Biomedical subjects
Publications and source records attributed to Michael R Lappin.
It is unlikely that human beings acquire a zoonotic infection from healthy cats without ectoparasites. The benefits of cat ownership to human mental health are well established. Veterinarians and physicians should work together closely to provide accurate information to cat owners so that logical decisions concerning cat ownership can be made by the owner.
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OBJECTIVE: To determine whether Ctenocephalides felis can transmit Mycoplasma haemofelis (Mhf) and Candidatus Mycoplasma haemominutum (Mhm) through hematophagous activity between cats. ANIMALS: 11 cats. PROCEDURE: 2 cats were carriers of either Mhf or Mhm. Nine cats had negative results via polymerase chain reaction (PCR) assay for Mhf and Mhm DNA; 3 of those cats were infected from the chronic carriers via i.v. inoculation of blood. At the time of maximum organism count for each of the Mycoplasma spp, 1 chamber containing 100 C felis was bandaged to the amplifier cats. Five days later, fleas, feces, larvae, or eggs from each chamber were analyzed for Mycoplasma spp DNA. Viable fleas from the chambers were allocated into new chambers (3 Mhm and 6 Mhf) and attached to naïve cats for 5 days. Cats were monitored daily for clinical signs and weekly via CBC and PCR assay for infection with Mhf or Mhm for a minimum of 8 weeks. RESULTS: Uptake of Mhf and Mhm DNA into fleas, feces, and, potentially, eggs and larvae was detected. Of the naïve cats fed on by Mhf-infected fleas, 1 cat transiently yielded positive PCR assay results for Mhf on 1 sampling date without clinical or hematologic changes consistent with Mhf infection. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that hematophagous transfer of Mhm and Mhf into fleas occurred and that C felis is a possible vector for Mhf via hematophagous activity.
OBJECTIVE: To determine whether administration of Crandell-Rees feline kidney (CRFK) cell lysates or vaccines against feline viral rhinotracheitis, calicivirus, and panleukopenia (FVRCP vaccines) that likely contain CRFK cell proteins induces antibodies against CRFK cell or feline renal cell (FRC) lysates in cats. ANIMALS: 14 eight-week-old cats. PROCEDURE: Before and after the study, renal biopsy specimens were obtained from each cat for histologic evaluation. Each of 4 FVRCP vaccines was administered to 2 cats at weeks 0, 3, 6, and 50. Between weeks 0 and 50, another 3 pairs of cats received 11 CRFK cell lysate inoculations SC (10, 50, or 50 microg mixed with alum). Clinicopathologic evaluations and ELISAs to detect serum antibodies against CRFK cell or FRC lysates were performed at intervals. RESULTS: Cats had no antibodies against CRFK cell or FRC lysates initially. All cats administered CRFK cell lysate had detectable antibodies against CRFK cell or FRC lysates on multiple occasions. Of 6 cats vaccinated parenterally, 5 had detectable antibodies against CRFK cell lysate at least once, but all 6 had detectable antibodies against FRC lysate on multiple occasions. Cats administered an intranasal-intraocular vaccine did not develop detectable antibodies against either lysate. Important clinicopathologic or histologic abnormalities were not detected during the study. CONCLUSIONS AND CLINICAL RELEVANCE: Parenteral administration of vaccines containing viruses likely grown on CRFK cells induced antibodies against CRFK cell and FRC lysates in cats. Hypersensitization with CRFK cell proteins did not result in renal disease in cats during the 56-week study.
