Friday, May 28, 2010

eimeria macusaniensis-Commonly known as EMAC in Alpacas

The most commonly read BLOG,
so this is more common than most of us are aware.
I thought i would publish a few more interesting documents on this subject.
I was very lucky enough to be able to have known a great man, Paul Presidente, who was the Parasite expert for Australia, with a special interest in Alpacas.
He was able to guide me through the maze of womrers etc, when we first started doing Quarantines, as New Zealand require the alpacas to have Zero count of all worm eggs, and Oocysts.
Paul died suddenly, as he walked to his car after work one night, he spent all hours there, i could be rining him up at 9pm at night with a question, and he undoubtedly was at work.
He was so dedicated, knowledgable and thankfully he was eager to tell you and help you with any problem that may arise.
He was also considerate enough to inform me of any new updates with parasites.
Thanks Paul.
I will never forget you, and you could never imagine how much your advice has helped me, and others.
I still refer to his notes from time to time.
Extracted from, MAF (New Zealand), Survellience Notes, July- Sept 06.
Register of new host-parasite records
Eimeria macusaniensis in an alpaca
Of the at least four coccidial parasites known to infect llamas and
alpacas, namely Eimeria lamae, E alpacae, E punonensis and
E macusaniensis (1)(2), only the first three have previously been
recorded in New Zealand(3). However, in July 2005 oocysts of
E macusaniensis were detected in the faeces of a ten-year-old female
alpaca on a property in Otago. Oocysts of this coccidian species, which
are readily recognisable by their dark brown colour and pyriform
shape, measure 81-100 μm long by 60-80 μm wide. They also have
thick oocyst walls (approximately 8-12 μm thick) and an obvious
micropylar cap (Figure 1). Eimeria macusaniensis is considered by
some to be highly pathogenic in alpacas(4). However, although this
coccidian may have the potential to cause death and disease in both
young and adult camelids, the regularity with which it is likely to do
so may have been somewhat overstated.
Lamanema chavezi in llamas and
During the performance of routine faecal egg counts on llama
and alpaca samples from a property in Canterbury, some rather
unusual worm eggs were detected. Although these resembled those
of Nematodirus in size (measuring 175 x 76 μm), they differed from
them in being more flat-sided and having a morula in a further stage
of development than the typical eight-cell-stage normally associated
with freshly excreted Nematodirus eggs. They also had an obvious
yellowish-brown colouration atypical of those of eggs of members
of this genus, apart, perhaps, from those of N battus, which have
been variously described as ‘markedly brown’(5) or ‘coffee coloured’(6)
(Figure 2). Similar eggs were subsequently detected in the faeces of
a further five llamas and alpacas from the same property.
Incubation of the worm eggs showed that they completed their
development to the third larval stage while still within the egg
(Figure 3). However, even after more than 30 days at 27oC very few
larvae had actually hatched. Development to the third larval stage
while still within the egg is characteristic of two known nematode
genera of camelids, Nematodirus and Lamanema. Examination of
the third-stage larvae isolated from these eggs showed that they were,
at 700 μm long, considerably shorter than those of Nematodirus
The following are some new host-parasite relationships
recently recorded at Gribbles Veterinary Pathology
laboratories or submitted to the author, for initial or
second opinion identifications, by other veterinary
diagnostic laboratories or persons in New Zealand.
(Sorry Pictures will not come over to this file)
Figure 1: Oocyst of Eimeria macusaniensis
Figure 3: Freshly passed suspected Lamanema egg
Figure2: Embryonated suspected Lamanema egg containing
third-stage larvae
Figure 4: Suspected Lamanema third-stage larvae
species and that they lacked the long whip-like tail sheaths typical
of members of this genus (Figure 4). Accordingly, based both on
the morphological features of their eggs and their third-stage larvae,
as well as the idiosyncrasies of their embryonic development and
delayed hatching, it was deduced that these eggs and larvae were
likely to be those of Lamanema chavezi.
Lamanema chavezi is a small (8-18 mm long) nematode of uncertain
taxonomic status(7)(8). It is also the only member of the genus and
appears not to have been previously recorded outside of South
America. Although believed to be a characteristic helminth of
South American camelids, being found in the small intestines of
alpacas (Vicugna pacos), llamas (Lama glama) and vicunas (Vicugna
vicugna)(9), L chavezi has also been recorded in the chinchillid rodent
Lagidium viscacia in Argentina(10). It is considered to be the most
pathogenic nematode parasite of South American camelids(9) and
is a rather unique trichostrongyloid in that the parasitic third- and
fourth-stage larvae undergo an enterohepatic migration(11). However,
