Use of anti-coronavirus antibody testing of cerebrospinal fluid for diagnosis of feline infectious peritonitis involving the central nervous system in cats

OBJECTIVE: To assess the use of measuring anti-coronavirus IgG in CSF for the diagnosis of feline infectious peritonitis (FIP) involving the CNS in cats. DESIGN: Prospective study. SAMPLE POPULATION: CSF and serum samples from 67 cats. PROCEDURES: CSF and serum samples were allocated into 4 groups: cats with FIP involving the CNS (n = 10), cats with FIP not involving the CNS (13), cats with CNS disorders caused by diseases other than FIP (29), and cats with diseases other than FIP and not involving the CNS (15). Cerebrospinal fluid was evaluated for concentrations of erythrocytes, leukocytes, and total protein. Anti-coronavirus IgG was measured in CSF and serum by indirect immunofluorescence assay. RESULTS: CSF IgG (range of titers, 1:32 to 1:4,096) was detected in 12 cats, including 6 cats with neurologic manifestation of FIP, 4 cats with FIP not involving the CNS, and 2 cats with brain tumors. Cerebrospinal fluid IgG was detected only in cats with correspondingly high serum IgG titers (range, 1:4,096 to 1:16,384) and was positively correlated with serum IgG titers (r = 0.652; P < 0.01), but not with any other CSF parameter. Blood contamination of CSF resulted in < or = 333 erythrocytes/microL in cats with CSF IgG. CONCLUSIONS AND CLINICAL RELEVANCE: The correlation between serum and CSF IgG and the fact that CSF IgG was detected only in strongly seropositive cats suggested that CSF anti-coronavirus IgG was derived from blood. Measurement of anti-coronavirus IgG in CSF was of equivocal clinical use.     

Immunoglobulin M-capture enzyme-linked immunosorbent assay testing of cerebrospinal fluid and serum from horses exposed to west nile virus by vaccination or natural infection

The West Nile (WN) virus, present in the United States since 1999, is a cause of encephalomyelitis in birds, alligators, humans, and horses. No data exist regarding detection of anti-WN virus immunoglobins in equine cerebrospinal fluid (CSF). The aims of this study were to evaluate the blood-brain barrier (BBB) in WN virus-infected (WNE) horses, to compare diagnostic testing in serum and CSF, and to describe the immunoglobulin M (IgM) response in serum and CSF of vaccinated horses. CSF was collected from the lumbosacral (LS) space (n = 13) or the allanto-occipital (AO) space (n = 14) of WNE horses. The albumin quotient (AQ) and IgG index were calculated, and the IgM-capture-enzyme-linked immunosorbent assay (MAC-ELISA) was used to detect anti-WN virus IgM in serum and CSF. CSF collected from the LS site had a higher (P < .02) IgG index compared to the AO site (0.34 +/- 0.04 versus 0.22 +/- 0.04 [mean +/- SE], respectively). The mean AQ, irrespective of collection site, did not exceed reference values. There was 100% agreement between CSF and serum testing for IgM by MAC-ELISA testing. However, the positive to negative antigen ratios were higher (P < .001) in CSF (34.5) versus serum (8.5), indicating lower nonspecific reactivity in CSF samples. Horses vaccinated against WN virus did not develop an IgM response at 1:400 mg/dL in serum; however, a few horses developed a weak IgM response in serum but not in CSF. In conclusion, MAC-ELISA testing of serum and CSF were equivocal. Also, examination of CSF data from WNE horses suggests a normal BBB integrity and increased intrathecal production of antibodies.     

Clinical, cerebrospinal fluid, and histological data from twenty-seven cats with primary inflammatory disease of the central nervous system.

