Detection of erythrocyte binding IgM and IgG by flow cytometry in sick dogs with Babesia canis canis or Babesia canis vogeli infection

The aim of this study was to examine by means of flow cytometry immunophenotyping (FCI) if sick dogs infected with Babesia canis canis (B. c. canis) or Babesia canis vogeli (B. c. vogeli) had anti-erythrocyte membrane binding IgG and/or IgM at the time of diagnosis. Diagnosis of Babesia infection was assessed by blood smear and by PCR-restriction fragment length polymorphism analysis in 30 sick dogs. Signalment, clinical history, physical examination and laboratory tests of B. c. canis (n=24) and of B. c. vogeli (n=6) infected dogs were studied. The majority of B. c. canis infected dogs showed anemia (92%) predominantly non-regenerative (94%), while the B. c. vogeli infected dogs had a regenerative anemia (67%). Eccentrocytosis was present in 33% of the B. c. canis infections. Four of six B. c. vogeli infected dogs had erythrocytes membrane antibodies. One dog resulted uncertain and one resulted negative to FCI. In contrast, all the B. c. canis infected dogs were negative for erythrocytes membrane binding immunoglobulins detection. In addition, the mean percentages of erythrocytes binding IgG and IgM were statistically much lower in B. c. canis than in B. c. vogeli infected dogs. At the time of the diagnosis, the formation of erythrocyte membrane binding IgG and IgM by immune mechanisms appears not to be involved in B. c. canis infections while it is present in the majority of B. c. vogeli infections.

Molecular survey of Rickettsia spp. in sick dogs in Italy

The aim of this retrospective study was to investigate the prevalence of Rickettsia spp. DNA in the blood of sick dogs from Italy. Canine blood samples (n=650) submitted for molecular testing of Rickettsia spp. to a diagnostic laboratory from February 2003 to March 2006 were studied. The Rickettsia spp. DNA detection was performed by Light Cycler real-time PCR using hybridization probes separately conducted with specific primers and probes. The total percentage of Rickettsia spp.-positive dog samples was 1.5% (10 out of 650). The percentage of Rickettsia spp.-positive dog samples submitted from north, central and southern Italy were 0.4% (1/248), 1.4% (3/219) and 3.3% (6/183), respectively. Five out of 138 dogs (3.6%) from Sicily were positive on Rickettsia PCR testing. A statistical difference was found between the percentages of positive samples from the Yorkshire terrier group (10.7%) compared with the mixed breed group (0.7%). No statistical differences were found between seasonal period, region and gender. Based on molecular data, there is infrequent rickettsiemia in dogs.

Canine leishmaniosis - new concepts and insights on an expanding zoonosis: part one

Recent research has provided new insights on the epidemiology, pathology and immunology of canine leishmaniosis (CanL) and its genetic basis. The prevalence of infection in endemic areas is considerably higher than that of apparent clinical illness. In addition, infection spreads rapidly among dogs in the presence of optimal conditions for transmission. Infection involves a variety of granulomatous and harmful immune-mediated responses, and susceptibility to the disease is influenced by a complex genetic basis. These concepts will be instrumental for devising control programs. This review, the first in a series of two articles on CanL, presents an updated view on progress in elucidating the epidemiology and pathogenesis of this challenging disease, and the second part focuses on advances in diagnosis, treatment and prevention.

Vaccination with plasmid DNA encoding KMPII, TRYP, LACK and GP63 does not protect dogs against Leishmania infantum experimental challenge

