Cerebral pyogranuloma associated with systemic coronavirus infection in a ferret

A 2‐year‐old male ferret was presented with central nervous system signs. Computed tomography (CT) of the brain revealed a well‐defined contrast‐enhancing lesion on the rostral forebrain that appeared extraparenchymal. Surgical excision of the mass was performed and the ferret was euthanised during the procedure. Histopathology of the excised mass showed multiple meningeal nodular lesions with infiltrates of epithelioid macrophages, occasionally centred on degenerated neutrophils and surrounded by a broad rim of plasma cells, features consistent with pyogranulomatous meningitis. The histopathological features in this ferret were similar to those in cats with feline infectious peritonitis. Definitive diagnosis was assessed by immunohistochemistry, confirming a ferret systemic coronavirus (FSCV) associated disease. This is the first case of coronavirus granuloma described on CT‐scan in the central nervous system of a ferret.     

Clinicopathologic features of a systemic coronavirus-associated disease resembling feline infectious peritonitis in the domestic ferret (Mustela putorius)

From 2002 to 2007, 23 ferrets from Europe and the United States were diagnosed with systemic pyogranulomatous inflammation resembling feline infectious peritonitis (FIP). The average age at the time of diagnosis was 11 months. The disease was progressive in all cases, and average duration of clinical illness was 67 days. Common clinical findings were anorexia, weight loss, diarrhea, and large, palpable intra-abdominal masses; less frequent findings included hind limb paresis, central nervous system signs, vomiting, and dyspnea. Frequent hematologic findings were mild anemia, thrombocytopenia, and hypergammaglobulinemia. Grossly, whitish nodules were found in numerous tissues, most frequently the mesenteric adipose tissue and lymph nodes, visceral peritoneum, liver, kidneys, spleen, and lungs. One ferret had a serous abdominal effusion. Microscopically, pyogranulomatous inflammation involved especially the visceral peritoneum, mesenteric adipose tissue, liver, lungs, kidneys, lymph nodes, spleen, pancreas, adrenal glands, and/or blood vessels. Immunohistochemically, all cases were positive for coronavirus antigen using monoclonal antibody FIPV3-70. Electron microscopic examination of inflammatory lesions identified particles with coronavirus morphology in the cytoplasm of macrophages. Partial sequencing of the coronavirus spike gene obtained from frozen tissue indicates that the virus is related to ferret enteric coronavirus.     

Pathological, clinical and mycological findings in experimental aspergillosis infections of starlings

A group of 24 wild starlings (Sturnus vulgaris), in undefined age categories but at least post-pubertal, constituted the material of this study. Six starlings were kept as a control group and 18 starlings served as the infection group. The starlings in the infection group were infected with inoculums of 1.35 x 10(6)/0.2 ml Aspergillus fumigatus via intratracheal route whereas the control group was administered only placebo in the same way. Six, four, two, four and two birds died on 2, 3, 4, 5 and 6 days post inoculation respectively. At the necropsy of the dead birds, caseous foci were determined in the lungs, on the air sacks, myocardium, thoracic wall and abdominal serosa. In the histopathological examination of the white-yellowish caseous foci ranging from pinhead to chick pean in size, necrotic granulomatous foci consisting of macrophages, heterophil leukocytes and gigant cells encapsulated with a fibrous tissue were observed. Hyphae and spores of A. fumigatus were determined in these foci using the Gridley staining method.     

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.     

An enteric coronavirus infection of cats and its relationship to feline infectious peritonitis

An enteric coronavirus that is antigenically closely related to feline infectious peritonitis virus (FIPV) is ubiquitous in the cat population. This virus has been designated feline enteric coronavirus to differentiate it from FIPV. The virus is shed in the feces by many seropositive cats; in catteries it is a cause of inapparent to mildly severe enteritis in kittens 6 to 12 weeks of age. The virus may produce a more severe enteritis in young specific-pathogen-free kittens. Feline enteric coronavirus selectively infects the apical columnar epithelium of the intestinal villi, from the caudal part of the duodenum to the cecum. In severe infections, there are sloughing of the tips of the villi and villous atrophy. Many cats recovering from the disease remain carriers of the virus. Recovered cats, observed for 3 to 24 months, remained healthy and did not develop peritonitis, pleuritis, or granulomatous disease. The relationship of feline enteric coronavirus and FIPV was studied. Although the viruses were antigenically similar, they were distinctly different in their pathogenicities. The enteric coronavirus did not cause feline infectious peritonitis in coronavirus antibody-negative cats inoculated orally or intraperitoneally nor in coronavirus antibody-positive cats inoculated intraperitoneally or intratracheally. Serologic tests, using FIPV, canine coronavirus, and transmissible gastroenteritis virus of swine as substrate antigens in fluorescent antibody procedures may not accurately identify FIPV infection. These tests do not appear to distinguish between FIPV and this feline enteric coronavirus.     

