Antibodies to spotted fever-group rickettsiae in dogs in North Carolina

A seroepidemiologic survey was conducted to determine the prevalence of antibodies reactive with 4 spotted fever-group (SFG) rickettsiae in sera of dogs from various geographic regions in North Carolina. Serum specimens were obtained from 600 dogs, and antibody titers were determined, using microimmunofluorescence. Data analysis (setting as the criterion for a positive result, a Rickettsia rickettsii titer greater than or equal to 1:64) overestimated the actual prevalence of canine exposure to this rickettsia. When data were analyzed by considering each dog's serologic response to all 4 rickettsial antigens simultaneously, the prevalence rate for exposure to R montana was 15%, to R rhipicephali was 11%, and to R rickettsii was 5%. A definitive exposure to R bellii was not observed, and the identification of the specific inciting rickettsia could not be established for 13% of the dogs, because of identical highest titers to 2 or more antigens. Our data indicate that canine exposure to R rhipicephali is prevalent in the eastern coastal region, whereas exposure to R montana takes place uniformly throughout the state. Rickettsia rickettsii exposure appears to be more prevalent in the central Piedmont region, but rarely is encountered in the western mountains. Regional seroprevalence for canine R rickettsii exposure approximates that for human exposure. Our findings support earlier suggestions that dogs may serve as environmental sentinels for establishing the geographic prevalence of foci of spotted fever.     

Clinical, hematologic, and humoral immune response in female dogs inoculated with Rickettsia rickettsii and Rickettsia montana

Female Beagles were inoculated intradermally with a sublethal dose of Rickettsia rickettsii and R montana. Three dogs (group 1) were inoculated with 2 X 10(2) plaque-forming units (PFU) of R rickettsia and were treated with tetracycline beginning on postinoculation day (PID) 12; 3 dogs (group 2) were inoculated with 2 X 10(2) PFU of R rickettsii but were not treated; 3 dogs (group 3) were inoculated with 2 X 10(2) PFU of R montana. Group-3 dogs failed to seroconvert and were inoculated a second time on PID 68. Groups 1 and 2 dogs inoculated with R rickettsii became depressed and developed occasional inappetence, fever, hematochezia, and ocular lesions. These dogs had a decrease in PCV and RBC count, an initial decrease in WBC count followed by leukocytosis, and a decrease in platelet count. Group-3 dogs inoculated with R montana remained healthy. After R rickettsii inoculation, the serologic response to spotted fever group (SFG) rickettsial antigens (R rickettsii, R rhipicephali, R montana, and R bellii) was similar. The antibody response to R rickettsii was first detected on PID 9, with peak titers reached by PID 20. Serum titers to R rickettsii remained stable or decreased one dilution through PID 120. Of 4 SFG rickettsial antigens, the highest serologic response was to R rickettsii. A cross-reacting antibody response with R rhipicephali and R montana was nearly identical and was only slightly less than the response to R rickettsii. Cross-reacting antibodies to R belli were of lower mean titer and of shorter duration than were cross-reacting antibodies to other SFG rickettsiae.(ABSTRACT TRUNCATED AT 250 WORDS)     

Central nervous system dysfunction associated with Rocky Mountain spotted fever infection in five dogs

Five dogs from the northeastern United States were presented with clinical signs of neurological disease associated with Rocky Mountain spotted fever (RMSF) infection. Four of the five dogs had vestibular system dysfunction. Other neurological signs included paresis, tremors, and changes in mentation. All of the dogs had an elevated indirect fluorescent antibody titer or a positive semiquantitative enzyme screening immunoassay titer for Rickettsia rickettsii at the time of presentation. Although a higher mortality rate has been reported for dogs with neurological symptoms and RMSF infection, all of the dogs in this study improved with appropriate medical therapy and supportive care.     