The purpose of this report is to present the clinical, cerebrospinal fluid (CSF) and histological data from 27 cats with inflammatory disease of the central nervous system (CNS). The cats were part of a study of 61 cats admitted to two university clinics over an eight-year period because of signs of CNS disease. The most frequent diseases were feline infectious peritonitis (FIP) (12/27) and suspected viral disease other than FIP (10/27). Typical CSF findings in cats with FIP were a protein concentration of greater than 2 g/L (200 mg/dL) and a white cell count of over 100 cells/microL, which consisted predominantly of neutrophils. In contrast, the CSF of cats with suspected viral disease had a protein concentration of less than 1 g/L (100 mg/dL) and a total white cell count of less than 50 cells/microL. In general, cats with FIP or suspected viral disease were less than four years of age. Neurological signs were usually multifocal in cats with FIP, but focal in cats with suspected viral disease. The CSF findings were variable in five other inflammatory diseases represented. Two cats with protozoan infection had normal CSF total cell counts but abnormal differential counts. The CSF findings were invaluable in differentiating FIP from other causes of inflammatory CNS disease.     

Shifts in circulating lymphocyte subsets in cats with feline infectious peritonitis (FIP): pathogenic role and diagnostic relevance

Cats with feline infectious peritonitis (FIP) are usually lymphopenic and have lymphoid depletion evident in spleen and lymph nodes. In particular, the number of CD4+ lymphocytes in tissues decreases during the evolution of FIP lesions. This decrease is most likely due to increased lymphocyte apoptotic rate. In contrast, cats infected with the Feline Coronavirus (FCoV) develop a follicular hyperplasia in the peripheral lymph nodes. The current study was devised to evaluate the possible pathogenic role of shifts in circulating lymphocyte subsets in FIP. Peripheral blood from cats with FIP was evaluated and compared with peripheral blood from clinically healthy cats living in both FCoV-free and FCoV-endemic catteries. Blood from cats with diseases other than FIP was also examined in order to define the diagnostic relevance of the changes. Lymphocyte subsets were analysed by flow cytometry, using a whole blood indirect immunofluorescence technique and mAbs specific for feline CD5, CD4, CD8, CD21. The results of the current study suggest that cats recently infected with FCoV that do not develop the disease have a transient increase in T cells; cats from groups with high prevalence of FIP have a moderate but persistent decrease in T cell subsets; cats with FIP have a very severe decrease in all the subsets of lymphocytes. Moreover, during FIP many lymphocytes do not express any membrane antigen, most likely due to early apoptosis. Cats with diseases other than FIP also had decreased number of lymphocytes: as a consequence, the diagnostic relevance of these findings is very low. Nevertheless, the lack of flow cytometric changes had a high negative predictive value (NPV), thus allowing to exclude FIP from the list of possible diagnoses in cats with normal cytograms.     

Changes in some acute phase protein and immunoglobulin concentrations in cats affected by feline infectious peritonitis or exposed to feline coronavirus infection

The possible role of some acute phase proteins (APPs) and immunoglobulins in both the pathogenesis and diagnosis of feline infectious peritonitis (FIP) has been investigated. Serum protein electrophoresis and the concentration of haptoglobin (Hp), serum amyloid A (SAA), alpha(1)-acid glycoprotein (AGP), IgG and IgM were evaluated in cats exposed to feline coronavirus (FCoV) and in cats with FIP. The highest concentration of APPs was detected in affected cats, confirming the role of these proteins in supporting a clinical diagnosis of FIP. Repeated samplings from both FIP affected and FCoV-exposed cats showed that when FIP appeared in the group, all the cats had increased APP levels. This increase persisted only in cats that developed FIP (in spite of a decrease in alpha(2)-globulins) but it was only transient in FCoV-exposed cats, in which a long lasting increase in alpha(2)-globulins was observed. These results suggest that changes in the electrophoretic motility of APPs or APPs other than Hp, SAA and AGP might be involved in the pathogenesis of FIP or in protecting cats from the disease.     

Clinical, cerebrospinal fluid, and histological data from thirty-four cats with primary noninflammatory disease of the central nervous system.

