Dr. Muhammad Jahangir

D.V.M, M.Sc (HONS) Vety Parasitology

Contact: 00-92-300-7701465  Drjahangir23@yahoo.com

ANAPLASMOSIS IN CATTLE

Anaplasmosis of cattle is common in yearling and mature cattle in summer season. In cattle severe debility, emaciation, anemia and jaundice, no hemoglobinuria are the major clinical signs.

 ETIOLOGY

Anaplasmosis is caused by microscopic parasites that live in the red blood corpuscles. The disease may be caused by a variety of anaplasma species, but the most important of these is Anaplasma marginale in cattle. This organism is widely distributed throughout the tropical and subtropical areas of the world and extends also into the temperate zones.

TRANSMISSION OF DISEASE

The disease is transmitted by ticks, which are the natural hosts of the anaplasma organism. Various species of the flies especially dog flies also play an important part in spreading the disease. They convey infection by biting. Animals over 3 years of age are usually affected by a peracute fatal form of the disease. Bovine anaplasmosis may also be spread mechanically by the use of unsterilized or insufficiently sterilized instruments and hypodermic needles and castrating during dehorning, tattooing or vaccination and by blood transfusions. The source of infection is always the blood of an infected animal. Spread from animal to animal occurs chiefly by insects vectors. Ticks, at least in some areas, are much the more important group of vectors.

CLINICAL FINDINGS

         In cattle the incubation period varies with the amount of infected material injected but it is usually being about 3-4 weeks or more after tick-borne infection. Cattle are usually affected during the warm months of the summer and early autumn. In the early stages of disease the temperature rises to above 105F.It may remain elevated or fluctuate with irregular periods of fever and normal temperature for from several days up to 2 weeks. Breathing is rapid and difficult. The animal shows signs of exhaustion, with cessation of rumination and loss of appetite. After the disease has been present for some time the skin and visible mucous membranes become yellow and anaemic, but hemoglobinuria is absent. Often the appetite becomes depraved, i.e. the animal may eat soil. The gait is stiff and unsteady and urination is frequent. Sometimes there is constipation and sometimes the faeces contain blood or are coated with mucous. The lymph nodes are enlarged; the coat is staring and there is swelling around the eyes. The disease may last for more than 2-4 weeks after the appearance of the first symptoms.

In chronic cases there is severe anaemia, from which the animal makes partial recovery only after several weeks. The animals most at risk are those of foreign breeds and those newly introduced into the area. In these the disease runs a violent course and often ends fatally. Cattle of all ages are affected but in general the disease is more severe in adults than in calves. Pregnant cows abort frequently.

NECROPSY FINDINGS

           At necropsy the most obvious findings are emaciation, jaundice and pallor of the tissues, and thin, watery blood.  The liver is enlarged and deep orange in color, the kidneys congested, the spleen enlarged with soft pulp and there may be hemorrhages in the myocardium. Postmortem identification of Anaplasm marginale can be established by staining blood smear with Giemsa and direct fluorescent stains.

 DIAGNOSIS

          A positive diagnosis of anaplasmosis depends upon positive transmission and complement-fixation tests. The history of the outbreaks, experience of the occurrence of the disease in the area and the presence of insect vectors may suggest the possible presence of anaplasmosis. Babesiosis is clinically much more acute, is accompanied by hemoglobinuria. The possible occurrence of more than one cause of hemolytic anemia in the same group of animals should not be over looked.

 TREATMENT

            In the early stages of the acute form of the diseases antibiotics, tetracycline 6-10mg/kg body weight given in a single injection is effective, although it is more usual to give three such daily injections. Supportive treatment should include massive blood transfusions administered slowly. Rough handling of animal should be avoided at all cost. During treatment care must be taken to ensure sterilization of equipment between cases. The advent of a long-acting tetracycline preparation has made treatment easier still. The L-200 product injected at the rate of 20mg/kg body weight intramuscularly every 7 days for 2-4 injections sterilized cattle of their parasitemia.

           Imidocarb,(Imipro Inj.) 3mg/kg body weight is an effective treatment for clinical cases.For complete sterility of animal requiring two injections of Imidocarb at the rate of 5mg/kg body weight.

           Control of tick vectors may be achieved with the use of Ivermectine (Actimec plus) at the rate of 200ug/kg body weight as a subcutaneous injection.

           Supportive treatment must also contain multivitamins with amino-acids i.e. Ami-vicom injection at the rate of 0.6-1ml/kg body weight for 3 days.

CONTROL

          Protection against anaplasmosis is regular dipping of cattle exposed to infection with Deltamethrin2.5%(Delta-25)at the rate of 1ml/1.5litres of water and spary in shed @ 2ml/ liters of water.