no obvious clinical signs of infection were evident in the llamas and
alpacas on the Canterbury property.
Other new helminth parasite records in
llama and alpacas
Based on the identification of adult worms recovered following
anthelmintic treatment from the faeces of llamas and alpacas
on the same Canterbury property as above, a number of other
nematode parasites were recorded in these hosts in New Zealand
for the first time. In llamas, these included Nematodirus
spathiger, Camelostrongylus mentulatus, Cooperia oncophora and
Trichostrongylus colubriformis. Another species of Trichostrongylus,
T vitrinus, was also recorded in the alpaca here for the first time.
Oxyuris karamoja in a rhinoceros
A nematode recovered from the perineal region of a white
rhinoceros (Ceratotherium simum) at Hamilton Zoo was identified
as Oxyuris karamoja. This parasite is somewhat similar to the horse
pinworm, Oxyuris equi, except that it is smaller (1-7 cm long) and
has a coarsely striated cuticle at the cephalic end and three hookshaped
teeth that protrude into the buccal cavity(12). Like O equi,
this species probably causes an anal pruritus in the rhinoceros
resulting in restlessness and improper feeding. The life cycle is direct
and infection is by the ingestion of infective eggs.
Syngamus trachea in a hihi
Small numbers of eggs of the nematode Syngamus trachea were
detected in the faeces of a stitchbird (hihi, Notiomystis cincta) from
the Mount Bruce National Wildlife Centre. Apart from this finding,
the parasite has previously been recorded in a variety of other
domesticated and wild birds in New Zealand including chickens,
pheasants, partridges, finches, blackbirds, starlings, silvereyes, kea,
kaka and kiwi(13)(14)(15)(16)(17). The main pathogenic effect of this parasite
is asphyxiation, seen clinically as ‘gapes’, but in heavy infections
migration of larvae through the lungs may cause clinical disease. Its
life cycle is direct but earthworms may act as transport hosts.
Heterakis gallinarum in a guinea fowl
The caecal nematode Heterakis gallinarum was recovered from
a guinea fowl (Numida meleagris) in the Hawke’s Bay. Although
previously unrecorded in this host, it has already been documented
in a number of other birds in this country(13)(18) and may be
widespread and common, at least in domestic fowls. Generally it
is a parasite of limited pathogenicity and its importance is mainly
related to the part it plays as a carrier of Histomonas meleagridis, the
causal agent of ‘blackhead’ (enterohepatitis).
(1) Guerrero CA. Coccidia (Protozoa: Eimeriidae) of the Alpaca Lama pacos.
Journal of Protozoology 14, 613-6, 1967.
(2) Guerrero CA, Hernandez J, Bazalar H, Alva J. Eimeria macusaniensis n.sp.
(Protozoa: Eimeriidae) of the alpaca Lama pacos. Journal of Protozoology 18,
162-3, 1971.
(3) McKenna PB. Register of new host-parasite records. Surveillance 28(1), 4-5,
(4) Lenghaus C, O’Callaghan MG, Rogers C. Coccidiosis and sudden death in an
adult alpaca (Lamas pacos). Australian Veterinary Journal 82, 711-2, 2004.
(5) Thomas RJ. A comparative study of the life histories of Nematodirus battus
and N. filicollis, nematode parasites of sheep. Journal of Parasitology 49, 374-
86, 1959.
(6) Jansen J. Where does Nematodirus battus Crofton and Thomas, 1951, come
from? Veterinary Record 92, 697-8, 1973.
(7) Rickard LG, Hoberg EP. Reassignment of Lamanema from Nematodirinae to
Molineinae (Nematoda: Trichostrongylidae). Journal of Parasitology 86, 647-50,
(8) Hoberg EP, Lichtenfels JR, Rickard LG. Phylogeny for genera of Nematodirinae
(Nematoda: Trichostrongylina). Journal of Parasitology 91, 382-9, 2005.
(9) Cafrune MM, Aguirre DH, Rickard LG. First report of Lamanema chavezi
(Nematoda : Trichostrongyloidea) in llamas (Lama glama) from Argentina.
Veterinary Parasitology 97, 165-8, 2001.
(10) Sutton CA, Durette-Desset M-C. Contribucion al conocimiento de la fauna
parasitologica Argentina XIV. Presencia de Lamanema chavezi Becklund, 1963
(Nematoda, Molineidae, Nematodirinae) parasito de camelidos en Lagidium
viscacia boxi. Bulletin du Museum national d’Histoire naturelle Series 7
Section A 4, 791-4, 1985.
(11) Guerrero CA, Rojas M, Alva J. Lamanema chavezi, an enterohepatic nematode
of South American camelidae and its control using levamisole. Revista
Latinoamericana de Microbiologia 23, 121-3, 1981.
(12) Skrjabin KI, Shikhobalova NP, Lagodovskaya.E.A. Oxyurata of animals and
man: Part one Oxyuroidea. In: Skrjabin KI (ed). Essentials of nematodology. Pp
1-599. Israel Program for Scientific Translations, 1974.
(13) Weekes PJ. Checklist of helminth parasites of birds in New Zealand. New
Zealand Journal of Zoology 9, 451-60, 1982.
(14) Orr MB. Animal Health Laboratory Network: Review of diagnostic cases - April
to June 1990. Surveillance 17(3), 29-31, 1990.
(15) Goold M. Fungal infection and concurrent giardiasis in a kaka. Kokako 1(2),
5-6, 1994.
(16) Jacob-Hoff R. Kiwi parasite survey. Kokako 5(3), 12, 1998.
(17) Anon. Syngamus trachea. Surveillance No.1, 19, 1977.
(18) Weekes PJ. Two nematodes from a wild brown quail. New Zealand Journal of
Zoology 10, 126, 1983.
Read next post which details a little bit more on EMAC

No comments: