Pericardial effusion in a cat with feline infectious peritonitis

This case report describes the disease progression of a male cat with pericardial effusion. Clinical signs (dyspnea, lethargy, and weakness) started very acutely. The initial laboratory profile showed only an increase in alanine aminotransferase enzyme activity. Diagnostic imaging revealed pericardial effusion. Effusion analysis showed a Rivalta-positive, modified transudate. Detection of feline coronavirus antigen in macrophages was negative. General condition and laboratory parameters dramatically worsened within seven days. Therefore, the owners decided to euthanize the cat. Even if effusion variables are macroscopically and microscopically suspicious for FIP, a definitive diagnosis of FIP could only be made by histology (including immunhistochemical staining).     

Chylous abdominal effusion in a cat with feline infectious peritonitis

A 10-year-old cat was diagnosed with chyloperitoneum based on the effusion characteristics. Feline coronavirus serology was positive. The owner declined further evaluation and elected euthanasia. Necropsy revealed vasculitis with multifocal areas of necrosis and lymphocytic-plasmacytic inflammation in multiple solid organs, most likely due to feline infectious peritonitis (FIP). Immunohistochemistry was negative for FIP antigen. Notwithstanding, the final diagnosis of FIP was based on the characteristic histopathological lesions. Underlying causes of chyloperitoneum in cats and humans are discussed, and possible pathogenesis of the chyloperitoneum in association with a vasculitis such as FIP is discussed.     

Priapism in a castrated cat associated with feline infectious peritonitis

This report describes a case of feline infectious peritonitis (FIP) in a castrated cat which first presented with the unusual sign of priapism. Laboratory examinations showed increased serum protein content and decreased albumin/globulin ratio. Serum electrophoresis revealed increased alpha 2- and gamma-globulin content. One month after the first examination, the cat died. At necropsy, histopathological evaluation of organs showed inflammatory granulomatous lesions compatible with non-effusive FIP and coronavirus-specific polymerase chain reaction confirmed the diagnosis. FIP antigen was demonstrated immunohistochemically in penile tissue.     

Papular cutaneous lesions in a cat associated with feline infectious peritonitis

A 7-month-old-intact male domestic shorthair cat was presented with fever, anterior uveitis in the right eye and respiratory distress when handled. These signs along with mild changes in serum protein levels and the exclusion of other potential causes were suggestive of feline infectious peritonitis (FIP). As the disease progressed, more clinical signs consistent with FIP, including renal involvement and later pleural effusion, became evident. Non-pruritic cutaneous lesions, characterized by slightly raised intradermal papules over the dorsal neck and over both lateral thoracic walls, were recognized at the end stage of the disease. The identification of papules in well-haired skin was difficult, and clipping of the fur facilitated their detection. Definitive diagnosis of FIP was made by histopathology and by immunohistochemical demonstration of coronavirus antigen in macrophages within kidney and skin lesions. The case was classified as a mixed form of FIP. Recognition of associated cutaneous lesions may facilitate a diagnosis of FIP in suspicious cases.     

Skin fragility syndrome in a cat with feline infectious peritonitis and hepatic lipidosis

A 6-year-old spayed female domestic shorthair cat with a 3-week history of inappetence, weight loss, and hiding was examined. A palpable abdominal fluid wave, dehydration, and a small tear on the left flank were noted during initial examination. When the cat was gently restrained for blood sampling, the skin on the dorsal neck tore, leaving a 15 cm x 7 cm flap of skin. Clinicopathological abnormalities included nonregenerative anaemia, hypoalbuminaemia, increased globulin concentration, and mildly elevated aspartate aminotransferase and alkaline phosphatase activities. Abdominal fluid was viscous and had a total protein of 5.3 g dL(-1) with 316 cells microL(-1), consistent with a modified transudate. Cytology of the abdominal fluid revealed 86% nondegenerate neutrophils, 13% macrophages, and 1% small lymphocytes. Histopathological evaluation and indirect immunohistochemistry confirmed a diagnosis of feline infectious peritonitis, hepatic lipidosis and feline skin fragility syndrome. Feline skin fragility syndrome has not previously been reported in association with feline infectious peritonitis (FIP). Its inclusion as a clinical sign associated with FIP may facilitate a diagnosis.     