OBJECTIVE: To evaluate plasma glipizide concentration and its relationship to plasma glucose and serum insulin concentrations in healthy cats administered glipizide orally or transdermally. ANIMALS-15 healthy adult laboratory-raised cats. PROCEDURE: Cats were randomly assigned to 2 treatment groups (5 mg of glipizide, PO or transdermally) and a control group. Blood samples were collected 0, 10, 20, 30, 45, 60, 90, and 120 minutes and 4, 6, 10, 14, 18, and 24 hours after administration to determine concentrations of insulin, glucose, and glipizide. RESULTS: Glipizide was detected in all treated cats. Mean +/- SD transdermal absorption was 20 +/- 14% of oral absorption. Mean maximum glipizide concentration was reached 5.0 +/- 3.5 hours after oral and 16.0 +/- 4.5 hours after transdermal administration. Elimination half-life was variable (16.8 +/- 12 hours orally and 15.5 +/- 15.3 hours transdermally). Plasma glucose concentrations decreased in all treated cats, compared with concentrations in control cats. Plasma glucose concentrations were significantly lower 2 to 6 hours after oral administration, compared with after transdermal application; concentrations were similar between treatment groups and significantly lower than for control cats 10 to 24 hours after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Transdermal absorption of glipizide was low and inconsistent, but analysis of our results indicated that it did affect plasma glucose concentrations. Transdermal administration of glipizide is not equivalent to oral administration. Formulation, absorption, and stability studies are required before clinical analysis can be performed. Transdermal administration of glipizide cannot be recommended for clinical use at this time.
OBJECTIVE: To determine regional seroprevalence estimates of Toxoplasma gondi-specific IgM and IgG in clinically ill cats throughout the United States. Sample Population-Sera from 12,628 clinically ill, client-owned cats. PROCEDURE: Toxoplasma gondii-specific IgM and IgG antibodies were detected by use of ELISAs. Sera from clinically ill cats previously submitted for T. gondii antibody testing were sequentially selected from our serum bank and the sample submission paperwork reviewed. The country was divided into 12 geographic regions. Overall prevalence as well as prevalence for each region, age group, season, sex (male vs female), and breed (domestic shorthair vs other) was calculated. Data were analyzed by logistic regression analysis. RESULTS: Overall, 31.6% of the cats were seropositive for T. gondii-specific IgM, IgG, or both. Percentage of cats seropositive for T. gondii antibodies ranged from 16.1% (southwestern United States) to 43.5% (northeastern United States). As age increased, odds of positive T. gondii antibody assay results (IgM alone, IgG alone, and any combination of IgM or IgG) increased. Males were more likely than females to be seropositive for T. gondii antibodies (IgG alone and any combination of IgM or IgG). Domestic shorthair cats were more likely than other breeds to be seropositive for T. gondii antibodies (IgM alone, IgG alone, and any combination of IgM or IgG). CONCLUSIONS AND CLINICAL RELEVANCE: Toxoplasma gondii-specific antibodies are common in serum samples of clinically ill cats from all regions of the United States. Seroprevalence increases as cats age and is higher in male and domestic shorthair cats, compared with females and other breeds.
Recent efforts by North American zoos to establish a genetically viable captive population of Pallas' cats (Otocolobus manul) have been compromised by high newborn mortality (approximately 60%), primarily because of toxoplasmosis. The basis for this extreme susceptibility to toxoplasmosis is unknown. In the present study, the general health status of wild Pallas' cats in Mongolia was evaluated, including assessment of basal hematologic parameters and fecal corticoid metabolite concentrations. The prevalence of exposure to Toxoplasma gondii in Mongolian Pallas' cats, local domestic cats, and prey species also was determined based on serology and/or polymerase chain reaction analysis. Biologic samples (blood, feces, and/or brain tissue) were obtained from 15 wild Pallas' cats, 15 domestic cats, and 45 prey animals (rodents and pikas) captured in Mongolia during the summers of 2000 and 2001. Comparative data were obtained from nine captive Pallas' cats maintained in North American zoos. Based on physical examinations, complete blood counts, and blood chemistry analyses, only minor differences were observed in the general health status of wild and captive Pallas' cats. Fecal cortisol metabolite concentrations did not differ (P > 0.05) between populations, indicating that Pallas' cats in captivity and in the wild have similar basal adrenocortical activity. A pronounced difference (P < 0.01) in seroprevalence to T. gondii was observed between populations. Whereas all captive Pallas' cats exhibited elevated immunoglobulin titers (IgG > 2,048) to T. gondii, only two of 15 (13%) wild Pallas' cats were seropositive, with both cats having lower IgG titers (< 1,024). Furthermore, no evidence of exposure to this parasite was found in any of the Mongolian domestic cats or prey species. These findings suggest that wild Pallas' cats have minimal opportunity for exposure to T. gondii in their natural habitat and, typically, do not become infected with this parasite until being brought into captivity. Accordingly, maintenance of a viable captive population may require implementing effective strategies to prevent exposure of immunologically naive Pallas' cats to T. gondii and to reduce parasite transmission between seropositive females and their highly susceptible offspring.
