Website Display
Search Website
News & Articles
GAME INDUSTRY TRENDS ANALYSIS 2024
.jpg)
How And When To Dip, Deworm And Vaccinate Your Cattle
How and when to dip, deworm and vaccinate your cattle
By Prof Cheryl McCrindle | 9 December 2024 | 5:30 am
Livestock health management has evolved over the decades to include disease prevention and growing farm revenue. The most effective health management strategies are those that include dipping, deworming, and vaccinating animals. Prof Cheryl McCrindle takes a closer look at these practices.
Plunge dipping, though stressful and often dangerous for cattle, especially calves, remains a common practice on extensive farms and may be mandated and overseen by state veterinary services during outbreaks of notifiable parasitic diseases. Photo: FW Archive
Originally, livestock veterinarians treated sick livestock. In the 1970s, however, this changed to disease prevention and improving profitability through early diagnosis. The best disease prevention strategy is to develop a system for dipping, deworming and vaccinating cattle specifically aligned to your farming system.
Dipping
Dipping is the main method used for controlling external parasites in cattle. The word was derived in the early 20th century when ‘dipping’ meant chasing the herd through a crush-pen so each animal, in turn, plunged into a deep pit filled with water containing a tick-killing chemical (later called an acaricide).
It remained on the skin and controlled ticks and biting flies for a specified time after dipping.
These were called ‘dips’, even when administered topically or, in the case of ivermectin, by injection or orally. The period that each dip was effective for was used to calculate the dipping interval, or the number of days, weeks or months between dipping.
East Coast fever, a fatal tickborne disease that killed approximately 1,5 million cattle in Southern Africa, was eliminated in 1960 by a compulsory weekly dipping schedule that commenced in 1901.
Plunge dipping was dangerous and stressful. Young calves would often drown if they weren’t separated from the herd before entering the crush. Occasionally, adult cattle inhaled dip and battled to breathe. Each animal’s brand number was ticked off in the ‘dipping record’.
The state veterinarian or animal health technician came by at regular intervals to check this document. If discrepancies were found, cattle were slaughtered and their carcasses burnt.
These early dipping programmes eliminated ticks and tsetse flies and protected cattle against midges, mosquitoes and biting flies. Plunge dipping is still used on extensive cattle farms. It can be prescribed by law and supervised by the state veterinary services during outbreaks of notifiable parasitic diseases.
Although dip tanks are seldom used today, the word ‘dip’ is still used to describe poisons used to kill biting flies and ticks. Dip tanks have been replaced by spray races. Another popular approach is hand spraying, where a pressurised tank full of diluted insecticide is carried over a farmworker’s shoulder.
Hand dressing is used by small-scale farmers. They smear tick grease around the head and under the elbows and tail of the animal or use pour-on dips along the back of each one.
The ear tag number should be written down or recorded using a cell phone. Data can be checked electronically, alerting the farmer to livestock that may not have been gathered with the herd.
In large-scale feedlots and dairies, electronic ear tags are scanned into a computerised database after automated spray dipping. Records must be made available if there is an outbreak of a notifiable disease.
Despite the advances made to animal dipping, challenges remain. One such challenge is parasite resistance to specific acaricides. An increase in ticks indicates that they are developing resistance. Always record both parasite levels and species on cattle being dipped.
If tick burdens increase, you may need to increase the frequency or change the type of dip. Often, the changes are seasonal, and dipping intervals are shorter in spring and summer.
Frequency and diseases controlled with dipping
Cattle should generally be dipped at least three times, at weekly intervals, when transitioning to new pastures or during spring when tick larvae hatch and cling to the tips of grass blades in grazing paddocks. Table 1 (see above) lists the cattle diseases that can be controlled by dipping your animals.
Chemicals used in cattle dips
The chemical originally used to kill ticks and biting flies was arsenic. Chronic exposure led to sick cattle or workers. Later, DDT was used and can still be isolated from soil around traditional dip tanks.
Dip residues in the tissues and bloodstreams of cattle help to control livestock parasites; however, total levels of these residues are regularly tested and prohibited in meat and milk for human and animal consumption.
Modern dips include organophosphates, amitraz, cymiazole, cypermethrin, deltamethin, ivermectin, and albamectin, or mixtures of these chemicals. In addition, piperonyl butoxide 2% m/v is used for pour-on dips. Some of these are effective against external and internal parasites.
It is absolutely critical to read the enclosed instructions carefully and observe withdrawal times. This will prevent side effects in young livestock and pregnant cows, or meat and milk residues. Organophosphate dips are affordable and easily available over the counter at co-operatives.