The purpose of this study was to report the clinical, cerebrospinal fluid (CSF), and histological data derived from a study of 34 cats with noninflammatory central nervous system (CNS) disease, and to report the activities of the enzymes lactate-dehydrogenase (LDH), aspartate transferase (AST), and creatine kinase (CK) in the CSF from 15 cats with a variety of CNS diseases. The cats were part of a study of 61 cats that were admitted to two university clinics because of signs of CNS disease. The most frequent noninflammatory diseases were neoplasia (n = 12) and ischemic encephalopathy (n = 4). The majority of cats with CNS neoplasia had a mild increase in CSF protein concentration (less than 1 g/L [100 mg/dL]), an increased percentage of neutrophils or lymphocytes, and a normal total white cell count. Cats with ischemic encephalopathy (IE) had a mild to moderate increase in CSF protein concentration (< or = 2 g/L [200 mg/dL]) and a mild increase in white cell count (< or = 10 cells/microL) with an increased percentage of lymphocytes. The enzymes LDH, AST, and CK in the CSF were not sensitive indicators of chronic CNS disease. The CSF differential cell count was frequently abnormal when the total white cell count was normal, and blood contamination in the CSF samples was a frequent problem that had to be considered in the interpretation of the results. The history, signalment, and clinical signs, when combined with the CSF findings, were valuable in the diagnosis of noninflammatory CNS disease.     

GS-441524对自然感染的猫传染性腹膜炎的治疗效果观察

试验旨在观察GS-441524对自然感染的猫传染性腹膜炎（FIP）病例的临床疗效，为临床用药提供参考。试验招募了25只于中国农业大学动物医院确诊为FIP的患猫，随机分为高剂量组（5 mg/（kg·d））（12只）和低剂量组（2.5 mg/（kg·d））（13只），每日皮下注射GS-441524治疗并记录体重、体温、注射药物的疼痛反应及每周的实验室及影像学检查结果以评价药物疗效。设定治疗周期为4周，部分病例根据实际情况延长治疗时间。结果显示，共计20只湿性FIP和3只干性FIP患猫完成试验，2只患猫退出。治疗时间为4~18周。20只湿性FIP患猫中，2只在1周内死亡，1只体腔积液增加，17只用药1周后积液减少，用药2~3周后积液消失。3只干性FIP患猫中，2只患猫的肠系膜淋巴结在用药1~2周后减小，1只无明显变化。所有患猫的精神和食欲在用药3~5 d内改善；体重在1~2周内开始增长；5只发烧的患猫用药2~3 d后体温恢复正常；14只贫血的患猫用药1~10周后恢复正常；16只患猫出现白细胞数量升高且淋巴细胞数量下降或中性粒细胞数量升高，用药1~2周内开始好转。所有患猫血清中白蛋白和球蛋白的比值（白球比）均<0.8，其中9只总蛋白升高，4只白蛋白降低，14只球蛋白升高，用药1~2周后开始好转。高剂量组的患猫4周药物有效率和治愈率分别为81.8%和60.0%，低剂量组的患猫4周药物有效率和治愈率分别为75.0%和22.2%。用药4周前后，高剂量组的患猫除白细胞总数（WBC）和白蛋白（ALB）外，其余指标均差异显著或极显著（P<0.05；P<0.01）；而低剂量组的患猫仅体重差异显著。除血红蛋白（HGB）、WBC和ALB外，药物对患猫的体重、红细胞（RBC）、红细胞压积（HCT）、淋巴细胞（LYM）、中性粒细胞（NEU）、总蛋白（TP）、球蛋白（GLOB）及白球比（A/G）改善情况差异显著（P<0.05），且高剂量药物效果更佳。综上，GS-441524能有效治疗自然感染的FIP，高剂量（5 mg/（kg·d））疗效更佳，最短治疗周期为4周。     

An immunoturbidimetric assay for rapid quantitative measurement of feline alpha-1-acid glycoprotein in serum and peritoneal fluid