Anaplasma phagocytophilum DNA was detected in blood of clinically ill cats from Massachusetts (n = 4) and Connecticut (1) by use of polymerase chain reaction assay and DNA sequencing. All 5 cats were allowed outdoors, and Ixodes scapularis were found on 3 cats. Clinical signs of fever, anorexia, and lethargy resolved quickly after treatment with doxycycline or tetracycline. Serum samples from each cat reacted with A. phagocytophilum morulae via an indirect fluorescent antibody assay; positive antibody titers persisted even after 21 to 30 days of treatment with tetracycline. To the authors' knowledge, this is the first report of A. phagocytophilum infection of domestic cats in North America. Results suggest that infection with the organism may be associated with clinical illness in some cats.
Objectives of this study were to determine prevalence of infection in feral cats in Northern Florida with a select group of infectious organisms and to determine risk factors for infection. Blood samples or sera from 553 cats were tested with a panel of antibody, antigen or PCR assays. Male cats were at higher risk for FIV, Mycoplasma haemofelis, and M. haemominutum. Infection with either FeLV or FIV was associated with increased risk for coinfection with the other retrovirus, M. haemofelis, or M. haemominutum. Bartonella henselae had the highest prevalence and was the only organism that did not have any associated risk for coinfection with other organisms. Feral cats in this study had similar or lower prevalence rates of infections than those published for pet cats in the United States. Thus, feral cats assessed in this study appear to be of no greater risk to human beings or other cats than pet cats.
There are several drugs available for the treatment of giardiasis in cats, including metronidazole. The purpose of this study was to determine whether metronidazole benzoate administered at a dose of 25 mg/kg, orally, twice a day for 7 days lessens or eliminates Giardia cyst shedding in cats with chronic infection. Twenty-six, adult, laboratory-reared cats were used in this study. Sixteen cats had been inoculated orally with cysts of a human Giardia sp. isolate and had completed a Giardia vaccine study in one animal holding room. The other ten cats were infected with the same Giardia sp. presumably by contamination from the adjacent room where the Giardia vaccine study cats were located. From each cat, a fecal sample was collected within 1 week of the start of treatment and then every 2 to 4 days for 15 days after treatment was completed. Fecal samples were analyzed for the presence of Giardia cysts using a commercially available direct immunofluorescence test (IFA). Clinical signs of drug toxicity were not detected during the study.
A 13-year old cat had 3-day duration of vomiting, lethargy, and anorexia. A complete blood count revealed a severe neutrophilia (126.9 x 10(3) cells/microl). Thoracic radiographs demonstrated a large solitary lung mass. A bone marrow aspirate documented myeloid hyperplasia. A left intercostal thoracotomy was performed and left cranial and caudal lung lobectomies were performed in order to remove the mass in its entirety. Histological diagnosis was squamous cell carcinoma of the lung. Following surgery, the severe neutrophilia began to decrease. It was in the normal range approximately 6 weeks postoperatively. The presence of a primary lung tumor combined with a mature neutrophilia with resolution following surgical resection suggests a paraneoplastic syndrome.
A quantitative Taqman polymerase chain reaction (PCR) assay was used to evaluate the response of Mycoplasma haemofelis experimentally infected cats to three antibiotic treatment regimes. Sixteen cats were intravenously inoculated with M. haemofelis from a chronically infected donor. The cats were randomly assigned to one of four treatment groups each containing four cats: oral doxycycline at 10 mg/kg/day for 14 days, oral enrofloxacin at 5 mg/kg/day for 14 days, oral enrofloxacin at 10 mg/kg/day for 14 days, and an untreated control group. DNA, extracted from blood samples collected on days 0, 7, 14, 21, 25, 28, 32, 35, 42 and 54 post-inoculation (PI), was subjected to quantitative Taqman PCR. The M. haemofelis copy number was significantly lower in the doxycycline group (P=0.008), the 5 mg/kg/day enrofloxacin group (P=0.006) and the 10 mg/kg/day enrofloxacin group (P=0.005) compared to the untreated control group. No significant differences were found between any of the three antibiotic treated treatment groups. All three antibiotic treatment regimes evaluated in this study were effective at reducing M. haemofelis copy number.