As they are used mainly by small-scale farmers, no residue testing is done. However, selling milk or meat containing residues, even on informal markets, can result in prosecution.
Deworming
Dewormer is a general term for the medications used to prevent or treat internal parasites of cattle, including worms (helminths), liver fluke, and insects. Eggs of roundworms and some tapeworms are excreted in manure and come to the surface with new grass after rain.
In beef cattle, deworming is linked to the monitoring of worm egg counts in manure from different camps or age groups. Deworm all beef cows and calves in the same camp separately, just after weaning, as different dewormers are used for pregnant cows and weaned calves.
Dewormers used for cows must be safe for unborn calves, while those for weaners fattened for slaughter should not result in meat residues.
As dairy cattle calve throughout the year, they are dewormed after drying off to prevent residues in milk. Their calves are separated from them at birth, and deworming programmes are linked to regular faecal monitoring.
In the US, fenbendazole, ivermectin, levamisole, albendazole and oxfendazole are not approved for use in dairy cattle or dairy heifers of breeding age, because of possible residues. If crossbred calves are being raised for slaughter as veal, record all treatment dates to ensure correct withdrawal times (four to six weeks) before slaughter.
Underground and surface water can contain giardiasis and cryptosporidiosis, which cause chronic diarrhoea and slow growth. Treatment is expensive, but maintaining high water quality can help prevent infection.
Table 2 (see bottom of previous page) outlines the internal parasites that can be controlled through deworming or dosing dairy and beef cattle.
Vaccination
The efficacy of vaccination, rather than slaughter-out policies, was proven during the rinderpest virus outbreak that killed millions of cattle in 1896. Currently in South Africa, vaccination (instead of slaughter) is being used to control foot-and-mouth disease.
Vaccines contain modified live or inactivated antigens that promote immunity by preventing disease organisms from multiplying or neutralising toxins. Antigens include inactivated disease-causing organisms (viruses, bacteria, protozoa), modified toxins or genetic fragments (DNA or RNA).
The immune reaction occurs about 10 to 21 days after vaccination. After the initial dose, a booster (second vaccination) will increase immunity. Live vaccines are effective for a longer period or can even promote life-long immunity; however, inactivated vaccines are safer.
For certain protozoal diseases like heartwater and redwater, infected blood containing a modified live organism is carefully injected intravenously. The animal is then treated with an antibiotic after a specified number of days, to kill or reduce the numbers of the parasite.
Your vaccine programme should match the seasonal cattle diseases likely to occur in your area. Vaccination strategies depend on the production system used, the location of the farm, time of year, climatic conditions, withdrawal strategies and affordability.
Vaccinating feedlot cattle may result in lesions that cause parts of the carcasses to be condemned at slaughter. Some vaccines can influence milk production or pregnancy outcomes.
They may even be fatal if incorrectly administered. If there is an outbreak of a cattle disease for which there is no current vaccine, your veterinarian can help facilitate a unique vaccine for your farm.
Only registered vaccines should be used on livestock. Detailed instructions regarding the storage, expiry date, dose and administration route must be included on the label or package . Always check these instructions before vaccinating.
Only registered vaccines should be used on livestock, with storage, expiration, dosage, and administration information provided on the label or .
To prevent cross-infections or abscesses, it is essential to use a sterile syringe, as well as a new needle for each animal vaccinated. Routes of vaccine administration include subcutaneous (injected under the skin), intramuscular (injected into muscle) or intravenous (slowly injected into the jugular vein), but are sometimes given orally, intranasally (into the nose) or as eye s.
The recommended site for intramuscular or subcutaneous injections is under the skin on the side of the neck in front of the shoulder. Injecting above and behind the shoulder is only recommended for adult cattle. It’s a more convenient site for Afrikaner and Brahman cattle, particularly aggressive bulls.
Injecting vaccines into the hindquarter muscles can cause abscesses or even life-threatening infections. Disposable needles and syringes must be put into a sealed container after use and disposed of as ‘medical sharps’.
Vaccines are usually administered at specific times of the year, and the type and age of the cattle are important (see Table 3 above).
Sources: Gilfoyle, D. 2010. ‘Veterinary Research and the African Rinderpest Epizootic: The Cape Colony, 1896–1898’. Journal of Southern African Studies. Visit bit.ly/3ZFM6Zt; ‘Vaccines and Vaccinations: Production Animals’. University of Minnesota (accessed 2024). Visit bit.ly/3BmKKsh.
Contact Us
