Pyogranulomatous panniculitis in a cat associated with infection by the Mycobacterium fortuitum/peregrinum group

A 6-year-old, spayed female, American domestic shorthair was presented with a 10-month history of nodules on the dorsum. Diagnosis of pyogranulomatous panniculitis caused by Mycobacterium fortuitum/peregrinum group was achieved by using tissue culture, chromatography, and histopathologic examination. Pathological findings, diagnosis, and clinical management of the condition are discussed.     

Pyogranulomatous meningoencephalitis associated with dematiaceous fungal (Cladophialophora bantiana) infection in a domestic cat.

A 6-month-old, castrated male domestic cat with progressive neurological signs of 2-3 weeks duration was necropsied. Macroscopic findings were restricted to the brain and included irregularly shaped, well-delineated but unencapsulated areas of intense black pigmentation involving the rostral portion of both cerebral hemispheres. Microscopically, numerous brown, oblong, segmented branching hyphae and conidial-like structures and extensive pyogranulomatous inflammation were identified throughout the cerebral lesion and in adjacent blood vessels. Hyphae and oval conidia were best demonstrated with either Gomori methenamine silver or periodic acid-Schiff stain. Fungal infection in the brain of this cat was unrelated to any concurrent immunodeficiency syndrome or immunosuppressive treatment. This report deals with a case of cerebral phaeohyphomycosis from which a different species of dematiaceous fungus, Cladophialophora bantiana, was isolated and identified.     

Pyogranulomatous cystitis associated with Toxoplasma gondii infection in a cat after renal transplantation

CASE DESCRIPTION: An 8-year-old spayed female domestic shorthair cat was evaluated for azotemia and a suspected mass in the urinary bladder 6 weeks after receiving a renal transplant. Ultrasonography revealed a mass at the ureteroneocystostomy site, and the mass was excised. Both the donor and recipient cats were seronegative for Toxoplasma gondii-specific IgG antibodies prior to transplantation. CLINICAL FINDINGS: Histologic evaluation of the mass revealed lesions indicative of extensive necrotizing pyogranulomatous cystitis with numerous intralesional T gondii tachyzoites and bradyzoite cysts. TREATMENT AND OUTCOME: Treatment with clindamycin was initiated; however, the cat's clinical condition continued to decline, and it was euthanized 9 days after the mass was excised. Necropsy revealed T gondii cysts within the renal allograft and the transplanted ureter, with no evidence of systemic spread of organisms. CLINICAL RELEVANCE: Toxoplasmosis should be considered as a differential diagnosis for azotemia in feline renal transplant recipients regardless of the results of assays for T gondii antibodies in the serum of donors or recipients. This report illustrated the need for improved screening of donor and recipient cats and the importance of minimizing exposure to potential sources of T gondii after transplantation.     

Granulocytopenia associated with thymoma in a domestic shorthaired cat

A 5-year-old, spayed female cat was referred because of a mass in the cranial mediastinum noted on thoracic radiographs. A thymoma was diagnosed following ultrasound and biopsy of the mass. Treatment was initiated with coarse-fraction radiation therapy using external-beam therapy (four fractions of 5 Gy). The mass responded, but granulocytopenia developed. Bone marrow examination showed a myeloid to erythroid ratio of approximately 1:1, with a left shift within the myeloid line. These findings, as well as the lack of toxic changes within the peripheral blood neutrophils, suggested immune-mediated destruction of peripheral granulocytes. Immune suppression with prednisone and cyclosporine was instituted. After 7 weeks, the neutrophil count returned to normal. The tumor was removed, and cyclosporine was reduced and eventually discontinued 3 weeks postsurgery.     

