CaseReport
Cor pulmonale secondary to pulmonary fibrosis in a 16-year-old mare
S. Le Corre* ,A. Thomas-Cancian, X.Peyrecave, A.Leblond andJ.L.Cador 
e
Equine Department, VetAgroSup,VeterinarySchoolofLyon, Universit 
e de Lyon, Marcy l ’ Etoile, France
*Corresponding authoremail:Solenn.lc@free.fr
Keywords: horse;pulmonary fibrosis; dyspnoea; hypoxia;corpulmonale
Summary
A16-year-old marewaspresented asan emergency tothe
Equine Hospital ofthe Veterinary SchoolofLyon, witha1-
month historyofrespiratory distress.Onadmission themare
was inpoor body condition, withasevere mixeddyspnoea
and nasal flaring associated withsevere hypoxaemia (PaO
2 42mmHg, SO282%, PCO2 50mmHg), markedtachycardia
(100 beats permin) andcyanotic mucousmembranes. Blood
analysis revealed markedhaemoconcentration (RBC
12.07 910
12/L, haematocrit 57.9%haemoglobin 20.1g/dL),
marked neutrophilic leucocytosis (WBC17.06 910 9/L,
neutrophils 13.5 910 9/L), hyperproteinaemia (80g/L), hyper-
globulinaemia (49g/L) and hyperlactataemia (3.49mmol/L).
Bilateral pulmonary wheezeswereheard onthoracic
auscultation. Thoracicultrasound showedunspeci fic B-lines
while chest radiographs revealedamoderate anddiffuse
interstitial miliarylungpattern primarily consistent withan
infectious, allergicortoxic interstitial pneumonia. An
ultrasound-guided transthoracicpulmonarybiopsydisclosed
severe multifocal interstitialpulmonary fibrosis involving about
40% ofthe pulmonary parenchyma, associatedwithmild
hyperplasia ofthe bronchiolar epitheliumandintraluminal
mucus accumulation ( Fig 1). Biopsy, naso-pharyngeal swab
and transtracheal washcytology andbacteriology couldnot
establish theaetiology ofthe respiratory distressandthe
pulmonary fibrosis. Multi-PCR analysisonthe naso-pharyngeal
swabs werenegative forEHV (equine herpesvirus)1,2,4and
5, EIV (equine in fluenza virus)andERV(equine rhinitisvirus)A and
B.To rule outany general orneoplastic in flammatory
process, anabdominal paracentesis, transrectalpalpation
and abdominal ultrasoundwerecarried out,without any
signi fi cant abnormalities found.Following anepisode ofatrial
fi brillation 9days afteradmission, acardiac ultrasound was
carried outand revealed signsofpulmonary hypertension
characterised bydilatation andhypertrophy ofthe right
cardiac chambers anddilatation ofthe pulmonary trunk,
consistent withcorpulmonale ( Fig 2). Despite thelack of
aetiologic explanation forthe primary pulmonary disease,the
general condition ofthe mare finally improved after2weeks
of intensive care,withtheadministration ofhigh-dosed
corticoids andantimicrobial therapy.
Keypoints
• Cor pulmonale iscardiac remodelling, uncommonly
observed in horses, secondary to pulmonary hypertension
leading to dilatation and hypertrophy of the right cardiac
chambers.
• Very little information exists about prognosis and outcome
of this cardiac remodelling over the long term in horses.
• In horses withchronic pulmonary diseases,early
diagnosis andtreatment ofthe underlying causeare
essential toprevent forany worsening ofthe lesions
that could leadtoaglobal cardiac insuf ficiency.
Fig 2:2D right parasternal long-axisechocardiogram ofthe left
ventricular out flow tract showing dilatation ofthe pulmonary
artery withitsdiameter equivalent tothe diameter ofthe aorta
(6 cm). RV:right ventricle, RA:right atrium, LV:left ventricle, AO:
aorta, PA:pulmonary artery.
Fig1:Pulmonary biopsyreveals interstitial multifocal fibrosis of
about 40%ofthe parenchyma (blackarrows), associated with
moderate hyperplasia ofthe bronchiolar epithelium(whitearrow)
(haematoxylin andeosin staining).
© 2018 EVJLtd
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EQUINE VETERINARY EDUCATION
Equine vet.Educ. (2019) 31(1) 27
doi: 10.1111/eve.12986_1