Assessment of serum antibody titers against canine distemper virus, canine adenovirus type II, and canine parvovirus in Alaskan sled dogs before and after a long-distance race

OBJECTIVE: To determine serum antibody titers against canine distemper virus (CDV), canine adenovirus type II (CAV-2), and canine parvovirus (CPV) in trained sled dogs prior to and after completion of a long-distance race. DESIGN: Prospective cohort study. ANIMALS: 195 Alaskan sled dogs (from 18 kennels) that participated in the 2006 Iditarod Trail Race. PROCEDURES: All 1,323 dogs participating in the race had been vaccinated against the 3 viruses at 19 to 286 days prior to initial blood sample collection (obtained within the month preceding the race). Within 12 hours of race completion, blood samples were collected from 195 dogs (convenience sample) and matched with each dog's prerace sample. Serum antibody titers (90% confidence intervals [CIs]) were determined via serum neutralization assays. RESULTS: After racing, geometric mean titers against CDV and CPV were significantly higher (2,495 [90% CI, 321 to 16,384] and 6,323 [90% CI, 512 to 32,768], respectively) than prerace values (82 [90% CI, 11 to 362] and 166 [90% CI, 32 to 1,024], respectively). Sixty-one of 194 (31.4%) dogs had > or = 4-fold increases in anti-CPV antibody titers after racing. Prerace serum antibody titers against CDV, CPV, and CAV-2 varied significantly by sled team but were not associated with time since vaccination. CONCLUSIONS AND CLINICAL RELEVANCE: Postrace increases in serum anti-CDV and anti-CPV antibody titer might reflect exposure of dogs to these agents immediately before or during racing. Dogs had no clinical signs of CDV-, CAV-2-, or CPV-associated disease; therefore, the clinical importance of these titer changes is uncertain.     

Rocky Mountain spotted fever in an urban canine population

A survey for the prevalence of Rocky Mountain spotted fever antibodies in dogs from a well-defined endemic area in Columbus, Ohio (Franklin County), was conducted during the summer of 1981. Seventy-three blood samples from dogs in this area were tested by microimmunofluorescence for antibodies to Rickettsia rickettsii and other rickettsial antigens. Thirty-three (45.2%) of these samples were positive for R rickettsii, with titers ranging from 1:8 to 1:2,048. For comparison, 137 blood samples from dogs at the Franklin County Dog Pound also were tested. One dog (0.7%) from the comparison group was seropositive to R rickettsii, with a 1:64 titer. The results indicated a nidus of this disease within the city of Columbus, Ohio.     

Kinetics of IgM and IgG responses to experimental and naturally acquired Rickettsia rickettsii infection in dogs

The kinetics of specific IgM and IgG antibody response was characterized in four 9-month-old Beagles after inoculation of 2 x 10(2) plaque-forming units (PFU) of Sheila Smith strain of Rickettsia rickettsii. Immunoglobulin M antibodies were first detected by indirect immunofluorescence on postinoculation (PI) day 9, peaked by PI day 20, and were no longer detectable by PI day 80. Immunoglobulin G antibodies became detectable between PI days 22 and 28, peaked by PI day 42, and decreased gradually through PI day 130. Subsequent challenges with R rickettsii on PI days 216 (2 x 10(2) PFU/dog) and 1,029 (5 x 10(4) tissue culture infective dose [TCID50]/dog) resulted in slightly different serologic responses. The initial challenge exposure failed to increase the concentration of IgG antibodies and induced only low concentrations of IgM antibodies. After the second challenge inoculation, IgM antibodies were not detectable and the concentration IgG antibodies increased slightly. Clinical abnormalities and seroconversion were documented in control dogs following each challenge exposure. Examination of acute and convalescent serum samples from 55 dogs in which Rocky Mountain spotted fever was suspected clinically suggested that sole evaluation of IgM antibodies in acute-phase serum would result in inaccurate diagnoses because of false-positive and -negative results. Use of a composite conjugate that detects IgM and IgG antibodies to R rickettsii appears to be satisfactory for diagnostic purposes; however, concurrent quantitation of IgM antibodies may facilitate serodiagnosis in a select group of dogs in which a four-fold increase in convalescent antibody titer is not detected by use of the composite conjugate.(ABSTRACT TRUNCATED AT 250 WORDS)     