Prevalence of feline infectious peritonitis in specific cat breeds

Although known that purebreed cats are more likely to develop feline infectious peritonitis (FIP), previous studies have not examined the prevalence of disease in individual breeds. All cats diagnosed with FIP at a veterinary teaching hospital over a 16-year period were identified. Breed, sex and reproductive status of affected cats were compared to the general cat population and to mixed breed cats evaluated during the same period. As with previous studies sexually intact cats and purebreed cats were significantly more likely to be diagnosed with FIP; males and young cats also had a higher prevalence of disease. Abyssinians, Bengals, Birmans, Himalayans, Ragdolls and Rexes had a significantly higher risk, whereas Burmese, Exotic Shorthairs, Manxes, Persians, Russian Blues and Siamese cats were not at increased risk for development of FIP. Although additional factors doubtlessly influence the relative prevalence of FIP, this study provides additional guidance when prioritizing differentials in ill purebreed cats.     

Prolonged survival of a cat diagnosed with feline infectious peritonitis by immunohistochemistry

A 4-year-old, neutered male, British shorthair cat was presented with inappetence, vomiting, hyperproteinemia, and hyperglobulinemia. An exploratory celiotomy identified enlarged mesenteric lymph nodes. Immunohistochemistry of lymph node biopsies confirmed feline infectious peritonitis. This patient had a prolonged survival of 787 d after initial presentation.     

Cutaneous lesions associated with coronavirus-induced vasculitis in a cat with feline infectious peritonitis and concurrent feline immunodeficiency virus infection

This report describes a clinical case of feline infectious peritonitis (FIP) with multisystemic involvement, including multiple nodular cutaneous lesions, in a cat that was co-infected with feline coronavirus and feline immunodeficiency virus. The skin lesions were caused by a pyogranulomatous-necrotising dermal phlebitis and periphlebitis. Immunohistology demonstrated the presence of coronavirus antigen in macrophages within these lesions. The pathogenesis of FIP involves a viral associated, disseminated phlebitis and periphlebitis which can arise at many sites. Target organs frequently include the eyes, abdominal organs, pleural and peritoneal membranes, and central nervous tissues, but cutaneous lesions have not previously been reported.     

A feline case of isolated fourth ventricle with syringomyelia suspected to be related with feline infectious peritonitis

A one-year-old female cat was unable to stand. Magnetic resonance imaging was performed, and an enlargement of the lateral, third, and fourth ventricles and syringomyelia were detected. The cat was diagnosed with an isolated fourth ventricle (IFV) with syringomyelia. The serum isoantibody test for the feline infectious peritonitis (FIP) virus was 1:3,200. After the cat died, a pathological examination revealed nonsuppurative encephalomyelitis. We suspected that the IFV, detected in the cat, was associated with FIP encephalomyelitis. To our knowledge, there has been no report on IFV in veterinary medicine.     

Hypervitaminosis A in the cat: a case report and review of the literature

A case of hypervitaminosis A with secondary entrapment and compression of the left brachial plexus nerve roots is described. A 9-year-old male castrated domestic shorthair, fed a home-made diet based on raw pork liver, was submitted for examination for a left forelimb lameness that evolved to paralysis over a 2-month period. Clinical examination revealed a flaccid paralysis and atrophy of all left forelimb muscles. An ipsilateral Horner's syndrome was also noted. Radiological examination of the cervical and thoracic spine showed massive new bone formation at the ventral aspect of the second cervical to sixth thoracic vertebra. The diagnosis of hypervitaminosis A was made, based on the clinical and radiographic findings, as well as the determination of serum vitamin A concentration, which was 630 microg/dl, three times above the upper normal limit for this species. Despite the unfavourable initial prognosis, the cat progressively regained function of the affected limb approximately 6 months after the diet was changed to a commercial canned food.     

Deletions in the 7a ORF of feline coronavirus associated with an epidemic of feline infectious peritonitis

A population of Persian cats experienced an epidemic of feline infectious peritonitis (FIP) over 2 years. Twelve cases of FIP occurred in litters born during this period. Cats contracting FIP were all genetically related through the sire. Feline coronavirus (FCoV) genomic RNA was detected consistently in this study in biologic samples from adult cats, kittens suffering from FIP, and their siblings. Analysis of viral 7a/7b open reading frame (ORFs) were analyzed and revealed two distinct virus variants circulating in the population, one with an intact 7a ORF and one with two major deletions in the 7a ORF. The 7b ORFs were intact and similar among all virus isolates, although point mutations resulting in amino acid changes were present. The sire was determined to be infected with both variants, and was persistently virus-infected. We speculate the deletion variant arose from the non-deletion variant during viral replication in this population, possibly in the sire.     

