CASE REPORT BOVINE BABESIASIS: A CASE REPORTED IN DEVON, ENGLAND W. G. COOMBS* Introduction Babesiasis (Texas fever, redwater, piroplasmosis) is an acute, intravascular hemolytic disease potentially affecting all domestic animals. It is a protozoal disease, transmitted by blood sucking ticks and the numerous species of Babesia are host-specific (13). At present babesiasis is responsible for serious worldwide economic loss (12), mainly through deaths of cattle from the disease, loss of condition in animals recovering from an acute attack, loss of milk production and the condemnation of carcasses at abattoirs. In addition, the cost of treatment and immunization imposes an additional burden on stock owners. The loss due to quarantine procedures and restricted cattle movement only exacerbates the disease problems. Although babesiasis has been diagnosed in Canada, most recently in an imported Polish Hunter in Alberta in the spring of 1975 (R. Jones, Ontario Veterinary College, personal communication, 1976), the disease is not considered indigenous. This is primarily due to the lack of a suitable vector. However, bovine babesiasis is considered endemic in southwest England. The agent, Babesia bovis, is thought to be transmitted only by the three host tick, Ixodes ricinus (13) and produces a syndrome characterized by fever, diarrhea, depression and hemolytic anemia. Transvorian transmission of B. bovis occurs and all life stages of the tick are potential agents of infection (13). Spread and seasonal (spring and fall) incidence of the disease is determined by the relative incidence of the tick (3). Perpetuation in wildlife hosts, notably deer, together with rough, hedge bordered pastures, make control of Ixodes both difficult and unrewarding. Diagnosis of the disease is based upon history, clinical signs, presence of a suitable vector, hemotological examination and serological studies. In cases where the disease is suspected but peripheral blood samples are negative for intra-erythrocytic organisms, or for post

mortem diagnosis, serological determination is indicated. Numerous techniques have been developed: card agglutination test (15), indirect hemagglutination test (4), complement fixation test (10), slide agglutination test (5) and immunofluorescent antibody test (8). Only the latter is applicable to the diagnosis of B. bovis. The other tests were developed solely for Babesia bigemina and/or Babesia argentina, neither species of which exists in England. A further technique used at Texas A&M University (V. E. Valli, Ontario Veterinary College, personal communication, 1976) involves impression smears of brain tissue in order to isolate the organism in capillary beds.

History This case involved a four year old South Devon cow noted one morning to be depressed, inappetent, with loose feces and burgundy colored urine. The owner had noticed the diarrhea and depression the day before examination on July 4, 1975. The cow had calved five months earlier, was not pregnant and was kept at pasture with the rest of the herd. She had been purchased one month previously from a neighboring county. The owner reported that he had had a similar problem in two of his Holstein cows in May.

Clinical Findings The cow was standing, slightly depressed and hanging her head. The rectal temperature was 41°C. There was minimal dehydration, the mucous membranes were pale and the heart sounds were very loud. The heart rate was 120 per minute, respiratory rate was 40 per minute and dypsnea was present. Intestinal and ruminal motility were increased and there was a thin stream of fluid diarrhea with spasm of the anal sphincter. A urine sample collected for analysis was noted to be a dark reddishbrown color, but clear. A peripheral blood sample was also collected for examination. The pasture was of good quality but unevenly grazed with a perimeter of thick, dense *Ontario Veterinary College, University of hedge. Ixodes ricinus ticks were not found on Guelph, Guelph, Ontario N1G 2W1. Present ad- this cow, but engorged adult female ticks were dress: R. R. #4, Shelburne, Ontario LON lSO. found on the groin and axilla regions of other cows in the herd. Schering Award 1976. l93 CAN. VET. JOURt., vol. 18, no. 7, July, 1977

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TABLE I HEMOGRAM OF A FOUR YEAR OLD COW WITH BABESIASIS

PCV Hb RBC BUN Reticulocytes WBC Neutrophils-Segs -Bands Lymphocytes Monocytes Eosinophils Basophils

19.2% 6.1 gm/100 ml 4.4 X 106/mm3 16 mg/100 ml + ve 20,000/mm3 77% 5% 11% 7% 1% 0%

