Clinicopathological changes and effect of imidocarb therapy in dogs experimentally infected with Babesia canis.

In this study one spleen-intact dog (A) and two splenectomised dogs (BSE, CSE) were infected with Babesia canis. All animals developed an acute disease characterised by fever, haemoglobinuria and anaemia, the latter being more severe in the splenectomised dogs. Fever and parasitised red blood cells were detected for three days after imidocarb treatment in the splenectomised animals. Haematological abnormalities included regenerative anaemia, thrombocytopenia and leukopenia (due to neutropenia and lymphopenia) in the acute phase, soon followed by leukocytosis, neutrophilia and left shift a few days later. Acute hepatopathy was detected in all dogs with elevated ALT activity, which was more seriously altered in the splenectomised dogs. Diffuse changes in liver structure and hepatomegaly were seen by ultrasonography. Liver biopsy and histology revealed acute, non-purulent hepatitis in the splenectomised dogs. Both splenectomised dogs were successfully cured after collection of 400 ml highly parasitised blood, proving that large-amount antigen production is possible with rescuing the experimental animals. Whole blood transfusion, imidocarb and supportive care with infusions, antipyretics, glucocorticoids and diuretics were applied. The spleen-intact dog clinically recovered after receiving supportive treatment, with no imidocarb therapy. Microbial infections developed in both splenectomised animals (BSE: haemobartonellosis, CSE: osteomyelitis caused by Escherichia coli), probably as a consequence of immunosuppression after splenectomy and glucocorticoid therapy.

Epidemiological and pathological study on the causes of abortion in sheep and goats in Hungary (1998-2005).

The objective of the investigations was to study the causes of abortion in sheep and goats in Hungary during a 7.5-year period. The authors investigated 246 cases of ovine and 75 cases of caprine abortions by different diagnostic methods. An infectious origin was found in 126 cases (51.2%) of ovine and 19 cases (25%) of caprine abortions. The most important cause of ovine and caprine abortions was Chlamydophila abortus infection with a prevalence of 46% and 17%, respectively. Other infections causing sheep and goat abortions were present only in 5.2% and 8% of the cases, respectively. The results obtained by different diagnostic methods are discussed.

Study on the role of gastric Helicobacter infection in gross pathological and histological lesions of the stomach in finishing pigs.

The prevalence of gastric Helicobacter infection in finishing pigs and the influence of this infection on gastric lesions was studied. Stomachs of 89 finishing pigs from 27 randomly selected herds were sampled at the slaughterhouse. Forty cases (Group A) were selected based upon the presence of gross pathological lesions in the pars oesophagea, and further 49 cases were obtained at random (Group B). Three samples of gastric tissue (junction of pars oesophagea and pars cardiaca, fundic area, and pyloric area) were collected from each stomach for histological and immunohistochemical examination. Helicobacter antigen was detected in 76 cases (85.4%). No association was found between the presence of Helicobacter in the stomach and the occurrence of gross pathological lesions in the pars oesophagea or gastritis detected on histological examination. However, a significant association was found between the occurrence of Helicobacter in the pyloric area and the presence of erosions/ulcers in the pars oesophagea (OR: 7.01, p = 0.022) in Group B. A significant association was also evident between the presence of Helicobacter and glandular lesions (dilatation of the glands + glandular abscess + degeneration of glandular epithelial cells). In conclusion, Helicobacter infection seems to be a contributing factor to pathological changes in the stomach of finishing pigs.

Screening of Hungarian cattle herds for Mycoplasma mycoides subspecies mycoides small colony infection with negative results.

At abattoirs and farms, 1248 sera were collected from animals representing 121 farms, and examined by complement fixation test using Mycoplasma mycoides subspecies mycoides small colony type (MmmSC) antigen. All sera were negative except seven from four farms, giving ++ reactions in the serum dilution of 1:10. On retesting, these sera and additional 30 sera collected repeatedly in both farms gave negative results. In isolation attempts, 953 lung samples collected from slaughtered cattle at the same abattoirs, and 326 nasal swabs collected from 11 herds proved to be negative for the presence of MmmSC, but M. bovis was isolated frequently. In the small farms 23.95% of the animals had pleurisy and/or pneumonia while in the large herds 34.69% had lesions. DNA extracted from 50 nasal swabs and 430 lung samples was examined by polymerase chain reaction (PCR) using M. mycoides cluster-specific primers. DNA from further 325 lung samples was tested by the more specific M. mycoides subspecies mycoides small colony/large colony/capri specific primers and 196 samples by nested PCR specific for MmmSC. All gave negative results. The detection level of cluster-specific primers and the more specific primers was 33.4 pg of DNA, whereas that of nested PCR was 0.33 pg.

Prevalence of bovine herpesvirus 1 (BHV-1) infection in Hungarian cattle herds.

