Horses (Equus caballus) are susceptible to tick-borne diseases. Two of them, Lyme borreliosis due to Borrelia burgdorferi and granulocytic anaplasmosis due to Anaplasma phagocytophilum were investigated in Algerian horses. The diseases have been less extensively studied in horses and results pertinent to Algeria have not been published. Blood samples were obtained from 128 horses. IgG antibodies directed against Anaplasma phagocytophilum and Borrelia burgdorferi were detected by an indirect immunofluorescence antibody test (IFAT) and ELISA. The potential effects of age, gender, breed, and health status on seropositivity were also evaluated. Using IFAT, 28 (21.8%) and 25 (19.5%) animals were positive for B. burgdorferi and A. phagocytophilum, respectively. Using ELISA, 19 (14.8%) and 33 (25.9%) animals were positive for these bacteria. The study shows that horses in Algeria are exposed or co-exposed to tick-transmitted zoonotic bacterial species.

The objective of this research was to evaluate the antibody response to multiple doses of an inactivated mixed vaccine against Histophilus somni, Pasteurella multocida, and Mannheimia haemolytica, and to investigate the influence of age at time of vaccination in the field. Healthy female Holstein calves received the vaccine at the age of 5–12 days and 2, 3, or 4 weeks later in the first experiment or at 1, 2, or 3 weeks of age and 4 weeks later in the second. Blood samples were collected at each vaccination and 3 weeks after the booster dose. Based on the antibody titres after the vaccinations, calves were divided into positive and negative groups for each of the bacteria. Calves in the control group were vaccinated only once at the age of 19–26 days. Antibody titres against H. somni and P. multocida were significantly increased by the booster. After the second vaccinations, the titres against each bacterium were higher than those of the control group, and the M. haemolytica-positive percentage in calves with high maternal antibody levels (MAL) exceeded that in calves with low MAL. In the first experiment, a majority of the M. haemolytica-positive calves tended to have received the primary dose at seven days of age or older. A booster dose of the inactivated bacterial vaccine in young Holstein calves increased antibody production and overcame the maternal antibodies. Calves should be vaccinated first at seven days of age or older.

The purpose of this study was to determine the effects of vitamin C supplementation on blood oxidative stress biomarkers and antibody response to vaccination in calves. Thirty-four clinically healthy 2 week old Japanese Black calves were randomly assigned to two groups. Seventeen calves formed the VC group which received 1,000 mg of vitamin C daily from 2 to 8 weeks of age, and the other 17 calves of the control group did not receive supplementation. All calves received an inactivated Histophilus somni vaccine at 4 and 8 weeks of age. Blood samples were taken at 2, 4, 8 and 12 weeks of age. The concentration of the serum reactive oxygen metabolites (d-ROMs), and the oxidative stress index (OSI), which is calculated from the d-ROMs and biological antioxidant potential, were significantly lower at 8 weeks of age in the VC group than in the control group (P < 0.05). The antibody titres to H. somni in the VC group were significantly higher than those in the control group at 12 weeks of age after the second vaccination (P < 0.05). Vitamin C supplementation to calves may reduce oxidative stress and enhance the antibody production after vaccination with H. somni.

The objective of this study was to compare the virulence of 3 major Korean porcine circovirus type 2 (PCV2) genotypes in terms of clinical signs, PCV2 viremia and antibody titers, lymphoid lesions, and PCV2-antigen within lymphoid lesions in experimentally infected pigs. Pigs were infected at 7 weeks with PCV2a, PCV2b, and PCV2d strains and necropsied at 28 days post-infection. No statistical differences were observed in clinical signs, PCV2 viremia and antibody titers, lymphoid lesions scores, and numbers of PCV2 antigens among the 3 major Korean PCV2 genotypes. The results of this study indicate that the 3 major Korean PCV2 genotypes, PCV2a, PCV2b, and PCV2d, have similar virulence.

