When trying to choose the correct product for your livestock there are a number of factors to take into account to ensure you get optimal coverage for the right price all while reducing the risk of resistance on your farm. Our guide to parasite control should give you all the information you need to make the right choice for you.
What kind of wormer should I use?
Wormers are used to treat and control parasitic infections from roundworm, lungworm, tapeworms and liver fluke. These wormers (or Anthelmintics) can be categorised into the following groups.
Group 1: Benzimidazoles (BZ)
Group 2: Levamisole (Imidazothiazoles) (LV)
Group 3: Macrocyclic lactones, including avermactins and milbemycins (ML)
Group 4: Amino acetonitrile derivatives (Monepantel) (AD)
Group 5: Spiroindoles (SI)
Wormers in these groups are effective against all the major species or roundworm and lungworm, with some also being effective against liver fluke and tapeworms. Wormers from Group 3 (ML) both injectables and pour ons are effective against ectoparasites.
| Parasite | Information | Products |
| Gutworms | Worming is a necessity when trying to break the cycle of gutworms especially where cattle are grazing in infected areas. Treatment should aim to reduce the disease and minimise contamination of the pasture. Symptoms of gutworm can include diarrhoea, decreased appetite and loss of weight. Gutworm can cause severe damage to the stomach and small intestine which will cause parasitic gastroenteritis, this will not only negatively affect the health of the animal but will affect the profitability for the farmer. |
Macrocyclic Lactone (ML), Benzimidazoles (BZ) and Levamisole (LV) products are most commonly used in the treatment of gutworm. |
| Lungworms | Lungworm infection usually occurs in younger livestock in the later stages of the grazing season. Without adequate lungworm control cattle can me more susceptible to pneumonia. Symptoms of lungworm can include a short, sharp cough that becomes worse with exercise, in severe cases the animal will have obvious difficulty breathing. Lungworm infections cause a high susceptibility to respiratory viruses and bacteria. Infected cattle are prone to contracting severe bronchial pneumonia which if left untreated can lead to death. |
Macrocyclic Lactone (ML), Benzimidazoles (BZ) and Levamisole (LV) products are most commonly used in the treatment of lungworm. |
| Liver Fluke |
There are many factors to take into account when treating for liver fluke in cattle. In particular you should take into account the risk, the time of year and the stage of development of the fluke. You should always seek advice from a vet or responsible seller. If rumen fluke is suspected you should discuss your options with your vet as treatment is not always required and there are very few products that have an impact on rumen fluke. |
Different flukicides will kill different stages of the fluke life cycle so it important to chose the correct product for the stage you are treating for. |
| Ectoparasites | The spread of mange and lice is caused by close contact between the animals, this is why ectoparasites spread more easily at the time of housing cattle. Because ectoparasites are spread so easily it is important to control an outbreak by not only treating cattle with obvious signs but all animals that have been in contact. | Ectoparasites can be controlled using synthetic pyrethroids or Macrocyclic Lactone (ML) Products |
Combination Products
Products that combine both a wormer and a flukicide can seem like an easy option when treating cattle but there are some important questions to ask before choosing a combination product
Do the cattle need to be treated for both worms and fluke?
Is the wormer appropriate for the stages of worms you are treating against?
Is the flukicide appropriate for the stages of fluke you are treating against?
The problem of wormer resistance when treating cattle is a growing problem not only in Ireland but in countries all around the world. Resistance is not always obvious at first but the results can be detrimental to your herd. Resistance is caused by the continuous use of the same group of wormer every year. A combination of tightly monitoring your herd and a strict dosing routine should reduce the risk of resistance on your farm.
Signs of resistance on your land
How to prevent resistance
Choosing the correct product for the parasites you are targeting is essential. This will give predictable results which will lessen the chances of having to retreat. This will in turn save time, money and reduce the chances of resistance on your farm. Below are some essential tips to ensure you are treating your livestock properly. Which ever product and method of administration you choose it is essential to always follow the manufacturer's instructions carefully.
- Choose an appropriate product for the parasites you are targeting
- Make sure to store wormers appropriately, normally away from sunlight, away from extreme temperatures and sometimes in a fridge. All these details will be available on documents accompanying the wormers.
- Ensure all dosing equipment is clean, compatible with your choice of wormer and is measuring correctly.
- Dose according to liveweight to avoid under or over dosing
- Record everything properly. Product used, amount used, batch number, expiry date, animal id, treatment date and withdrawal periods
- Do not mix wormers together as this can cause the product to be inactive
Pour Ons
- Pour Ons should be applied accurately, each product will have its own instructions.
- Animals should not be treated when wet or if rain is expected, unless the product specifically says it is ok to do so
-Pour Ons and Spot Ons should be applied down the back line of the sheep, this ensures an even spread around the animals body
- Use appropriate and calibrated guns, always ensure to thoroughly clean all equipment after use
Injectables
- Clean and sterile equipment should always be used, if using the same syringe for multiple animals the needle should be disinfected between injections
- Use an appropriate sized needle for the animal you are injecting
- Make sure the animal is appropriately restrained before injecting
- For subcutaneous injections raise a fold of skin and inject into the space created, as shown in the diagram below
- For intramuscular injections you need to ensure that the product is being injected into the muscle and not being deposited under the skin, as shown in the diagram below.
- Dispose of used needles and syringes in an appropriate sharps container
Oral Drenches
- Ensure all drenching equipment is clean and calibrated
- Ensure the animal is restrained with their head held up
- Slide the nozzle of the dosing gun into the into the gap between the animals molar and incisor teeth and then over the back of the tongue.
