Deep and superficial skin scrapings from a feline immunodeficiency virus-positive cat

An 8-year-old, neutered male, domestic shorthair cat housed at the North Carolina State University, College of Veterinary Medicine, Laboratory Animal Research facility as part of a research colony was examined because of mulifocal skin lesions. The lesions consisted of patchy alopecia with mild crusting of the periauricular region, neck, and dorsum; periauricular excoriations; marked dorsal seborrhea and scaling; and generalized erythematous papules. A moderate amount of ceruminous exudate was present in both ear canals. Results of testing for feline immunodeficiency virus (FIV) were positive. An ear swab specimen and superficial and deep skin scrapings were obtained, mounted with oil on glass slides, and coverslipped for microscopic examination. Two populations of mites were observed: a large population of slender, long (approximately 200 microm), adult mites with long, tapering abdomens that comprised two-thirds of the total body length; and a smaller population of more translucent and shorter mites (approximately 100 microm) with wide, blunt abdomens that had prominent transverse ridges. The interpretation was demodicosis, with Demodex cati and D gatoi co-infection. Histologic sections of biopsies from skin lesions on the neck, dorsum, and periauricular area contained a mild perivascular and perifollicular inflammatory infiltrate composed predominantly of histiocytes, lymphocytes, and plasma cells. Diffusely within the follicular lumina and occasionally within the superficial keratin, a myriad of Demodex organisms were observed. Intrafollicular mites were compatible in appearance with D cati whereas those in the corneal layer were suggestive of D gatoi. Demodicosis is an uncommon disease of cats, and rare cases of dual infection have been documented, occasionally in FIV-infected cats. The dual infection emphasizes the importance of doing both superficial and deep skin scrapings and of recognizing the unique microscopic features of different Demodex mites.     

Disseminated Mycobacterium avium complex infection in a cat: presumptive diagnosis by blood smear examination

Disseminated mycobacteriosis was diagnosed in a 4-year-old, castrated male Domestic Shorthair cat following the observation of one to three retractile, non-staining bacilli in neutrophils and monocytes on a Wright-Leishman-stained blood smear Organisms were bright red following acid-fast staining by Kinyoun's technique. The cat had a history of progressive weight loss, anemia, fever, and sporadic vomiting after eating. In addition to blood smears, mycobacteria also were observed in bone marrow aspirates. During necropsy, multiple small white nodules were observed in the spleen and liver. An enlarged sternal lymph node and ascites also were present. In histologic sections, mycobacteria were observed in granulomas within the lungs, liver, spleen, colon, mesenteric and sternal lymph nodes, omentum, and kidney. Mycobacterium avium complex was isolated from cultures of liver, spleen, lung, and kidney. Occult feline leukemia virus infection, detected by immunofluorescent testing of bone marrow aspirates, may have predisposed this cat to bacterial infection. The serum ELISA test for group-specific feline leukemia virus antigen was negative.     

Intracranial meningioma causing partial amaurosis in a cat

Objective To describe a case of intracranial meningioma causing visual impairment in a cat, successfully treated by surgery. Procedures An adult neutered male domestic cat was referred with a 10‐month history of progressive visual impairment and altered behavior. Investigations included physical, ophthalmologic and neurological examinations as well as hematology, serum biochemistry and CT scan of the head. Results The menace response was absent in the left eye and decreased in the right eye. Electroretinograms were normal on both eyes, as was ophthalmic examination, ruling out an ocular cause and allowing a presumptive diagnosis of partial amaurosis due to a post‐retinal lesion. CT scan demonstrated a large sessile extra axial mass along the right parietal bone and thickening of the adjacent bone. Cerebrospinal fluid was not collected because high intracranial pressure represented a risk for brain herniation. A right rostrotentorial craniectomy was performed to remove the tumor. Ten days after surgery, vision was improved, neurological examination was normal and normal behavior was restored. Ten months after surgery, ophthalmological examination showed no visual deficit and CT scan did not reveal any sign of recurrence. Conclusion Advanced imaging techniques allow veterinarians to detect early cerebral diseases and to provide specific treatment when it is possible. In cases of feline amaurosis due to intracranial meningioma, the vital prognosis is good while the visual prognosis is more uncertain, but recovery of normal vision and normal behavior is possible as demonstrated in the present case.     