Diagnosis and Laboratory Findings Based on clinical signs, history and the knowledge that the condition is endemic in the county of Devon, a tentative diagnosis of babesiasis was made. The cow was treated with the babesiacidal drug aminocarbalide1 at a dose of 7 mg/kg administered intramuscularly. Remission of clinical signs occurred within 24 hours and complete recovery was uneventful. The urine was positive for protein and hemoglobin and negative for the presence of red and white blood cells. Results of the hemogram are in Table I. There was a marked regenerative anemia with leukocytosis, neutrophilia and a left shift. The plasma was evenly discolored with a pinkish tinge indicating the presence of hemoglobinemia.

Using blood taken just below the buffy coat of a centrifuged sample and examining the periphery of the blood smear, the presence of the erythrocytic parasite B. bovis was noted. Piroplasmid bodies, 1.5 u in diameter, occurring in pairs at an obtuse angle, were found in an estimated 30% of red blood cells, confirming the field diagnosis of babesiasis.

Discussion With the presenting clinical signs a number of conditions were considered. Anaplasmosis and eperythrozoonosis are not present in England (1) and theileriasis is both an inapparent and uncommon disease (1). Postparturient hemoglobinuria is most often seen within a few weeks of calving and is associated with hypophosphatemia. Water intoxication is primarily a condition of calves (7) and in this case water was always available free choice and no nervous disorder was present. Copper

1Diampron, May-Baker Ltd., England.

poisoning, although reported in cattle, is primarily a condition of sheep (1). These cattle were not receiving a copper supplement and, if present, the disease is peracute and more severe (1). Cruciferous plant poisoning was discounted as these plants were not found in the pasture. Bracken fern was also not found on the farm, nor did this cow have bleeding from body orifices. Bacillary hemoglobinuria is not common in England (1), being predominantly a disease of the western United States. Usually there is abdominal pain present and diarrhea is not generally found. Leptospirosis was also considered and could not be discounted. However, there was no history of abortions, no calves were found ill, the disease tends to be chronic in adults and the summer was very dry with little surface water. Due to lack of straining on urination and as urine coloration and lack of turbidity indicated hemoglobinuria versus hematuria, such conditions as enzootic hematuria, pyelonenephritis, cystitis and urethritis were not considered as diagnoses. This report describes an early or "stage one" case of babesiasis (J. C. MacKellar, Tavistock, Devon, England, personal communication, 1975). Cattle treated in this stage respond well, showing a clearing of the urine and increased appetite within 12-24 hours. If left untreated the disease progresses rapidly, terminating in death of the animal within two to three days. The severe stages are characterized by a very rapid heart rate with extremely loud cardiac sounds heard easily at a few feet distant from the cow. The pulse is feeble and a hemic murmur is usually present. Respiratory dypsnea is marked and the mucous membranes are pale and jaundiced. Milk yield terminates and dehydration is severe. Diarrhea is replaced by constipation although spasm of the anal sphincter is still present. Hemoglobinuria is present throughout the course of the illness. In endemic areas some practitioners treat all animals having fever and "narrow-bored" diarrhea for babesiasis as hemoglobinuria may not occur until one or two days later (M. P. Cranwell, Ontario Veterinary College, personal communication, 1976). The treatment administered depends upon the stage of the disease. Stage one illnesses can be treated solely with babesiacidal drugs. Blood transfusions (11), fluid therapy, enemas and hematinics (14) are widely used in the severe stages and do much to reduce the overall mortality rate to two to three percent (3). Even with treat'ment severely affected animals are slow to recover. Milk yields often take months to return to previous levels. 194

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Prevention and control of babesiasis should be aimed both at adequate tick control and at minimizing the effects of infection. The former involves primarily good pasture husbandry with close grazing to reduce tick cover. Old pastures should be burned or plowed. Pasture scavenging with sheep will both interrupt the life cycle of B. bovis and allow more practical dipping programs. The education of farmers to enhance early diagnosis and treatment is important in control. Owners of animals in endemic areas are generally aware of the disease and deaths are uncommon. Nevertheless, farmers should be encouraged to observe their animals urinate at grass once a day. As a vaccine for B. bovis has not yet been developed (12), the effects of natural infection can be minimized by exposing calves to tick infested pastures at an early age when they are refractory to the disease. Due to this early establishment of premunity, clinical manifestations in adults are rare unless general immunosuppression is induced. Passive immunity of calves born of exposed dams will last until six weeks of age

