[Opinion among veterinarians on equine Lyme disease - results of a questionnaire study]. / Tierärztliches Meinungsbild zur Equinen Lyme-Borreliose ­ Ergebnisse einer Fragebogenstudie.

AIM: Recording equine veterinarians opinion on equine Lyme disease. MATERIAL AND METHODS: A survey was conducted to get a general impression of the opinion of German equine vets on the topic of equine Lyme Borreliosis. The main focus of this questionnaire study was set on the diagnostic and therapeutic approach of the horse vets. RESULTS: Overall almost half of the veterinarians (48 %) detected only rarely or never serological antibodies against Bb , 47 %found occasionally and 5 % frequently Borrelia antibodies within their clientel.Concerning the existence of clinical LB in horses, 51 % of the veterinarians reported clinical cases, 43 % thought it might be possible but have not seen cases themselves and 6 % categorically ruled out the existence.On average, further diagnostic measures for LB diseases were initiated 15 ± 9 times per year and 1.4 ± 1.0 cases of equine LB diseases were diagnosed per year. In the majority of 68 % of the cases, the veterinarians chose serological tests as diagnostic measures, followed by a combination of serological tests and Antigen detection tests (27 %) and only 5 % of the veterinarians were using Antigen detection tests exclusively. Blood and skin biopsies were submitted most frequently for direct Antigendetection. The treatment of horses with positive laboratory results indicating Lyme disease and clinical symptoms assessed as suitable was carried out by 93 % of the veterinarians with antibiotics and 7% with homeopathy. Doxycycline (68 %) was used most frequently. The antibiotic treatment was applied over a period of 3 (31 %) to 4 (63 %) weeks.Regarding the question of a possible vaccination, 39 % of veterinarians do not offer vaccination against Lyme borreliosis, 20 % have not yet used it, but do not categorically reject it, and 41 % regularly carry out vaccinations against Lyme borreliosis. CONCLUSION AND CLINICAL RELEVANCE: The opinion on the clinical relevance of Equine Lyme Borreliosis among german equine veterinarians vary considerably. Uniform diagnostic guidelines and, possibly, recommendations for therapy would serve to counteract the existing uncertainty concerning this disease within the equine veterinary community.

In vitro susceptibility of Borrelia burgdorferi isolates to three antibiotics commonly used for treating equine Lyme disease.

BACKGROUND: Lyme disease in humans is predominantly treated with tetracycline, macrolides or beta lactam antibiotics that have low minimum inhibitory concentrations (MIC) against Borrelia burgdorferi. Horses with Lyme disease may require long-term treatment making frequent intravenous or intramuscular treatment difficult and when administered orally those drugs may have either a high incidence of side effects or have poor bioavailability. The aim of the present study was to determine the in vitro susceptibility of three B. burgdorferi isolates to three antibiotics of different classes that are commonly used in practice for treating Borrelia infections in horses. RESULTS: Broth microdilution assays were used to determine minimum inhibitory concentration of three antibiotics (ceftiofur sodium, minocycline and metronidazole), for three Borrelia burgdorferi isolates. Barbour-Stoner-Kelly (BSK K + R) medium with a final inoculum of 106 Borrelia cells/mL and incubation periods of 72 h were used in the determination of MICs. Observed MICs indicated that all isolates had similar susceptibility to each drug but susceptibility to the tested antimicrobial agents varied; ceftiofur sodium (MIC = 0.08 µg/ml), minocycline hydrochloride (MIC = 0.8 µg/ml) and metronidazole (MIC = 50 µg/ml). CONCLUSIONS: The MIC against B. burgorferi varied among the three antibiotics with ceftiofur having the lowest MIC and metronidazole the highest MIC. The MIC values observed for ceftiofur in the study fall within the range of reported serum and tissue concentrations for the drug metabolite following ceftiofur sodium administration as crystalline-free acid. Minocycline and metronidazole treatments, as currently used in equine practice, could fall short of attaining MIC concentrations for B. burgdorferi.

Protection against tick-transmitted Lyme disease in dogs vaccinated with a multiantigenic vaccine.

