Clinal sign Diagnosis & Treatment of Dictyocaulus viviparus

Pathogenesis of Dictyocaulus viviparus

Clinical Signs:

·         Mildly affected animals cough intermittently, particularly when exercised

·         Moderately affected animals  show

o   Frequent bouts of coughing

o   Tachypnoea (>60respiration per min)

o   On auscultation, squeaks and crackles sound will be heard over the posterior lungs lobes

·         Severely affected animals show:

o   Severe Tachypnoea (rapid breathing; polypnea) (>80 respiration per min)

o   Dyspnea (difficult breathing/shortness of breathing) and

o   Frequently adopt the classic ‘air hunger’ position of mouth breathing with the head and neck outstretched.

o   Deep harse cough and on auscultation, squeaks and crackles sound will be heard over the posterior lungs lobes

o   Salivation, anorexia and sometimes pyrexia.

o   Often the smallest calves are suffered more death may be found in 24-48hrs.

·         Animals recovers gradually, complete recovery takes weeks or months,

·         However, a portion of convalescing calves suddenly develops severe respiratory signs associated with pyrexia, which usually terminates fatally 1-4days later. (Post patent parasitic bronchitis) 

·         Older animals acquired a strong immunity in endemic areas.

Diagnosis:

• Clinical History
• The time of year
• Grazing on permanent or semi-permanent pasture
• Clinical signs
• Coproscopy
• Larvae count form feces (50-1000/g)

Treatment:

• Benzimedazole/ Levamisole/Avermectin (effective for all stages of lungs worms)

Control:

• Use of lung worm vaccine for immunizing the young calves.
• Live vaccine prepared by attenuation of larvae by irradiation
• Currently available in Europe
• Given orally at 8 weeks of age
• Two doses of vaccine are given at an interval of2- 4 weeks
• Regular deworming
• Prophylactic anathelmintics use
• Strategic anthelmintics use