Giardia in a selected population of dogs and cats in Germany - diagnostics, coinfections and assemblages.

Infections with the zoonotic endoparasite Giardia duodenalis are widely spread among dogs and cats worldwide. Since the question whether the infection might be transmitted from domestic animals to their owners is still an important topic, a reliable detection of patent Giardia infections and the determination of the associated Giardia assemblages is of major concern. The objectives of the present study were to determine the prevalence of Giardia infections in dogs and cats living in Germany using different diagnostic tests and to identify the Giardia assemblages of infected animals. Furthermore, a possible correlation of coinfections with other endoparasites was analysed. All samples were investigated by enzyme-linked immunosorbent assay (ELISA), merthiolate-iodine-formalin concentration technique (MIFC) and zinc chloride flotation. ELISA-positive samples were additionally screened with a direct immunofluorescence assay (IFA). Faecal DNA was extracted from all Giardia cyst-positive samples and used for multilocus sequence typing with nested PCRs targeting the following gene loci: SSU rRNA (SSU), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi). Samples from dogs and cats tested positive for Giardia coproantigen (ELISA) in 30.6% and 17.9%, respectively. The MIFC technique revealed Giardia cysts in 33.9% of canine and in 34.6% of feline ELISA-positive samples, while using IFA, cysts were present in 90.4% of canine and in 76.9% of feline ELISA-positive samples. Coinfections with other endoparasites besides Giardia were found in both dogs and cats, yet a statistically significant correlation could solely be drawn for the canine samples. The success rate of the different PCR protocols varied between 23.1% (tpi) and 91.3% (SSU) for dogs and between 25.0% (gdh) and 90.0% (SSU) for cats. Dog-specific Giardia assemblages C and D were detected in 42 and 55 canine isolates, respectively. The cat-specific Giardia assemblage F was detected in 14 feline isolates. Two canine and two feline samples harboured the zoonotic assemblage A. According to the results of the study, Giardia is a common endoparasite in dogs and cats from Germany. The exclusive application of MIFC is insufficient for a reliable identification of patent Giardia infections since the IFA revealed a higher sensitivity for the detection of Giardia cysts in feline and canine faecal samples. Even though the majority of investigated animals harboured the species-specific Giardia assemblages C, D and F, a zoonotic potential arising from assemblage A could not be excluded.

Clinical features of canine granulocytic anaplasmosis in 18 naturally infected dogs.

BACKGROUND: Anaplasma phagocytophilum, the causative agent of canine granulocytic anaplasmosis (CGA), is a Gram-negative intracellular organism transmitted by ixodid ticks. Thus far, only a few clinical studies evaluating dogs with CGA have been published. OBJECTIVES: Evaluation of dogs naturally infected with A. phagocytophilum in which known co-infections were excluded. ANIMALS: Eighteen dogs with CGA. METHODS: Prospective study. The diagnosis of CGA was based on a positive PCR test result; dogs with co-infections were excluded. History, clinical findings, CBC, clinical biochemistry, infectious disease screening, diagnostic imaging, and the course of disease were evaluated. RESULTS: CGA was diagnosed based on a positive PCR test for A. phagocytophilum; 10 dogs also had morulae in neutrophils. Six of 18 dogs were seronegative to A. phagocytophilum, the others were seropositive. All dogs were acutely ill. The most common clinical findings were lethargy, inappetence, fever, and splenomegaly. Abnormal laboratory results included thrombocytopenia, anemia, lymphopenia, hypoalbuminemia, and abnormally high plasma alkaline phosphatase activity. In 6 of 10 dogs tested, the platelet-bound antibody test was positive; Coombs' test was negative in 9 dogs. All dogs were treated with doxycycline and recovered. PCR testing as well as blood smear analysis for morulae were negative in 14 tested dogs 2-8 weeks after beginning treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Clinical findings in dogs with CGA were nonspecific. Positive platelet-bound antibody test results suggest immune-mediated platelet destruction as an important pathogenic mechanism. With correct diagnosis and treatment, prognosis is good.

The molecular characterisation of Giardia from dogs in southern Germany.