BACKGROUND: Urinary tract inflammation and hemorrhage are believed to be common causes of proteinuria in dogs based on results of studies that measured total urine protein concentration. A method to quantify urine albumin (UAlb) concentration in dogs recently has become available; however, the effect of inflammation on albuminuria is unknown. OBJECTIVES: The goals of this study were to determine the effects of urinary tract inflammation, as indicated by pyuria and sample blood contamination, on UAlb concentration and on urine protein:creatinine (UPC) ratio in dogs. METHODS: Urine samples were obtained from dogs with pyuria that were presented to a veterinary teaching hospital or were part of a laboratory colony. To mimic the effects of hematuria, canine whole blood was added to a microscopically normal canine urine sample that had baseline albumin and total protein concentrations below the limits of detection. UAlb concentration was measured using a canine albumin-specific competitive ELISA. UPC ratio was determined using routine methods. RESULTS: Of 70 samples with pyuria, 67% had negligible UAlb concentrations and 81% had normal UPC ratios. UAlb concentration but not UPC ratio was significantly higher (P < 0.05) in samples with concurrent hematuria or bacteriuria. When whole blood was added to normal urine, UAlb concentration did not exceed 1 mg/dL until the sample became visibly pink; the UPC did not exceed 0.4 at any dilution. CONCLUSIONS: Many dogs with pyuria do not have albuminuria or proteinuria; however, albuminuria may be more likely in dogs with pyuria and concurrent hematuria or bacteriuria. Hematuria may not cause an increase in UAlb concentration until it becomes macroscopic and even then may not increase the UPC ratio.
OBJECTIVE: To assess efficacy of Giardia vaccination as a treatment for giardiasis in experimentally infected cats. DESIGN: Original study. ANIMALS: 16 young-adult cats. PROCEDURE: Cats were experimentally infected by orogastric administration of Giardia cysts. On weeks 4, 6, and 10, cats in the treatment group (n = 8) were given Giardia vaccine SC. For the first 28 weeks after infection, 3 fecal samples from each cat were examined weekly for Giardia cysts, and cyst numbers were counted. Fecal consistency was scored daily for the duration of the study. Results from vaccinated and unvaccinated cats were compared by logistic regression. RESULTS: All cats became infected and were shedding Giardia cysts by the end of week 2. Throughout the study, diarrhea was rare and was mild and transient when it did occur. By week 28, 5 of 8 vaccinated cats and 7 of 8 control cats had patent Giardia infections. Magnitude of infection, based on number of fecal samples with cysts and number of cysts per sample, decreased progressively in both groups over time. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of 3 doses of a Giardia vaccine did not completely eliminate the organism from experimentally infected cats in the study period. Since clinical signs were minimal in both groups of cats, it could not be determined whether vaccination lessened severity of clinical disease. Results may have been negatively influenced by the large inoculation dose. Whether Giardia vaccination is an effective treatment for giardiasis in naturally infected cats remains to be determined.