A serological survey of Ehrlichia canis, Ehrlichia equi, Rickettsia rickettsii, and Borrelia burgdorferi in dogs in Oklahoma

Serum samples from 259 dogs were tested for antibodies to Ehrlichia canis, Ehrlichia equi, Rickettsia rickettsii, and Borrelia burgdorferi using the indirect fluorescent antibody test. The sera were obtained from submissions to the Oklahoma Animal Disease Diagnostic Laboratory during a 14-month period from June 1986 through July 1987. The rate for positive antibody titers to E. canis was 53%, to E. equi was 33%, to R. rickettsii was 38%, and to B. burgdorferi was 18%. Higher percentages of sera serologically positive to E. canis were found in the spring through the fall months, but there were no seasonal variations for E. equi, R. rickettsii, and B. burgdorferi. There was no consistent pattern of titers to the 4 antigens when age-groups of the dogs were compared. Forty-four different breeds were tested.     

Antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern Connecticut

Blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (SFG) rickettsiae during 1978-1980 in southern Connecticut. Of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against Rickettsia montana (n = 34), R rickettsii (n = 31), R rhipicephali (n = 19), or the unclassified 369-C rickettsia (n = 90). End points greater than or equal to 1:8,192 to R rickettsii and to R rhipicephali were recorded for 6 and 3 sera, respectively. Seropositivity rates from southwestern and southeastern Connecticut were similar (about 11%), with positive sera obtained from each region in nearly all months of the investigation. Rates were between 10% for dogs 2 to 7 years old and 14% for those greater than or equal to 8 years. Eight of 629 Dermacentor variabilis, 1 of 18 Ixodes dammini, and 2 of 3 Amblyomma americanum were positive by direct immunofluorescence for SFG rickettsiae. Thirteen D variabilis contained unidentified, long, bacillus-like organisms that differed from the short, ovoid (coccal) forms typical fo the spotted-fever agent, R rickettsii. With the exposure to infected ticks and production of type-specific antibodies against at least 4 SFG antigens, dogs may serve as suitable enzootic or epizootic indicators of rickettsial activity.     

Measurement of serum antinuclear antibody titer in dogs with and without systemic lupus erythematosus: 120 cases (1997-2005)

OBJECTIVE: To determine serum antinuclear antibody (ANA) titers in dogs with systemic lupus erythematosus (SLE) and in dogs with related clinical and clinicopathologic findings. DESIGN: Retrospective case series. ANIMALS: 120 dogs. PROCEDURES: Information that was evaluated included signalment, clinical signs, results of routine laboratory testing, ANA titer, and diagnosis. RESULTS: The most common clinical signs were arthralgia, myalgia, and stiffness (n = 41 [34.2%]); the most common clinicopathologic abnormality was thrombocytopenia (30 [25%]). Serum ANA titer was < 160 (seronegative) in 89 dogs (74.2%), 160 in 14 dogs (11.7%), 320 in 5 dogs (4.2%), and > or = 640 in 12 dogs (10%). Immune-mediated disease was confirmed in 40 dogs, 18 of which fulfilled the criteria for a definitive or probable diagnosis of SLE. Only 1 of 47 dogs with no major signs compatible with SLE had immune-mediated disease, compared with 26 of 57 dogs with 1 major sign and 13 of 16 dogs with > or = 2 major signs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that measurement of ANA titer was not a useful diagnostic test in dogs without any major clinical or clinicopathologic abnormalities suggestive of SLE. In contrast, there was a good chance that results of the ANA assay would be positive and that the dog would be found to have immune-mediated disease if at least 2 major signs were evident. Findings suggest that it would be reasonable to limit the use of the ANA assay to those dogs that have at least 1 major sign compatible with a diagnosis of SLE.     

