CHEMICAL ABLATION OF AN EXTENSIVE ETHMOIDAL HEMATOMA IN
A HORSE USING 10% FORMALIN – CASE REPORT
Luis Claudio Lopes Correia da Silva, Renata Farinelli de Siqueira, Andre Luis do Valle
De Zoppa
Ethmoid hematomas in the horse are encapsulated, expansive and destructive masses that
usually originate near or within the ethmoid labyrinth or occasionally from the paranasal
sinuses. A fifteen year old, male, Arab endurance horse was referred to the Veterinary
Hospital of São Paulo University for evaluation of bilateral bloody nasal discharge. These
episodes were frequent, occurring mainly after workouts. Upon physical examination,
there was right-sided airflow obstruction and an abnormal respiratory noise especially
pronounced on inspiration. Skull radiographs demonstrated increased opacity in the
region of the right ethmoid turbinate region of the nasal cavity. Endoscopic examination
was performed via both nostrils. Evaluation from the right side revealed a huge green to
black mass that appeared to originate from the area of the ethmoid labyrinth. This mass
filled the nasal passage.
There was associated inflammation of the local mucous
membranes. When viewing via the left nostril, the same mass could be viewed when
caudal to the region beneath the nasal septum. Due to this mass localization and the good
temperament of this horse, the treatment of choice was transendoscopic intralesional
injection of 10% formalin, performed as a standing procedure. On the first occasion 50
ml was injected to multiple sites via both nostrils. After one week the hematoma became
blackened, considerably smaller. There was an hemorragic and mucoid nasal discharge
with a fetid odor. At this point a further 20 ml of 10% formalin was injected and the
horse was treated with sulphadiazin and trimethropin. Endoscopic examinations and retreatment was performed at four-week intervals. The lesion significantly reduced in size
and disappeared following four injections. The horse maintained good body condition
and returned to athletic activity. Although multiple injections of intralesional 10%
formalin were necessary, complications associated with other methods of ablation
including general anesthesia were avoided. Additionally the horse returned to full athlete
function.
Faculdade de Medicina Veterinária e Zootecnia – Universidade de São Paulo - [email protected]
(R. Dr. Homem de Mello 407 apto 191, Perdizes, São Paulo, Brasil)