Vaccination of dogs, the domestic reservoir of Leishmania infantum, is the best method for controlling zoonotic visceral leishmaniasis. This strategy would reduce the incidence of disease in both the canine and, indirectly, the human population. Different vaccination approaches have been investigated against canine leishmaniasis (CaL) but to date there is only one licensed vaccine against this disease in dogs, in Brazil. DNA immunization is a promising method for inducing both humoral and cellular immune responses against this parasitic disease. Here, we report the results of a multiantigenic plasmid DNA vaccine encoding KMPII, TRYP, LACK and GP63 L. infantum antigens against experimentally induced CaL. Twelve dogs were randomly assigned to two groups receiving, at a 15 days interval, either four doses of plasmid DNA or similar injections of PBS. After vaccination, dogs were intravenously challenged with 5 x 10(7) promastigotes of L. infantum. The vaccine showed to be safe and well-tolerated. Neither cellular immune response nor antibodies directed against whole Leishmania antigen were detected after immunization in vaccinated dogs, although anti-LACK-specific antibodies were sporadically detected in two vaccinated dogs before challenge, thus suggesting that antigens were indeed expressed. A delay in the development of detectable specific immune response and parasite multiplication in vaccinated dogs was observed after challenge. Nevertheless, the multiantigenic Leishmania DNA vaccine was unable to induce protection against parasite dissemination or disease. This study emphasizes the need to strengthen DNA vaccines in order to obtain effective immune responses in models other than the murine.

Detection of Leishmania infantum DNA by fret-based real-time PCR in urine from dogs with natural clinical leishmaniosis

The aim of this study was to detect Leishmania infantum DNA by real-time PCR in urine from different groups of dogs with clinical leishmaniosis. Urine from 10 clinically healthy dogs and 43 dogs with clinical leishmaniosis diagnosed by positive serology and/or bone marrow PCR were studied. The group of 43 dogs with clinical leishmaniosis was divided into three subgroups: 13 dogs with renal insufficiency and proteinuria (urine protein-creatinine ratio greater than one), 13 dogs with only proteinuria, and 17 dogs with neither renal insufficiency nor proteinuria. The detection of Leishmania DNA was performed by light cycler real-time PCR using hybridization probes in each urine sample. Leishmania positive PCR was found in 47% (20/43) of the urine from leishmaniotic dogs, while all urine from clinically healthy dogs were negative. The percentages of positive Leishmania PCR were 85% (11/13) in dogs with renal insufficiency and proteinuria, 23% (3/13) in dogs with proteinuria and 35% (6/17) in dogs with neither renal insufficiency nor proteinuria. Dogs with renal insufficiency and proteinuria presented a statistical significant greater percentage of positive Leishmania PCR in urine when compared with the other subgroups (P<0.02). This study demonstrates the presence of Leishmania DNA in urine of dogs with leishmaniosis. Those dogs with severe renal damage present a greater number of Leishmania parasites in urine.

Febrile illness associated with Rickettsia conorii infection in dogs from Sicily

We report serologic and molecular evidence of acute, febrile illness associated with Rickettsia conorii in 3 male Yorkshire terriers from Sicily (Italy).

Cross-sectional serosurvey of feline leishmaniasis in ecoregions around the Northwestern Mediterranean

A cross-sectional serosurvey using Leishmania infantum ELISA was performed on 445 cats living in ecoregions around the Northwestern Mediterranean basin; 58 cats from an area of the US where leishmaniasis is not endemic were used as negative controls. ELISA results were further confirmed in 69 cats by Western blot (WB). Finally, 76 of them were also tested for FeLV and FIV. Seroprevalence by ELISA-prot A was 6.29%, and that by ELISA-IgG was 5.25%. Positive cat sera recognized patterns of polypeptides in WB, including L. infantum-specific antigenic fractions. There was no association with retroviruses. Leishmania-specific antibodies are prevalent in cats living in ecoregions around the Northwestern Mediterranean basin; thus, leishmaniasis must be included in the differential diagnosis of diseases in cats living in these ecoregions. Their role as peridomestic reservoirs for L. infantum needs further characterization, but it could be hypothesized that the cat is a secondary reservoir host, rather than an accidental one.

