Disseminated infection with Phialemonium obovatum in a German shepherd dog

Diagnosis and management of lumbar Aspergillus spp. discospondylitis using intraoperative cytology and external stabilization in a dog with disseminated infection

Background:

Discospondylitis is an infection of the intervertebral disc and adjacent vertebral endplates. The infectious agent is most commonly a bacterial organism and fungal causes are uncommon.

Case Description:

A 1.5-year-old female entire pug was referred with a 6-week history of right head tilt and progressive non-ambulatory paraparesis. On neurological examination, right facial paralysis and mid and caudal lumbar pain were also detected. Magnetic resonance imaging and computed tomography of the head and spine were performed 3 weeks apart. Findings were consistent with osteolysis of the petrous temporal bone and L2-L3 and L5-L6 vertebral subluxation caused by discospondylitis and osteomyelitis. Disseminated aspergillosis was diagnosed following biopsy and stabilization using an external skeletal spinal fixator. Voriconazol was administered as a medical treatment after surgery. The dog died 3 months later without failure of the construct.

Conclusion:

To the authors’ knowledge, this is the first report using an external fixator for fungal lumbar discospondylitis. The use of an external skeletal spinal fixator should be considered when choosing the surgical technique.

Therapy of Non-Dermatophytic Mycoses in Animals

This review focuses on aspects of antimycotic therapy specific to veterinary medicine. In the first part, drug availability, limited mostly by economic consideration but also by clinical applicability and specific adverse effects, is described for polyenes, 5 fluorocytosine, azoles, echinocandins and terbinafine. In the second part, current knowledge and experience in the treatment of selected fungal infections are overviewed. These mycoses include disseminated mold infections in small animals (dogs and cats) and avian species, upper respiratory tract infections of small animals (sino-nasal and sino-orbital aspergillosis) and horses (guttural pouch mycosis), eumycetoma, infections caused by dimorphic fungi, (blastomycosis, histoplasmosis, coccidioidomycosis, paracoccidioidomycosis and sporothrichosis) and by yeasts and yeast-like microorganism (Cryptococcus spp. and Malassezia pachydermatis).

Canine keratomycosis in 11 dogs: a case series (2000-2011)

Keratomycosis is rarely reported in dogs. The purpose of this study was to review the signalment, clinical characteristics, predisposing factors, and outcome of 11 cases of canine keratomycosis. Medical records of included dogs were reviewed and follow-up information was obtained by re-examination of patients following their initial diagnosis. All 11 patients possessed predisposing factors for fungal keratitis, including an underlying endocrinopathy, pre-existing corneal disease, intraocular surgery, and/or prolonged use of either topical antibiotics or corticosteroids at the time of initial examination. Diagnostic techniques included corneal cytology demonstrating yeast or hyphae in 6 of 11 eyes, and fungal cultures with positive results in 7 of 11 eyes. Fungal organisms isolated included Cladosporium spp. (n = 1), Chrysosporium spp. (n = 1), Curvularia spp. (n = 2), Aspergillus spp. (n = 1), Penicillium spp. (n = 1), and Phialemonium spp. (n = 1). Of the 11 patients, 6 responded to medical management alone. Two resolved after a superficial keratectomy, and three were enucleated due to either endophthalmitis or progression of corneal disease. This study identified potential risk factors for developing fungal keratitis.

Mixed infection caused by Lecythophora canina sp. nov. and Plectosphaerella cucumerina in a German shepherd dog

We describe an opportunistic, disseminated infection in a German shepherd dog associated with two fungal organisms not previously reported to cause disease. Lecythophora canina, a new species here described, was isolated from an osteolytic bone lesion. A fine needle aspirate of the lesion demonstrated septate hyphae. Plectospharella cucumerina (anamorph Plectosporium tabacinum) was isolated from a urine sample. Clinical manifestations were blindness, altered mentation, and osteomyelitis. Treatment with itraconazole and terbinafine for greater than one year resulted in stable clinical disease.

Sequential opportunistic infections in two German Shepherd dogs

Two German Shepherd dogs with sequential opportunistic infections are described. The first was a 2-year-old male with cryptococcal rhinitis that spread to involve the optic nerves and brain. It was successfully treated with combination therapy utilising amphotericin B administered for 2 years, but the dog developed a disseminated Aspergillus deflectus infection 5 years later and was euthanased. The second case was a 4-year-old male that presented for a severe, deep-seated infection of the right antebrachium, with gradual extension to contiguous tissues. Neosartorya fischeri (anamorph; Aspergillus fischerianus) was isolated in pure culture and detected in histological sections. The infection was refractory to itraconazole, but resolved after amputation of the affected limb. Five months later, the dog developed a localised cutaneous lesion on the proximal pelvic limb, from which Pythium insidiosum was isolated and then visualised in tissue sections, together with a structure thought to be grass seed. This lesion was treated by wide surgical resection, although it was reported that the dog died of disseminated disease some months later. These cases provide further circumstantial evidence that young adult German Shepherd dogs have a predilection to developing invasive infections with fungi and other saprophytic pathogens.

Disseminated Geosmithia argillacea infection in a German shepherd dog

We report a systemic mycosis in a German Shepherd dog caused by Geosmithia argillacea. Although this etiologic agent microscopically resembles a Penicillium species, and is histopathologically compatible with members of the genus Aspergillus, morphologic features and molecular characterization clearly separate it from these genera. This appears to be the first report of disseminated disease by this species in humans or animals. In vitro antifungal susceptibility testing suggests resistance to amphotericin B and voriconazole and susceptibility to caspofungin, itraconazole, and posaconazole.

Phialemonium: An Emerging Mold Pathogen That Caused 4 Cases of Hemodialysis-Associated Endovascular Infection

Phialemonium species are emerging as fungal opportunistic pathogens of humans; infections caused by these fungi often have a fatal outcome. We report a series of 4 patients undergoing chronic hemodialysis who developed intravascular infection with Phialemonium curvatum. All isolates were of a distinct morphological type but were shown by partial ribosomal sequencing to be closely related to reference isolates of P. curvatum. Two patients in our case series died; both developed overwhelming infection associated with fungemia and endocarditis. Recent literature corroborates our experience that Phialemonium infection presents unique diagnostic challenges and that optimal management, particularly with regard to antifungal therapy, is not known.

Phialemonium curvatum infection after bone marrow transplantation

We report a case of cutaneous infection caused by Phialemonium curvatum GAMS et COOKE, 1983, after bone marrow transplantation. The genus Phialemonium was created by GAMS & MCGINNIS in 1983 including three new species: Ph. obovatum, Ph. curvatum and Ph. dimorphosporum, and represents an intermediate genus between Acremonium and Phialophora. Nowadays, the genus Phialemonium is considered to be a pheoid fungus which may cause the eventual lesions observed in pheo- and hyalohyphomycosis. Species of this genus have been described as opportunistic agents in humans and animals, mainly as a result of immunosuppression. In the present case, the patient had multiple myeloma and received an allogenic bone marrow transplant from his HLA-compatible brother. Two months after transplantation, he developed purplish and painful nodular lesions on the right ankle. Some of these lesions drained spontaneously and apparently hyaline mycelial filaments were observed, whose culture was initially identified as Acremonium sp. Subsequent studies showed that the fungus was Phialemonium curvatum. The infection was treated with amphotericin B, followed by ketoconazole. The patient was submitted to surgical debridement followed by two skin grafts to repair the bloody area. The duration of the treatment was 4 months and secondary prophylaxis with ketoconazole alone was maintained for one additional month. No recurrence was observed after discontinuation of treatment. The authors comment on the pathogenicity of the genus Phialemonium.