These diseases are spread via the blood between dogs by ticks. These diseases include Anaplasmosis, Ehrlichiosis, , Lyme’s Disease, and Rocky Mountain Spotted Fever. All four of these organisms can infect people as well as dogs.
Anaplasma is a member of the rickettsia family and has two species, A. platys and A. phagocytophilum.
These organisms are spread by ticks and infect the red blood cells and blood platelets, which leads to anemia and excessive bleeding because the blood does not clot normally. Clinical signs will range from lethargy and depression to epistaxis (bloody nose). Anaplasma can be diagnosed by a blood test and is treated with Tetracycline or Doxycycline which kills the organism. After treatment dogs can be re-infected if re-exposed. Prevention is accomplished by preventing ticks from feeding on the dog,
Ehrlichia is also a member of the rickettsia family and is divided into three groups that each have multiple species. They are spread by tick bites between dogs. Clinical signs can vary depending upon the type of the disease. The acute phase of the disease occurs 1 to 3 weeks after infection marked by depression, lack of appetite, lethargy, weight loss and fever and lasts for 2 to 4 weeks. Chronic signs of infection include non-specific signs as seen in the acute phase plus can be accompanied by bleeding tendencies, enlarged lymph nodes, and an enlarged spleen. Ehrlichia is diagnosed by a combination of a positive screening test that tests for antibodies against the organism, combined with typical clinical signs and the absence of any other diagnosis. Dogs with a positive titer, even if not showing signs dogs should be treated with Tetracycline or Doxycycline which kills the organism. Like Anaplasmosis, re-infection can occur after if treatment dogs are re-exposed. Prevention is accomplished by preventing ticks from feeding on the dog,
Lyme disease is caused by the spirochete bacteria Borriella burgdorferi. It is spread through the bites of ticks, most commonly the deer tick. Clinical signs in dogs most commonly include lameness in one or more lets. Typically, the joints are swollen and fever is present. In chronic infections, the changes in the joints are crippling and irreversible. Diagnosis of Lyme’s Disease is very difficult and must meet four criteria:
1. Patient must have a history of exposure to ticks from an endemic area
2. Typical clinical signs must be present
3. A positive serological test must be present
4. A prompt response to antibiotic treatment must occur.
Treatment involves administering antibiotics for a minimum of 3-4 weeks. Dogs respond well to antibiotics but can become re-infected after treatment. Lyme’s Disease is prevented by a combination of preventing ticks from biting your dog along with a vaccination against the Borrelia organism in areas where the disease is endemic. Lyme’s disease is transmissible to people, therefore it is important to keep ticks off of your dog as well as yourself. A dog that is infected with the Borrelia organism has not been shown to infect people. People become infected with Lyme’s disease when an infected tick feeds on them.
ROCKY MOUNTAIN SPOTTED FEVER
Rocky Mountain Spotted Fever is another rickettsial disease caused by the orgainism Rickettsia rickettsii. It is spread through ticks which serve as a source of the organism. Clinical signs of RMSF can include some of the following: fever, decreased appetite, depression, lameness, lymph node enlargement, neurological signs, gastrointestinal signs, skin necrosis and/or peripheral edema. Because these clinical signs are so non-specific, diagnosis of RMSF can be difficult. Serological testing is available, however, interpretation of results can be very difficult. RMSF must be high on the differential list for any dog with appropriate historical, physical, and laboratory findings in an area known to be endemic for RMSF.
Treatment of dogs with RMSF is done with oral antibiotics, usually in the Tetracycline family, for a minimum period of 21 to 28 days. In acute cases, supportive treatment such as fluids, will be needed.
Prevention of RMSF is accomplished by preventing ticks from feeding on your dog.