FECAL EGG COUNTS: A VALUABLE TOOL

Anthelmintic Resistance

Anthelmintic (dewormer) resistance in cattle is much less critical than it is in small ruminants, though it certainly is present, and growing, in the industry. The more exposure a parasite population has to a dewormer class, the more resistance it will display. This means that if a producer is only using one dewormer class on their operation, and using it often, the parasites that are present both in their animals and on their pastures are likely displaying resistance to that dewormer. In order to protect the dewormers that are still working, diagnosis of parasitisms must be determined via fecal egg counts, and only individual animals treated rather than the whole herd.  More about the fight against anthelmintic resistance.

Fecal Egg Counts: A Valuable Diagnostic Tool

Fecal Egg Counts are the best tool for monitoring intestinal parasites and a standardized estimation of amount of parasites that are in our animals. This process remains one the most efficient and affordable methods for diagnosing parasites in cattle and can help producers determine which animals require deworming and which animals can be left untreated. See the test modification for cattle using our Small Ruminant Test Kit.

Targeted treatments Deworming animals based on treatment thresholds [see table below]—rather than on convenience or blind dewormings— can save producers a lot of money by reducing unnecessary treatments. On a typical cattle operation, 80% of the parasites are going to be found in 20% of the animals (the “80:20 Rule”), so, generally speaking, if a producer is deworming their entire herd, they are wasting money on treating 80% of their animals. Not only is there money wasted for unnecessary treatments, but every time a dewormer is administered, resistance to that dewormer is increased in the parasite populations, termed “anthelmintic resistance”. This dewormer resistance will eventually render any of the dewormers that are available useless if they continue to be administered needlessly and blindly. We see this problem in the small ruminant and camelid industry and will eventually see it in the cattle industry if we do not curb the problem now. 

Another useful application for fecal egg counts is using them to make culling decisions. If an animal consistently has a high egg count and must be repeatedly dewormed, a producer can make the decision to get rid of that animal based on repeated fecal egg count results. The 80:20 Rule can also be applied, and culling the 20% of animals that carry most of the parasites on your operation will get rid of the majority of your worm problem. 

Treatment Thresholds and Treatment Targets for Cattle

A treatment threshold is a generalized table of fecal egg count spread displayed in eggs per gram of feces (EPG) that is used to determine if an animal has a high enough parasite burden to warrant treatment. Using a treatment threshold will help to reduce and slow anthelmintic (dewormer) resistance that will arise on your operation. Each time a dewormer is administered to a population of parasites, resistance to whatever product is used will be compounded; meaning each time you deworm the same population of parasites on your operation using the same dewormer, more and more resistance is being built against the dewormer with each administration, eventually rendering the product useless. The generalized treatment threshold for cattle is laid out in the table.