Lymphatic dwelling filarioid nematodes in reindeer Rangifer tarandus tarandus, (cervidae) in Finland, identified as Rumenfilaria andersoni Lankester & Snider, 1982 (nematoda: Onchocercidae: Splendidofilariinae).

A filarioid nematode inhabiting the lymphatic vessels of the subserosal rumen and mesenteries associated with a high prevalence of its microfilariae in peripheral blood was observed in Finnish reindeer (Rangifer tarandus tarandus) in 2004 and 2006. Adult specimens were collected by dissecting lymphatic vessels from slaughtered animals, where some of the nematodes were seen through the wall of the dilated vessels as thin white winding threads obscuring the vessel. The morphology of adult worms and microfilaria is described based on light and scanning electron microscopy. These filariae belong to the subfamily Splendidofilariinae of the Onchocercidae and resemble Rumenfilaria andersoni, recovered from different host and localization, the ruminal veins of Alces alces in Canada. Comparison of paratypes of this species revealed only minor differences which were not sufficient to separate the filarioid parasitic in R. tarandus in Finland and we identify the nematode as R. andersoni. However, the findings suggest two different parasite populations. The finalizing of this taxonomic question in the future requires an integrated approach, in which the DNA-based and morphological identifications are consistent.

Setaria tundra microfilariae in reindeer and other cervids in Finland.

Harmful parasites of the wild northern boreal mammals are still surprisingly poorly studied. In 2003-2006, a peritonitis outbreak caused by the filarioid nematode, Setaria tundra, emerged in Finland's reindeer population. In order to gain knowledge about the basic biology, epidemiology, and transmission dynamics of this parasite, samples for S. tundra were collected from reindeer and other cervids during the follow-up period 2004-2006. Using morphology and molecular biology methods, we describe here S. tundra's first larval stage, microfilaria (smf), for the first time scientifically. The prevalence and densities of smf were higher in reindeer calves than in adults, overall prevalence being 42%. The overall smf prevalences for moose, wild forest reindeer and roe deer were 1.4-1.8%, 23%, and 39%, respectively. The focus of microfilaremia moved north and settled down in the south simultaneously with the peritonitis outbreak. The peak microfilaremia occurred in the first summer after the infection, and smf disappeared from the blood after 2 years. Captive reindeer were smf positive over the year. The prepatent period of S. tundra was estimated to be about 4 months, and the life span at least 14 months. This parasite likely has an important impact on boreal ecosystems.

Outbreak of parasitic peritonitis in reindeer in Finland.

In 2003, there was an outbreak of peritonitis in reindeer in the southern and middle part of the Finnish reindeer herding area caused by the filarioid nematode Setaria species. In the province of Oulu, the proportion of reindeer viscera condemned owing to parasitic lesions increased from 4.9 per cent in 2001 to 40.1 per cent in 2003. In 2004, the focus of the outbreak moved approximately 100 km north. A total of 260 adult and pre-adult Setaria species nematodes were collected for morphological and molecular studies. The parasite was indistinguishable in terms of morphology and molecular biology from Setaria tundra. Samples of parasites were also collected from wild cervids. In elk, only a few cases of pre-adult encapsulated S tundra nematodes were detected on the surface of the liver but there was no peritonitis. Two roe deer had S tundra nematodes in their abdomen but no peritonitis. Of 34 wild forest reindeer, 21 had changes associated with S tundra. At meat inspection of the affected reindeer carcases, the changes observed included ascites, green fibrinous deposits, adhesions, and live and dead S tundra nematodes. There were histological lesions of granulomatous peritonitis with lymphoplasmacytic and eosinophilic infiltration. No specific bacterial growth was found. The parasitic infection had no significant effects on the pH or the organoleptic quality of the meat. There was a significant positive correlation between the worm count and the degree of peritonitis (P<0.001) and a negative correlation between the degree of peritonitis and the thickness of the back fat layer (P=0.015).

The morphology of the filaroid nematode Setaria tundra, the cause of peritonitis in reindeer Rangifer tarandus.

In Finland during 2003-2005, large numbers of nematodes, tentatively identified as Setaria sp., were observed in the peritoneal cavity of reindeer Rangifer tarandus during a peritonitis outbreak associated with poor body condition. The morphology of worms recovered from slaughtered reindeer is described based on light and scanning electron microscopy. Worms were confirmed as belonging to the superfamily Filarioidea by the presence of microfilariae-producing females and the size and the shape of the male spicules. Further classification to the genus Setaria was based on the location of worms in the peritoneal cavity and the morphology of spicules and the peribuccal crown. The present measurements correlate with those in the description of Setaria tundra by Rajewsky (1929) and only minor differences were present compared with descriptions of key parts of identification of S. yehi from the American white-tailed deer Odocoileus virginianus and mule deer O. hemionus. Current morphological findings support our earlier studies employing a polymerase chain reaction and confirm the occurrence S. tundra in reindeer in Finland.

Canine intestinal helminths in Finland: prevalence, risk factors and endoparasite control practices.

In this survey, the prevalence of canine gastrointestinal helminths in Finland was investigated by coprological examination (n = 541) and possible risk factors for helminth infections in dogs were analysed. In addition, the dog owners (n = 296) completed a questionnaire about use of anthelmintics, sources of information about parasites and antiparasitic treatments and reasons for choosing the drugs. The prevalence of gastrointestinal helminths was 5.9%. Eggs from four different species were identified in the faecal samples. Toxocara canis eggs were present in 17 dogs (3.1%), Uncinaria stenocephala eggs in 14 dogs (2.6%) and Diphyllobothrium latum eggs in 2 dogs (0.4%). Moreover, one sample contained eggs of Trichuris vulpis (0.2%). Kennel housing and visits abroad were identified as risk factors for T. canis and U. stenocephala infections. Most dogs (86.0%) received anthelmintic treatment at least once a year. Hunting dogs were dewormed least; one-third was treated less than once a year. Approximately, half of the owners occasionally changed the anthelmintic used. The most important trait of the anthelmintic was its broad spectrum, fenbendazole being the most commonly chosen. Veterinarians, dog magazines and dog breeders were the predominant sources of information concerning parasites and deworming strategies.

