Coccidioides posadasii in a Dog With Cervical Dissemination Complicated by Esophageal Fistula

Abstract

A 5-year-old male, neutered mixed breed dog with a history of a mass with an associated draining tract on the ventral cervical region was diagnosed with an esophageal fistula. The dog exhibited serosanguinous discharge from the draining tract, with enlarged left superficial cervical and mandibular lymph nodes, and was reported to have difficulty with deglutition of solid foods. Computed tomography revealed a communication of the draining tract with the esophagus along with enlargement of the left lateral retropharyngeal, left medial retropharyngeal, and mandibular lymph nodes. This prompted surgical exploration and debridement of the site, with closure of the esophageal fistula. Histopathology of thyroid gland, skeletal muscle, and adipose tissue obtained during surgical exploration showed spherules consistent with Coccidioides spp. infection. Antibody titers performed post-operatively were consistent with an active Coccidioides spp. Infection. By fungal culture and subsequent PCR and DNA sequencing, C. posadasii was identified as the species infecting the dog. Over the course of 85 days of antifungal therapy, discharge from the draining tract, lymphadenomegaly, and cutaneous and subcutaneous nodules resolved. In conclusion, this is the first reported case of disseminated coccidioidomycosis to the cervical region of a dog with involvement of the thyroid gland, skeletal muscle, adipose tissue, connective tissue, and secondary esophageal fistula. Coccidioides spp. infections should be considered a differential diagnosis in unusual cases for dogs that live in or have traveled to endemic areas.

Evaluation of Host Constitutive and Ex Vivo Coccidioidal Antigen-Stimulated Immune Response in Dogs with Naturally Acquired Coccidioidomycosis

“…Investigation into the immunopathogenesis of this disease could provide insight into the wide spectrum of clinical manifestations in dogs with coccidioidomycosis [ 4 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]. Guided by what has been learned from human clinical and mouse experimental studies, the primary objective of the study reported here was to compare constitutive and Coccidioides spp.…”

Lymph Node Abscessation Secondary to Neoplasia in Two Dogs

“…Lymphadenitis is defined as the presence of increased inflammatory cells within the lymph node and further defined by the predominant inflammatory cell type present [ 3 ]. Disseminated coccidioidomycosis, Coccidioides posadasii, was described in a canine with an oesophageal fistula and enlargement of the medial and lateral retropharyngeal lymph nodes [ 4 ].…”

“…A deep neck abscess in humans has been described as an abscess or infection deeper than the superficial layer of the deep cervical fascia [6.] Underlying factors can include dental disease, tonsillitis, trauma, foreign body penetration into the oral cavity, neoplasia, or unidentified causes, which represent 20-50% of cases in humans [ 4 , 6 , 7 ]. Cervical abscesses in the dog can similarly be associated with trauma, foreign body penetration or migration, dental disease, or iatrogenic introduction via fine needle aspirates.…”