Leishmania-specific isotype levels and their relationship with specific cell-mediated immunity parameters in canine leishmaniasis

In the current retrospective study, Leishmania infantum-specific IgG, IgA and IgM levels were determined by ELISA in 106 untreated dogs with clinically-patent leishmaniasis (Sx) and in 171 clinically healthy dogs (Asx) from Spain to investigate the relationship between these Ig isotypes and clinical status. In addition, we studied if different Leishmania-specific humoral pattern exists between Asx dogs with and without cellular mediated immunity (CMI). Fifty-six dogs were assessed by means of lymphoproliferation assay (LPA), interferon production (IFN) and leishmanin skin test (LST), 71 dogs by means of both LPA and IFN and 44 only by LST. Both Sx and Asx dogs produced Leishmania-specific IgG, IgA and IgM antibodies, however the levels and proportion of positive dogs for each Ig isotype were significantly higher in Sx than in Asx ones (P<0.001). Analysis of immunological profiles determined for each cellular technique (positive and negative cellular response for each technique combined with positive or negative specific humoral response) showed that Asx dogs constituted a high heterogeneous group. No correlations were observed between CMI tests and specific IgG or IgM levels. However, a significant inverse correlation was demonstrated between specific IgA levels and LPA response (Spearman's r=-0.220; P=0.035). In general, the low correlation detected between CMI tests and isotype levels might indicate that the immune response is not strongly polarized in the majority of Asx dogs. Additionally, this study suggests that dogs developing T-cell response are probably able to avoid the dissemination of the parasite at least to mucosal surfaces and, as a consequence, to produce low or background specific IgA levels. Further studies are needed to investigate the relationship between specific IgA and parasite load, especially at mucosal site.

A long term experimental study of canine visceral leishmaniasis

Previous studies on Leishmania infantum and the canine immune response are derived mainly from short-term studies. To date, there have been no longitudinal studies that perform a serial analysis of the intensity of infection in conjunction with immunological parameters and clinical signs in Leishmania-infected dogs. For this purpose, six dogs were infected experimentally by the i.v. route and were monitored for 1 year. Clinical, immunological (humoral and cellular response) and parasitological (parasitaemia) parameters were evaluated monthly. Four dogs developed clinico-pathological signs compatible with leishmaniasis, whereas two dogs showed few abnormalities during the study. Evaluation of clinical, immunological and parasitological parameters showed that the intensity of Leishmania infection in blood samples, as indicated by the amount of Leishmania DNA, was correlated significantly with IgG, IgG1, IgG2, IgA, and IgM concentrations and with clinical signs. Parasitaemia and Leishmania-specific cell-mediated immunity were inversely correlated. Moreover, higher quantities of Leishmania DNA were detected in the liver, spleen, lymph node, skin and bone marrow of dogs exhibiting clinical signs than those exhibiting few such signs. These findings suggest that progressive disease in experimental canine leishmaniasis is associated with specific T-cell unresponsiveness and unprotective humoral responses which allow the dissemination and multiplication of L. infantum in different tissues.

Molecular Survey of Ehrlichia canis and Anaplasma phagocytophilum from Blood of Dogs in Italy

We investigated the prevalence of Ehrlichia canis (E. canis) (n = 601) and Anaplasma phagocytophilum (A. phagocytophilum) (n = 460) infection by means of real-time PCR from blood of Italian dogs. The prevalence of E. canis in northern, central, and southern Italy was 2.9%, 8%, and 9.7%, respectively. The prevalence of A. phagocytophilum was 0%.

Validation of an Automated Spectrophotometric Assay for the Determination of Cholinesterase Activity in Canine Serum

The determination of enzymatic activity of cholinesterase is a useful diagnostic method to detect exposure to anticholinesterase compounds in human and in veterinary medicine. We validated a modification of the Ellman method in canine serum and applied it to the diagnosis of dogs poisoned with anticholinesterase substances. The method used butyrylthiocholine as substrate and potassium hexacyanoferrate as chromophore. The reference range calculated on 60 clinically healthy dogs was set between 3405 and 6561 U/L (chi-square test for normal distribution, p > 0.05). The overall mean intra-assay and inter-assay coefficients of variation were 0.53% and 3.83%, respectively. The assay was linear when using two sera with 12,538 U/L and 6604 U/L serum cholinesterase activity (r(2) = 0.997) and 0.999, respectively). The mean recovery values of pooled sera with a mean pseudocholinesterase (PChE) activity of 12,081 U/L and pooled sera with a mean PChE activity of 3415 U/L were 103.5% and 102.8%, respectively. Six dogs with a diagnosis of anticholinesterase compound intoxication showed a decrease in cholinesterase activity of at least 50% of normal activity with a mean +/- SD of 487 +/- 291 U/L ranging from 169 to 847 U/L. This technique conforms to the current standard for precision, linearity and accuracy and is a useful method for the complementary diagnosis of organophosphate or carbamate insecticide intoxication in dogs.

