13-year-old Brittany spaniel

Transverse images of the skull were acquired through C3 pre- and post-intravenous contrast administration.

There is asymmetric but bilateral loss of nasal turbinates in the mid-nasal cavity. There are multifocal pockets of minimally contrast-enhancing fluid and soft tissue dense material predominantly within the left nasal passage. There are similar areas of focal soft tissue density and fluid occupying both frontal sinuses. There is mineralization of the orbital ligaments bilaterally and the falx cerebri. Mandibular and medial retropharyngeal lymph nodes are symmetric and unremarkable. The second right maxillary premolar is absent, as well as the first left and right maxillary molars, except for small remnants of the caudal roots bilaterally.

DDx
Destructive rhinitis with differentials of chronic inflammatory disease, granulomatous disease or neoplasia. Obstructive sinusitis.

Diagnosis
Numerous nasal mites (Pneumonyssoides caninum) were seen on endoscopy. Biopsy results indicated a lymphocytic, plasmocytic, eosinophilic rhinitis.
Treatment: Oral ivermectin resolved nasal discharge.

This case was consistent with a non-specific rhinitis as reported in the following articles. Nasal mites should be considered in these cases.

Saunders JH, Van Bree H, Gielen I, Rooster H. Diagnostic value of computed tomography in dogs with chronic nasal disease. Vet Radiol Ultrasound 2003; 44(4): 409-413.

Lefebvre J, Kuehn NF, Wortinger A. Computed tomography as an aid in the diagnosis of chronic nasal disease in dogs. J Small Anim Prac 2005; 46(6): 280-285.

Nasal mites (Merck Vet Manual)