Case Study: 'Visiting your vet can keep the parasites at bay'
Published 15/07/2014 | 02:30
Question: In mid-September, just after weaning, the suckler calves are scouring and not thriving as well as expected. They are grazing with the cows on permanent pasture and have not been dosed yet. What could be the problem?
Answer: There are a number of possibilities. Gutworms are high on the list.
By mid-June, worm eggs, even from the cows, will have hatched and developed into infective larvae (several cycles may have occurred by then).
With moisture and rain, the worms will have moved from dung pats onto the pasture. Close grazing will also increase the larval intake by the calves.
The condition is called parasitic gastroenteritis (PGE).Faecal testing of 10 to 15 dung samples (which may be pooled in the laboratory) will aid the diagnosis.
The dung samples should indicate if you have a heavy worm burden; a medium level of worms, or only a light or insignificant number of worms active on the pasture. Your vet will likely also consider secondary copper deficiency and coccidiosis as part of the possible diagnoses.
Be careful that lungworm levels may also be at critical numbers. If necessary, an appropriate anthelmintic (worm dose) with the appropriate product will deal with this problem. Your farm vet is best placed to advise on the most suitable product on your individual farm.
It is also possible to check the faecal egg counts after dosing to ensure there is no resistance to the anthelmintic used. Therefore, once the wormer has been administered and given time to have worked (say one week later), a random sampling of a few fresh dung samples should show a particularly low or zero egg count.
Also, second-year grazers may also need to be monitored to see that they are not also in trouble or are adding to the problem of massive egg numbers onto the grassland.
Question: In our suckler farm described above after housing in November, all the weanlings (both home-reared and bought in) are coughing persistently. What is causing this?
Answer: This is a tricky situation in that both virus pneumonia and lungworm are high on the list of differential diagnoses. Clinical examination plus laboratory testing will help the vet decide where the problem and solution lies. In fact, both diseases could be interacting. The bought-in weanlings are challenging the biosecurity on the farm and possibly introducing new viruses that are causing pneumonia. Extended grazing may also have increased the season for lungworm activity, so this may also need attention.
A herd health programme would likely prevent many of these diseases and keep the animals thriving well.
Question: Three cull cows are fattened for slaughter and the factory report live fluke in their livers.What does this mean?
Answer: Collection and communication of inspection results (CCIR) from the factory in this case has provided direct evidence that your cows are infected with fluke. It would be appropriate to faecal test other groups of stock and put a fluke management program in place. This may include some or all of the following:
"Draining or fencing-off some of the wetter areas and avoiding the poaching of a lot of those damper pastures;
"Strategic dosing in early summer to reduce the number of snails becoming infected. Also dose and quarantine any of the bought-in animals;
"Monitor fluke burdens both by faecal testing and from the factory liver reports. Always press your factory outlet to give you full feed-back on all postmortem findings on your stock.
"If yours is a mixed enterprise of sheep and cattle, then use the information from both factories to guide you on parasite burdens on the farm. Faecal sampling at an appropriate time after dosing with a flukacide will assist in assessment of resistance;
"Appropriate treatment of affected groups with a flukacide, followed by some post-dosing dung sampling, goes a long way to monitoring and controlling fluke infestation and fluke-dose efficacy on your farm.