Thoracic mass in a cynomolgus macaque (Macaca fascicularis)

A male cynomolgus macaque at the age of 3 years and 11 months suffered sudden cardiac arrest during a surgical operation. This animal had been clinically asymptomatic for 6 months from the acclimatization period to death. At necropsy, a white mass approximately 5 cm in diameter was found at the base of the heart. Histopathologically, the mass consisted of a granuloma with a number of multinucleated giant cells and multiple necrotic foci. Fungal hyphae characterized by parallel cell walls, distinct septa, and branching were observed in the lesion. The granuloma extended into the thoracic lymph nodes and the subepicardium of the left atrium, compressed the bronchioli, and was separated from the pulmonary parenchyma by a thick fibrous layer. The hyphal morphology and results of polymerase chain reaction assays demonstrated that the pathogen was Aspergillus sp.     

Serologic response of domestic ferrets (Mustela putorius furo) to canine distemper and rabies virus vaccines

Nine unrelated 12-week-old naive domestic ferrets (Mustela putorius furo) were used to evaluate the serologic responses to commercial canine distemper virus (CDV) and rabies virus (RV) vaccines. Five of the ferrets (group 1) were inoculated 3 times at 2-week intervals with a multivalent modified-live virus vaccine of canine cell-line origin, containing CDV and an inactivated RV vaccine. Four of the ferrets (group 2) were inoculated once with the multivalent modified-live virus vaccine containing CDV and were not inoculated with the RV vaccine. Both group-1 and group-2 ferrets seroconverted to the CDV component of the vaccine. Group-1 ferrets also seroconverted after RV vaccination and maintained serum antibody titers to both CDV and RV for at least 7 months. Domestic ferret sera were found to have IgG epitopes similar to sera of domestic dogs and cats. Domestic ferret sera did not contain antibodies to feline coronavirus or FeLV antigens.     

实验性新城疫雏鸡免疫器官的病理学研究

给２８日龄伊莎雏鸡人工接种新城疫病毒后，应用常规病理学检验、细胞化学和免疫组化技术对免疫器官的病理学变化作了研究。接毒１２ｈ，法氏囊滤泡的髓质、胸腺小叶的髓质、脾白髓、盲肠扁桃体的淋巴小结及弥散淋巴组织的部分淋巴细胞和网状细胞首先出现核浓缩、胞浆固缩等坏死变化。接毒１～３ｄ（潜伏期），骨髓、法氏囊滤泡、胸腺小叶、脾白髓和红髓、盲肠扁桃体粘膜层及弥散淋巴组织的淋巴细胞、巨噬细胞和网状细胞发生核浓缩、碎裂、胞浆固缩，强嗜酸性等坏死变化。接毒４～６ｄ死亡病例，这些免疫器官的淋巴组织散在呈蜂窝状空泡结构坏死灶（法氏囊为滤泡坏死），进一步崩解成无结构嗜酸性颗粒状物质。这些坏死变化可作为雏鸡新城疫诊断的根据。     

Abscess-forming inflammatory granulation tissue with Gram-positive cocci and prominent eosinophil infiltration in cats: possible infection of methicillin-resistant Staphylococcus

