dioxide level) and pulse oximetry
There was no evidence of recurrence (oxygen saturation).
of the squamous cell carcinoma on the Supraorbital, auriculopalpebral,
lower right eyelid on clinical examination. infratrochlear blocks and local infiltration of
Snowflake was diagnosed with mild the base of the third eyelid were performed
cataracts in her right eye, deemed unlikely using mepivacaine. The patient was
to interfere with her vision. reversed with intramuscular atipamezole to
antagonise the medetomidine.
There are few publications detailing
anaesthesia in reindeer and this protocol
was a novel approach to maintaining a safe
level of sedation in a well domesticated
A fundus camera used to examine Snowflake animal. The use of these nerve blocks to
facilitate ophthalmic surgery have not been
Treatment and anaesthesia reported before and are in the process of
The third eyelid was removed under sedation being published.
and after the application of local anaesthetic Snowflake made a good recovery from
blocks and topical tetracaine eye drops. the surgical procedure and both of her eyes
Cryotherapy was applied to the wound edge appear to be comfortable. On discharge
as an adjunctive therapy. The third eyelid Snowflake was prescribed meloxicam
was submitted for histopathology, which (alternate days), gentamycin and bromfenac
confirmed the diagnosis of squamous cell eye drops to prevent infection and reduce
carcinoma. The tumour had been removed the inflammatory response.
completely.
Risks and complications associated with For small animal referrals, please call:
the surgery in other species are medial 01707 666399
Email:
Snowflake and her daugher with the team qmhreception@rvc.ac.uk

10 Autumn 2023