Synonyms

No known synonym

Name of the disease in English

Onchocerciasis-Worm nodule diease

The disease in brief

Onchocerca spp. is a parasite very present in tropical and subtropical zones; the parasite is also present in Europe sporadically. The microfilariae present in the blood are ingested by biting midges (Culicoids, Simulium) at the time of their blood meal. The parasites evolve in the insect and are transmitted to another bovine during a blood meal. Inapparent infestation is widespread and the clinical and economic consequences of the parasite are limited.

Clinic & diagnosis

We suspect the disease when we observe small nodules (1 cm) in the thickness of the skin, especially on the lower half of the body or on the limbs.

Typical sign of the disease

No description

Pictures

See below

Diagnostic formulas

No description

Differential diagnosis

-Bovine parafilariasis DR15

-Stephanophilariasis N302

-Demodicosis DR34

– Ulcerative lymphangitis caused by Corynebacterium pseudotuberculosis -N311

-Atypical Mycobacteria dermatitis N303

Confirm a suspicion?

Biopsy 1cm2 of the nodule tissue to place in 10% formalin, for histological examination.

Prognosis and treatment

Treatment is with ivermectin at a dose of 200µg/kg body weight.

Prevention

No specific prevention of this parasite; controlling insect populations around cattle could help limit the spread ofOnchocerca but is quite illusory given the species in question.

References

-Veterinary Medicine-Pocket companion -9th Edition BLOOD DC-page 492