Faecal samples were obtained randomly from asymptomatic dogs visiting veterinary clinics (kept individually) and sanctuaries (kept in groups) in southern Germany. Of 60 Giardia positive samples, 55 samples successfully amplified at the 18S rDNA locus. In both dogs kept individually and dogs kept in groups, assemblage A was most prevalent (overall, n=33, 60%), followed by mixed infections with assemblages A&C (overall, n=15, 27.3%), while assemblages C&D alone were less often detected (overall, n=5, 9.1% and n=2, 3.6%). The occurrence of zoonotic genotypes was more prevalent in individual than in group dogs. Genotyping at the gdh locus confirmed the 18S results and clustered the assemblage A isolates into A-I. This is the first large-scale urban survey in Central Europe, which has not only confirmed the high prevalence of Giardia in asymptomatic domestic dogs, but has also shown that the zoonotic assemblage A occurs commonly in domestic dogs living in urban environments, and more frequently than the dog-specific assemblage. Although it was not possible to obtain samples from pet owners in this study, the results demonstrate that a significant proportion of dogs in urban areas of southern Germany harbour zoonotic Giardia, and should thus be considered a potential reservoir for infection in humans.

Anaplasma phagocytophilum in dogs in Germany.

A total number of 111 dogs were included in the present prospective study investigating the prevalence of Anaplasma phagocytophilum in dogs in Germany. Dogs were divided into two groups. Dogs of group 1 (n = 49) showed clinical and/or haematological signs seen in infections with A. phagocytophilum, whereas those of group 2 (n = 62) did not have any evidence of anaplasmosis. For each dog, an A. phagocytophilum 16S rRNA-nested polymerase chain reaction (PCR) of ethylenediaminetetraacetic acid (EDTA)-anticoagulated whole blood analysis, a microscopic evaluation of a buffy coat and a serum indirect fluorescent antibody test (IFAT) were performed. Forty-eight seroreactive dogs were identified altogether, which amounts to an overall point prevalence of 43.2%. There was no significant difference between the seroreactivity to A. phagocytophilum antigens among group 1 (44.9%) and 2 (41.9%) (P > 0.5). Seven dogs (6.3%) had positive PCR results. All of them were seroreactive. Six belonged to group 1. Morulae in neutrophilic granulocytes were found in two dogs of group 1 but in none of group 2. Both dogs were seroreactive. Very high antibody titres (> or =1:1024) were detected significantly more frequently in dogs with clinical signs attributable to infection with A. phagocytophilum (group 1) than in those without (group 2) (P < 0.001). There was no significant correlation of overall positives or antibody titres to age, breed, sex, or whether the dogs were family or working dogs. Dogs with high tick infestation were significantly more often seroreactive to A. phagocytophilum than those with no or low tick infestation (P = 0.007). In conclusion, there seems to be a high risk of infection with A. phagocytophilum in Germany. Results of this study suggest that severe illness solely caused by A. phagocytophilum may be possible although definitive evidence does not exist. Very high antibody titres (>1:1024) may be associated with clinical anaplasmosis.

Embryogenesis and the first-stage larva of Thelazia lacrymalis.

The female reproductive system of Thelazia lacrymalis (Nematoda: Thelaziidae) was investigated by light and scanning electron microscopy (SEM) with regard to the developmental stages and the stage deposited by the gravid nematode. Female T. lacrymalis have a didelphic and opisthodelphic type of reproductive system with paired ovaries, oviducts and uteri and a single vagina and vulva. Round and spindle-shaped primary oocytes are documented within the ovaries and oviducts, respectively. The distal part of each uterus provides a fertilization chamber filled with spermatozoa, followed by a sphincter-like part. Further anterior, the uteri broaden gradually containing dividing zygotes, small and large morulae, tadpole-stage embryos and horseshoe-shaped embryos which increase in length and become slimmer forming pretzel-stage embryos and larvae rolled up. The larvae stretch gradually and finally lie straight but still covered with their egg membrane in the vagina. The egg membrane encloses the whole larva and is enlarged at the pointed tail of the larva forming a bulb. At the SEM level, the first-stage larva is shown to have a terminal mouth and three hooks directed posteriorly and a striated cuticle. As morphologically identical larvae were also found in lavages of the conjunctival sac of horses infected with T. lacrymalis, this nematode species can be described as ovoviviparous.

[Endoparasitic fauna and incidence of species in yearling and adult horses in Upper Bavarian breeding farms with regular anthelmintic prophylaxis lasting for many years]. / Endoparasitenfauna und Befallshäufigkeit der Arten bei Jährlingen und erwachsenen Pferden in oberbayerischen Zuchtbetrieben mit jahrelanger, regelmässiger Anthelminthikaprophylaxe.

