Anaplasma (A.) phagocytophilum is the causative agent of anaplasmosis, a bacterial disease which is transmitted through bites from ticks of the genus Ixodes. A. phagocytophilum is a gram-negative, obligate intra-cellular bacterium which attacks mostly neutrophilic granulocytes, but also, in rare cases, eosinophilic granulocytes. Anaplasmosis occurs worldwide, its prevalence depending on the distribution area of the transmitting vectors.
Borrelia is the causative agent of Lyme borreliosis, a bacterial disease which is transmitted through bites from ticks of the genus Ixodes. The gram-negative bacteria are collectively referred to as Borrelia burgdorferi sensu lato. In this group, the genospecies Borrelia burgdorferi sensu stricto, Borrelia garinii and Borrelia afzelii are pathogenic for dogs and horses. Whereas in the U.S. only B. burgdorferi sensu stricto is relevant, more than 80 % of Borrelia in European ticks belong to the pathogenic genospecies B. garinii or B. afzelii. Dogs and horses have a significantly increased risk of infection because of their higher frequency of contact with ticks. Most of the infections, however, proceed asymptomatically. Infection does not confer strong immunity. Reinfection is therefore possible. Antibodies against B. burgdorferi can be found in the serum of specifically infected or vaccinated animals. An infection with B. burgdorferi is associated with a variety of clinical symptoms, which generally occur weeks or months after infection.
Ehrlichiosis is a disease which is transmitted to animals and humans by ticks. In canine ehrlichiosis, especially the pathogen Ehrlichia (E.) canis plays a role, which is mainly transmitted by the brown dog tick (Rhipicephalus sanguineus) and may lead to canine monocytic ehrlichiosis (CME). E. canis is a gram-negative, obligatory intracellular bacterium which mainly affects the mononuclear cells of the blood. CME occurs in tropical and moderate climates worldwide. The geographical distribution of E. canis increases with the further distribution of the vector tick which is accelerating due to climate change.
Leishmaniasis is a zoonotic infection that is caused by protozoa of the Leishmania genus. Leishmania infantum, Leishmania chagasi and Leishmania donovani, which belong to the Leishmania donovani complex, are of particular importance. These monocellular parasites are transmitted to humans or animals via the bite of female sandflies of the genera Phlebotomus (Africa, Asia, Europe) or Lutzomyia (Central and South America). Dogs are considered as the most important reservoir. Due to the zoonotic potential, infected dogs are a major problem in veterinary and human medicine. It is assumed that 50 % to 80 % of dogs in endemic areas are infected with Leishmania. However, Leishmania infection is not synonymous with canine leishmaniasis. Less than 10 % of infected dogs show clinical symptoms. Certain dog breeds and the age of the dog are associated with a predisposition for the development of leishmaniasis. The immune response of the dog is also crucial for manifestation.
The distribution area of ticks is continuously increasing due to global warming. Consequently, tick‑borne diseases such as anaplasmosis, borreliosis and tick‑borne encephalitis (TBE) occur more frequently in dogs and horses as well.
Toxoplasmosis is a zoonosis which occurs worldwide and is caused by the sporozoon Toxoplasma gondii. All warm-blooded animals can become infected with Toxoplasma (T.) gondii. The asexual reproduction of T. gondii can take place in the most diverse tissues of the warm-blooded intermediate hosts. The only final hosts are cats or other felidae, in whose intestine the sexual reproduction takes place. This leads to the formation of oocysts which are secreted into the environment with the cat’s faeces.
Autoantibodies against cell nuclei
The detection of anti‑nuclear antibodies (ANA) is an important diagnostic indicator in many autoimmune diseases. ANA are directed against various cell nuclear components. These encompass nucleic acids, cell nuclear proteins and ribonucleoproteins.