Blood smear from a cat: features to "dys"cover

A 4-year-old, spayed female, domestic shorthair cat was presented for lethargy, nonregenerative anemia, and inappetence. Results of a CBC included macrocytic, normochromic, nonregenerative anemia and a glucocorticoid-associated leukogram. On blood smear examination, neutrophils had abnormal features including hyposegmentation and a diffuse chromatin pattern with nuclear filament formation and nuclear blebbing. Microscopic examination of a roll preparation of bone marrow revealed hypolobulated megakaryocytes with asynchronous maturation of nuclei. The granulocytic to erythrocyte (G:E) ratio was 76. Segmented neutrophils had asynchronous maturation and dysplastic features. The entire erythroid lineage was markedly decreased for the degree of anemia and rare dysplastic features were noted in erythroid precursor cells. The interpretation of bone marrow findings was erythroid hypoplasia, megakaryocytic dysplasia, and granulocytic hyperplasia with dysplasia. Histopathologic examination of a bone marrow core sample also revealed myeloid hyperplasia and erythroid hypoplasia. The result of a direct immunofluorescence assay for FeLV performed on the bone marrow roll preparation was positive. A diagnosis of dysmyelopoiesis associated with FeLV infection was made. This case was unique in that the dysplastic changes occurred in cell lines that did not have associated cytopenias. The dysmyelopoiesis most closely resembled myelodysplastic syndrome with refractory cytopenia (MDS-RC); however, secondary dysmyelopoiesis could not be ruled out.     

Intra-abdominal mass aspirate from a cat in heat

A 3-year-old intact female domestic shorthair cat was presented for the evaluation of a palpable intra-abdominal mass in the left caudal abdomen. The cat had a history of anorexia, depression and prolonged estrus over a period of about 1 month. Smears prepared from a fine needle aspirate of the mass revealed large round to oval cells arranged individually or in loose clusters surrounded by pink, fibrillar matrix material. Cytoplasm was basophilic, with many variably-sized vacuoles and variable numbers of small purple granules. The vacuoles within the cells were strongly positive with Oil-Red-O stain. The cytologic features were most suggestive of a neoplasm of epithelial cell origin or inadvertent aspiration of a fatty liver. At laparotomy, the mass was found to involve the left ovary. Histologically, the tumor consisted of dense sheets and nests of irregular polyhedral, pleomorphic cells with abundant, finely vesiculated cytoplasm. The tumor cells were separated into lobules by strands of connective tissue. Based on histologic evaluation, a diagnosis of ovarian luteoma was made. In this report, we document the cytologic and histologic features of an uncommon feline tumor, a luteoma, and address its possible misdiagnosis as hepatic lipidosis when using cytology alone to make a diagnosis.     

Dermal mass aspirate from a Persian cat

A 1-year-old spayed female Persian cat with alopecia and weight loss had numerous variably ulcerated dermal nodules. Cytologic examination of an aspirate of one of the nodules revealed pyogranulomatous inflammation along with septate hyphae and basophilic round bodies, 0.5–1.0 μm in diameter, surrounded by a thin clear halo (arthrospores). The cytologic diagnosis was dermatophytic pseudomycetoma. Histologically, there were dermal granulomas containing poorly staining, septate hyphae with bulbous spores embedded within abundant amorphous eosinophilic material (Splendore-Hoeppli reaction), and the histologic diagnosis was pseudomycetoma-associated chronic multifocal severe granulomatous dermatitis with lymphocytic perifolliculitis and furunculosis. Microsporum canis was cultured from the lesion. Pseudomycetomas are distinguished from fungal mycetomas, or eumycotic mycetomas, by the findings of multiple lesions, lack of a history of skin trauma, an association with dermatophytes, most commonly Microsporum canis , and, histologically, lack of true cement material and a more abundant Splendore-Hoeppli reaction in pseudomycetomas. Additionally, pseudomycetomas differ from dermatophytosis, in which lesions are restricted to epidermal structures. Persian cats have a high incidence of pseudomycetoma formation, suggesting a heritable predisposition. The prognosis is fair with systemic antifungal therapy. When examining cytologic specimens from Persian cats with single or multiple dermal nodules, especially if pyogranulomatous inflammation is present, a diagnosis of pseudomycetoma should be suspected and is warranted if arthrospores and refractile septate hyphae are present.     

Multiple viral plaques with sebaceous differentiation associated with an unclassified papillomavirus type in a cat

Abstract

CASE HISTORY AND CLINICAL FINDINGS

A 15-year-old neutered male domestic short-haired cat was presented due to multiple 0.5–2?cm-diameter crusting plaques in the left preauricular region, over the bridge of nose, and in the right periocular region. The plaques did not appear to cause discomfort.     