Acquired scoliosis associated with hydromyelia and syringomyelia in two dogs

Progressive scoliosis resulting from hydromyelia and syringomyelia was found in 2 dogs. In one dog, hydromyelia was associated with pachymeningeal fibrosis, with adhesions in the cervical portion of the spinal cord. In the other case, a cause was not established. Neither dog had congenital CNS malformations. The clinicopathologic findings in the 2 dogs are described, and the etiology and pathogenesis of hydromyelia and syringomyelia are discussed.     

Chemotactic responses of neutrophils in cats with spontaneous feline infectious peritonitis

The culture supernatant of peritoneal exudate cells (PEC) from cats with effusive feline infectious peritonitis (FIP) was chemotactic for peripheral blood neutrophils (PBN) from healthy cats, magnitude of the chemotactic activity being approximately 10-fold lower than that in zymosan-activated fresh serum of healthy cats (ZAS). The migration profile of PBN from healthy cats was slightly different between the PEC culture supernatant and ZAS. These findings suggest that the chemotactic activity detected in the PEC culture supernatant is distinct from that in ZAS. The chemotactic responses of PBN from FIP cats to ZAS were reduced, as compared with that from healthy controls. In contrast, the neutrophil chemotactic response and sensitivity to the PEC culture supernatant in FIP cats were not remarkably different from those in healthy controls. Furthermore, the chemotactic responsiveness of PEC from FIP cats to ZAS was slightly different from that of PEC to the PEC culture supernatant. These results suggest that neutrophils from FIP cats have altered reactivities against these chemoattractants.     

Histiocytic sarcoma of macrophage origin in a cat: case report with a literature review of feline histiocytic malignancies and comparison with canine hemophagocytic histiocytic sarcoma

Mild nonregenerative anemia was detected in a 9-year-old neutered male domestic shorthair cat during a routine examination. Bone marrow core biopsy revealed erythroid hyperplasia; however, a specific cause was not identified. Over the next 8 months the anemia progressed, eventually becoming mildly regenerative, and moderate thrombocytopenia developed. On ultrasonographic examination, marked splenomegaly, mild hepatomegaly, and abdominal lymphadenopathy were found. Cytologic evaluation of splenic aspirates revealed increased numbers of mildly to moderately pleomorphic histiocytes that frequently had phagocytosed RBCs, leukocytes, and occasionally platelets. Histopathologic examination of the spleen and liver revealed effacement of splenic architecture by a histiocytic sarcoma (HS), and neoplastic histiocytes in hepatic sinusoids. A second bone marrow aspirate revealed neoplastic infiltration by similar cells. The histiocytes in all tissues were mildly to moderately pleomorphic and markedly erythrophagocytic. The immunophenotype of histiocytes in the spleen was CD1c(-)/CD11b(+)/CD18(+)/MHC-II(+), supporting a macrophage cell lineage. The clinical, pathologic, and immunophenotypic findings in this cat were similar to those in hemophagocytic HSs in dogs. To our knowledge, this is the first report of a HS of purported macrophage phenotype in a cat.     

Retrospective analysis of seizures associated with feline infectious peritonitis in cats

Seizures have been reported frequently in feline infectious peritonitis (FIP) but have not been studied in detail in association with this disease. The purpose of this study was to perform a retrospective analysis of neurological signs in a population of 55 cats with a histopathologically confirmed neurological form of FIP. Seizure patterns were determined and it was attempted to relate occurrence of seizures with age, breed, sex and neuropathological features. Fourteen cats had seizure(s), while 41 cats had no history of seizure(s). Generalised tonic-clonic seizures were seen in nine cats; and complex focal seizures were observed in four patients. The exact type of seizure could not be determined in one cat. Status epilepticus was observed in one patient but seizure clusters were not encountered. Occurrence of seizures was not related to age, sex, breed or intensity of the inflammation in the central nervous system. However, seizures were significantly more frequent in animals with marked extension of the inflammatory lesions to the forebrain (P=0.038). Thus, the occurrence of seizures in FIP indicates extensive brain damage and can, therefore, be considered to be an unfavourable prognostic sign.     

Malignant thymoma with widespread metastases in a dog: case report and brief literature review

A malignant thymoma of epithelial type with metastases to the liver, spleen and bone marrow in a 16 year old female Cocker Spaniel dog is described. Lesions were considered to be incidental findings at necropsy.