In this epidemiological study 127 horses from five breeding farms in Upper Bavaria were included. The horses were coproscopically examined in intervals of four weeks over a 16-month period. Since 1992 in all farms regular prophylactic treatments with anthelmintics have been carried out. In 127 horses at least five species were established, such as Parascaris equorum, Anoplocephala perfoliata, Gasterophilus intestinalis and small strongyles, whose third stage larvae were characterized by eight or twelve intestinal cells. Infections with small strongyles occurred most frequently, followed by G. intestinalis, A. perfoliata and P. equorum. Seven horses excreted eggs of P. equorum, three yearlings, and a two, four, five and seven year old animal, each. 113 of the 127 examined horses showed infections with strongyles, hence, almost all animals of the farms I-V. The evaluation of horses with strongyle infections as regards to the frequency of the coproscopically established eggs revealed a high incidence independent of age. The maximal epg-values showed no obvious age-dependent differences varying between < or = 67 and 3733. The horses excreted strongyle eggs with epg-values of > or = 333 predominantly during the summer. With an epg-value of > or = 333, independently of age the 23 horses treated with Ivomec-P as well as 20 of the 24 horses given Banminth remained coproscopically negative three to four weeks after treatment. The animals treated with Rintal or Panacur continued to excrete strongyle eggs three to four weeks following the anthelmintic application. The use of anthelmintics in horses with epg-values < 333 revealed analogous results. Infections with A. perfoliata were established in all farms, altogether in 32 horses independently of the age of the animals. Eggs of G. intestinalis have been observed only in two farms, but almost in all horses there.

[Endoparasites of donkeys and horses kept in communal housing in Upper Bavaria; species spectrum and incidence]. / Endoparasiten von Eseln und Pferden bei gemeinsamer Haltung in Oberbayern: Artenspektrum und Befallshäufigkeit.

In this epidemiological study of endoparasites 37 donkeys and 23 horses were included, which were examined coproscopically in regular intervals over a 15 month period. The animals derived from ten farms, in which regular prophylactic treatments with anthelmintics had been practiced at least for two years before this investigation. This study revealed the presence of at least twelve parasite species in donkeys, Eimeria leuckarti, Gasterophilus intestinalis, Fasciola hepatica, Anoplocephala perfoliata, Strongyloides westeri, Parascaris equorum, Dictyocaulus arnfieldi, Trichostrongylus axei and small strongyles, whose third stage larvae were characterized by eight, twelve, 16 or 18 intestinal cells. At least four parasite species were established in horses, E. leuckarti, G. intestinalis, P. equorum and small strongyles, whose third stage larvae were provided with eight intestinal cells. Infections with E. leuckarti, S. westeri and P. equorum were encountered in foals only and with D. arnfieldi in 16.2% of the donkeys. Incidences for small strongyles were highest, exhibiting neither age- and farm-dependent nor host species-dependent differences and amounting to 91.9% in donkey and 86.6% in horses. Considering all donkeys and horses, 35.1% and 43.5%, respectively, were infected at least with two, and 29.7% and 4.3%, respectively, with three parasite species. The species composition of the endoparasite fauna was always dominated by small strongyles. This field study indicates that the species composition of the endoparasite fauna in comparison to former investigations has not or only slightly changed in spite of widespread use of broad-spectrum anthelmintics for years. In addition, it has to be considered that donkeys continue to act as reservoir of D. arnfieldi and as source of infection for horses.

[Spectrum of species and incidence of endoparasites in foals and their mother mares from breeding farms with and without anthelmintic prophylaxis in upper Bavaria]. / Artenspektrum und Befallshäufigkeit von Endoparasiten bei Fohlen und ihren Mutterstuten aus Zuchtbetrieben mit und ohne Anthelminthika-Prophylaxe in Oberbayern.

In this epidemiological study 37 foals and mares were included, which have been coproscopically examined in regular intervals over a period lasting up to 13 months. The animals derived from nine breeding farms. In three of these farms no anthelmintics were used before this investigation, whereas in six farms at least three years before regular prophylactic treatments with anthelmintics have been carried out. This investigation revealed no differences in the species spectrum of endoparasites as well as in the incidence of infections as regards to the breeding farms with and without anthelmintic prophylaxis, however, significant differences between foals and mares. At least nine species were established in foals, Strongyloides westeri in 54.1% of the animals, Parascaris equorum in 64.9%, small strongyles, whose third stage larvae showed either eight or 12 intestinal cells, in 83.8%, Anoplocephala perfoliata in 16.2%, Eimeria leuckarti in 64.9%, Giardia in 5.4%, Cryptosporidium parvum in 2.7% and Gasterophilus intestinalis in 21.6%. Parasitic infections with two or more species were found in 83.8% of the foals. The species spectrum of endoparasites in mares from breeding farms without anthelmintic prophylaxis consisted of at least three species of small strongyles, whose third stage larvae were characterized by eight, 12 or 16 intestinal cells. In mares from breeding farms practising regular anthelmintic prophylaxis, however, at least seven species were ascertained, the same small strongyles, P. equorum, A. perfoliata, E. leuckarti and G. intestinalis.

