This is a complete description about the Anaplasmosis in ruminants. It describes about the etiology, life cycle, epidemiology, pathogenesis, clinical signs, necropsy findings, diagnosis, differential diagnosis, treatment and prevention and control of Anaplasmosis.

1. Analpasmosis/Yellow fever/Yellow bag/Gall sickness
Anaplasmosis is a intra-erythrocytic rickettsial disease of cattle, buffaloes,
sheep and goats characterised by debility, anaemia and jaundice
Etiology
 It is caused by various species of Anaplasma (means organism without
cytoplasm) of order rickettsiale
Anaplasma is a gram negative round shaped organism and measured
about 0.3-1.0 µm
 Now also includes A. bovis, A. platys, and A. phagocytophilum, which
were previously known as Ehrlichia bovis, E. platys, and E.
phagocytophila

2. The following organisms have been recorded
• Anaplasma marginale: Margin of RBC of cattle and deers and severe
forms
• Anaplama centrale: Central part of the RBC, but can also be seen at the
margin of the RBC and causes mild form in the cattle
• Anaplasma ovis: Margin of the RBCs of the sheep and goats and causes
mild to severe form
• Paranaplasma caudatum: It means a round organism with tail
• Paranaplasma discoides: It means an organism appearing like a disc
found in the cattle
• These two paranaplasma organisms produce mild to severe form of the
disease

3. Epidemiology
Incidence
 It is one of the important disease of cattle, sheep, goats, buffaloes
and some ruminants
Tropical and sub-tropical regions worldwide including south and
central America, the USA, Southern Europe, Africa, Asia and Australia
 It causes severe economic loss which may be due to
a) Decrease in milk production b) Mortality
The severity of disease in animal increases as the age advances
a) Less than one year of cattle: Mild form
b) 1-2 years of age : Acute form without mortality
c) 2-3 years of age: Acute form with few deaths
d) More than 3 years of age: Per acute form with mortality of 50-80%

4. Life cycle
The life cycle of rickettsial agent is not clearly
understood and the development in the tick is
unknown
When the organism is introduced by the tick into
the blood, the RBCs will pinocytize the organism
The stage which enter the RBC is called initial body
and this body after entering the RBCs forms a food
vacuole which develops into an inclusion body,
which undergoes repeated binary fission giving
rise to numerous initial bodies.
From one inclusion body, 8-16 initial bodies are
formed
 These initial bodies will get inside the other RBCs
Life cycle of Anaplasma in Vector Ticks
and Host Cattle

5. Pathogenesis
 Continuous erythrocytic destruction leads to anaemia and degree of
anaemia is directly proportional to the level of parasitaemia
 In anaplasmosis anaemia occurs due to Autoimmune mechanism in
which surface antigen of RBC is slightly modified which is considered as
foreign by the immune cells and considered foreign and destroyed by
immune cells of body
Atleast, 15% erythrocytes have to be parasitized before there is a clinical
manifestation of the disease
The appearance of immature erythrocytes lead to anisocytosis and
polychromasia

6. Clinical findings
IP- 3-4 weeks with tick borne infection and 2-5 weeks with the incubation of blood
 Initially, there is fever (104-1060F) which may be continuous or fluctuating type
 Partial or complete anorexia and depression
Symptoms of anaemia like pale mucous membranes, weakness, increase in heart and
respiratory rates, jaundice may or may not be seen
Faeces passed may be slightly yellow coloured, which some veterinarian consider is
very characteristic of anaplasmosis
Decrease in milk yield and abortion can occur
 At the terminal stage of the disease, some animals can have attacking behaviour and
then falling down and dies
Rarely, in peracute cases sudden onset of high fever, anaemia, icterus, severe dyspnoea
and death may be noticed within 24 hours in adult animals in areas experiencing the
disease for the first time

7. Generally , 10-30% of
erythrocytes are infected at peak
rickettsemia, although this figure
may be as high as 65%
Bos indicus breeds of cattle
appear to possess a great
resistance to A. marginale
infection than B. taurus breeds