Mucoid Pseudomonas aeruginosa infection in a cat with severe chronic rhinosinusitis

A 6‐year‐old male neutered Bengal cat was presented to the University of Wisconsin Veterinary Care Hospital with a history of severe chronic rhinitis that was unresolved from kittenhood. In weeks prior to presentation, the cat's upper respiratory signs had significantly worsened and a left‐sided facial swelling overlying the left frontal sinus was noted. Skull computed tomography, rhinoscopy, bilateral nasal biopsies, bacterial and fungal cultures of fluid from the left frontal sinus, and cryptococcal fungal antigen testing were performed. The cat was diagnosed with severe chronic rhinosinusitis and determined to have an infection with a mucoid variant of Pseudomonas aeruginosa (P aeruginosa). This case highlights an atypical cytomorphologic appearance of the well‐known bacterial pathogen, P aeruginosa, an appearance that could be confused cytologically with other microorganisms, such as septate fungi. Mucoid variants of P aeruginosa are often associated with progressive lung or airway disease in people with cystic fibrosis and have not been previously documented in feline respiratory tract disease. This report also presents a brief review of chronic rhinosinusitis (CRS) in cats and describes a novel interventional treatment approach to feline CRS via sinusotomy and sinus flushing for severely affected cats.     

Chronic diarrhea associated with Campylobacter jejuni infection in a cat

Campylobacter jejuni was isolated from a cat with chronic diarrhea. The diarrheic cat and another cat (which previously had diarrhea) in the same household had bactericidal antibody titers to the C jejuni. Clinical response to antibiotic therapy and not recovering Campylobacter sp from normal feces after treatment also supported the diagnosis of Campylobacter-associated diarrhea. Although the owner had a protracted episode of diarrhea, C jejuni was not isolated from the owner's feces, nor was a bactericidal antibody detected in the owner's serum.     

Suppurative rhinitis associated with Haemophilus species infection in a cat

A young cat with signs of chronic rhinitis was evaluated for underlying anatomical, inflammatory, or infectious disease. Initial diagnostics were significant for the isolation of an unusual pathogen, Haemophilus species. Isolation using a human RapID NH system erroneously identified the isolate as H. segnis, a human pathogen. No database of veterinary pathogens (Haemophilus) are included in the system and animal pathogens will either be erroneously identified or yield a unique biocode not listed. Because of the unique nature of the pathogen we explored the possibility of immunosuppression as a contributory factor to infection. A variety of laboratory tests were employed to evaluate immune function. The clinical indications and utility of immune function testing are discussed. No immune dysfunction was identified.     

Cutaneous granulomas associated with Mycobacterium fortuitum infection in a cat

Feline mycobacterial skin infections are reviewed briefly. A case of skin granulomas in a cat associated with the presence of the fast–growing acid–fast bacillus, Mycobacterium fortuitum , is reported. Surgical excision was followed by recurrence, but resolution of the lesions was obtained by tetracycline therapy for 12 weeks interspersed with a 14–day course of choloramphenicol. An attempt at experimental transmission to a kitten was unsuccessful. The characteristics of the fast–growing mycobacteria and the possible sources of infection are discussed.     

Pyogranulomatous skin disease and cellulitis in a cat caused by Rhodococcus equi

This report describes a case of Rhodococcus equi infection causing pyogranulomatous skin disease and cellulitis in a two-year-old female domestic shorthaired cat. The case differed from previously reported cases in cats in its clinical presentation and in the locations of the lesions, which were similar to those seen in horses. The presence of an intracellular organism was confirmed by cytology and on histopathology. The aetiological diagnosis was confirmed by routine biochemical tests specific for R. equi on a pure isolate obtained from a biopsy specimen. The report also reviews the literature of the documented feline cases and discusses the common pitfalls in the diagnosis of such infections.     

Reversible pulmonary hypertension associated with lungworm infection in a young cat

Two ten-week-old kittens presented with dyspnea. Two weeks later dyspnea had worsened and both kittens had developed a heart murmur. One kitten died and necropsy showed severe granulomatous pneumonia and moderate bronchi(oli)tis and peribronchi(oli)tis caused by Aelurostrongylus abstrusus. The results from echocardiography, thoracic radiography and the other kitten's fecal examination were interpreted as severe parasitic pneumonia caused by A. abstrusus infection with pulmonary hypertension. Repeated administration of milbemycine-oxime and praziquantel resulted in cessation of larvae shedding and resolution of clinical, radiographic and echocardiographic signs of bronchopneumonia and pulmonary hypertension.