KLOSSIELLA AND HEPATOZOON 



2S7 



Disease: Hepatozoonosis. 



Hosts : Dog, cat, jackal, hyena and 

 palm civet or musang {Payadoxurns 

 herniaphroditns). The forms described 

 from the cat, jackal and hyena under the 

 names H. felis, H. rotitndata and H. 

 cliai/oni. respectively, are practically 

 indistinguishable morphologically, and 

 are probably all the same species. Laird 

 (1959) believed that the form he found in 

 the palm civet in Malaya was H. caiiis. 



Location: The schizonts are in the 

 spleen, bone marrow and to a lesser ex- 

 tent in the liver. The gamonts are in the 

 polymorphonuclear leucocytes. 



Geographic Distribution : India, 

 Malaya, Singapore, Indochina, Central 

 Africa, North Africa, Middle East, Italy. 

 This species is well known in dogs, but 

 has been reported from cats only by 

 Patton (1908) in Madras (Laird, 1959). 



Morphology: The gamonts in the 

 leucocytes are elongate rectangular bodies 

 with rounded ends measuring about 8 to 12 

 by 3 to 6|_L, and with a central, compact 

 nucleus. Their cytoplasm stains pale blue 

 and their nucleus dark reddish with 

 Giemsa stain. They are surrounded by a 

 delicate capsule. They may emerge from 

 the leucocytes and capsule and lie free in 

 citrated blood. Leitao (1945) saw schi- 

 zonts in the circulating blood which he 

 said were difficult to distinguish from 

 platelets. 



Life Cycle : The life cycle of H. 

 canis was worked out by Christophers 

 (1906, 1907, 1912) and Wenyon (1911). 

 Schizogony takes place in the spleen and 

 bone marrow, and Rau (1925) saw it in the 

 liver also. There are several types of 

 schizonts. One type produces a small 

 number (usually 3) of large merozoites, 

 another type produces a large number of 

 small merozoites, and intermediate types 

 produce merozoites of intermediate num- 

 bers and size. The small merozoites are 

 the ones which enter the leucocytes to 

 form gamonts. 



The vector is the brown dog tick, 

 Rhipiceplialus sanguineus . Both the 



nymph and adult can transmit the infection, 

 but there is no transovarian transmission. 

 The oocysts are found in the haemocoel. 

 They are about 100 fi in longest diameter 

 and contain 30 to 50 sporocysts 15 to 16/1 

 long, each containing about 16 banana- 

 shaped sporozoites and a residual body. 

 Dogs become infected by eating infected 

 ticks. 



Pathogenesis : H. canis has often 

 been found in apparently healthy dogs, but 

 it may also cause serious disease and 

 death (Rau, 1925; Rahimuddin, 1942). 

 The principal signs are irregular fever, 

 progressive emaciation, anemia and 

 splenomegaly. Lumbar paralysis has 

 also been reported. Affected dogs may 

 die in 4 to 8 weeks. 



Diagnosis : Hepatozoonosis can be 

 diagnosed by identifying the gamonts in 

 stained blood smears or in stained smears 

 of spleen pulp, bone marrow or liver. 



Treatment: Unknown. 



Prevention and Control : Since//. 

 canis is transmitted by the brown dog 

 tick, elimination of ticks will eliminate 

 the disease. 



OTHER SPECIES OF HEPATOZOON 



Hepatozoon niuris (Balfour, 1905) 

 occurs in the wild and laboratory Norway 

 rat and black rat thruout the world. 

 Schizogony takes place in the parenchymal 

 cells of the liver, and the gamonts are 

 found in the monocytes and rarely in the 

 polymorphonuclear leucocytes. The vector 

 is the spiny rat mite, Ecltinolaelaps 

 echidninus. Massive infections may cause 

 marked degenerative changes in the liver 

 and death, but little or no effect has been 

 observed in lightly infected wild rats. 



Hepatozoo)! nnisculi (Porter, 1908) 

 was reported from the white mouse in 

 England. It differs from H. niuris in that 

 schizogony takes place only in the bone 

 marrow. 



Hepatozoon cuniculi (Sangiorgi, 1914) 

 was reported from the domestic rabbit in 