Serological and molecular evidence of exposure to arthropod-borne organisms in cats from northeastern Spain

One hundred sixty-eight cat sera from Spain were tested for IgG antibodies to Rickettsia conorii (Rc), Ehrlichia canis (Ec), Anaplasma phagocytophilum (Ap) and Bartonella henselae (Bh) antigens using IFA and for FeLV antigen and FIV antibody by ELISA. For 47 whole blood samples, PCR testing was performed for Rickettsia, Ehrlichia and Bartonella. Seroprevalences were: Bh (71.4%), Rc (44%), Ec (11.3%), FeLV (8.5%), FIV (7.4%) and Ap (1.8%). Bh antibodies were associated with seroreactivity to both Ec and Rc antigens. FIV antibodies were associated with illness and cats older than 2 years. Bartonella henselae and B. clarridgeiae (Bcl) DNA was amplified from seven and one sample, respectively.

Dynamics of Leishmania-specific immunoglobulin isotypes in dogs with clinical leishmaniasis before and after treatment

Concentrations of Leishmania-specific immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA) isotypes were analyzed by enzyme-linked immunosorbent assay (ELISA) in 23 dogs naturally infected with Leishmania infantum before and 1 year after initiating drug therapy. Results showed a high expression and prevalence of Leishmania-specific IgG (176.4 +/- 89 ELISA units [EU]), IgM (105.3 +/- 95.5 EU), and IgA (153.6 +/- 98 EU) in dogs before treatment (median +/- interquartile range EU). One year after treatment was started, dogs were classified as responsive dogs (RDs; n = 13) or unresponsive dogs (UDs; n = 10) based on clinicopathologic findings. Both groups of dogs experienced a statistically significant decrease (P < .05) in Leishmania-specific IgG (RDs = 27%, UDs = 41%), IgM (RDs = 42%, UDs = 29%), and IgA (RDs = 56%, UDs = 46%). Concentrations of specific IgG and IgM were not different at diagnosis or after treatment between the 2 groups. However, the median value for Leishmania-specific IgA 1 year after treatment was significantly lower (P < .05) in RDs (60.8 +/- 67 EU) than in UDs (117 +/- 54 EU). Examination of our data indicates that both the IgA isotype, which is mostly produced by mucosal plasma cells, and the IgM isotype are increased in infected symptomatic dogs, as previously reported for IgG. These 3 isotypes decreased significantly 1 year after initiation of medical treatment.

Stability of stored canine plasma for hemostasis testing

BACKGROUND

A review of the literature revealed limited information about the stability of samples for coagulation testing in dogs.

OBJECTIVE

The aim of this study was to evaluate the stability of individual coagulation factors, clotting times, and other parameters of hemostasis in stored canine plasma.

METHODS

Citrated plasma samples were obtained from 21 dogs. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen concentration, and factor I, II, V, VII, VIII, IX, X, XI, and XII activities were measured on an automated coagulation analyzer with commercially available reagents. Antithrombin (AT) activity and D-dimer concentration were measured on an automated chemistry analyzer using validated kits. Samples were analyzed within 1 hour after collection (initial analysis) and once daily for 2 or 4 consecutive days following storage at room temperature (RT) or 4 degrees C, respectively.

RESULTS

Storage time at either temperature did not have any effect on PT, factor II, V, VII, X, or XII activities, D-dimer concentration, or AT activity. In contrast, aPTT was significantly prolonged after 72 and 96 hours at 4 degrees C; fibrinogen concentration was decreased after 48 hours at RT; the activities of factors VIII and IX were decreased after 48, 72, and 96 hours at 4 degrees C; and factor XI activity was decreased after 72 hours at 4 degrees C.