We occasionally encounter feline cervical or mesenteric lesions diagnosed histopathologically as abscess or inflammatory granulation tissue with eosinophil infiltration. Gram-positive cocci accompany the lesions. In the present study, such lesions obtained from 27 cats were examined to evaluate the histopathologic features and the nature of the causative bacteria. The average age was 7.3 +/- 3.5 years. No sex predilection was observed. Most frequent locations of the lesions included the abdominal cavity with/without mesenteric lymph nodes (11/27, 41%) and subcutaneous tissue or lymph nodes of the neck (9/27, 33%). Common clinical presentation was a localized mass. Grossly, the lesions contained abscesses in the center and were surrounded by fibrous tissue. Microscopically, the necrotic zone contained bacterial colonies. Large numbers of eosinophils and macrophages infiltrated the area surrounding the necrotic tissue. The surrounding connective fiber-rich granulation tissue demarcated the eosinophilic abscess. The bacteria were Gram-positive cocci in 23 of the 27 cats and were positive for anti-staphylococcus antiserum in 19 of the 23 cats. In 15 out of 17 lesions, the colonies expressed immunoreactivity to penicillin-binding protein 2', which is a drug-resistance gene product of methicillin-resistant Staphylococcus (MRS) species. These findings suggest strongly that MRS causes this type of infectious lesion.     

Clinical and pathologic features of neuronal ceroid-lipofuscinosis in a ferret (Mustela putorius furo)

Clinical and pathologic features of neuronal ceroid-lipofuscinosis in a 4-month-old ferret are reported. Clinical signs including neurological symptoms appeared at 3 months of age and progressed rapidly. By magnetic resonance imaging, severe cerebral atrophy was recognized. Histopathologically, there was severe neuronal loss and diffuse astrogliosis with macrophage accumulations; lesions were found predominantly in the cerebral cortex. Intracytoplasmic pigments were observed in surviving neurons and macrophages throughout the brain. The pigments were intensely positive for periodic acid-Schiff, Luxol fast blue, and Sudan black B and exhibited a green autofluorescence. Electron microscopic examination revealed the accumulation of electron-dense granular material within lysosomes of neurons and macrophages. Immunohistochemically, a large number of saposin-positive granules accumulated in the neuronal cells, astrocytes, and macrophages of the lesions, but significant immunoreactivity for subunit c of mitochondrial adenosine triphosphate synthase was not observed. Based on these findings, the animal was diagnosed as affected by neuronal ceroid-lipofuscinosis.     

Suspected metastatic coccygeal chordoma in a ferret (Mustela putorius furo).

A chordoma was removed from the tail base of a 6.5-year-old ferret (Mustela putorius furo). A nodule was observed in the area of tumor development when the ferret was purchased at 3 months of age. Although the nodule did not enlarge for 2 years, slow, steady growth of the tumor was observed for 4 years before surgical removal. Eight months after removal of the chordoma, the ferret developed 2 cutaneous masses. One was adjacent to the vulva, close to where the chordoma had been removed from, whereas the other was in the nasofacial region. After 4 months of slow growth, both masses were removed and both were histologically and immunohistochemically consistent with chordoma. Over the next 8 weeks, additional masses developed in the facial, maxillary gingival, and scapular regions. Enlargement of the gingival mass caused dysphagia, and the ferret was euthanized. Although a necropsy was not performed, these additional masses had a clinical appearance and texture that was similar to the 2 previously removed cutaneous chordomas. To the authors' knowledge, this is the first report of a ferret coccygeal chordoma that developed close to the base of the tail. Ferret chordomas have been reported previously to metastasize to the subcutis overlying the tumor. However, this is the first report of a ferret chordoma that metastasized to a location distant to the primary site of neoplasm development. Cell proliferation indices did not predict this metastatic behavior. It is hypothesized that the long clinical period before removal may have predisposed this neoplasm to metastasis. Observations from this case suggest that chordomas in ferrets may have metastatic potential and so should be removed promptly.     

Comparative properties of feline coronaviruses in vitro.

Two feline coronaviruses were characterized to determine their biological properties in vitro and their antigenic relatedness to a previously recognized feline infectious peritonitis virus and canine coronavirus. The viruses, designated WSU 79-1146 and WSU 79-1683, were shown to have comparable growth curves with the prototype feline infectious peritonitis virus. Treatment of the feline infectious peritonitis virus strains with 0.25% trypsin indicated that they were relatively resistant to proteolytic inactivation when compared with the feline enteric coronavirus strain. This observation may serve as a useful in vitro marker to distinguish closely related members of the feline coronavirus group. Plaque assay results indicated that the feline infectious peritonitis virus strains produced large homogeneous plaques in comparison to the feline enteric coronavirus strain and canine coronavirus, which showed a heterogenous plaque size distribution. No naturally temperature sensitive mutants were detected in either of the feline coronavirus populations. Both of the viruses were antigenically related to feline infectious peritonitis virus and to a lesser extent to canine coronavirus by virus neutralization.     