OBJECTIVE To determine whether luteinizing hormone receptors (LHRs) are expressed in canine femoral head subchondral bone (FHSB), hip joint round ligament (RL), cranial cruciate ligament (CCL), and femorotibial joint synovium (FJS) specimens. SAMPLE 1 specimen each of the FHSB, RL, CCL, and FJS obtained from the left hind limbs of 19 fresh canine cadavers. PROCEDURES 1 section of each FHSB, RL, CCL, and FJS specimen was processed with rabbit polyclonal IgG anti-human LHR antibody, and 1 section was treated with negative control reagents. Percentage immunoexpression of LHRs in FHSB and FJS sections was analyzed by assessment of 100 bone marrow cells or synoviocytes in 3 adjacent hpf (400×). In each RL and CCL section, immunoexpression of LHRs in fibrocytes was semiquantitatively analyzed on the basis of the mean of the product of percentage staining score (from 0 [no staining] to 3 [> 50% of cells stained]) and staining intensity score (from 0 [no staining] to 2 [moderate to strong staining]) for 3 adjacent hpf. RESULTS All tissues examined had variable LHR expression. Expression of LHRs in FHSB, CCL, or FJS specimens did not differ between sexes or between sexually intact and gonadectomized dogs. However, RL specimens from female dogs had significantly greater LHR expression scores, compared with findings for male dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that LHRs are expressed in structural support tissues of canine hip and femorotibial joints. Further research is required to determine the LHRs' function, mechanism of action, and potential contribution to the pathogenesis of hip dysplasia or CCL rupture in dogs.

A prospective study of 65 research beagles kept in a rabies-free environment was undertaken to determine the duration of immunity after they received licensed rabies vaccines. The eventual goal was to extend mandated rabies booster intervals to 5 or 7 years and help reduce the risk of vaccine-associated adverse events. Three groups of dogs were vaccinated with 1 of 2 commercial rabies vaccines or saline at 12 and 15 weeks of age. Beginning 5 years 5 months later, vaccinated and unvaccinated dogs were challenged with virulent rabies virus and observed for 90 days over a series of 3 trials. Humoral and cellular immune responses were examined by serology and flow cytometry. Brain tissue from all challenged dogs was tested for rabies virus. Challenge trial 1 was confounded due to insufficiently virulent virus. In trials 2 and 3 virulent challenge provided 100% mortality in controls. Vaccinate survival was 80% (4/5) after 6 years 7 months, 50% (6/12) after 7 years 1 month, and 20% (1/5) after 8years 0 months. Antibody responses 12 days post-challenge correlated strongly with survival. In a separate non-challenge trial, administration of either a recombinant or a killed rabies vaccine demonstrated memory antibody responses 6 years 1 month after initial vaccination compared with unvaccinated controls. Our data demonstrated that i) duration of immunity to rabies in vaccinated dogs extends beyond 3 years; ii) immunologic memory exists even in vaccinated dogs with serum antibody titer < 0.1 IU/mL; and iii) non-adjuvanted recombinant rabies vaccine induces excellent antibody responses in previously vaccinated dogs 14 days after administration.

Immunohistochemistry has been used extensively to evaluate protein expression in clinical and research settings. However, immunohistochemistry is not always successful in veterinary medicine due to the lack of reliable antibody options, poor tissue preservation, labor-intensive staining, and antigen-retrieval optimization processes. RNAscope in-situ hybridization (ISH) is a powerful technology that uses a specific sequence probe to identify targeted mRNA. In this study, we demonstrate RNAscope ISH in 4 common canine malignancies, which are traditionally diagnosed by histopathology and immunohistochemistry. Probes were designed for commonly targeted mRNA markers of neoplastic tumors; these included c-kit in mast cell tumor, microphthalmia-associated transcription factor in malignant melanoma, ionized calcium-binding adapter molecule(-1) in histiocytic sarcoma, and alkaline phosphatase in osteosarcoma. A strong staining signal was obtained by these 4 targets in each canine malignancy. These results support the use of RNAscope ISH for definitive diagnosis in canine malignancies.