8.  In India, subacute and chronic cases usually recorded and now few cases of
peracute anaplasmosis is encounter
Recovered animals act as carriers throughout their life and infertility problems
like repeat breeding in cows and function of testes may be altered in bulls
Course of the disease is 2 days to 2 weeks
 Sheep and goats: the disease runs a sub clinical course but rarely in some cases
particularly in goats a severe anaemia may occur and a clinical picture similar to
cattle may be seen

9. Necropsy findings
Pale mucous membranes and muscles, accumulation of small
quantities of serous fluid in cavities, splenomegaly with dark soft pulp,
haemorrhage on the myocardium and congested kidney are seen
Diagnosis
Clinical signs of fever and anaemia and passing yellow coloured faeces
is suggestive of anaplasmosis
Confirmed by blood smear examination and serological tests

10. Blood examination
Blood smear examination: Make a thin to moderate blood
smear, air dry it and fix it in methanol and do Giemsa staining. If
small spherical shaped organisms at the periphery or center of
the RBCs will be Anaplasma
Wet mount method: Organisms appear like small spherical
glistering bodies either at the periphery or center of the RBCs.
Haematology:The TEC, PCV and Hb values are decreased
Serological test: Capillary tube agglutination test, card
agglutination test, CFT, IPT and ELISA are being used for the
diagnosis of Anaplasmosis
Among those, CFT appear to be best
Cell mediated immune response test: CMI test like lymphocyte
stimulation test has been used for the diagnosis of Anaplasmosis

11. Differential Diagnosis
Tropical bovine theileriois: Enlarged superficial lymph nodes, high temperature
and Schizont on lymp node biopsy smear
Babesiosis: High temperature, haemoglobinuria and blood smear examination
Bacillary haemoglobinuria: High temperature, haemoglobinuria and blood
smear examination
Leptospirosis: High fever, Haemaglobinuria, Blood in milk.
Haemonchosis: Normal body temperature and faecal examination
Coccidiosis: Normal body temperature and faecal examination

12. Treatment
To eliminate the Anaplasma organisms administer any one of the following drugs.
Oxytetracycline, chlortetracycline or tetracycline @5-10 mg/kg body weight i/m
or i/v for 5-7 days.
To overcome carrier status, administer long acting tetracycline @ 20 mg/kg body
weight once in three days for 4 times
Imidocarb: It is administer @ 3 mg/kg body weight s/c or i/m
To overcome anaemia following can be done
 a)To overcome severe anaemia administer blood @15 ml/kg body weight
 b) If the anaemia is not severe administer the following
Iron dextran preparation equivalent to 50 mg elemental iron per mi like Imferon
or Iron-sorbital-citric acid complex equivalent to 75 mg elemental iron in 1.5 ml of
Jectofer or Feritas @ 5-10 ml/cow, i/m once in 3 days for 4 times
Administer Vitamin B12 preparation like Macrobin @ 5 ml/cow, 2ml/calf i/m
along with the Iron dextran preparation
Antipyretic

13. Prevention and control
Test the animal and treat the infected animals
 Vector control: Eliminate the ticks by using 0.25-0.5% of malathion, sumithion,
asuntol 0.02%-0.03% of sumicidin, 12.5% deltamethrin, 12.5% amitraz and 1%
flumethrin or Ivermectin as pour on solution etc.
Flumethrin 1% may be used as pour on solutions
Sterilise the syring and needles to overcome the contamination
Vaccination: At present no vaccine is available in India. However,following
vaccine is used in America.
Live attenuated Anaplasma marginale: It is prepared by irradication of die
organisms and passaging of these organism in deer or sheep for 138 times
Live A. Marginale or A. Central vaccine: Here blood from the suffering animal is
injected to calves less than one year of age to produce pre-immunity
Killed or inactivated A. marginale vaccine; Administered twice s/c at an interval
of 6 weeks
Live A. Central vaccine: Here severity of A. Marginale is reduced by A. Central
inoculation