Internal Parasites In Beef Cattle
Beef cattle are at risk for internal parasites and this is particularly true for animals that
graze in pastures. The parasitic levels vary for every pasture however, and are dependent on the species of cattle.
These are some documented facts regarding internal parasites and beef cattle.
• If a pasture is heavily stocked the risk of internal parasitic involvement is
• Beef cattle from a drylot show fewer infestations of internal parasites than those animals kept in pastures.
• Young cattle are known to present with more internal parasites than their older counterparts.
Cattle farmers and herd owners should understand what problems are caused by internal parasites and be familiar
with the most common types.
Effects of Internal Parasites on Beef Cattle
The effects of any internal parasites will depend on the degree of infection, and the age and
condition of the affected animal. Cattle that develop parasitic infections can show one or more of the following
• Decreased productivity of milk
• Lack of weight gain
• Rough coat
• Spontaneous abortions or infertility problems
• Decreased energy
• Listless behavior
Animals with Greatest Risk of Internal Parasite Infection
The most likely cattle to be infected with one or more internal parasites are
• animals that are under stress, especially during early lactation
• cattle that are very young
Most mature bovines will have developed a level of immunity to most of these internal parasitic
Internal Parasites that are a Threat to Cattle
Beef cattle can fall victim to a number of internal attackers including Helminths and Protozoans. The most common
threat is from the Helminths or “worms”.
• roundworms (or nematodes)
• tapeworms (or cestodes)
• flukes or (trematodes)
Economic Threat is Greatest with Roundworms
The Roundworms are one of the most crushing threats economically to the livestock owners in many states. There are
2 common roundworms that create the most problems;
• the brown stomach worm
Although the tapeworms and flukes can be a problem with some herds they do not present as much of
an economic threat because the effect on the cattle is less. Flukes are only a problem if the snail population is
allowed to expand because these worms need the snail to complete their life cycle.
It is obvious that an internal parasite can be a big concern with any beef cattle herd. The roundworms have a life
cycle that makes it possible for one or two infected animals to spread the worms to the entire herd. Internal
infestations are often difficult to notice in the early stages which means by the time the problem is recognized
other animals will have been exposed and possibly infected. Understanding the causes, knowing the effects created
by internal worms, and taking preventive measures for your animals will decrease your chance of having to deal with
these potentially devastating parasites. If internal parasites should occur within your beef cattle herd there are
some specific ways that you can handle the problem so that you can minimize your losses.