CONCLUSIONS

Results suggest that storage of canine plasma for 2 days at RT does not have a significant effect on hemostasis test results with the exception of a slight decrease in fibrinogen concentration. In contrast, aPTT and factors VIII, IX, and XI were unstable in refrigerated plasma after 48 or 72 hours of storage.

A retrospective study of 60 cases of eccentrocytosis in the dog

BACKGROUND

Eccentrocytes are RBCs that appear in a peripheral blood smear to have their hemoglobin shifted to one side of the cell. This abnormality, which is confined to the RBC membrane and cytoskeleton, is induced by oxidative damage. Eccentrocytes have been reported rarely in dogs and are associated with onion and garlic ingestion and the administration of oxidant drugs.

OBJECTIVE

The purpose of this study was to describe the occurrence and severity of eccentrocytosis in dogs and the diseases or disorders associated with eccentrocytes.

METHODS

Detailed history, and results of physical examination, CBC, biochemical and coagulation profiles, and urinalysis from all canine patients admitted during a 2.5-year period were evaluated. Eccentrocytes, when observed, were graded 1+ (few) to 4+ (many). The severity of eccentrocytosis was compared with that of anemia and reticulocytosis.

RESULTS

Eccentrocytes were found in blood smears from 60 of 4251 dogs (1.4%) and were associated with mild to moderate anemia in 40 (66.6%) of the cases. Eccentrocytosis was found in 16 (26.6%) dogs with drug administration, 11 (18.3%) with presumptive onion and garlic ingestion, 8 (13.3%) with vitamin K antagonist intoxication, 7 (11.6%) with ketoacidotic diabetes, 5 (8.3%) with T-cell lymphoma, 4 (6.6%) with severe infections, 1 (1.6%) with compensated diabetes mellitus, and 8 (13.3%) with other conditions. Certain dog breeds, such as Whippet, Boxer, and English Setter, and young dogs seemed to be overrepresented.

CONCLUSIONS

We describe, for the first time, associations between eccentrocytes and diabetes mellitus, T-cell lymphoma and vitamin K antagonist intoxication in dogs. The significance of eccentrocytes should not be underestimated, because they can be a signal of an oxidative process.

A serological study of exposure to arthropod-borne pathogens in dogs from northeastern Spain

There is limited information regarding the prevalence of many vector borne pathogens in Europe and especially in Spanish dogs. We investigated 206 sick and 260 clinically healthy dogs from three different regions in northeastern Spain for antibodies to Rickettsia conorii (Rc), Ehrlichia canis (Ec), Anaplasma phagocytophilum (Ap), Bartonella henselae (Bh), Bartonella vinsonii subsp. berkhoffii (Bvb), Leishmania infantum (Li) and Borrelia burgdorferi (Bb) and for antigen of Dirofilaria immitis (Di). Total prevalences were the following: Rc (56.4%), Li (30%), Ec (16.7%), Bh (16.8%), Ap (11.5%), Bvb (1.07%), Di (0.6%) and Bb (0.6%). Seroprevalences for Rc, Ec, Ap, Bh, and Bvb and Bb and Di antigens were similar among the three different study sites. The Ec seroprevalence, as determined by Snap 3DX, was statistically lower in dogs from Mallorca (0%) than Tarragona (16%) and Barcelona (5%) (P < 0.0001). Detection of Rc antibodies was associated with seroreactivity to Ec and Ap antigens (P = 0.018 and P = 0.002, respectively). IFA Ec antibodies were associated with Ap seroreactivity (P < 0.0001). There was no association between the clinical status, sex, time of the year when samples were collected, life-style or exposure to fleas or ticks and a positive test result for Ec, Bh, Bvb, or Bb antibodies or Di antigens. Li seroreactivity was associated with illness and living outdoors (P < 0.0001, P = 0.029; respectively), Rc seroreactivity with the male gender (P = 0.028) and Ap seroreactivity with living outdoors (P = 0.045). This study indicates that exposure to Rc, Li, Ec or related Ehrlichia spp., Bh and Ap or a related spp., is common whereas Di, Bb and Bvb is uncommon among dogs from the Mediterranean basin. We also provide serological data that suggests the existence of a novel Ehrlichia species on Mallorca island.

