Fungal sinusitis resulting in suspected trigeminal neuropathy as a cause of headshaking in five horses

Authors

  • A. R. Fiske-Jackson,

    1. Equine Referral Hospital, Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, UK
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  • P. J. Pollock,

    1. Weipers Centre for Equine Welfare, Division of Large Animal Medicine and Public Health, School of Veterinary Medicine, University of Glasgow, UK.
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  • T. H. Witte,

    1. Equine Referral Hospital, Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, UK
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  • L. Woolford,

    1. Equine Referral Hospital, Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, UK
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  • J. D. Perkins

    Corresponding author
    1. Equine Referral Hospital, Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, UK
      email: jperkins@rvc.ac.uk
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email: jperkins@rvc.ac.uk

Summary

Primary fungal sinusitis was identified in 5 horses displaying signs of headshaking. All 5 horses had fungal plaques adhered to the infraorbital canal (IOC). Headshaking signs were exhibited by 3 horses prior to treatment and 2 horses after treatment. Standing computed tomography (CT) identified erosion of the IOC in the 2 cases in which it was performed. Fungal culture and PCR identified 3 species of fungi, Rhizomucor pusillus, Scedosporium apiospermum and Aspergillus nidulans which have not previously been described as a cause of sinusitis in horses. Surgical debridement followed by topical antifungal therapy was used in all 5 horses. Recurrence of the fungal plaques in 4 horses necessitated further treatment. The headshaking signs and nasal discharge resolved in 3 horses allowing a return to their previous use. Two horses developed persistent headshaking signs despite multiple treatments. Primary fungal sinusitis should be considered as a cause of headshaking signs in horses, due to a suspected trigeminal neuropathy. Computed tomography is valuable in identifying erosion of the IOC which is not identified with conventional radiography. Three out of the 5 cases were treated successfully but permanent resolution of the fungal infection is difficult to achieve once the bone overlying the infraorbital nerve has been eroded.

Ancillary