Symptom Identification and Prevention Methods for Foot-and-Mouth Disease in Cattle and Sheep
Foot-and-mouth disease, commonly known as “aphthous fever” and “epidemic aphthae,” is an acute, febrile, highly contagious infectious disease. In our daily lives, it mainly affects cloven-hoofed animals such as pigs, cattle, and sheep. Because this disease is extremely contagious and has a very high mortality rate in calves, Qinnong Network now introduces the causes, symptoms, and related prevention and control measures of this disease to everyone, hoping to bring some help to farmers.
I. Pathogenesis of Foot-and-Mouth Disease
During the infection and onset of foot-and-mouth disease, the virus first adsorbs onto susceptible cells, producing a nonspecific binding, and further undergoes specific adsorption with receptors on susceptible cells, causing a series of changes in the cells. The altered cells engulf the foot-and-mouth disease virus as a food vacuole into the cell interior, and their lysozymes cleave the viral capsid, releasing the viral nucleic acid and completing the virus's infection of the cell.
II. Transmission Routes of Foot-and-Mouth Disease
The foot-and-mouth disease virus is mainly transmitted through the respiratory tract, and damaged skin and broken mucous membranes are also routes for virus invasion; contaminated livestock products, feed, drinking water, vehicles, feeding utensils, and so on can all become sources of infection. Foot-and-mouth disease virus present in the air can spread with the wind to places 10~60km away, so air is also an important transmission route. Its transmission characteristics are fast spread and a high incidence rate.
III. Clinical Symptoms of Foot-and-Mouth Disease
Generally, affected animals develop erosions or blisters on the skin of areas such as the oral mucosa, teats, and hooves. Cattle infected with foot-and-mouth disease generally show relatively severe signs. The incubation period of foot-and-mouth disease in cattle is generally 7~36d. In the early stage of illness, there will be obvious features such as elevated body temperature and conjunctival congestion. As the illness continues to progress, lesions will begin to appear in the oral cavity, and blisters will also appear. Generally, more than 90% of cattle infected with foot-and-mouth disease have typical pododermatitis.
Analysis of causes of death: The causes of death are mostly secondary myocarditis due to foot-and-mouth disease, or because the sanitation and cleaning work on the farm is inadequate, secondary infections easily occur, causing them to develop septicemia or other diseases.
IV. Patterns of Foot-and-Mouth Disease Occurrence in Cattle and Sheep
1. It occurs frequently every winter, mostly between November and March of the following year.
2. The most deaths occur in calves and fattening cattle, mainly manifesting as sudden death.
3. Sudden death is more likely during injections and intravenous drips.
4. Sudden death is likely after being frightened.
V. Preventive Measures for Foot-and-Mouth Disease
For foot-and-mouth disease, prevention must be emphasized over treatment. This is what is meant by treating disease before it occurs. If these diseases can be prevented before they happen, the harm caused by the disease will be minimized.
1. Immunization work is still the key point
At present, most of the vaccines supplied on the market and freely provided by the state are trivalent inactivated vaccines against foot-and-mouth disease type O, Asia I, and type A. The dosage for cattle is 1ml/head, and the dosage for sheep is 0.5ml/animal. After immunizing adult goats with the trivalent foot-and-mouth disease vaccine, the herd qualification rate of immune antibody levels reaching the Ministry of Agriculture standard can be maintained for about 4 to 5 months; after immunizing adult sheep, the herd qualification rate of immune antibody levels reaching the Ministry of Agriculture standard can be maintained for more than 6 months; the effect of 2 immunizations is better than 1 immunization; after booster immunization of calves, the herd qualification rate of immune antibody levels reaching the Ministry of Agriculture standard can be maintained for about 6 months.
Can pregnant female animals be vaccinated against foot-and-mouth disease? --- The foot-and-mouth disease vaccine is one of the biological products that can cause relatively strong stress reactions in animals. After injecting foot-and-mouth disease vaccine into cows that have just become pregnant and cows near calving, the risk of miscarriage is greatly increased. After pregnant ewes are injected with foot-and-mouth disease vaccine, stillbirth and miscarriage are likely to occur. Even if the lambs are born successfully, what follows is that the ewes have little milk or even no milk, and the lambs move slowly. Therefore, for ewes, try to avoid the gestation period; for cows, because the gestation period is longer, it is difficult to avoid, so during vaccination it is best to avoid one month before and after calving, as well as the period just after conception and 2 weeks before mating.
2. Strengthen feeding management
Provide cattle and sheep with sufficient nutrition to improve their immunity and disease resistance, and the probability of infection with foot-and-mouth disease virus will be lower. It is recommended that farming friends must choose high-quality premixes and reasonably match the daily ration to provide comprehensive nutrition for cattle and sheep. Do a good job in disinfection: pens without livestock can be disinfected with caustic soda or lime, and pens with livestock can be disinfected with 84 disinfectant, Lysol water, potassium permanganate, benzalkonium bromide, and so on. It is best to alternate acid and alkaline disinfectants.
3. Do not purchase cattle from epidemic areas.
When purchasing cattle, try not to go to epidemic areas, and cattle bought back home should be vaccinated with the trivalent foot-and-mouth disease vaccine in time.
VI. What should be done after infection with foot-and-mouth disease?
1. Detect early and isolate early, and keep a close watch on high fever.
2. Add liquid feed to increase the cattle's nutrition.
3. Keep the environment quiet and avoid noise.
4. Do not chase them or let them engage in strenuous exercise.
5. Treatment of affected areas: wash with potassium permanganate or hydrogen peroxide, apply gentian violet, penicillin, and so on, and for the oral cavity, sprinkle human-use Bingpeng San.
6. Fever-reduction plan: It is recommended to use drugs with traditional Chinese medicine properties to reduce fever. For specific medication and dosage, you can call for consultation, and we will provide reference treatment plans according to the different physiological stages and body weights of cattle and sheep.
7. Do not carry out targeted treatment for foot-and-mouth disease. For the old and weak groups that recover after infection during an epidemic, strengthen disinfection every day, supplement nutrition, and prevent secondary infection.
After reading the above content, have you deepened your understanding of foot-and-mouth disease a lot? Some people may ask: Does foot-and-mouth disease have any impact on the human body? Qinnong Network also gives the answer here: Under normal circumstances, foot-and-mouth disease is not transmitted to humans, but there are reports that a small number of mutated viruses may infect humans, mainly children with weaker resistance, but they can recover quickly through treatment. If you accidentally eat the meat of a diseased animal, there is no need to panic. The foot-and-mouth disease virus is not heat-resistant and not acid-resistant, and the virus can be killed after heating and cooking. Moreover, the gastric acid concentration in the human stomach is very high, and the virus will also be killed by strong acid when it enters the stomach, so there is no need to be overly nervous. However, for the sake of safety, children and the elderly should still be kept away from livestock farms or farms with foot-and-mouth disease, and when purchasing meat food, pay attention to the certificate of quarantine compliance.