BACKGROUND: Alpha-1-acid glycoprotein (AGP) is an acute phase protein that increases in concentration in infectious and inflammatory conditions. The serum and peritoneal fluid concentrations of AGP may be useful in the diagnosis of feline infectious peritonitis (FIP), a lethal disease of cats. Currently AGP can be measured by radioimmunodiffusion (RID) assays, which are time consuming and difficult. OBJECTIVES: The objectives of this study were to develop a rapid immunoturbidimetric assay for measurement of AGP in feline serum and peritoneal fluid and to compare the results with those obtained by RID. METHODS: AGP was purified by perchloric acid precipitation and ion-exchange chromatography from a pool of peritoneal fluid obtained from cats with FIP, as determined by a panel of laboratory tests, including serum AGP concentration, albumin: globulin ratio, and total protein concentration, anti-coronavirus antibody titers, and effusion analysis. The purified AGP in a complete Freund's adjuvant and Tween 20 mixture was injected into a sheep and blood was collected at monthly intervals. Anti-AGP antiserum, as confirmed by ELISA and Western blot techniques, and a pool of peritoneal fluid from cats with FIP were used to prepare standards. Clinical samples of feline peritoneal fluid (n=55) and serum (n=59) were assayed for AGP and results from the immunoturbidimetric and RID methods were compared. RESULTS: Significant correlation (P < .001) was obtained between methods for both peritoneal fluid (R2=.9259) and serum (R2=.9448) samples. Coefficients of variation for the immunoturbidimetric method were <5%. CONCLUSIONS: This rapid immunoturbidimetric assay for measurement of feline AGP in serum and peritoneal fluid may be of value in the diagnosis of FIP and possibly other inflammatory diseases in cats.     

Laboratory profiles in cats with different pathological and immunohistochemical findings due to feline infectious peritonitis (FIP)

Blood was collected from 55 cats with feline infectious peritonitis (FIP) and from 50 control cats in order to define whether differences in pathological findings and in distribution of feline coronaviruses (FCoV) can be associated with changes in haemograms, serum protein electrophoresis, and antibody titres. Compared to controls, the whole group of FIP-affected cats had blood changes consistent with FIP. Based on the pathological findings or on the immunohistochemical distribution of viral antigen, FIP-affected cats were divided in the following groups: subacute against acute lesions; low against strong intensity of positivity; intracellular against extracellular positivities; positive against negative lymph nodes. Lymphopenia was more evident in cats with acute forms, strong intensity of positivity, extracellular antigen and negative lymph nodes. Cats with positive lymph nodes had the most evident changes in the protein estimations. These results suggest that differences in pathological findings might depend on different reactive patterns to the FCoVs.     

Effects of blood contamination of cerebrospinal fluid on western blot analysis for detection of antibodies against Sarcocystis neurona and on albumin quotient and immunoglobulin G index in horses.

OBJECTIVE: To determine effects of blood contamination on western blot (WB) analysis of CSF samples for detection of anti-Sarcocystis neurona antibodies, and on CSF albumin and IgG concentrations, albumin quotient (AQ), and IgG index in horses. DESIGN: Prospective in vitro study. SAMPLES: Blood with various degrees of immunoreactivity against S neurona was collected from 12 healthy horses. Cerebrospinal fluid without immunoreactivity against S neurona was harvested from 4 recently euthanatized horses. PROCEDURE: Blood was serially diluted with pooled nonimmunoreactive CSF so that final dilutions corresponded to 10(-3) to 100 microliters of blood/ml CSF, and WB analysis was performed on contaminated CSF samples. Number of RBC, albumin and IgG concentrations, AQ, and IgG index were also determined. RESULTS: Antibodies against S neurona were detected in CSF contaminated with 10(-3) microliters of strongly immunoreactive blood/ml. In CSF samples contaminated with 10 microliters of blood/ml, AQ remained within reference range. Volume of blood required to increase IgG index varied among blood samples and was primarily influenced by serum IgG concentrations. Number of RBC in contaminated samples was correlated with volume of blood added, but not with degree of immunoreactivity detected in contaminated CSF samples. CONCLUSIONS AND CLINICAL RELEVANCE: During collection of CSF from horses, contamination with blood may introduce serum antibodies against S neurona at concentrations sufficient for detection by WB analysis, thus yielding false-positive results. When blood is moderately or strongly immunoreactive, the amount of contaminating albumin may be small enough as to not increase AQ above reference range. In these cases, AQ and IgG index should be interpreted with caution.     

