Bulgarian Journal of Veterinary Medicine (2005), 8, No 2, 141148 CLINICAL AND HAEMATOLOGICAL STUDIES IN DOGS, EXPERIMENTALLY INFECTED WITH TRICHURIS VULPIS Z. KIRKOVA, P. PETKOV & D. GOUNDASHEVA Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria Summary Kirkova, Z., P. Petkov & D. Goundasheva, 2005. Clinical and haematological studies in dogs, experimentally infected with Trichuris vulpis. Bulg. J. Vet. Med., 8, No 2, 141148. The experiment was performed on 9 mixed-breed dogs (6 infected and 3 non-infected controls). The experimental infection was provoked with Trichuris vulpis (10000 eggs/kg). The clinical signs and the following haematological parameters were monitored: haemoglobin, packed cell volume, red blood cell counts and morphology, mean corpuscular haemoglobin (MCH), mean corpuscular hae- moglobin concentration (MCHC), mean corpuscular volume (MCV), haemoglobin index (HbI), erythrocyte sedimentation rate (ESR), total and differential white blood cell counts. A typical clinical signs of the disease was the diarrhoea that resulted in full exhaustion and cachexia. In infected dogs, elevated haemoglobin and MCH values were observed between post infec- tion days 60 and 207, decreased MCV by day 15 and 35 and no changes in PCV, HbI values and red blood cell morphology. Also, a leukocytosis with eosinophilia, neutrophilia (on the account of seg- mented neutrophils’ elevation), lymphocytopenia and enhanced ESR were found out. Key words: dogs, Trichuris vulpis, trichurosis INTRODUCTION Trichurosis is a nematodosis of carni- vores, caused by Trichuris vulpis Froelich (1789) belonging to the Trichuridae fam- ily. The most typical clinical signs of trichurosis are: diarrhoea (often chronic and bloody mucoid), abdominal discom- fort (from unclear distress to acute pain), pica, dehydratation, weight loss and dry, dirty hair coat (Miller, 1941, Smith, 1954, Prelesov & Grosev, 1994), depression, rapid exhaustion (Rubin, 1954, Cardani et al., 1978). Several cases, in which the disease was manifested by alternating episodes of diarrhoea and constipation (Widmer & Van Kruiningee, 1974; Ewing & Bull, 1996), neurological and beha- vioural disorders as fits and hysteria (Em- (Emmerson, 1941) were also reported. The reported clinical manifestations are related by some authors (Smith, 1954) to the intensity of invasion (the infection with hundreds to thousands of parasites in the large intestine is accompanied by bloody diarrhoea, dehydratation, anaemia and death whereas the infection with up to 12 parasites is asymptomatic), to the loca- tion of parasites and to the individual traits of the host (age, body condition and pre-sence of other parasitic infections). Burrows & Lillis (1964) have pro- vided evidence that T. vulpis is haemato- phague, but there are no studies upon the haemotological changes in infected dogs. The opinions about anaemia as a sign ac-