[Incidence of Parascaris equorum in foals and their mares after strategic use of wide-spectrum anthelmintics for several years]. / Zur Befallshäufigkeit von Parascaris equorum bei Fohlen und ihren Mutterstuten nach jahrelangem planmässigen Einsatz von Breitspektrum-Anthelminthika in Zuchtbetrieben.

In this epidemiological survey 30 foals and their mares from seven breeding farms were investigated. Six farms used wide spectrum anthelmintics strategically at least for three years, on one farm no anthelmintic prophylaxis was practiced. Excretion of P.-equorum-eggs occurred in all breeding farms and in 80% of the foals, but in only one mare. In foals infection with roundworms was detected at the earliest 85 days post partum. Before first shedding of P.-equorum-eggs wide spectrum anthelmintics had been administered to two and to one foal(s) one and two times, respectively, to four animals three times and to one foal each four, five, six and seven times. After metaphylactic use of wide spectrum anthelmintics in the control of an infection with roundworms or other helminths, eggs of P. equorum were found in one foal already 12, 17, 54, 55, 70 and 71 days after treatment with Ivomec-P each and 65 days after use of Panacur in one foal. After application of Banminth roundworm eggs were detected 12, 27, 45, 47, 49 and 62 days in one foal each and 19 and 56 days in two foals each. In eight foals each P.-equorum-eggs were noticed 72 and 196 days after anthelmintic treatment.

[Eimeria leuckarti infections in foals and their mothers in upper Bavaria]. / Eimeria-leuckarti-Infektionen bei Fohlen und ihren Mutterstuten in Oberbayern.

In this epidemiological study 30 mares and their foals from seven farms in Upper Bavaria were investigated. Eimeria-leuckarti-oocysts were found in 24 foals (80%), but only in one mare. Oocysts were first detected 28 days post partum at the earliest and 191 days post partum at the latest. In foals, excretion of oocysts usually occurred intermittently with coproscopically negative intervals of up to 15 weeks, and was most frequent in June (8 foals), July (17 foals), and August (10 foals). With the exception of two animals which had mild diarrhoea, the oocyst-shedding foals showed no clinical signs.

[Trichomonad infections of the oral cavity in horses in southern Germany]. / Trichomonaden-Infektionen der Mundhöhle bei Pferden in Süddeutschland.

Trichomonads of the oral cavity were found in 9 of 60 investigated horses. Apart from dental tartar, the oral cavity showed no clinical signs in all positive horses. The clinical investigation of these horses additionally revealed colic in 4 and coughing in 4 horses as well as lumbago in 1 animal. By means of scanning electron microscopy the trichomonads were shown to be round or piriform with an average length of 7.6 microns and greatest width of 6.3 microns. They had 4 anterior flagella with an average length of 8.3 microns, an undulating membrane measuring 8.7 microns with no trailing flagellum as well as an axostyle extending on average 7.8 microns beyond the body, and therefore have to be placed into the genus Trichomonas.

[Fauna and incidence of endoparasites in kittens and their mothers from different husbandry situations in south Germany]. / Fauna und Befallshäufigkeit von Endoparasiten bei Katzenwelpen und ihren Müttern unterschiedlicher Haltung in Süddeutschland.

In this epidemiological study 100 litters of Southern Germany were investigated. 70 litters were kept on farms and 30 litters originated from mother cats kept indoors. At least 9 species were detected in litters from farms, 77.1% of these litters were infected with T. cati, 1.4% with hookworms, 10% with Capillaria, 10% with H. taeniaeformis, 67.1% with I. felis, 48.6% with I. rivolta, 17.1% with Toxoplasma/Hammondia, 4.3% with C. parvum and 1.4% with Giardia. In litters kept indoors only 5 species were established. 3.3% were infected with T. cati, 46.6% with I. felis, 33.3% with I. rivolta, 6.6% with Giardia and 3.3% with C. parvum. Analogous differences as regards to the keeping conditions existed also for the mother cats.

