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Diagnosis of a Dicrocoelium Dendriticum Infection in New World Camelids: a Case Report

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Diagnosis of a Dicrocoelium Dendriticum Infection in New World Camelids: a Case Report Case Report Veterinarni Medicina, 57, 2012 (3): 154–162 Diagnosis of a Dicrocoelium dendriticum infection in New World Camelids: a case report D. Klein1, H. Prosl2, D. Thaller3, M. Floeck1 1Clinic for Ruminants, University of Veterinary Medicine, Vienna, Austria 2Institute of Parasitology and Zoology, University of Veterinary Medicine, Vienna, Austria 3Institute of Pathology and Forensic Veterinary Medicine, University of Veterinary Medicine, Vienna, Austria ABSTRACT: Dicrocoelium dendriticum plays an important role in New World Camelids as infected animals may suffer from severe clinical symptoms even leading to death of the animals. Intra vitam diagnosis may be difficult as clinical signs are atypical and Dicrocoelium eggs are shed only intermittently in faeces. The aim of this paper is to present four clinical cases of dicrocoeliosis in lamas as well as three asymptomatic infected animals to sup- port the veterinarian in practice to diagnose infections. Furthermore, it is the first time that ultrasonographic examinations are described in this context. All seven lamas had been admitted to the Clinic for Ruminants at the University for Veterinary Medicine in Vienna. None of the animals had a history of D. dendriticum infection. The ultrasonographic examination of the liver revealed in all diseased animals as well as in two asymptomatic lamas hyperechoic areas representing calcified bile ducts typical for an infection with liver flukes. These findings together with blood examination of liver enzymes and parasitological examination may lead to the intra vitam diagnosis of dicrocoeliosis in lamas and alpacas. With an early diagnosis, the therapy of Dicrocoelium spp. could become more effective and the number of animals rescued may be increased. Keywords: lama; liver fluke; ultrasound One of the major health problems of New World inner body temperatures and anaemia in diseased Camelids are infections with endoparasites. The animals. small liver fluke (Dicrocoelium dendriticum) plays D. dendriticum has been diagnosed in 25.5% an important role in lamas and alpacas in central (Hengrave Burri et al. 2005a) to 34% (Hertzberg European areas as infections may range in seri- and Kohler 2006) of New World Camelids with ousness from severe disease to the death of the no clinical signs observed in Switzerland. In 69% animal (Wenker et al. 1998; Gunsser et al. 1999). In of New World Camelid farms examined in the the literature from North and South America this course of a parasite observation programme in endoparasite is nearly never mentioned (Cheney Switzerland, D. dendriticum infections have been and Allen 1989). Possibly these severe courses of found (Schönmann 2006). So far there are no stud- the disease may result from a lack of evolutionary ies concerning the prevalence of D. dendriticum in adaptation of New World Camelids to this parasite Austrian New World Camelid herds. in Europe (Wenker 2004). This paper presents case reports of seven lamas Affected animals show atypical clinical symp- with clinically apparent liver disease caused by D. toms, e.g., loss of body weight, depressed attitude dendriticum as well as clinically inapparent in- with increased lying times and decreased food in- fected animals. Our intent is that this article will take. Faecal consistency may be altered; however, assist veterinarians in practice to diagnose infec- diarrhoea is nearly never observed. Furthermore tions with this parasite. Further, this is the first time Wenker et al. (1998) revealed regularly decreased that ultrasonography is described in this context. 154 Veterinarni Medicina, 57, 2012 (3): 154–162 Case Report Case description Case 1 In summary, seven lamas that have been referred The first two animals were male lamas which to the Clinic for Ruminants at the University of were kept as companion animals on one farm. The Veterinary Medicine in Vienna from five differ- animals had contact to small ruminants and swine. ent herds are presented. Four of these animals An endoparasitic treatment had been performed by were transferred to the Institute of Pathology and the owner with albendazole and doramectin. One Forensic Veterinary Medicine at the University of of the two animals (lama 1) had a history of de- Veterinary Medicine, Vienna for further exami- pressed attitude, increased lying times, difficulties nation. In the course of the post mortem exami- to rise and decreased appetite. Another animal on nation, samples from