Anyone involved in cattle production is aware of the danger of internal parasites in cattle. Internal parasites, such as lung worms and coccidia, live in the gastro-intestinal tracts of cattle. They will cause decreased production and in some cases even death.
Through proper management you can get this parasites under control. The thing to remember is that cattle internal parasite control is not a once-a-year thought that only occurs before spring grazing. The different types of parasites will emerge at different times of the year so your management plan must be year round.
Now there are many different types that you can come across depending on your area but I will talk about 4 that are fairly common here in Texas. If you are not sure what types are common in your area I encourage you to talk with your local veterinarian.
The 4 types of cattle internal parasites
In order to make a solid animal health plan it is important to know what you are going dealing with. Now this is in no way is meant to replace a veterinarian’s knowledge.
Hairworms
The gastrointestinal tract of cattle is where you will find hairworms living and taking up space. These can also be referred to as stomach worms or intestinal worms.
These worms will mature in about 3 weeks at which time they will lay eggs. They are generally transmitted when soil temperatures are between 55 to 85 degs Fahrenheit. This parasite is more active during the rainy periods in spring. from April to June, and the month of October. They will hibernate during the colder months in winter, November through March. The higher temperatures and the nutrient depletion that occur during July through September will kill these parasites.
How they are spread
These worms can be spread in these conditions:
- Infected cattle pass eggs in manure onto the ground
- The eggs will then hatch in the manure
- Rain then washes the eggs from the manure onto the grass
- Then cattle will swallow the larvae that are on the wet grass during moderate temperatures
Clinical signs of infestation
Signs of infestation can be:
- Pale mucous membranes
- Bottle jaw
- Pot belly
- Diarrhea
- Not grazing
- Not Chewing cud
- Rough and dry haircoat
- Weakness and inability to stand
Methods of Control
Maintaining good nutrition is the most important way to control hairworms in cattle. When cattle have a well balanced diet with enough protein, vitamins, and minerals fewer worms are able to be established. Your cows are also better able to withstand the effects of these worms when their nutritional needs are being met.
In order to maintain good nutrition:
- Rotate pastures regularly
- Prevent overcrowding and overgrazing
- Provide good quality pasture, hay, and supplements
As with any internal parasite it is important that you use the right de-wormer at the right time of year to get the best results. For stomach worms this means administering the drugs 3 to 6 weeks after their optimal conditions are present.
Lungworms
Lungworms will cause a lung disease in your cattle with clinical signs that are very similar to what you would see with viruses, bacteria and allergies.
Proper timing with a de-wormer is very important in the way of controlling this disease. For liver flukes you need to administer these drugs 4 to 6 months after the parasite’s optimal conditions are present.
The way that they transmit from cattle to cattle and how to control them are the same as with hairworms. Lung worm disease will often occur in previously unexposed cattle such as with calves or cattle that have been moved.
Liver Flukes
Cattle that are living in wetter areas with a more alkaline soil type may develop liver fluke infections.
How they are transmitted:
- Infected cattle, deer, and rabbits pass eggs in the manure and drop the manure in the water.
- The eggs will then hatch in the water and the larvae will develop into snails
- Cattle then swallow the cysts that get on grass or hay
Clinical signs of infestation
Signs of digestive inefficiency are shown in young cattle with acute liver disease. In the older ones it is present with chronic liver disease. They will also show signs that are similar to those with malnutrition and hairworms.
Methods of Control
Treatment for this internal parasite during late summer, such as August 15 to September 1, will eliminate the flukes that were acquired during the spring and early summer. The best treatment is to time administering during the weak point in it’s life cycle, the adult stage.
Another option that you can use is to either drain or fence off any wet areas that are on your place. This can prevent cattle from being exposed to the fluke’s carrier: the snail. Though in some cases this may not be practical for every producer.
Coccidia
This parasite can cause an intestinal disease in young cattle, usually 3 weeks to 6 months old. Though it has been know to affect cattle up to 2 years old
How they are transmitted:
- Infected cattle pass cysts in manure onto the ground
- Rain will then wash the cysts from the manure
- The cysts will then develop under moist and moderate conditions
- Cattle then swallow the cysts on the moist ground
Clinical signs of infestation
Transmission is common during rainy times in spring and fall. A problem with diagnosis is that the diarrhea caused by coccidia can be confused with the diarrhea caused by hairworms, bacteria, and viruses. So getting checked by your local veterinarian is the only way to know for sure.
Methods of control
Wormers are ineffective against coccidia. The drugs that are labeled for this are amprolium, such as Amprol and Corid; decoquinate, such as Deccox; lasalocid, such as Bovatec; and sulfonamides.
After 1 week of optimal conditions has occurred give the drug in either feed or water for 2 weeks to calves in a manure contaminated environment such as haying or feeding areas. Other methods of control are similar to that for hairworms.
Importance of Strategic deworming
As was mentioned earlier in order to be effective deworming is not a once-a-year type of treatment. Really when to deworm depends on certain conditions for the internal parasite to thrive. So it is always important to talk with your local vet to develop the right schedule to be the most effective.
A general rule of thumb that is used is to deworm cattle in the spring before they move onto the new pastures so they do not bring the parasites with them. Then you will deworm again in the fall in order to get the ones that they may have picked up since then,
With the amount of treatments that cattle will be getting it is important to prevent any possibility of resistance developing. A way that you can do this is by rotating the dewormer that you will be using. The main thing to know about this is that you shouldn’t just change the brand name but what the active ingredient is.
Here is a table I found from the Texas AgriLife extension service that covers the different types and what they will treat.
Courtesy of Texas AgriLife Extension
If you would like to learn more about making your operation be more efficient and profitable then check out my e-book “Nuts and Bolts of Successful Ranching”.