Persistence of antibodies to Borrelia burgdorferi in dogs of New York and Connecticut

Multiple blood samples were obtained from privately owned dogs living in tick-infested areas of New York (Westchester County) and Connecticut, where Lyme disease in human beings has been reported. Of the 175 dogs examined, 127 (72.6%) had limb/joint disorder, whereas the remaining 48 dogs were considered healthy. Results of analysis of 419 serum samples revealed IgM antibody to Borrelia burgdorferi in healthy and lame dogs during all seasons. Prevalence of seropositivity was significantly (P less than 0.01) greater, using a polyvalent ELISA (89.5%) than using a class-specific ELISA for IGM antibody (57.8%). Mean antibody titers obtained by use of polyvalent ELISA were likewise higher than IgM titers. Analysis of paired serum samples from dogs with limb/joint disorder indicated that 118 (92.9%) remained positive for IgM or IgG antibodies when retested weeks or months after initial testing. In 48 dogs without history of joint involvement or other signs of disease, 43 (89.6%) had antibody to B burgdorferi 2 or more times. Serotest results also revealed little or no change in antibody titer for lame dogs given antibiotics or for healthy dogs 2 or more months after initial sample collection.     

Serologic evidence of Rickettsia akari infection among dogs in a metropolitan city

OBJECTIVE: To determine whether dogs in New York, NY are naturally infected with Rickettsia akari, the causative agent of rickettsialpox in humans. DESIGN: Serologic survey. ANIMALS: 311 dogs. PROCEDURE: Serum samples were obtained from dogs as a part of a study on Rocky Mountain spotted fever and borreliosis or when dogs were examined at area veterinary clinics for routine care. Dog owners were asked to complete a questionnaire inquiring about possible risk factors at the time serum samples were obtained. Samples were tested for reactivity to spotted fever group rickettsiae by use of an enzyme immunoassay (EIA). Twenty-two samples for which results were positive were tested by use of an indirect immunofluorescence antibody (IFA) assay followed by confirmatory cross-absorption testing. RESULTS: Results of the EIA were positive for 24 (7.7%) dogs. A history of tick infestation and increasing age were significantly associated with whether dogs were seropositive. Distribution of seropositive dogs was focal. Seventeen of the 22 samples submitted for IFA testing had titers to R rickettsii and R akari; for 11 of these, titers to R akari were higher than titers to R rickettsii. Cross-absorption testing indicated that in 6 of 7 samples, infection was caused by R akari. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dogs can be naturally infected with R akari. Further studies are needed to determine the incidence of R akari infection in dogs, whether infection is associated with clinical illness, and whether dogs can serve as sentinels for human disease.     

Perinuclear antineutrophilic cytoplasmic antibody and response to treatment in diarrheic dogs with food responsive disease or inflammatory bowel disease

The goal of this study was to investigate the correlation between perinuclear antineutrophilic cytoplasmic antibody (pANCA) and clinical scores before and after treatment in diarrheic dogs with food-responsive disease (FRD) or inflammatory bowel disease (IBD). pANCA serology was evaluated prospectively by indirect immunofluorescence in 65 dogs with signs of gastrointestinal disease, and if positive, pANCA antibody titers were determined. Thirty-nine dogs with FRD responded to a novel diet, and 26 dogs with IBD were treated with corticosteroids. The severity of clinical signs was scored by means of a canine IBD activity index (CIBDAI). At initial examination, a significantly (P = .002) higher percentage of dogs were pANCA-positive in the FRD group (62%) compared with the IBD group (23%). pANCA titers were significantly higher (P = .003) before treatment in the FRD group (median titer 100) compared with the IBD group (median titer 1). However, there was no difference in pANCA titers between the groups after respective treatments because dogs in the IBD group had a significant increase in pANCA titer after treatment. The CIBDAI score decreased significantly (P < .001) after treatment in both groups (74% moderate to severe in FRD dogs before versus 8% after treatment; 85% moderate to severe in IBD dogs before versus 32% after treatment). There was no correlation between pANCA status in FRD or IBD dogs before treatment and scores for CIBDAI, endoscopy, or histopathology before or after treatment, except for the endoscopic duodenal score in dogs with FRD after treatment (P = .03). A positive pANCA test before therapy may aid in the diagnosis of FRD.     

