Why dung sampling is important before dosing

Dung sampling your calves can save you money this grazing season, according to Vet Frank O’Sullivan.

He said it is an excellent practice to carry out as you’re not overexposing animals to anthelmintics and you’re saving yourself time and money.

“Another advantage of sampling is that sampling tells you if the wormer you used on an infected group actually worked,” he said.

Over exposure to anthelmintics can also cause problems such as parasite resistance to the drug.

Dung samples that test negative, especially where the animals appear healthy with no cough means that dosing is not necessary and this is where money is saved, O’Sullivan said.

The types of internal parasites farmers can expect to infect their young stock this year include Lungworms (Hooze) and stomach or gut worms.

Coughing in calves and yearlings at grass is one of the main symptoms of lungworm and this parasite should not be overlooked, he advises, even if the dung samples have tested negative.

“Lungworm is most damaging in the immature stage as it infiltrates the lung tissue (prepatent hooze).

“All lungworm, including adults, tend to elicit an inflammatory response in addition to physically blocking the airways, causing a husky cough in the animal. The animals can be in severe respiratory distress and may even die.”

Adult lungworm produce eggs in the airways. These eggs are coughed up by the animal, then swallowed sending larvae out onto pasture in faeces.

These larvae remain in the dung pats until wet and moist weather allow the parasites move throughout the pasture where they are ingested again. This completes the lungworm life-cycle.

Gut worms, on the other hand may cause ill thrift possibly with diarrhoea. O’Sullivan said that sampling should be carried out again after worming (10 days to three weeks depending on the wormer) to see if the wormer actually worked.

If there are worms still there, there could be a resistance problem to that specific wormer. If results are negative, the wormer has done its job.

Interpretation of results needs to consider many factors:

  1. 1. Are the animals grazing intensively? If they are the risk of parasites, lungworm and gut worm infection is increased.
  2. Is there currently wet warm weather following a period of dry weather? If so, lungworm risk will be high.
  3. Are there any other diseases or nutrition stressors on the animals (for example copper deficiency, BVD or shortage of grass)? These issues may allow the parasites have a significant effect.

“Not considering these factors along with the sample results could be detrimental. Control of parasites is part of the overall herd health plan that the vet and farmer agree on.”

Sampling costs in the region of €20-30 per group and covers fluke and most worms with lungworm perhaps costing that bit extra, he said and results are usually ready within the week.