A snapshot of 3 cattle health challenges you need to be thinking about in the warm weather
By Rhonda McCurry
Deworming is not a new animal health protocol but it very well could be the most important one for livestock owners.
Though it’s always been an issue, during the past ten years controlling parasites and implementing parasite resistance has been an even bigger concern for ranchers. Even sheep, goat and horse owners must incorporate deworming practices – and never overlook this routine. Due to the impact of parasites over the past 40 years, animal health companies have dramatically changed and improved deworming products.
And while there has been new information and products to help with parasite issues Jody Wade, senior field veterinary consultant with Boehringer Ingelheim Animal Health, says deworming will continue to be a major concern for the livestock industry.
Due to the work of well-known parasitologists such as Craig Reinemeyer from East Tennessee Clinical Research and Ray Kaplan from University of Georgia College of Veterinary Medicine, ranchers now recognize parasite resistance is here to stay. Without routine testing and veterinary intervention in client animals regardless of the specie, Dr. Wade says the issues will only continue to get worse.
The big problem with parasite control comes down to resistance.
“Anthelmintic resistance is an inevitable consequence of the use of anthelmintics (parasite control products that expel worms and other internal parasites from the host) over time,” Dr. Wade says. “Resistant parasites have genes that protect them from the effects of the anthelmintic. The parasites may be resistant to one or multiple products at the same time.”
Dr. Wade says ranches can also acquire anthelmintic‐resistant parasites with herd additions. Anthelmintic resistance is usually suspected when a deworming protocol fails to give the expected production responses. However, poor performance or clinical signs of parasitism that don’t improve following deworming should not immediately be interpreted as a failure of the product. Wade says to remember other factors including proper product storage, proper product administration, dosage and route.
“Diagnostic testing is required to determine the existence and extent of parasite problems and anthelmintic resistance on each ranch,” Dr. Wade explains. “Quantitative fecal egg counts are essential in determining the magnitude of parasite problems and the fecal egg count reduction test (FECRT) can be used to estimate anthelmintic resistance.”
Parasite control is not the only economic loss factor in beef cattle production. Bovine Respiratory Disease Complex (BRDC) accounts for huge, annual economic losses for every aspect of beef cattle production. Therefore, it is very important for veterinarians and cattlemen to understand the complexity of this disease so that quick recognition and treatment can be implemented along with other disease prevention protocols.
Respiratory systems in cattle are vulnerable to BRDC because of the size, structure and mechanics of the bovine lung. Cattle have 25-percent less lung than any other mammal of equal size.
The BRD complex of viruses includes acronyms most ranchers are familiar with, including Infectious Bovine Rhinotracheitis Virus (IBR); Bovine Respiratory Syncytial Virus (BRSV); Bovine Viral Diarrhea Virus (BVD) and Parainfluenza 3 Virus (PI 3). IBR, BRSD, BVD, and PI3 have received the most attention and appear to be the most significant contributors to BRDC. There are three primary bacteria that contribute to this disease as well: manheimia hemolytica, pasteurella multocida and histophilus somnus.
In cattle operations, pure single infections with any of these viruses or bacteria are rarely observed. However, Dr. Wade says mixed infections are much more common with the end result being BRDC. Vaccination of cattle theoretically pre-exposes the animals to the viruses before they can become infected with the natural disease-causing counterparts.
“Vaccination is the only preventative means available to fight viral infection,” Dr. Wade explains. “Stress detracts from the animal’s ability to mount an immune response, so though it is necessary, vaccination may still not be enough.”
Dr. Wade says one of the diseases ranchers deal with is a Clostridial disease known as Blackleg. Clostridium species are an anaerobic, spore-forming, rod shaped, Gram-positive bacteria that produce potent exotoxins that enhance the disease. This particular bacteria (Clostridium chauvoei) is found in soil, and once ingested into the intestinal tract of animals Blackleg can remain viable in the environment for many years on the farm. Other clostridial diseases ranchers should educate themselves about include, Malignant Edema, black disease, black neck, red water disease, botulism, enterotoxemia (overeating disease) and tetanus.
“The usual routes of infection are through contamination of a wound or ingestion of the bacteria,” Dr. Wade shares. “The need for pre-infection vaccination is of critical importance in controlling clostridial diseases because past history has shown that treatment is usually of poor consequence.”
Though some of these clostridial diseases are uncommon, they can occur. Dr. Wade says clostridial vaccines are readily available in many combinations and are very effective especially when administered at frequent intervals.
Ranchers should be aware carcass blemishes may result from clostridial vaccines even when given to young animals many months before slaughter. Therefore, he says, vaccines should be given only in the neck region and at the lowest volume possible.
As always ranchers should follow the manufacturer’s label and consult their veterinarian to help put an effective vaccination protocol together.
“Always consult your local veterinarian to see what issue, disease or problem is impacting your region of the country,” Dr. Wade adds. “Don’t think routine deworming and parasite control should be tapered off. These diseases will wreak havoc on your animals and your pocketbook.”