In an effort to develop a safe and effective vaccine for the prevention of Lyme borreliosis that addresses concerns raised over currently available vaccines, dogs were vaccinated twice with a multiantigenic preparation of Borrelia burgdorferi, strain N40, on days 0 and 20 of the experiment. About 70 and 154 days after the first immunization, dogs were challenged by exposing them to field-collected Ixodes scapularis ticks harboring B. burgdorferi. Vaccinated dogs were completely protected from infection by all criteria utilized to assess infection, developed high-titer anti-B. burgdorferi serum antibodies and growth inhibitory activity which persisted for over 200 days, and did not demonstrate any untoward consequence of vaccination. Serum absorption experiments revealed that borreliacidal and most likely protective antibodies in dogs receiving the multiantigenic preparation were not only elicited against the OspA antigen, but were also produced against additional yet to be determined targets on B. burgdorferi organisms. These data demonstrate that a multiantigenic vaccine is effective in preventing Lyme disease transmitted via the natural vector.

Seroepidemiological survey for antibody to Borrelia burgdorferi in cows.

Antibody to Borrelia burgdorferi was examined in 380 healthy and 38 clinical cases of cows from Hokkaido and Shizuoka in Japan. In healthy animals, IgG and IgM antibody to B. burgdorferi HO14 strain were found in 44 cows (14.6%) and 24 cows (8.0%) from Hokkaido. In contrast, antibody-positive case was not observed except for only 1 case which was IgM positive (1/79: 1.3%) in cows from Shizuoka. Mean antibody levels of healthy animals in Hokkaido and Shizuoka were 0.651 and 0.263 (IgG antibody to HO14 strain), 0.642 and 0.169 (IgG to HP3 strain), 0.613 and 0.367 (IgM to HO14 strain) and 0.582 and 0.286 (IgM to HP3 strain). The differences of the antibody levels between cows from Hokkaido and Shizuoka were significant. Seasonal difference was found in seropositive cows from Hokkaido. The rate of seropositive cows was high in summer (23.4% in June and 11.8% in July) but low in winter (0% in January and February). The pattern was discussed to be associated with activation of ticks. One of 4 cows with arthritis showed significantly higher IgG antibody level than that of healthy cows and cows with some disease, although the serum was collected from Shizuoka where antibody-positive animals for B. burgdorferi were rare among healthy cows. This high IgG antibody may suggest that the arthritis of such cows was caused by infection with B. burgdorferi. Two of 7 cows with unclassified abortion showed positive antibody reaction in Hokkaido. These cases, however, may not be related to the B. burgdorferi infection because the positive rate was similar to those of healthy cows in the same season.

Evaluation of granulocytic ehrlichiosis in dogs of Missouri, including serologic status to Ehrlichia canis, Ehrlichia equi and Borrelia burgdorferi.

Canine granulocytic ehrlichiosis was diagnosed in 37 dogs by finding ehrlichial morulae in 0.1 to 26.2% of their blood neutrophils and eosinophils. All 37 dogs had clinical signs of arthritis or muscular stiffness. Titer to Ehrlichia canis was determined in sera from 31 of the 37 dogs; 25 dogs had titer ranging from 1:20 to 1:5,120. In the other 6 dogs, titer to E canis was less than 1:10. The most common hematologic abnormality in these dogs, other than rickettsiemia, was thrombocytopenia. Granulocytes infected with ehrlichial organisms were not found in another 10 dogs that had clinical signs of arthritis or muscular stiffness. Of these 10 dogs, 3 had titer to E canis ranging from 1:40 to 1:320. Titer in the other 7 dogs was less than 1:10. Ehrlichial morulae were not found in the granulocytes of 18 healthy dogs. Of these 18 dogs, 9 had titer to E canis ranging from 1:20 to 1:5,120. Titer in the other 9 dogs was less than 1:10 Titer to Borrelia burgdorferi was determined in dogs with granulocytic ehrlichiosis, arthritic dogs without detected rickettsiemia, and in healthy dogs. Low titer determined by 2 laboratories was considered to be nonspecific reaction in all 3 groups of dogs and, thus, did not indicate that the arthritic disorders were attributable to canine borreliosis.