OBJECTIVE: To determine whether fenbendazole effectively eliminates Giardia organisms from chronically infected cats that have a concurrent Cryptosporidium parvum infection. ANIMALS: 16 clinically normal cats. PROCEDURE: Eight cats with chronic concurrent Giardia and C parvum infections received fenbendazole (50 mg/kg, PO, q 24 h) for 5 days (treatment-group cats). Feces from each cat were collected and processed 3 days weekly for 23 days after treatment. By use of an immunofluorescent assay for detection of Giardia lamblia cysts and C parvum oocysts, organism numbers were counted and scored. Fecal results from treatment-group cats were compared with those of 8 untreated cats with Giardia infection but no C parvum infection (control-group cats). RESULTS: Four of 8 treatment-group cats had consistently negative results for Giardia infection after treatment. These 4 cats had consistently positive results for C parvum oocysts prior to treatment and consistently negative results after treatment. One treatment-group cat had positive results for cysts on all fecal samples, and 3 treatment-group cats had 1 to 3 negative results and then resumed shedding large numbers of cysts; each of these cats had consistently positive results for C parvum oocysts. When compared with control-group cats, treatment-group cats shed less Giardia cysts during week 1 after treatment but not during week 2. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of fenbendazole decreases Giardia cyst shedding to less than detectable numbers in some cats. In our study, persistent C parvum infection may have been associated with failure of fenbendazole to eliminate Giardia infection.
OBJECTIVE: To compare treatment with enrofloxacin and doxycycline with no treatment in cats experimentally infected with Haemobartonella felis. DESIGN: Prospective case-control study. ANIMALS: 16 cats. PROCEDURE: Cats were inoculated with large-form H. felis from a chronically infected donor. Cats were assigned to 1 of 4 treatment groups: doxycycline (5 mg/kg [2.3 mg/lb], p.o., q 12 h), low-dose enrofloxacin (5 mg/kg, p.o., q 24 h), high-dose enrofloxacin (10 mg/kg [4.5 mg/lb], p.o., q 24 h), and an untreated control group. Clinical signs, Hct, blood smears, and a polymerase chain reaction (PCR) assay were used to monitor progression of the infection. RESULTS: All cats were confirmed to be infected with H. felis via blood smear evaluations and PCR assay results. Treatment had no effect on Hct during the intratreatment period, but Hct values were significantly greater in the low-dose enrofloxacin group, compared with the control group, during the posttreatment period. During the intratreatment period, H. felis organism counts per 1,000 RBC in the doxycycline treatment and the high-dose enrofloxacin treatment groups decreased at a significantly faster rate than those in the control group. In the posttreatment period, organism counts in the doxycycline treatment group and the low- and high-dose enrofloxacin groups decreased at significantly faster rates than counts in the control group. There was no significant effect of treatment on the number of positive PCR assay results. Two cats treated with enrofloxacin and 1 cat treated with doxycycline completely cleared the H. fe is organism despite presumed immunosuppression caused by glucocorticoids. CONCLUSIONS AND CLINICAL RELEVANCE: Results support the hypothesis that enrofloxacin has anti-H. felis effects.
OBJECTIVE: To determine whether detection of virus-specific serum antibodies correlates with resistance to challenge with virulent feline herpesvirus 1 (FHV-1), feline calicivirus (FCV), and feline parvovirus (FPV) in cats and to determine percentages of client-owned cats with serum antibodies to FHV-1, FCV, and FPV. DESIGN: Prospective experimental study. ANIMALS: 72 laboratory-reared cats and 276 client-owned cats. PROCEDURES: Laboratory-reared cats were vaccinated against FHV-1, FCV, and FPV, using 1 of 3 commercial vaccines, or maintained as unvaccinated controls. Between 9 and 36 months after vaccination, cats were challenged with virulent virus. Recombinant-antigen ELISA for detection of FHV-1-, FCV-, and FPV-specific antibodies were developed, and results were compared with results of hemagglutination inhibition (FPV) and virus neutralization (FHV-1 and FCV) assays and with resistance to viral challenge. RESULTS: For vaccinated laboratory-reared cats, predictive values of positive results were 100% for the FPV and FCV ELISA and 90% for the FHV-1 ELISA. Results of the FHV-1, FCV, and FPV ELISA were positive for 195 (70.7%), 255 (92.4%), and 189 (68.5%), respectively, of the 276 client-owned cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that for cats that have been vaccinated, detection of FHV-1-, FCV-, and FPV-specific antibodies is predictive of whether cats are susceptible to disease, regardless of vaccine type or vaccination interval. Because most client-owned cats had detectable serum antibodies suggestive of resistance to infection, use of arbitrary booster vaccination intervals is likely to lead to unnecessary vaccination of some cats.