different organs have been the farm had already died with similar symptoms. taken and fixed in 4 % buffered formaldehyde so- The second lama (lama 2) was referred to the clinic lution. For histological examination, tissues were as a companion for lama 1. routinely embedded in paraffin, cut into 5 μm Lama 1. Clinical examination of this eight year thick slices and stained with haematoxylin and old lama revealed depression, poor body condi- eosin (HE). tion, enhanced vesicular breathing sounds with Table 1. Blood analysis of five lamas with a Dicrocoelium dendriticum-infection Lama Parameter Reference* 1 3 5 6 7 Red blood cell count Erythrocytes (1012/l) 10.9–14.3 10.38 13.74 10.39 8.99 10.77 Haemoglobin (mmol/l) 8.27–10.26 7.1 8.1 7.5 6.2 6.6 Haematocrit (l/l) 0.29–0.39 0.42 0.36 0.34 0.29 0.32 MCV (fl) 24.8–29.2 40.2 27.0 32.8 32.5 30.0 MCH (fmol) 0.66–0.73 0.68 0.60 0.73 0.69 0.61 MCHC (mmol/l) 24.8–26.7 16.9 22.4 22.0 21.3 20.5 White blood cell count Leucocytes (109/l) 9.7–16.1 37.7 12.7 12.4 24.3 9.7 Non-segmented granulocytes (%) 0–2.3 0 0 0 0 0 Segmented granulocytes (%) 42.4–73.5 95.5 81.5 75.1 93.0 55 Lymphocytes (%) 8–32.5 3.3 12.6 12.5 4.0 35 Monocytes (%) 1.5–6.0 0.7 1.7 1.1 2.0 1 Eosinophiles (%) 5.8–27.7 0.4 3.0 10.5 0 9 Basophiles (%) 0–1 0.5 0.3 1.0 0 Non-segmented granulocytes (109/l) 0–0.3 0 0 0 0 0 Segmented granulocytes (109/l) 4.62–11.19 35.97 10.42 9.27 22.58 5.34 lymphocytes (109/l) 1.09–4.28 1.24 1.61 1.54 0.97 3.4 Monocytes (109/l) 0.18–1.13 0.26 0.22 0.14 0.49 0.10 Eosinophiles (109/l) 0.8–3.7 0.15 0.38 1.3 0 0.87 Basophiles (109/l) 0–0.12 0 0.06 0.04 0.24 0 Values outside the normal range* are bold outlined *Hengrave Burri et al. (2005b) 155 Case Report Veterinarni Medicina, 57, 2012 (3): 154–162 Table 2. Results of blood metabolite measurements of six animals with diagnosed Dicrocoelium dendriticum infections Lama Parameter Reference* 1 3 4 5 6 7 Total protein (g/l) 58–69.3 73 – – – – – AST (IU/l) 177–285 729 562 – 251 188 – GGT (IU/l) 27.1–51.5 793 810 – 29 202 31 GLDH (IU/l) 6–50.3 442.7 292.1 – 87.44 75,2 8.88 CK (IU/l) 49–556 – 953 – – – – Bilirubin (µmol/l) 0.21–1.38 8.38 3.25 – 1.37 1.88 0.0 Urea (mmol/l) 6–10.2 23.7 23.0 105 6.5 – – Creatinine (µmol/l) 123.8–179.7 335.93 344.7 6.49 167.96 – – Values outside the normal range* are bold outlined *Hengrave Burri et al. (2005b) – = not examined rustling and a holosystolic heart sound at auscul- The animal was treated orally with albendazole tation. Activity of the compartments could not be (Valbazen 10%-Suspension, Fa. Pfizer Corporation detected. The consistency of faeces was normal. Austria, Vienna) at a dosage of 10 mg/kg body Blood gas analysis showed a mild acidosis with a weight twice within a five day interval. Fourteen pH of 7.29 and a base excess of 3.7 mmol/l. Results days after the second treatment, D. dendriticum of additional blood examinations are shown in eggs could still be found in a moderate amount Tables 1 and 2. within the faeces. After another administration of a Ultrasonographic examination revealed the ac- higher dose of albendazole (15 mg/kg body weight) cumulation of anechogenic fluid in the pleural and the egg count was increased. abdominal cavity as well as signs of pericarditis. Therefore, therapy recommended by Wenker and Within the liver bile ducts appeared highly echoic, others (1998), utilising 50 mg of oral Praziquantel/kg although no appreciable acoustic shadows could be body weight (Cestocur 2.5%-Suspension, Fa. Bayer, seen. The liver parenchyma appeared homogeneous. Leverkusen, Germany) was performed. A parasito- The parasitological examination of the faeces logical control revealed a considerable reduction revealed gastrointestinal strongylides, Capillaria in the shedding of D. dendriticum eggs via faeces. spp., Eimeria spp. as well as D. dendriticum. The lama was sent back home to the owner. Two This animal died and a post mortem examina- years later no clinical signs of dicrocoeliosis could tion confirmed a poor body condition, ascites and be seen in the lama and another parasitological a mild hydrothorax. Small liver flukes could be seen examination revealed mild D. dendriticum shed- macro- and microscopically within the bile ducts. ding (107 eggs per gram faeces). Furthermore, the histological examination of the liver revealed a cirrhosis and moderate fresh necro- sis. High calcifications of renal tubuli and proteinu- Case report 2 ria could also be seen. The heart showed a mild fibrotic pericarditis and a mild right- and left heart The lamas from the second case report originated hypertrophy as well as myocardial degeneration from a farm where the animals were used for trek- with a reactive inflammation.
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