Artifactual changes in canine blood following storage, detected using the ADVIA 120 hematology analyzer

BACKGROUND

Artifactual changes in blood may occur as a consequence of delayed analysis and may complicate interpretation of CBC data.

OBJECTIVE

The aim of this study was to characterize artifactual changes in canine blood, due to storage, using the ADVIA 120 hematology analyzer.

METHODS

Blood samples were collected into EDTA from 5 clinically healthy dogs. Within 1 hour after blood sample collection and at 12, 24, 36 and 48 hours after storage of the samples at either 4 degrees C or room temperature (approximately 24 degrees C), a CBC was done using the ADVIA 120 and multispecies software. A linear mixed model was used to statistically evaluate significant differences in values over time, compared with initial values.

RESULTS

The HCT and MCV were increased significantly after 12 hours of collection at both 4 degrees C and 24 degrees C, and continued to increase through 48 hours. The MCHC initially decreased significantly at 12-24 hours and then continued to decrease through 48 hours at both temperatures. Changes in HCT, MCV, and MCHC were greater at 24 degrees C than at 4 degrees C at all time points. A significant increase in MPV and a decrease in mean platelet component concentration were observed at all time points at 24 degrees C. Samples stored at 24 degrees C for 48 hours had significantly higher percentages of normocytic-hypochromic RBCs, and macrocytic-normochromic RBCs, and lower platelet and total WBC counts.

CONCLUSIONS

Delayed analysis of canine blood samples produces artifactual changes in CBC results, mainly in RBC morphology and platelet parameters, that are readily detected using the ADVIA 120. Refrigeration of specimens, even after 24 hours of storage at room temperature, is recommended to improve the accuracy of CBC results for canine blood samples.

Advantages of real-time PCR assay for diagnosis and monitoring of canine leishmaniosis

The aim of the present study is to highlight the advantages of real-time quantitative PCR intended to aid in the diagnosis and monitoring of canine leishmaniosis. Diagnosis of canine leishmaniosis is extremely challenging, especially in endemic areas, due to the diverse and non-specific clinical manifestations, and due to the high seroprevalence rate in sub-clinical dogs. Veterinarian clinicians are usually confronted with cases that are compatible with the disease, and with several diagnostic tests, sometimes with contradictory results. We have developed a new TaqMan assay, targeting the kinetoplast, applied to 44 samples of bone marrow aspirate or peripheral blood. The dynamic range of detection of Leishmania DNA was established in 7 logs and the limit of detection is 0.001 parasites in the PCR reaction. At the time of diagnosis parasitemia ranges from less than 1 to 10(7)parasites/ml. The ability to quantify the parasite burden allowed: (i) to elucidate the status of positive dogs by conventional PCR, although larger studies are necessary to clarify the dividing line between infection and disease, (ii) to estimate the kinetics of the parasite load and the different response to the treatment in a follow-up and (iii) to validate blood as less invasive sample for qPCR. The continuous data provided by real-time qPCR could solve the dilemma for the clinician managing cases of canine leishmaniosis by differentiating between Leishmania-infected dogs or dogs with active disease of leishmaniosis.

Immune response to Leishmania infantum in healthy horses in Spain

Leishmania infantum infection has recently been described in horses in Europe. We report the results of a study on the immune response to L. infantum in horses living in an area endemic for leishmaniosis in NE Spain. Two ELISAs using protein A and anti-horse IgG conjugates were adapted to measure specific antibodies to L. infantum in horse sera. A lymphocyte proliferation assay (LPA) of peripheral blood mononuclear cells to L. infantum antigen was also performed to detect specific cellular immune response to Leishmania. Anti-L. infantum antibodies were detected in the serum of 16 of the horses studied (n=112) using the protein A assay but not in the assay using the anti-horse IgG conjugate. Specific lymphocyte proliferation was observed in 20 out of 55 horses. This study shows that horses in the area studied mount specific immune responses to L. infantum, and must therefore be considered among the species exposed to the parasite in this region. The infrequency of leishmaniosis in horses suggests that the immune response in this species is effective in controlling the infection.