Coronavirus antibody detection in cats by computer-assisted kinetics-based enzyme-linked immunosorbent assay (KELA): field studies

A total of 2238 feline serum samples submitted to the New York State Diagnostic Laboratory over a 1-year period were tested for the presence of coronavirus antibodies, using the computer-assisted, kinetics-based enzyme-linked immunosorbent assay (KELA). Cats from which sera were obtained were categorized by sex, age, breed, and disease status, and variations in mean antibody titers for different sub-classifications within each category were analyzed by computerized statistical analysis. As expected, higher mean antibody titers were recorded for cats with feline infectious peritonitis, and for cats with a recent history of possible coronavirus exposure. However, an unexpected inverse relationship between coronavirus antibody titer and age was also found. Certain cattery-oriented pure breeds appeared to have higher mean antibody titers, because their sample populations contained a higher percentage of younger cats and cats of unknown age-groups which, over-all, had higher mean titers. Taken together, the data substantiated the efficacy of the computer-assisted KELA for routine detection of serum coronavirus antibodies in cats.     

Mycobacterium genavense Infection in a Domestic Ferret (Mustela putorius furo)

Mycobacterium genavense infection was diagnosed in an adult ferret with ptosis of the left eye, a proliferative lesion of the conjunctiva of the nictitating membrane, conjunctival swelling, and tumefaction of the periorbital tissues with a watery ocular discharge and the presence of a retrobulbar mass. The diagnosis was based on characteristic cytology of the retrobulbar mass and left mandibular lymph node that revealed granulomatous inflammation. Ziehl-Neelsen staining showed the presence of positive acid-fast bacilli in the cytoplasm of the macrophages. The diagnosis was confirmed by sequence analysis of the 16S rRNA gene amplified by using a multiplex polymerase chain reaction from a fresh lymph node biopsy. Therapy with marbofloxacin, rifampicin, and clarithromycin was recommended for 6 months and after this period, the veterinarian who was treating the ferret reported the disappearance of clinical signs. Six months after the end of the antibiotic treatment, the symptoms described previously reoccurred. Confirmatory laboratory tests were not performed but a recurrence of M genavense infection was suspected and the veterinarian, in agreement with the owner, euthanized the ferret.     

Pathogenesis of feline enteric coronavirus infection

Fifty-one specific pathogen-free (SPF) cats 10 weeks to 13 years of age were infected with a cat-to-cat fecal-oral passed strain of feline enteric coronavirus (FECV). Clinical signs ranged from unapparent to a mild and self-limiting diarrhea. Twenty-nine of these cats were FECV na?ve before infection and followed sequentially for fecal virus shedding and antibody responses over a period of 8-48 months. Fecal shedding, as determined by real-time polymerase chain reaction (RT-PCR) from rectal swabs, appeared within a week and was significantly higher in kittens than older cats. FECV shedding remained at high levels for 2-10 months before eventually evolving into one of three excretion patterns. Eleven cats shed the virus persistently at varying levels over an observation period of 9-24 months. Eleven cats appeared to have periods of virus shedding interlaced with periods of non-shedding (intermittent or recurrent shedders), and seven cats ceased shedding after 5-19 months (average 12 months). There was no change in the patterns of virus shedding among cats that were excreting FECV at the time of a secondary challenge exposure. Four cats, which had ceased shedding, re-manifested a primary type infection when secondarily infected. Cats with higher feline coronavirus (FCoV) antibody titers were significantly more likely to shed virus, while cats with lower titers were significantly less likely to be shedding. Twenty-two kittens born to experimentally infected project queens began shedding virus spontaneously, but never before 9-10 weeks of age. Natural kittenhood infections appeared to be low grade and abortive. However, a characteristic primary type infection occurred following experimental infection with FECV at 12-15 weeks of age. Pregnancy, parturition and lactation had no influence on fecal shedding by queens. Methylprednisolone acetate treatment did not induce non-shedders to shed and shedders to increase shedding.     