[Trichomonad infections of the oral cavity in cats in south Germany]. / Trichomonaden-Infektionen der Mundhöhle bei Katzen in Süddeutschland.

In this investigation trichomonads were isolated from the oral cavity in 21 of 110 examined cats, and only from those which were simultaneously FeLV, FIV or FIP positive. By means of scanning electron microscopy the trichomonads were shown to be round or piriform parasites which were on average 7.9 microns long and 6.2 microns wide at maximum width. They had 4 anterior flagella, which were on average 9.4 microns long, an undulating membrane measuring 6.7 microns with no trailing flagellum as well as an axostyle extending on average 5.0 microns beyond the body, and therefore should be attributed to the genus Trichomonas.

Morphology and structural organization of Haller's organ during postembryonic development of Argas (Persicargas) walkerae (Ixodoidea: Argasidae).

Scanning-electron-microscopic investigations of Haller's organ in larvae, nymphs I, II, III and IV, and male and female adult Argas (Persicargas) walkerae ticks showed that morphology and structural organization change during postembryonic development. Stage-dependent differences existed regarding setal numbers of the anterior pit as well as formation and reticulation of cuticular projections in the capsule cavity. The anterior pit increased in size in the course of postembryonic development. It contained only seven setae in larvae, one conical, setiform and grooved seta each as well as two porose and fine setae. Nymphs I, II, III and IV adult ticks had equal numbers of setae; however, one additional unilaterally serrate and grooved seta each were present. Setal length increased continuously during postembryonic development and attained maximum values in adult ticks. The capsule consisted of roof and cavity and was located distinctly lateral in larvae, slightly lateral in nymphs I and II, and in all other stages directly on the longitudinal axis of tarsus. The capsule roof showed a reticular structure. The slit-like main aperture was located peripherally and arranged transversally to the longitudinal axis of tarsus I in larvae. Nymphs and adult ticks had a central, circular main aperture. Stage-dependent cuticular projections of varying form protruded into the capsule cavity. Larvae had only single, free-standing projections which ramified slightly and communicated with each other. Projections were more heavily reticulated in nymphs I and II. In nymphs III and IV as well as male and female adult ticks, a long centrally situated tube of reticular appearance was seen, which was supported by a large number of radially organized and interlocking pillars and communicated with the capsule roof. In all tick stages there were always four porose setae present, arranged on the capsule floor.

Investigations on the host seeking and finding of Argas (Persicargas) walkerae (Ixodoidea: Argasidae).

In investigations concerning the influence of stimuli emitted by chickens on the host-finding behaviour of hungry female adult Argas walkerae ticks, we found that 92.5% of the ticks migrated to the stimulus source following their simultaneous exposure to odours and to a CO2 gradient increasing in the direction of the chicken, as opposed to 67.5% following their exposure to kairomones of chickens in the absence of CO2. Migration of the ticks toward the stimulus source was precipitated by a wide range of CO2 concentrations (varying from 0.06 to 1 vol% within the odour mixture) but always required an increasing CO2 gradient in the direction of the chicken, whereby differences in concentration of 0.01 vol% over a distance of 2.5 cm were sufficient. During exclusive confrontation with either CO2 or heat in a gradient otherwise analogous to that emitted by a chicken, only 27.5% and 55% of the female ticks migrated to the stimulus source, respectively. Accordingly, odours emitted by chickens are considered to represent an essential stimulus modality, whereas body heat and CO2 are regarded merely as secondary, non-specific stimulatory agents. Investigations involving the exposure of ticks to a habitat similar to a chicken roost revealed that host seeking and finding are not influenced by gravity and occur only in darkness and that the portion of host-finding ticks diminishes with increasing distance from the blood donor.

[Multimorbidity in aged dogs and cats]. / Altersmultimorbidität bei Hund und Katze.

As in humans, an increase in the incidence of concurrent diseases occurs in dogs and cats with age. To some extent considerable species specific differences occur; the dog is affected more than the cat. In advanced age more chronic diseases are observed as in humans. The following diseases show a particular predisposition in aged dogs and cats: The dog exhibits especially non-inflammatory skin diseases, cardiopathies, chronic diseases of the respiratory tract, oral cavity, liver, kidneys and urinary tract, diseases of the CNS, and tumours, whereas the cat suffers from the leukaemia complex, to a lesser extent from non-inflammatory skin and cardiac diseases, also from chronic diseases of the oral cavity, gastrointestinal tract, liver, kidneys and urinary tract, endocrine system, and tumours.