Anaplasmosis, formerly known as gall sickness, is a potentially life threatening disease of cattle and other ruminants caused by obligate intraerythrocytic parasites of the order Rickettsiales, family Anaplasmataceae, genus Anaplasma.  Clinical bovine anaplasmosis is usually caused by A marginale . Cattle are also infected with A caudatum , which may result in severe disease, and A centrale , which generally results in mild disease.

Anaplasmosis is not contagious. Anaplasmosis is spread animal to animal by insects that take large blood meals, such as ticks, mosquitoes, horseflies and stable flies. It also can spread from an infected herd to another near-by herd. Humans may also spread the disease by dehorning, tattooing, vaccinating, etc.  Most transmission occurs via numerous species of tick vectors. At least 16 species of ticks of 7 genera have been shown experimentally to transmit A marginale.  The incubation period following infection varies from 24 to 35 days.

Anaplasmosis is a disease caused by a parasite that attaches to red blood cells which causes the animal’s body to destroy the cell. If enough red blood cells are destroyed, anemia can result. This can lead to fever, depression, dehydration, difficult breathing and possibly death. Cattle of any age may become infected, but the severity of illness increases with age. The most serious economic consequences are loss of weight and condition, slowed growth, abortions, and reduced potency in males.  In cattle that are three years of age or older, the death rate is 30 to 50 percent in animals that display clinical signs Sometimes affected animals become excited and aggressive when not enough oxygen reaches the brain. If infected cattle are able to survive, they remain as carriers for the rest of their lives.

As previously stated, there is a strong correlation between age of cattle and severity of disease. Calves are much more resistant to disease (though not infection) than older cattle. In endemic areas where cattle first become infected with A marginale early in life, losses due to anaplasmosis are minimal. After recovery from the acute phase of infection, cattle remain chronically infected carriers of the parasite and immune to further clinical disease. However, these chronically infected cattle may relapse to anaplasmosis when immunosuppressed (eg, by corticosteroids), when infected with other parasites, or after splenectomy. Carriers serve as a reservoir for further transmission. Serious losses due to anaplasmosis occur when mature cattle with no previous exposure are moved into endemic areas or under endemically unstable situations when transmission rates are insufficient to ensure all cattle are infected before reaching the more susceptible adult age.

The carcasses of cattle that die from anaplasmosis are generally markedly anemic and jaundiced.  Blood is thin and watery. The spleen is characteristically enlarged and soft, with prominent follicles. The liver may be mottled and yellow-orange. The gallbladder is often distended and contains thick brown or green bile. Hepatic and mediastinal lymph nodes appear brown.

Anavac is a modified live vaccine which triggers the animal’s immune system resulting in a lifetime of protection from anaplasmosis.

Furthermore, only ONE DOSE is required. There’s no need for additional roundups for booster shots. Anavac is recommended for use on animals from one to twelve months old and may be shipped only within California . It is available in 10-dose and 50-dose vials.

More AnaVac facts and details (including shipping and storage)

Please contact us for further information, pricing and ordering.