Serological survey of Neospora caninum in dogs in the Czech Republic and a long-term study of dynamics of antibodies

The main aim of the present study was to establish the prevalence of antibodies against Neospora caninum dogs from the Czech Republic and to examine the dynamics of antibody titers during a long-term period. For this purpose, sera of 858 dogs were examined for the presence of anti-N. caninum antibodies using an indirect immunofluorescent antibody test (IFAT). Four groups of dogs of various origins were included in the survey: the first group (A, n=470) comprised dogs purchased by the Czech Army from the civilian sector throughout the Czech Republic, with 22 (4.7%) N. caninum-positive dogs, second group (B, n=115) represented police dogs with no seropositive animal, third group (C, n=195) were pet dog sera collected for veterinary clinic with 5 (2.6%) anti-N. caninum sera and the fourth group (D, n=78) of canine shelter dogs with the seroprevalence of 19.2%. The differences in seroprevalence were significant (P< or =0.01) between groups B and A, and between D and A. None of the serologically positive animals had clinical signs of neurological disorders. Coprological examination did not reveal any dog shedding N. caninum oocysts. The seropositivity rates for N. caninum were analyzed in relation to other data, such as age, breed and gender. Increased prevalence rates of anti-N. caninum antibodies were found in the older age strata of the dog population sample tested in the present study. We found significantly higher (P=0.02) prevalence in 3-3.5-year-old dogs (11.1% of 36), as compared to 1-1.5-years-old dogs (2% of 98). A longitudinal study of antibody dynamics was carried out in 19 initially seropositive dogs over a period of 4 years. The second and third examinations revealed that antibody titers decreased in majority of positive dogs (10, 52.6%), of which in seven cases (36.8%) the titers fell to levels that are currently considered as being seronegative (titer <1:50), or even became undetectable (titer <1:25).     

Serum antibody response to canine parvovirus, canine adenovirus-1, and canine distemper virus in dogs with known status of immunization: study of dogs in Sweden

Serum antibody titers to canine parvovirus (CPV), canine adenovirus-1 (CAV-1), and canine distemper virus (CDV) were measured in dogs with known immunization status. The dogs represented 3 groups: nonvaccinated dogs less than 12 months old; vaccinated dogs less than 12 months old; and adult dogs greater than 12 months old. For practical reasons, the population from which the specimens were obtained could be considered as free from natural infection with CAV-1 and CDV. In nonvaccinated dogs less than 12 months old, antibodies against all 3 viruses were measured at the time the dogs were given their first vaccination. Altogether, 50.7% of the dogs had titer greater than or equal to 1:10 to CPV, and 26.1 and 46.2% had titer greater than or equal to 1:8 to CAV-1 and CDV, respectively. The concentration of maternal antibody seemed to be of major importance for failure of immunization with use of inactivated CPV vaccine, but not with CAV-1 and CDV vaccination. In dogs less than 12 months old and vaccinated against CPV infection with inactivated virus, only 11.5% had titer greater than or equal to 1:80. In dogs vaccinated against infectious canine hepatitis and canine distemper, 63.2 and 78.3%, respectively, had titer greater than or equal to 1:16. In adult dogs greater than 2 months old and vaccinated against CPV infection, less than 50% had titer greater than or equal to 1:80, regardless of time after vaccination. There was no significant difference in titer between vaccinated and nonvaccinated dogs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Leptospirosis in dogs: a serologic survey and case series 1996 to 2001