Redescription of Besnoitia tarandi (Protozoa: Apicomplexa) from the reindeer (Rangifer tarandus).

Besnoitia tarandi tissue cysts were found in naturally-infected reindeer (Rangifer tarandus) from Finland. Infectivity of its tissue cysts, bradyzoites, and tachyzoites to animals and cell culture was studied. The bradyzoites and tissue cysts were not infectious to out-bred mice, rabbits or gerbils. When fed tissue cysts, neither cats nor dogs excreted oocysts. However, the parasite was lethal to interferon-gamma gene knock out mice irrespective of the route of inoculation. The parasite was grown successfully in African Green Monkey cells from tissues of two reindeer for the first time. Non-dividing, uninucleate tachyzoites from smears from cell cultures were 5.6 x 1.4 microm (4.5-7.4 x 1.0-1.9, n=50) in size. Longitudinally-cut bradyzoites in tissue sections measured 7.4 x 1.3 microm (6.5-7.8 x 1.0-1.6, n=30). Ultrastructurally, tachyzoites and bradyzoites were similar to those in other Besnoitia species, and in particular to parasites described from cattle (Besnoitia besnoiti) and equids (Besnoitia bennetti) in that their bradyzoites lacked enigmatic bodies. Based on comparative analysis of three portions of nuclear ribosomal DNA (the small and large subunits and the first internal transcribed spacer) B. tarandi was found to be more closely related to the other congeners described from ungulates. The parasite was formally redescribed and specimens deposited in the US National Parasite Collection.

Intestinal parasites in swine in the Nordic countries: prevalence and geographical distribution.

In Denmark (DK), Finland (FIN), Iceland (I), Norway (N), and Sweden (S), 516 swine herds were randomly selected in 1986-1988. Individual faecal analyses (mean: 27.9 per herd) from eight age categories of swine showed that Ascaris suum, Oesophagostomum spp., Isospora suis, and Eimeria spp. were common, while Trichuris suis and Strongyloides ransomi-like eggs occurred sporadically. Large fatteners and gilts were most frequently infected with A. suum with maximum prevalences of 25-35% in DK, N and S, 13% in I and 5% in FIN. With the exception of the remarkably low A. suum prevalence rates in FIN, no clear national differences were observed. Oesophagostomum spp. were most prevalent in adult pigs in the southern regions (21-43% in DK and southern S), less common in the northern regions (4-17% adult pigs infected), and not recorded in I. I. suis was common in piglets in DK, I, and S (20-32%), while < 1% and 5% were infected in N and FIN, respectively. Eimeria spp. had the highest prevalences in adult pigs (max. 9%) without clear geographical differences. I. suis and Eimeria spp. were recorded for the first time in I, and I. suis for the first time in N.

Ivermectin as a bird anthelmintic--trials with naturally infected domestic fowl.

To evaluate the use of ivermectin as a bird anthelmintic, 29 White Leghorn hens naturally infected with Ascaridia spp., Heterakis spp. and Capillaria spp. were treated with 0.2, 2 or 6 mg/kg intramuscularly or 0.2 or 0.8 mg/kg orally. Faecal samples were collected before treatment and at autopsy, 2, 6, or 16 days after treatment, when the intestines were also examined for helminths. None of the treatments gave satisfactory anthelmintic results.

[An aphasmid nematode in the ear capillaries of the reindeer, Lappnema auria n. gen., n. sp. (Robertdollfusidae)]. / Un nématode aphasmidien dans les capillaires de l'oreille du renne, Lappnema auris n. gen., n. sp. (Robertdollfusidae).

Lappnema auris n. gen., n. sp. induces the formation of large nodules on the ears of reindeer, Rangifer tarandus, in Finland; it occurs in subcutaneous capillaries of this organ. The morphology is degenerate. Females are viviparous, 5-6 mm long and 20-25 micrometers wide; infective larvae are almost 2 mm long and 10 micrometers wide. Males are unknown and spermatozoa have not been observed; parthogenetic reproduction seems likely. The genus is similar to Durikainema macropi Spratt and Speare, 1982, the only other aphasmidian from blood vessels and a parasite of marsupials in Australia.

Studies on Onchocerca tarsicola Bain and Schulz-Key, 1974 in reindeer (Rangifer tarandus) in northern Finland.

A survey revealed that Onchocerca tarsicola Bain & Schulz-Key, 1974 is a widespread parasite among reindeer in northern Finland. Of 407 animals studied from 12 reindeer herds, 124 (30.5%) were infected. There was a marked difference in infection levels between different reindeer herds and the frequency as well as the intensity of infection was highest in old animals whereas the parasites were rare in yearlings.

Generalized eosinophilic myositis with sarcosporidiosis in a Finnish cow.

A case of generalized eosinophilic myositis with sarcosporidiosis in a Finnish cow is reported. The whole carcass was condemned because of massive changes in skeletal muscles. Cat or man are the final hosts of Sarcocystis bovifelis or Sarcocystis hominis. The aetiology of eosinophilic myositis remains open and so does the question whether sarcosporidiosis has something to do with it.