Cardiomyopathy in Dystrophin-Deficient Hypertrophic Feline Muscular Dystrophy

A colony of cats affected with hypertrophic feline muscular dystrophy was used to study the occurrence of cardiomyopathy associated with dystrophin deficiency. Affected male and female cats, obligate carrier females, and unaffected healthy littermates were followed from 12 weeks of age into adulthood. Thoracic radiography, 2-D echocardiography, and 2-D-derived M-mode echocardiography were performed at 3-month intervals until 12 months of age and regularly thereafter. From 9 months of age, all affected cats had larger hearts than normal and carrier animals. Left ventricular wall thickness in systole and in diastole and interventricular septal thickness in systole were greater in affected cats 12 months and older when compared with normal or heterozygous animals (P < .05). The myocardium of affected cats was diffusely hypoechoic and thickened. Multiple hyperechoic foci were in the myocardium and papillary musculature. Shortening fraction was normal in all cats. Changes seen in carrier females included enlargement and hyperechogenicity of the papillary musculature after the age of 2 years. Gross and light microscopic examination revealed left ventricular wall thickening with multiple foci of mineralization in 2 of 5 hearts from dystrophin-deficient cats. Although approximately 10% of the normal dystrophin amount was present in the skeletal muscle, dystrophin could not be detected in the myocardium. Early onset concentric myocardial hypertrophy was present in all adult cats. Lesions were mainly localized in the myocardium of the left ventricular free wall and interventricular septum, papillary musculature, and the endocardium. Clinical signs of heart failure developed only infrequently in cats with hypertrophic feline muscular dystrophy.     

Immunohistopathological findings in the lungs of calves naturally infected with Mycoplasma bovis

Histology and immunohistochemistry were used to analyse the lesions and distribution of Mycoplasma bovis antigen in the lungs of 18 naturally infected calves. Microscopic examination of pneumonic lungs revealed two distinct patterns of necrosis and inflammation. The first pattern was observed in six of 18 (33.3%) calves in which microscopic lesions were characterized by large irregular areas of coagulative necrosis surrounded by a dense zone of degenerated neutrophils. Moderate amounts of mycoplasmal antigen were in the centre and periphery of these necrotic foci and, to a lesser extent, in mononuclear cells of the peribronchial lymphoid tissue. The second pattern was observed in 18 of 18 (100%) calves and consisted of rounded foci of caseous necrosis composed by granular eosinophilic material surrounded by a rim of granulation tissue. Large amounts of M. bovis antigen were detected in the centre and periphery of these necrotic foci and, to a lesser extent, in the peribronchial lymphoid tissue, and alveolar and interstitial macrophages. It was concluded that both caseous and coagulative necrosis of the lung parenchyma was primarily caused by M. bovis. Infection with M. bovis should be suspected in bovine necrotic bronchopneumonia, particularly in cases in which the pulmonary necrosis is part of a pyogranulomatous inflammation centred around airways. The pattern of caseous necrosis with pyogranulomatous inflammation is characteristic of M. bovis infection while the pattern of coagulative necrosis is similar to and must be differentiated from Mannheimia haemolytica and Haemophilus somnus infection.     

Differential role for low pH and cathepsin-mediated cleavage of the viral spike protein during entry of serotype II feline coronaviruses

Feline infectious peritonitis (FIP) is a terminal disease of cats caused by systemic infection with a feline coronavirus (FCoV). FCoV biotypes that cause FIP are designated feline infectious peritonitis virus (FIPV), and are distinguished by their ability to infect macrophages and monocytes. Antigenically similar to their virulent counterparts are FCoV biotypes designated feline enteric coronavirus (FECV), which usually cause only mild enteritis and are unable to efficiently infect macrophages and monocytes. The FCoV spike protein mediates viral entry into the host cell and has previously been shown to determine the distinct tropism exhibited by certain isolates of FIPV and FECV, however, the molecular mechanism underlying viral pathogenesis has yet to be determined. Here we show that the FECV strain WSU 79-1683 (FECV-1683) is highly dependent on host cell cathepsin B and cathepsin L activity for entry into the host cell, as well as on the low pH of endocytic compartments. In addition, both cathepsin B and cathepsin L are able to induce a specific cleavage event in the FECV-1683 spike protein. In contrast, host cell entry by the FIPV strains WSU 79-1146 (FIPV-1146) and FIPV-DF2 proceeds independently of cathepsin L activity and low pH, but is still highly dependent on cathepsin B activity. In the case of FIPV-1146 and FIPV-DF2, infection of primary feline monocytes was also dependent on host cell cathepsin B activity, indicating that host cell cathepsins may play a role in the distinct tropisms displayed by different feline coronavirus biotypes.