All leptospirosis microscopic agglutination test titers for the Leptospira serovars icterohaemorrhagiae, canicola, grippotyphosa, bratislava, hardjo, and pomona conducted on 1,260 blood samples from dogs at the University of Illinois Veterinary Diagnostic Laboratory between March 1996 and March 2001 were evaluated. Low titers (1:100 to 1:400) were predominantly L. icterohaemorrhagiae and L. canicola, which represented the predominant serovars (65.4%) among all positive samples with low titers. L. grippotyphosa was the predominant serovar (72.1%) among samples with clinically significant titers (greater than 1:800). The medical records of 87 dogs with a titer greater than 1:800 that were patients at the Veterinary Teaching Hospital of the University of Illinois were reviewed. A clinical diagnosis of leptospirosis was made in 15 cases (17.2%) based on the elevated titer, appropriate clinical signs, lack of recent vaccination, and lack of concurrent disease that could explain the clinical signs present. Renal disease was present in 10 of the cases, concurrent renal and hepatic disease in two, and hepatic disease in three. In 12 cases, the predominant serovar was L. grippotyphosa; titers to L. grippotyphosa and L. bratislava were equal in magnitude in three cases.     

Leptospirosis in dogs: a serologic survey and case series 1996 to 2001

All leptospirosis microscopic agglutination test titers for the Leptospira serovars icterohaemorrhagiae, canicola, grippotyphosa, bratislava, hardjo, and pomona conducted on 1,260 blood samples from dogs at the University of Illinois Veterinary Diagnostic Laboratory between March 1996 and March 2001 were evaluated. Low titers (1:100 to 1:400) were predominantly L. icterohaemorrhagiae and L. canicola, which represented the predominant serovars (65.4%) among all positive samples with low titers. L. grippotyphosa was the predominant serovar (72.1%) among samples with clinically significant titers (greater than 1:800). The medical records of 87 dogs with a titer greater than 1:800 that were patients at the Veterinary Teaching Hospital of the University of Illinois were reviewed. A clinical diagnosis of leptospirosis was made in 15 cases (17.2%) based on the elevated titer, appropriate clinical signs, lack of recent vaccination, and lack of concurrent disease that could explain the clinical signs present. Renal disease was present in 10 of the cases, concurrent renal and hepatic disease in two, and hepatic disease in three. In 12 cases, the predominant serovar was L. grippotyphosa; titers to L. grippotyphosa and L. bratislava were equal in magnitude in three cases.     

Canine Ehrlichiosis in Six Dogs with Persistently Increased Antibody Titers

Chronic ehrlichiosis was diagnosed in six dogs on the basis of increased immunofluorescent antibody titers to Ehrlichia canis. Although clinical signs varied, all six dogs were anemic, hyperglobulinemic, and an IgG monoclonal gammopathy was documented in five dogs in which serum protein electrophoreses were performed. All dogs were treated with tetracycline for at least 14 days; four dogs also received immunosuppressive drugs. Clinical signs resolved within 1 week, hematologic abnormalities resolved in 1 to 5 months, and increased globulin concentrations normalized in 1 to 15 months; however, E. canis antibody titers remained increased for 15 to 31 months after initiation of treatment. Results of this study show that increased E. canis titers can persist in dogs with ehrlichiosis for many months after clinical recovery.     

Susceptibility and reservoir potential of the dog to spotted fever-group rickettsiae