Isolated lepromatous conjunctivo-corneal granuloma in a cat from Italy

Objective  To describe a case of a conjunctivo-corneal mass in a cat associated with acid-fast bacilli.
Methods  A 2-year-old female black European Short-Hair cat, living outdoors in a suburban environment in Italy, was referred for evaluation of a nodular, vascularized mass of 2 weeks duration. The mass involved the dorsal bulbar conjunctiva at the temporal canthus of OS and invaded the sclera and cornea. Routine ophthalmic and systemic examination, serologic testing, cytology and histology of the mass were performed. Mycobacterium specific polymerase chain reaction (PCR) of variable regions 1, 2 and 3 of the 16S ribosomal RNA (rRNA) gene was also performed.
Results  Neutrophils, lymphocytes, macrophages and giant cells with intracytoplasmic acid-fast bacilli were seen on cytological examination. The histological examination confirmed the presence of a granulomatous lesion with acid-fast bacilli within macrophages. Bacteriological culture of the material from the lesion was negative for Mycobacterium spp. Mycobacterium 16S rRNA gene specific PCR was positive.
A diagnosis of feline leprosy was made. The owners refused any treatment, and 1 year later the lesion was still present.
Conclusions  Veterinary ophthalmologists should be aware of conjunctivo-corneal leproma as an unusual symptom of leprosy.     

Intracellular success: cytologic findings in an ulcerated submandibular mass from a cat

A 1-year-old neutered male domestic shorthair cat had an ulcerated, proliferative lesion in the submandibular area that did not respond to antibiotic therapy. Impression smears from the mass revealed septic pyogranulomatous inflammation, with large numbers of pleomorphic bacteria observed intracellularly within macrophages as well as neutrophils. Bacterial culture was consistent with a diagnosis of Rhodococcus equi, a facultative intracellular coccobacillus capable of replicating within macrophages. The cat's lesion resolved after treatment with rifampin and clarithromycin. R equi should be considered as a differential diagnosis when coccobacilli are recognized within macrophages in cytologic samples.     

Surgical removal of an ependymoma from the third ventricle of a cat

A 10-year-old spayed domestic shorthaired cat was presented for behavioural changes, signs suggestive of visual deficits and aimless circling. Neuro-ophthalmological examination suggested the cat had central blindness. CT scans following administration of iohexol demonstrated a contrast-enhancing mass in the vicinity of the third ventricle resulting in obstructive hydrocephalus. Following rostral tentorial craniotomy and incision through the cerebral cortex, the third ventricle was approached via the dilated left lateral ventricle. An ependymoma was seen through a dorsocaudolateral incision into the third ventricle, and removed by gentle manipulation and suction. The cat recovered unremarkably, regaining normal vision and behaviour.     

Toxoplasma gondii-like organisms in skin aspirates from a cat with disseminated protozoal infection

An 8-year-old, male domestic shorthair cat was referred to the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania with a 3-day history of lethargy, inappetance, hyperemic skin nodules, coughing, and vomiting. Laboratory results included nonregenerative anemia, lymphopenia, thrombocytopenia, hypoalbuminemia, hyponatremia, and increased alanine aminotransferase and aspartate aminotransferase activities. Cytology of the skin nodules revealed many spindle- to crescent-shaped protozoal organisms, with morphology consistent with Toxoplasma gondii or Neospora caninum. Gross necropsy, histopathologic, immunohistochemical, and transmission electron microscopic findings confirmed a systemic protozoal infection; however, the organism exhibited characteristics of both N caninum and T gondii. Diagnosis of a T gondii-like infection was based on internal structures of the organism and positive reaction to rabbit polyclonal antibodies to T gondii. Reports of toxoplasmic dermatitis are rare in the cat and dog, and this is the first reported diagnosis of T gondii-like protozoa in skin aspirates.     

Aberrant migration and surgical removal of a heartworm (Dirofilaria immitis) from the femoral artery of a cat

A cat was evaluated for an acute‐onset of right pelvic limb paresis. Thoracic radiographs revealed normal cardiac size and tortuous pulmonary arteries. Abdominal ultrasound identified a heartworm (HW) extending from the caudal abdominal aorta into the right external iliac artery and right femoral artery. The cat was HW‐antigen positive. Echocardiography revealed a HW within the right branch of the main pulmonary artery and evidence of pulmonary hypertension. An agitated‐saline contrast echocardiogram revealed a small right to left intracardiac shunt at the level of the atria. Surgical removal of the HW was performed with no substantial postoperative complications. There was return of blood flow and improved motor function to the limb. The cat remains mildly paretic on the affected limb with no other clinical signs.     