Clinicopathological findings in naturally occurring cases of babesiosis caused by large form Babesia from dogs of northeastern Italy

There are few extensive studies about clinicopathological findings of spontaneous canine babesiosis caused by a large form of the parasite found in Europe. To further characterize and describe clinicopathological findings in dogs affected with this large form of Babesia in northeastern Italy, we evaluated 23 Italian dogs with canine babesiosis by means of clinical history, physical examination, hematological, biochemical, hemostatic tests, serum electrophoresis and urinalysis. Seventeen dogs (74%) had recently traveled on a hunting trip (within 5-15 days of being presented to the clinic) to Bosnia and Herzegovina (n=7), to Croatia (n=8) and to Hungary (n=2). The duration of clinical signs ranged from 1 to 5 days prior to the arrival at the clinic. The main clinical signs were dehydration (100%), apathy (74%), anorexia or decrease appetite (70%) and fever (68%). The anemia was present in 74% of the dogs and classified as mild (35%), moderate (59%) and severe (6%). In all cases, the anemia was normocytic and normochromic. Only three dogs presented erythrocyte regeneration. Seventy percent of dogs had hemolytic anemia and 30% had non-hemolytic anemia. Sixty-nine percent of dogs showed leucopenia and 74% neutropenia. Leucocitosis, due to mature neutrophilia and lymphocytosis, was present in one dog. Activated lymphocytes were noted in 61% of dogs. In all dogs, thrombocytopenia and an elevated hyperfibrinogenemia were present. Significant prolonged activated partial thromboplastin time (aPTT) was only found in one case. In four dogs, both plasma fibrinogen/fibrin degradation products (FDPs) and D-Dimer were increased. Antithrombin (AT) was slightly decreased in 11 of the 23 dogs. In the majority of cases, mild elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatinekinase (CK), total bilirubin and lactic acid and decrease of total iron and total iron binding capacity (TIBC) were present. In conclusion, the main clinicopathological findings were a mild to severe thrombocytopenia, a mild to moderate hemolytic anemia, neutropenia and hyperfibrinogenemia.

Papular dermatitis due to Leishmania spp. infection in dogs with parasite-specific cellular immune responses

Papular dermatitis due to Leishmania spp. infection was diagnosed in three boxers and two Rottweilers with Leishmania-specific cellular immunity. Diagnosis was based on histological and immunohistochemical examination of papules in four dogs and on cytological examination in one dog. Serum protein electrophoresis was within reference ranges and low antibody levels to Leishmania infantum were detected. Delayed-type hypersensitivity (DTH) reaction to leishmanin was evaluated before treatment in three dogs with positive results. After meglumine antimoniate therapy for 3 to 4 weeks and allopurinol treatment for 6 to 10 months, all dogs were clinically normal, had positive DTH reactions to leishmanin and reduced antibody titres. In conclusion, we suggest that this previously unreported cutaneous presentation of canine leishmaniosis appears to be associated with specific immunocompetence and, consequently, with a favourable prognosis.

Comparison of three assays for the evaluation of specific cellular immunity to Leishmania infantum in dogs

Cellular immune response to Leishmania plays a key role in canine leishmaniosis. However, there are few assays to evaluate this response in the dog. Here, we evaluated and compared three assays of specific cellular immune response to Leishmania infantum in dogs: the leishmanin skin test (LST), lymphocyte proliferation assay (LPA) and IFN-gamma cytopathic effect inhibition bioassay (IFNB). Fifty-six healthy dogs from an endemic area for leishmaniosis on the island of Mallorca were studied. In all, 37 dogs showed a positive LST and 32 a positive IFNB, 24 were positive for both assays. The 17 dogs positive for LPA also gave positive results for either LST or IFNB, or both. These findings indicate that although LST is the method of choice, IFNB is a complementary test. Therefore, both assays should be performed and analyzed jointly. In comparison with LST and IFNB, LPA is much less sensitive, and yields many false negative results.