Despite dry pasture conditions across the United States, internal and external parasites will continue to challenge beef cattle operations heading into fall and winter. An effective parasite control program in the fall can help cattle maintain body condition and make the most of purchased feedstuffs.

Boehringer Ingelheim Vetmedica, Inc., Professional Service Veterinarians from three key beef cow-calf regions share the following insights with cattle producers as they head into the fall:

·      Diagnostics:Internal parasites are hard to diagnose without proper diagnostic tests. Work with your herd veterinarian to find out what species of parasites are challenging your herd. The main species to control varies from region to region in the fall of the year.

·      Different ages of cattle have different challenges:  Younger animals such as calves and replacement heifers are the most susceptible animals in the herd to internal parasites. By the time cattle have passed their second grazing season, they have developed a degree of ability to control Cooperia species on their own.  Cattle do not appear to develop resistance to abomasal parasites such as Ostertagia (brown stomach worm) and Haemonchus.

·       Read the label: The types of parasites controlled and for how long vary from product to product. Read the label to ensure you are controlling the parasites challenging your herd and that you are administering the proper dosage.

Fall parasite control challenges vary from region to region. Professional Services Veterinarians with Boehringer Ingelheim Vetmedica, Inc. offer the following insights for beef producers in three regions of the country.

Northern High Plains

Dr. Jerry Woodruff, Senior Professional Services Veterinarian with Boehringer Ingelheim Vetmedica, says that producers in the Northern High Plains states are most concerned with control of external parasites, such as lice, as they enter the fall months leading into cooler weather.

“Louse infestations are a significant concern for northern producers heading into late fall,” says Dr. Woodruff. “Another concern is the brown stomach worm, which goes into an arrested development stage within the animal as winter approaches. Producers should select a parasite control program that is effective against external parasites, as well as the inhibited form of Ostertagia.”

Despite the dry pasture conditions, Dr. Woodruff emphasizes that a parasite load can still be present and reinfestation is possible. The types of parasite challenges vary somewhat depending on the age of the animal. Young stock face challenges from Ostertagia ostertagi (brown stomach worm), Cooperia and Nematodirus, while more mature animals are likely challenged by brown stomach worm.

Dr. Woodruff recommends that producers use a pour-on in late fall for cows and replacement heifers to help with any external parasite challenges. Bulls that are being wintered over could benefit from a parasite control treatment for internal and external parasites in fall and a repeat application in late winter, just before spring breeding season.

Dr. Woodruff encourages producers to work with their herd veterinarian to determine the types of parasites challenging the herd and select products with proven persistence and efficacy.