Ž .Veterinary Parasitology 74 1998 319–323

Short communication

Canine hepatozoonosis in Brazil: description ofeight naturally occurring cases

Luıs F.P. Gondim, Aguemi Kohayagawa, Nayro X. Alencar,´Alexander W. Biondo, Regina K. Takahira, Sonia R.V. Franco )ˆ

Department of Veterinary Clinical, Faculdade de Medicina Veterinaria e Zootecnia, UniÕersidade Estadual´( )Paulista UNESP P.O. Box 560, Botucatu, Sao Paulo, Brazil˜

Received 30 January 1996; accepted 16 October 1996

Abstract

ŽEight cases of canine hepatozoonosis were diagnosed at the Veterinary Hospital Faculdade de.Medicina Veterinaria e Zootecnia, Universidade Estadual Paulista, Campus de Botucatu , between´

October 1993 and April 1994. Clinical signs included anorexia, pale mucous membranes, weightloss, pain, diarrhoea, vomit, gait abnormalities, fever, polyuria and polydipsia. Haematologicfindings revealed anaemia in seven cases, leucocytosis with neutrophilia in three cases, lymphope-nia in three cases and monocytosis in four cases. Serum biochemistries included alterations inmany parameters. The micrometry of Hepatozoon canis gametocytes ranged from 6.8=4.0 mmto 7.5=4.5 mm. Parasitaemia ranged from less than 0.5% to 2%. In all the cases reported otherconcurrent diseases were present. Diagnosis of canine hepatozoonosis was made by identifying H.canis gametocytes within leucocytes in stained blood smears. q 1998 Elsevier Science B.V.

Keywords: Hepatozoon canis; Dog

1. Introduction

Hepatozoon canis is a protozoan classified in the family Haemogregarinidae and istransmitted by the dog tick Rhipicephalus sanguineus. It has been recognized in Asia,

ŽAfrica, Europe, North America and South America Ezeokoli et al., 1983; Barton et al.,.1985; Garcia et al., 1990; Murata et al., 1991 . The dog becomes infected with the

ingestion of a tick containing sporulated oocysts. The ingested sporozoites are thenreleased in the dog’s intestinal tract, penetrate the gut wall and are carried by blood or

) Corresponding author. Tel.: q55-014-821-2121-R-2115; fax: q55-821-2343.

0304-4017r98r$19.00 q 1998 Elsevier Science B.V. All rights reserved.Ž .PII S0304-4017 96 01120-X

( )L.F.P. Gondim et al.rVeterinary Parasitology 74 1998 319–323320

Table 1Ž .Haemograms of dogs naturally infected by H. canis Jain, 1986

Parameters Case number Normal range

1 2 3 4 5 6 7 86Ž .Red blood cells 10 rml 2.2 3.4 1.52 4.56 7.58 4.06 1.12 2.22 5.5–8.5

Ž .Hemoglobin grdl 5.5 7.5 3.4 8.5 16.5 8.1 2.2 4.6 12–18Ž .Hematocrit % 16 23 10 30 50 29 7 17 37–55

a Ž .MCV fl 72.7 67.6 65.8 65.8 66.0 71.4 62.5 76.6 60–77b Ž .MCHC grdl 34.4 32.6 34.0 28.3 33.0 27.9 31.4 27.1 32–36

c Ž .MCH pg 25.0 22.1 22.4 18.6 21.8 19.9 19.6 20.7 19–23Ž .White blood cells ml 23,000 9500 6800 29,900 50,100 9200 14,000 9400 6000–17,000Ž .Band neutrophils ml 0 190 0 0 2004 92 144 94 0–300

Ž .Neutrophils ml 20,700 6460 4012 23,023 38,577 7544 11,200 8084 3000–11,500Ž .Lymphocytes ml 230 1235 1496 1794 1503 1104 560 564 1000–4800

Ž .Monocytes ml 2070 1330 1088 5083 8016 1104 2100 658 100–1350Ž .Eosinophils ml 0 285 204 0 0 184 0 0 100–1250

a MCV, Mean corpuscular volume.b MCHC, Mean corpuscular hemoglobin concentration.c MCH, Mean corpuscular hemoglobin.

lymph to the liver, spleen, lymph nodes, kidneys, bone marrow or muscle, whereschizogony occurs. Some merozoites enter neutrophils or monocytesand develop intogametocytes. When a tick ingests a blood meal from an infected dog, the gametocytesare released within the gut of the tick. Subsequently, oocysts containing sporozoites are

Žformed in the tick body cavity, and the cycle is continued Craig et al., 1978; Ezeokoli et.al., 1983 .

Diagnosis of the disease is made by identifying a cyst-like structure with H. canisorganisms from biopsy specimens or by finding gametocytes of the parasite within bloodneutrophils and monocytes.