Hungarian cattle herds were surveyed for bovine herpesvirus 1 (BHV-1) infection by ELISA of milk and serum samples. In 1993, 75% of the large cattle herds (consisting of more than 50 cattle) and all small herds (small-scale producers' stocks), while in 1997 90% of the small herds were included in the survey. In the case of large herds, 79.3% of the herds and 64.1% of the samples tested were found to be positive. Of the small herds, 13.5% and 15.7% tested positive in 1993 and 1997, respectively. The majority of large herds were Holstein-Friesian dairy stocks. Small herds with an infection rate markedly exceeding the average were found in those counties where the small herds had been in close contact with the large-scale farms, or where new herds were established by using animals of uncontrolled infectious bovine rhinotracheitis (IBR) status originating from large farms. Attention is called to the importance of maintaining the IBR-free status of small herds that constitute one-third of the Hungarian cattle population.

Detection of antibodies to Neospora caninum in bovine postabortion blood samples from Hungary.

In order to obtain data on the occurrence of the protozoan parasite Neospora caninum as a potential factor in the aetiology of reproduction problems in cattle, 97 postabortion sera were examined by ISCOM ELISA and IFAT for the presence of antibodies in N. caninum. The results showed 10% and 9% seropositivity by the ELISA and IFAT, respectively. In 2 of the 10 seropositive cases no other fetopathogenic agents (such as Chlamydia sp., Leptospira spp. or bovine viral diarrhoea virus) were detected. These data confirm the presence of N. caninum in cattle in Hungary.

Influence of management technology and parturition on antibody levels in cows with bovine leukosis.

Sera from 97 Holstein-Friesian cows kept in isolation (herd I) were tested on 9 occasions with an interval of 90 days. The cows had previously given a positive reaction with bovine leukaemia virus antigen in the agar gel immunodiffusion (AGID) test. During the period of loose housing (at tests 1-3) 0-3 cows per test (0-3.1%) gave a negative reaction. When the same animals were kept in the tie-in system (at tests 4-7) the number of negative reactors varied between 9 and 26 (16.9-20.1%). Twenty-eight cows of herd II were tested serologically by the AGID test on a total of 9 occasions from day 60 before term up to postpartum day 90. The lowest antibody level was obtained at calving, when 7 cows gave a negative result in the AGID test. In three cows the decline of antibody level was so pronounced that their serum was negative even after postpartum day 60. One cow was negative even at the end of the test period (on postpartum day 90). The variation in serum antibody level was demonstrable also by ELISA; however, by that test none of the animals gave a negative result. The antibody level demonstrable in the milk reached its peak at calving and then it underwent a gradual decline; however, it did not drop below the detectability limit by the end of the test period. It is concluded that in bovine leukosis infected herds the performance of the AGID test is extremely impaired by the use of the tie-in housing system, as well as by a combined effect of tying in and parturition. Therefore, during the leukosis eradication and qualification of herds kept in a tie-in system, ELISA is the method that can be used, instead of AGID, with satisfactory efficacy even for the testing of sera.

Checking of immunity against Newcastle disease by ELISA.

A total of 284 seven- to twelve-week-old Tetra SL chickens were assigned to 18 groups and immunized with a full or fractional dose of monovalent or multivalent inactivated vaccines subcutaneously or intramuscularly. Sera were taken from the birds at the time of challenge and tested for antibodies to Newcastle disease virus (NDV) by enzyme-linked immunosorbent assay (ELISA). The vaccinated birds were challenged with 10(6) ELD50 of virulent NDV subcutaneously. A close positive correlation (r = 0.954) was found between the protection percentage of the different groups and the group's arithmetical mean net extinction percentage (NE%) calculated from the net extinction values obtained for sera of birds belonging to the given group. NE% is easy to calculate and a good indicator of the flocks' immunity status. In our case: if NE% exceeded 80, the protection percentage of the flock was between 93.3 and 100%; if NE% was between 60 and 80, the protection percentage was between 75 and 87%, while with an NE% less than 60 the protection percentage ranged between 6.7 and 64.3%.

Trials with an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of subclinical genital infections in rams caused by Histophilus ovis and Actinobacillus seminis.

The performance of an enzyme-linked immunosorbent assay (ELISA) was evaluated in the serological diagnosis of subclinical genital infection in 6 naturally infected ram flocks and 2 experimentally infected ram hoggets. The test employs lipopolysaccharide (LPS) antigen prepared by autoclaving from Actinobacillus seminis and Histophilus ovis. A total of 193 sheep (118 unmated virgin rams and 75 mature breeding rams) were examined clinically, serologically (by ELISA) and bacteriologically (semen bacteriology) at the same time. Serum samples from all animals were also tested by an ELISA employing LPS antigen prepared from Brucella ovis in the same way. Shedding of A. seminis and H. ovis did not show close correlation with serological positivity (Table 1), as only 9 (15.0%) out of the 60 A. seminis shedders were ELISA seropositive at the same time. As regards H. ovis only 10 (19.2%) out of the 52 H. ovis shedders were ELISA seropositive at the same time. The results indicate that, when used alone, the ELISA employing LPS antigen is unsuitable for diagnosing subclinical genital infection caused by H. ovis and A. seminis in rams. The authors discussed shortly the employing fields of this ELISA test in the diagnostic work.