Ascaris

Ascaris is a genus of parasitic nematode worms known as the "small intestinal roundworms"

Morphology of Ascaris:

• Adult: cylindrical shape, creamy white or pinkish in color
• Male: average 15–30 cm and is more slender than female
• Female: average 20–35 cm in length.

Pathogenesis :

  Main pathologic events occur during pre patent stage.

-          In heavy infection, the migrating larva may cause severe damage & mechanical destruction

-          Hypersensitivity and allergic reaction.

-          The fibrotic liver after inflammation heals, gives rise to so called “Milk spot” or “white spot” lesions &  made whole liver unfit for human consumption.

-          Hemorrhage may occur in liver & in most cases lung.

-          Lung hemorrhages can be followed by desquamation of alveolar epitheliums, edema & infiltration of the eosinophils & other cells in pulmonary parenchyma.

-          Extensive lung lesions give rise to clinical signs of severe respiratory embarrassment (thumps) where breathing is rapid, shallow & marked by forcible expiratory efforts & cocarisughing & pigs may die.

-          Death from severe lung damage in 15 days after infection.

-          Numerous adult parasites may form a bundle and create intestinal obstruction.

-          Ascarids may wander and cause vomition, biliary obstruction in bile duct thus biliary stasis and can produce peritonitis.

-          Adlt may create diarrhoea by interference with proper nutrition and normal growth.

Clinical sign

-          Depends on severity of infection.

-          Severe respiratory distress in growing pig.

-          Malnutrition and lesions of interstitial pneumonia.

-          Hepatic fibrosis & diarrhoea in some case.

-          Pneumonia in heavily infected newborn pigs especially a cough & exudates into the lungs.

 

Diagnosis

-          Clinical & necropsy findings.

-          Demonstration of  larva in sputum in early stage.

-          Presence of Ascaris egg in the faeces. (Sometimes due to coprophagia pigs may shed egg in feces without having adult in their intestine, thus  false positive result can occur)

Treatment

-          Migrating larva is not affected by anthelminties.

               For adult

- Piperazives       100-400 ng/kg with food.

- Dichlorlos        orally @ 10 mg/kg.

-          - Leuamisole   

-          Regular anthelmintic medication.

-          Good sanitation at furrowing.

-          Limited access of baby pig to contamination.            

Source

• healthline.com
• Wikipedia.org
• Cvasu Parasitology Notes
• Medical Parasitology