Acknowledgments To Drs. M. Cranwell, J. Mills, J. Lumsden and V. E. Valli at the Ontario Veterinary College for their help in the preparation of this paper. In particular, warm appreciation is extended to Dr. Campbell MacKellar, Tavistock, England for his advice, friendship and selfless encouragement. References 1. BLOOD, D. C. and J. A. HENDERSON. Veterinary Medicine, Fourth Edition. London:

Bailliere Tindall. 1974. 2. BRYANT, J. E., B. ANDERSON and K. H. WILLERS. Control of piroplasmosis in Florida. J. Am. vet. med. Ass. 154: 1034-1036. 1969. 3. COLLINS, J. D., T. 0. NULLAIN and A. R. 4.

5.

6.

(9).

With the increasing movement of all domestic animals from infected countries, it behooves Canadian practitioners to be aware of

7.

Irish vet. J. 19: 211-214. 1965. 8. JOHNSTON, L. A. Y., R. D. PEARSON and G.

the potential confrontation with babesiasis. The similarity of the syndrome with diseases in other domestic animals (2, 6), notably equine infectious anemia and the not infrequent difficulty in diagnosis warrants due consideration to the disease.

9.

10.

Summary A case report of babesiasis in a four year old South Devon cow seen in the county of Devon, England is presented. Notable points concerning the disease, its diagnosis and treatment are discussed. Practical applications to its control and prevention are also outlined.

11.

Resume

13.

L'auteur rapporte un cas de bab6siose qu'il a diagnostique chez une vache "South Devon", agee de quatre ans, dans le comte de Devon, en Angleterre. II commente certains points importants qui concernent la maladie, son diagnostic et son traitement. II mentionne aussi des applications pratiques, relatives a la prevention et a l'eradication de la maladie.

FERGUSON. Observations on bovine babesiasis in Ireland. Irish vet. J. 24: 42-51. 1970. CURNOW, J. A. and BARBARA CURNOW. An indirect haemagglutination test for the diagnosis of Babesia argentina infection in cattle. Aust. vet. J. 43: 286-290. 1976. CURNOW, J. A. The use of a slide agglutination test to demonstrate antigenic differences between Babesia bigemina parasites. Aust. vet. J. 49: 290-293. 1973. DORNER, J. L. Clinical and pathologic features of canine babesiasis. J. Am. vet. med. Ass. 154: 648-652. 1969. HANNON, J. Water intoxication of calves.

12.

14. 15.

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LEATCH. Evaluation of an indirect fluorescent antibody test for detecting Babesia argentina infection in cattle. Aust. vet. J. 49: 373-377. 1973. MAHONEY, D. F. and D. R. Ross. Epizootiological factors in the control of bovine babesiasis. Aust. vet. J. 48: 292-298. 1972. MAHONEY, D. F. Bovine babesiasis. Diagnosis of infection by complement fixation test. Aust. vet. J. 38: 48-52. 1962. MACKELLAR, J. C. Application of blood transfusion in cattle with reference to redwater. Vet. Rec. 74: 763-765. 1962. SEDDON, H. R. Protozoal and viral diseases of domestic animals in Australia. Commonwealth Department of Health, 10. 1966. SOULSBY, E. J. L. Hehninths, Arthropods, and Protozoa of Domestic Animals, Sixth Edition. London: Bailli'ere Tindall and Cassell. 1968. TAMMEMAGI, L. Iron-dextran in the treatment of anaemia associated with bovine babesiasis. Aust. vet. J. 42: 260-261. 1966. ToDoRovic, R. A. A babesiasis card agglutination test. Am. J. vet. Res. 35: 13471350. 1974.

Bovine babesianis: a case reported in Devon, England.

CASE REPORT BOVINE BABESIASIS: A CASE REPORTED IN DEVON, ENGLAND W. G. COOMBS* Introduction Babesiasis (Texas fever, redwater, piroplasmosis) is an ac...
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