This study was initiated to determine the degree of susceptibility of dogs to virulent and nonvirulent spotted fever-group rickettsiae and to evaluate dogs as sources of infection for ticks. Dogs were exposed either by inoculation (syringe) or by infective tick bite to the following rickettsial serotypes: (1) Rickettsia rickettsii (Wachsmuth and Sawtooth female 2 strains), (2) R montana (M/5-6 B strain), and (3) R rhipicephali (3-7-female 6 strain). Results indicated that dogs inoculated with 1,000 or 10,000 egg infective doses of virulent R rickettsii developed a rickettsemia that was detectable as early as 4 days after inoculation to as late as 10 days. Conversely, none of the dogs inoculated with R montana (M/5-6 B) or R rhipicephali (3-7-female 6) or exposed to ticks infected with these strains developed detectable rickettsemia, fever, or other observable clinical signs. None of the 394 ticks that fed on rickettsemic dogs (R rickettsii) infected by inoculation became infected, and only 3 of 348 ticks (0.9% infection rate) were infected after feeding on dogs which had been infected by tick bite. All ticks fed on dogs exposed to R rhipicephali and R montana were shown to be free of rickettsiae. The largest concentrations of plaque-forming units (PFU) in Vero cell culture from undiluted whole blood were found on day 6 and on day 7 in dogs that were inoculated with 10,000 and 1,000 R rickettsii, respectively, of the Sawtooth female 2 strain. The highest rickettsial concentration observed for the dog infected by tick feeding was on day 9.(ABSTRACT TRUNCATED AT 250 WORDS)     

Antinuclear antibodies can be detected in dog sera reactive to Bartonella vinsonii subsp. berkhoffii, Ehrlichia canis, or Leishmania infantum antigens

The presence of antinuclear antibodies (ANAs) is used to support a clinical diagnosis of systemic lupus erythematosus (SLE) in dogs. However, clinicians must interpret the detection of ANAs with caution, particularly in light of increasing evidence that dogs with known bacterial and protozoal infections can have high ANA titers. Retrospectively, medical records were reviewed for all dogs that were concurrently tested for antinuclear antigens and Bartonella vinsonii (berkhoffii), Ehrlichia canis, or Rickettsia rickettsii antigens between 1990 and 2000. When analyzed on the basis of reactivity to a specific infectious agent, 75% of the B vinsonii (berkhoffii) seroreactors, 16.7% of the E canis seroreactors, and 0% of the R rickettsii seroreactors had concurrent ANAs. Subsequent prospective testing did not detect ANAs in convalescent sera from dogs experimentally infected with B vinsonii (berkhoffii), E canis, or R rickettsii. However, 10-20% B vinsonii (berkhoffii), E canis, or Leishmania infantum reactive sera from naturally infected dogs contained ANAs. In addition, 45% of sera from dogs that are reactive to multiple vectorborne organisms were more likely to contain ANAs when compared to sera from dogs reactive to only 1 test antigen. When interpreting the relevance of seroreactivity to nuclear antigens, clinicians should recognize that dogs with seroreactivity to B vinsonii (berkhoffii), E canis, or L infantum antigens (especially those with seroreactivity to more than one of these pathogens) may produce ANAs.     

Hemostatic Abnormalities in Dogs With Hemangiosarcoma

The hemostasis profiles of 24 dogs with histologically confirmed hemangiosarcoma were prospectively evaluated. Microangiopathic hemolysis was defined as the presence of schistocytes; disseminated intravascular coagulation was defined as 1) thrombocytopenia, 2) fibrin(ogen) degradation products greater than 10 micrograms/mL, 3) prolongation of one or more coagulation times (activated partial thromboplastin time or one-stage prothrombin time) by greater than 25% of the control, 4) fragmented red blood cells (greater than or equal to 1+ based on a semiquantitative grading scale), and 5) fibrinogen less than or equal to 80 mg/dL. Three of the five criteria listed above had to be met for disseminated intravascular coagulation to be diagnosed. Fifty percent of the dogs were considered to have disseminated intravascular coagulation at presentation. Thrombocytopenia was present in 75% of the dogs and was the most common abnormality. The mean platelet count was 137,800/microL. Twenty-five percent of the dogs died as a result of the hemostatic abnormalities. Only 12% of the dogs had microangiopathic hemolysis without other evidence of disseminated intravascular coagulation. Hemostatic abnormalities are present in many dogs with hemangiosarcoma at the initial clinical presentation and represent an important clinical finding.