Presumptive pseudohypoaldosteronism secondary to chronic urinary tract obstruction from sloughed urinary bladder mucosa and urinary tract infection in a cat

Objective – To describe a case of presumptive secondary pseudohypoaldosteronism (PHA) in a cat with urinary tract infection and chronic urethral obstruction. The obstruction was believed to have resulted from sloughed urinary bladder mucosa secondary to pressure necrosis. Case Summary – A 5‐year‐old, 4 kg, castrated male Siamese cat presented for vomiting and stranguria. Medical history included a perineal urethrostomy for urethral obstruction. Physical examination revealed a large, painful, nonexpressible urinary bladder. Point‐of‐care testing demonstrated electrolyte derangements consistent with a postrenal azotemia and metabolic acidosis. Results of urine culture was positive for bacterial growth. Diagnostic imaging revealed presence of retroperitoneal fluid, marked urinary bladder wall thickening, bilateral hydroureter, mild bilateral pyelectasia, and small nephroliths. The patient was treated for a urinary tract obstruction and infection. In the 3 weeks following initial discharge, the patient was evaluated on multiple occasions for lethargy, intermittent vomiting, inappropriate urination, and progressive polyuria and polydipsia. Although the urinary bladder was easily expressed during repeat examinations, it was persistently distended and subjectively thickened upon palpation. Repeat ultrasound of the urinary tract showed evidence of sloughed tissue in the bladder lumen, likely secondary to chronic urethral obstruction and pressure necrosis. A cystotomy was performed to remove the necrotic tissue, and a revised perineal urethrostomy was done due to a partial urethral stricture. Bladder biopsies were obtained at this time. Postoperatively, the cat was reported by the owners to be urinating normally but continued to be polyuric and polydipsic in the week following discharge. One week after surgery, the cat presented in hypovolemic shock with laboratory findings consistent with a presumptive diagnosis of secondary PHA. New or Unique Information Provided – PHA has not been reported previously in a cat. This case report suggests that aldosterone resistance should be considered in cats with consistent laboratory findings and a history of documented obstructive uropathy and urinary tract infection.     

Genetic and biological characterization of feline foamy virus isolated from a leopard cat (Prionailurus bengalensis) in Vietnam

Foamy viruses have been isolated from various mammals and show long-term co-speciation with their hosts. However, the frequent inter-species transmission of feline foamy viruses (FFVs) from domestic cats to wild cats across genera has been reported. Because infectious molecular clones of FFVs derived from wild cats have not been available, whether there are specific characteristics enabling FFVs to adapt to the new host species is still unknown. Here, we obtained the complete genome sequences of two FFV isolates (strains NV138 and SV201) from leopard cats (Prionailurus bengalensis) in Vietnam and constructed an infectious molecular clone, named pLC960, from strain NV138. The growth kinetics of the virus derived from pLC960 were comparable to those of other FFVs derived from domestic cats. Phylogenetic analysis revealed that these two FFVs from leopard cats are clustered in the same clade as FFVs from domestic cats in Vietnam. Comparisons of the amino acid sequences of Env and Bet proteins showed more than 97% identity among samples and no specific amino acid substitutions between FFVs from domestic cats and ones from leopard cats. These results indicate the absence of genetic constraint of FFVs for interspecies transmission from domestic cats to leopard cats.     

Screening for proteinuria in cats using a conventional dipstick test after removal of cauxin from urine with a Lens culinaris agglutinin lectin tip

Proteinuria is an important indicator of urinary tract disease and urine dipsticks are simple and sensitive tools to screen for this marker. However, the use of dipsticks to screen for proteinuria may not be appropriate in cats, since cauxin, a 70 kDa glycoprotein, is secreted by the kidneys in clinically normal animals of this species. To circumvent this problem, a Lens culinaris agglutinin (LCA) lectin tip was developed to remove cauxin from feline urine, followed by conventional urine dipstick testing for proteinuria. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) with Coomassie brilliant blue R-250 staining indicated that >90% cauxin in the urine of 13 clinically normal cats was trapped by the LCA lectin tip, so that the dipstick protein ‘score’ changed from ‘positive’ (?30 mg/dL) for untreated urine to ‘negative’ (?10 mg/dL) for lectin tip-treated urine. In contrast, SDS–PAGE indicated that lectin tip-treated samples from 20 animals with renal disease contained high concentrations of albumin and low-molecular weight proteins; dipstick testing of lectin tip-treated urine resulted in a consistently positive protein score. The accuracy of the dipstick method for detecting cats with abnormal proteinuria is enhanced if dipsticks are used with urine samples that have first been passed through the LCA lectin tip.