Clinicopathological findings and disease staging of feline infectious peritonitis: 51 cases from 2003 to 2009 in Taiwan

Fifty-one cats histopathologically confirmed to have been naturally infected by feline infectious peritonitis (FIP), were collected to analyse the clinical and laboratory findings and to characterise disease staging. Effusive FIP was found in 33 cats, non-effusive FIP in 12 cats, and mixed-type in six cats. Highly significant decreases in haematocrit and albumin levels and an increase in total bilirubin level were noted in both effusive and non-effusive FIP, at first presentation and before death. In serial blood examinations of the effusive group, anaemia and increases in bilirubin and aspartate aminotransferase (AST) were observed from 2 weeks to 0-3 days before death. The packed cell volume, bilirubin, AST, potassium, and sodium levels were established to predict disease staging and survival time. Cumulative points ranging from 0 to 4, 5 to 11 and excess of 12, indicate that the cat can survive for at least 2 weeks, less than 2?weeks and less than 3 days, respectively.     

Cerebrospinal fluid constituents collected at the atlanto-occipital site of xylazine hydrochloride sedated, healthy 8-week-old Holstein calves.

Cerebrospinal fluid (CSF) collected at the atlanto-occipital site and serum were obtained from 10 male, 8-week-old, Holstein calves after sedation with xylazine hydrochloride. Glucose, creatine kinase, alkaline phosphatase, urea nitrogen, creatinine, sodium, potassium, chloride, calcium, phosphorus, total protein, and albumin were determined in serum and CSF. Optical characteristics, specific gravity, total red blood cell and nucleated cell counts and differentials were also evaluated in the CSF. Additionally, CSF protein electrophoresis and immunoglobulin concentrations were determined. Then, albumin quotients (AQ) were derived. Erythrocytes were observed in 9 of 10 CSF samples. Total nucleated cell counts ranged from 0-10 cells x 10(6)/L with a mean of 3 cells x 10(6)/L. Differential nucleated cell count in the CSF consisted primarily of lymphocytes/small mononuclear cells (57%), fewer monocytes/ large mononuclear cells (38%), and scant neutrophils (4%) and eosinophils (0.05%). The concentration of sodium (134 to 139 mEq/L) was similar to that of serum, but the concentration of potassium (2.8 to 3 mEq/L) was lower than that of serum. Creatine kinase activity (0 to 4 U/L) of CSF was markedly lower than serum activity. The CSF glucose concentration was approximately 80% of the serum value. Cerebrospinal fluid total protein concentration determined by electrophoresis ranged from 110 to 330 mg/L with a mean of 159 mg/L. Cerebrospinal fluid albumin ranged from 48 to 209 mg/L with a mean of 86 mg/L. In all CSF samples, radial immunodiffusion of unaltered CSF and concentrated CSF (four-fold concentration) revealed quantities undetectable by the present techniques in which the lowest standard values for IgG1, IgG, and IgM determinations was 70 mg/L and IgG2 was 30 mg/L. The albumin quotient ranged from 0.15 to 0.65 with a mean of 0.25. Based on the results of this study, CSF may be collected at the atlanto-occipital site safely and efficiently in calves, and reported values for CSF from adult cattle may not be suitable for evaluation of CSF collected from immature cattle.     

