Early orthopaedic symptoms in a dog with systemic aspergillosis

Del Magno S., Gruarin M., Foglia A., Agnoli C., Dondi F., Pisoni L. EARLY ORTHOPAEDIC SYMPTOMS IN A DOG WITH SYSTEMIC ASPERGILLOSIS Introduction Systemic aspergillosis is a rare disease in dogs. The unusual orthopaedic presentation in this case report could be helpful in the timely diagnosis of the pathology. Case description A female, 1.5 years old, mixed-breed dog, was presented for lameness in the left hindlimb. A periosteal proliferation was present on radiographs on the left ileal wing and gluteal enthesistis was suspected. After therapy with NSAID the clinical condition worsened with generalized enlargement of the lymph nodes, azotemia and pyelonephritis. Fungal hyphae were detected in the urine and in the lymph nodes. MRI of the pelvis reveals a severe lesion involving muscle and the bone of the left ileal wing, resulting in osteolysis. Surgical biopsy demonstrated a mycotic myositis and osteomyelitis. Culture from urine and lymph nodes were indicative of infection by Aspergillus spp, group Aspergillus terreus. The antymycogram showed sensibility to itraconazole, voriconazole and amphotericin B. Itraconazole (10 mg/kg 24q) was started and the clinical situation improved. After 1 month the dog had evidence of discospondylitis of L1-L2 and a worsening of the dilatation of the renal pelvis and of the ureters. The dosage of the itraconazole was elevated to 7 mg/kg 12q. After 16 months the dog was euthanized because of severe osteomyelitis of the left femur .The necropsy confirmed the mycotic osteomyelitis of the left ileal wing, of the femur, discospondylitis and pyelonephritis. Discussion Systemic mycosis usually are promoted by immunosuppression and the route of entrance for Aspergillus are believed to be either pulmonary or gastroenteric. In the case reported the dog did not have any demonstrated predisposing factor to immunosuppression. A primary local infection of the iliac wing is not probable because no surgery or wound was detected. Systemic infection by Aspergillus has major incidence in young female German Sheperd dogs and the dog of the present case was may have been related to this breed. MRI was performed because in humans it is considered one of the best advanced diagnostic imaging techniques at detecting the soft tissue involvement in mycotic osteomyelitis. The surgical curettage of mycotic osteomyelitis was not performed because of the generalized nature of the infection, and only a biopsy was performed surgically in the iliac region. The sensibility shown in vitro by the fungus to itraconazole, was not sufficient in vivo, even at high dosage, to eliminate the infection. Other drugs like voriconzole were not used because of the relatively high costs, while amphotericin B was considered risky in such an azotemic patient. Nevertheless the survival of the dog was of 16 months from diagnosis and can be considered satisfactory in comparison to the outcome reported in literature.