Ehrlichiosis
Ehrlichioses are bacterial diseases caused by rickettsiae of the genus Ehrlichia spp., which affect a wide variety of domestic animals, in addition to humans.
In Mexico, Ehrlichia canis infects some white blood cells, such as lymphocytes and macrophages. This organism causes canine monocytic ehrlichiosis, also known as canine hemorrhagic fever. There are also reports warning about the potential transmission of the disease to humans.
Clinical signs
Canine ehrlichiosis can present acutely or chronically. Acute disease is characterized by fever, enlarged lymph nodes, an enlarged spleen, anorexia, and lethargy. Complete blood counts may reveal mild anemia, a decrease in white blood cells, and platelets. All of this causes petechiae (small hemorrhages in the mucous membranes), nosebleeds, swelling of the paws, blood in the urine, and an increased tendency to bleed. Case fatality is not a common occurrence in acute ehrlichiosis.
Chronic symptoms are due to damage to the bone marrow, which leads to a decrease in blood cells. This occurs because blood cells are produced in the bone marrow.
Animals with chronic ehrlichiosis show significant weight loss, and lesions occur in the spleen, kidneys, lungs, eyes, and central nervous system.
When the disease reaches humans, the symptoms are similar to those of a common cold.
Transmission
Ehrlichia canis is transmitted by the brown dog tick Rhipicephalus sanguineus . These ticks, having three hosts, can transmit the infectious agent to several dogs.
The disease can also be transmitted through blood transfusions, which contain infected white blood cells.
Disease management
Canine ehrlichiosis is considered endemic to Mexico. The disease should be suspected when the animal's clinical history indicates a history of tick infestations.
The disease is known to affect dogs of any breed and age, however, there are reports of high mortality and morbidity (transmission) in German Shepherd dogs.
A dog that recovers from acute illness may become a carrier, so proper diagnosis and treatment are vitally important.
The main measure for controlling the disease is to eliminate the tick, since antibiotic treatment is ineffective.