Epidemiology of feline infectious peritonitis among cats examined at veterinary medical teaching hospitals

OBJECTIVE: To determine proportions of cats in which feline infectious peritonitis (FIP) was diagnosed on an annual, monthly, and regional basis and identify unique characteristics of cats with FIP. DESIGN: Case-control study. SAMPLE POPULATION: Records of all feline accessions to veterinary medical teaching hospitals (VMTH) recorded in the Veterinary Medical Data Base between January 1986 and December 1995 and of all feline accessions for necropsy or histologic examination at 4 veterinary diagnostic laboratories. PROCEDURE: Proportions of total and new feline accessions for which a diagnosis of FIP was recorded were calculated. To identify characteristics of cats with FIP, cats with FIP were compared with the next cat examined at the same institution (control cats). RESULTS: Approximately 1 of every 200 new feline and 1 of every 300 total feline accessions at VMTH in North America and approximately 1 of every 100 accessions at the diagnostic laboratories represented cats with FIP. Cats with FIP were significantly more likely to be young, purebred, and sexually intact males and significantly less likely to be spayed females and discharged alive than were control cats. The proportion of new accessions for which a diagnosis of FIP was recorded did not vary significantly among years, months, or regions of the country. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that FIP continues to be a clinically important disease in North America and that sexually intact male cats may be at increased risk, and spayed females at reduced risk, for FIP. The high prevalence of FIP and lack of effective treatment emphasizes the importance of preventive programs, especially in catteries.     

Diagnostic Features of Clinical Neurologic Feline Infectious Peritonitis

Feline infectious peritonitis (FIP) is a fatal Arthus-type immune response of cats to infection with FIP virus, a mutant of the ubiquitous feline enteric coronavirus (FECV). The disease may occur systemically or in any single organ system, and primary neurologic disease is a common subset of such manifestations. We examined 16 domestic cats with clinical neurologic FIP and 8 control cats with nonneurologic FIP, with the intention of identifying the ante-and postmortem diagnostic tests that most contribute to accurate diagnosis. Of the 16 cats with neurologic FIP, 15 were less than 2 years of age and all 16 originated from large multiplecat households. The most useful antemortem indicators of disease were positive anti-coronavirus IgG titer in cerebrospinal fluid, high serum total protein concentration, and findings on magnetic resonance imaging suggesting periventricular contrast enhancement, ventricular dilatation, and hydrocephalus. Postmortem diagnosis was facilitated by FIP monoclonal antibody staining of affected tissue and coronavirus-specific polymerase chain reaction. Most cats with neurologic and ocular forms of FIP had patchy, focal lesions, suggesting that recently developed technologies described in this report may be useful for evaluation of cats with suspected FIP.     

Vaccine efficacy of a cell lysate with recombinant baculovirus-expressed feline infectious peritonitis (FIP) virus nucleocapsid protein against progression of FIP

The Type II feline infectious peritonitis virus (FIPV) infection of feline macrophages is enhanced by a monoclonal antibody (MAb) to the S protein of FIPV. This antibody-dependent enhancement (ADE) activity increased with the MAb that showed a neutralizing activity with feline kidney cells, suggesting that there was a distinct correlation between ADE activity and the neutralizing activity. The close association between enhancing and neutralizing epitopes is an obstacle to developing a vaccine containing only neutralizing epitopes without enhancing epitopes. In this study, we immunized cats with cell lysate with recombinant baculovirus-expressed N protein of the Type I FIPV strain KU-2 with an adjuvant and investigated its preventive effect on the progression of FIP. Cats immunized with this vaccine produced antibodies against FIPV virion-derived N protein but did not produce virus-neutralizing antibodies. A delayed type hypersensitivity skin response to N protein was observed in these vaccinated cats, showing that cell mediated immunity against the FIPV antigen was induced. When these vaccinated cats were challenged with a high dose of heterologous FIPV, the survival rate was 75% (6/8), while the survival rate in the control group immunized with SF-9 cell-derived antigen was 12.5% (1/8). This study showed that immunization with the cell lysate with baculovirus-expressed N protein was effective in preventing the progression of FIP without inducing ADE of FIPV infection in cats.     

