Verminous haemorrhagic dermatitis is a
filariasis of
cattle marked by a cutaneous haemorrhagic nodule. It is referred sometimes to as "summer wound" (
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
''Sommerwunden'').
It is caused by infestation with the nematode ''Parafilaria bovicola''. Transmission involves fly
vectors of the genus ''
Musca'', which ingest
microfilaria
::''Microfilaria may also refer to an informal "collective group" genus name, proposed by Cobbold in 1882. While a convenient category for newly discovered microfilariae which can not be assigned to a known species because the adults are unknown, ...
e when feeding on the skin lesions.
The disease has been reported in
Bulgaria,
France,
Germany,
Morocco,
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
,
Tunisia, and especially
South Africa.
In Germany, the nodules are known to develop on the upper side on the body. In Morocco, the haemorrhagic lesions are mainly seen on the belly, neck and forelimbs, where it can lead to a wide plages of subcutaneous necrosis, with swelling of the arm.
Ivermectin is efficient for individual treatments of the illness. But surgical excision, although very haemorrhagic, is far more efficient.
A similar disease, sometimes referred to as ''Cascado'', occurs in
Asia (
Indonesia,
Malaysia) and is caused by ''Stephanofilaria'' species.
Epidemiology
Epidemiology differs among the countries in which it has been reported, and is dependent upon temperature and rainfall patterns, and the subsequent multiplication of the fly vectors.
In Germany, the verminous nodules start in May and June, 2 to 4 weeks after the beginning of pasture feeding. They heal spontaneously in October and November.
In Morocco, the disease is observed in years when heavy rainfalls occur in March and April. Numerous cases are then observed in April and May, in the immediate surroundings of the ponds. Some cases will heal spontaneously, but some others lead to wide subcutaneous lesions which require a veterinary treatment. The repartition and gravity of the skin lesions suggests that the causative agent may be slightly different from the one observed in Western Europe.
[Lucien Mahin, Observations on diseases of cattle in Morocco, 1977-2008, unpublished data.]
External links
Related page of the Merck Veterinary Manual
References
Bovine diseases
Veterinary helminthology
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