Table 2Ž .Serum biochemistries of dogs naturally infected by H. canis Kaneko, 1989

Parameters Case number Normal range

4 5 6

Ž .Urea mgrdl 74 126 21 21.4–59.92Ž .Creatinine mgrdl 2.2 5.2 0.3 0.5–1.5

Ž .SAP IUrl 1807 437 189 20–156Ž .ALT IUrl 85 266 24 21–102Ž .AST IUrl 126 263 33 23–66Ž .GGT IUrl 19 11 2.0 1.2–6.4

Ž .Total Protein grdl 6.6 6.1 3.5 5.4–7.1Ž .Albumin grdl 1.5 2.2 2.4 2.6–3.3Ž .Globulin grdl 5.1 3.9 1.1 2.7–4.4

Ž .Total bilirubin mgrdl 16 1.9 0.8 1.71–8.55Ž .CK IUrl 877 4521 53 1.15–28.40

Serum biochemistry parameters were not analyzed for cases 1, 2, 3 and 8.

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Table 3Individual parasitemia and micrometry of H. canis gametocytes

Ž . Ž .Case number Parasitemia % Micrometry of gametocytes mm

1 -0.5 7.5=4.52 -0.5 7.0=4.253 -0.5 7.33=4.04 0.5 7.0=4.255 -0.5 7.0=4.256 0.5 7.33=4.337 2.0 6.83=4.08 0.5 7.25=4.5

Several drugs have been used in an effort to treat hepatozoonosis, however, theŽresponse has been variable. So there is no effective therapy at this time Ezeokoli et al.,

.1983; Elias and Homans, 1988 .Although canine hepatozoonosis has been reported throughout the world, it was only

Ž .recently described in Brazil Massard, 1979; Mundim et al., 1992 , and many cases arecurrently being diagnosed.

The purpose of this manuscript is to describe eight cases admitted to the VeterinaryŽHospital Faculdade de Medicina Veterinaria e Zootecnia, Universidade Estadual´

.Paulista, Campus de Botucatu , in which gametocytes of H. canis were detected incirculating neutrophils and monocytes.

2. Materials and methods

Eight naturally occurring cases of canine hepatozoonosis were referred to theVeterinary Hospital from October 1993 to April 1994. Seven of the dogs were mixedbreed and the other, a Weimaraner. They ranged in age from 2 months to 11 yrs. Therewere four males and four females. All eight animals originated from the region of

Ž .Botucatu Sao Paulo state .˜

Fig. 1. H. canis in three neutrophils.

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Ž .Fig. 2. H. canis and E. canis arrow in a same neutrophil.

Laboratory procedures included haemograms, serum biochemistries, micrometry ofH. canis gametocytes and parasitaemia level of the infected animals. The erythrocytecount, leucocyte count and haemoglobin concentration were determined using an

Ž .automatic counter CELM-CC510 . Packed cell volume was determined by the micro-haematocrit method and the differential leucocyte counts were estimated as percentages

Ž .by counting 100 leucocytes in stained blood smears by the method of Rosenfeld 1947 .The serum biochemistry assays were done by spectrophotometric methods. The microm-etry of H. canis gametocytes was determined by optic microscopy and the parasitaemialevel was performed manually by counting 200 leucocytes.

3. Results

Clinical findings: Anorexia, pale mucous membranes, weight loss, pain, diarrhoea,vomiting, gait abnormalities, fever, polyuria and polydipsia were the most commonsigns observed clinically.

Laboratory findings: Haemograms demonstrated anaemia in seven cases; leucocytosiswith neutrophilia in three cases; lymphopenia in three cases and monocytosis in four

Ž .cases Table 1 . Serum biochemistries revealed alterations in many parameters that aresummarised in Table 2. The micrometry of H. canis gametocytes ranged from 6.8=4.0

Ž .mm to 7.5=4.5 mm. Parasitaemia ranged from less than 0.5% to 2.0% Table 3 .Diagnosis: Diagnosis of canine hepatozoonosis was made by identifying H. canis

Ž .gametocytes within leucocytes in stained blood smears Fig. 1 . In all the cases reported,other concurrent diseases were present. Ehrlichia canis morulae was found in two casesŽ .Fig. 2 ; Toxocara spp. in one case; Ancylostoma sp. in two cases; nephropathy withhepatopathy in two cases; microfilaraemia with nephropathy in one case; Babesia canisinfection in one case and umbilical hernia in one case.

4. Discussion

In all the cases observed, some of the clinical signs and laboratory abnormalitiescould be attributed to concurrent disease. A slight parasitaemia was found in most of the

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Ž .dogs less than 0,5% , and only one dog reached 2.0%, which is similar to reportedŽ .cases of hepatozoonosis Ibrahim et al., 1989 Leucocytosis with neutrophilia, a typical

Ž .haematological finding in hepatozoonosis Gaunt et al., 1983 , was only observed inthree dogs, but this finding may be representative of diseases other than hepatozoonosis.Alterations in serum biochemistries could be related to specific diseases in some cases.Elevated alkaline phosphatase has been reported in dogs with hepatozoonosis because of

Ž .periosteal new bone proliferation Craig et al., 1978 . In this study alkaline phosphatasewas found to be elevated in three dogs which was related to H. canis infection.Immunosuppression caused by a concurrent disease may predispose to H. canis infec-

Ž .tion Gossett et al., 1985 . All the eight dogs observed in this study had concurrentdiseases which could be implicated with the severity of the pathology observed.

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