Calculation of the total plasma concentration of nonvolatile weak acids and the effective dissociation constant of nonvolatile buffers in plasma for use in the strong ion approach to acid-base balance in cats

OBJECTIVE: To determine values for the total concentration of nonvolatile weak acids (Atot) and effective dissociation constant of nonvolatile weak acids (Ka) in plasma of cats. SAMPLE POPULATION: Convenience plasma samples of 5 male and 5 female healthy adult cats. PROCEDURE: Cats were sedated, and 20 mL of blood was obtained from the jugular vein. Plasma was tonometered at 37 degrees C to systematically vary PCO2 from 8 to 156 mm Hg, thereby altering plasma pH from 6.90 to 7.97. Plasma pH, PCO2, and concentrations of quantitatively important strong cations (Na+, K+, and Ca2+), strong anions (Cl-, lactate), and buffer ions (total protein, albumin, and phosphate) were determined. Strong ion difference was estimated from the measured strong ion concentrations and nonlinear regression used to calculate Atot and Ka from the measured pH and PCO2 and estimated strong ion difference. RESULTS: Mean (+/- SD) values were as follows: Atot = 24.3 +/- 4.6 mmol/L (equivalent to 0.35 mmol/g of protein or 0.76 mmol/g of albumin); Ka = 0.67 +/- 0.40 x 10(-7); and the negative logarithm (base 10) of Ka (pKa) = 7.17. At 37 degrees C, pH of 7.35, and a partial pressure of CO2 (PCO2) of 30 mm Hg, the calculated venous strong ion difference was 30 mEq/L. CONCLUSIONS AND CLINICAL RELEVANCE: These results indicate that at a plasma pH of 7.35, a 1 mEq/L decrease in strong ion difference will decrease pH by 0.020, a 1 mm Hg decrease in PCO2 will increase plasma pH by 0.011, and a 1 g/dL decrease in albumin concentration will increase plasma pH by 0.093.     

Immune response of neonatal specific pathogen-free cats to experimental infection with Bartonella henselae

The purpose of this study was to determine whether neonatal cats develop and maintain a persistent bacteremia for longer than do adult cats with a normal mature immune system, and whether neonatal cats are susceptible to infection with Bartonella henselae by oral inoculation. Neonatal specific pathogen-free (SPF) cats were inoculated with B. henselae intradermally (n = 4) or orally (n = 5) or with 0.9% NaCl (n = 2). Blood was collected periodically through 16 weeks post-inoculation (PI) for serology, bacteriology and complete blood count. Cats inoculated orally or intradermally at 3-5 days of age were bacteremic through 12-16 weeks PI, similar to what is documented for adult cats inoculated intradermally or intravenously. One cat inoculated at age 2 weeks was bacteremic through 10 weeks PI; the other was not bacteremic. Intradermally inoculated neonatal cats produced serum IgG antibodies to B. henselae but orally inoculated neonatal cats did not. Infected cats with and without serum IgG antibodies to B. henselae became blood-culture negative simultaneously, suggesting that IgG is not required to clear bacteremia.     

Prevalence of diseases of the spinal cord of cats

A retrospective review of records of 205 cats with histologically confirmed disease of the spinal cord was performed to identify the prevalence of disease in this nonrandomly selected population of cats. Clinical records were reviewed, and age, duration of neurologic illness, and clinical and histopathologic findings in cats with spinal cord disease were abstracted. Disease processes were classified into 7 categories and 23 groups. The most common diseases affecting the spinal cord of cats were feline infectious peritonitis (FIP), lymphosarcoma (LSA), and neoplasia of the vertebral column secondarily affecting the spinal cord. Information on age, onset and duration of clinical signs, and lesion localization at the postmortem examination in cats belonging to the 7 categories of disease were analyzed to create a practical list of differential diagnoses. Cats were also subcategorized into 3 groups based on their age at death. FIP was the most common disease of cats younger than 2 years of age. LSA and vertebral column neoplasia were the most common diseases affecting cats between 2 and 8 years of age. Vertebral column neoplasia was the most common disease affecting cats older than 8 years of age. Results of this histopathologic study showed that FIP and LSA were the most common disease processes affecting the spinal cord of cats. However, at least 21 other groups of diseases and their relative prevalence were identified.