TETANUS IN LIVESTOCK: CAUSES, SYMPTOMS AND PREVENTION & TREATMENT

Tetanus is a wound-infection disease that can develop rapidly, causing death in cattle, buffalo, and other animals at a high mortality rate (90–100%). The toxin produced by the bacterium Clostridium tetani is the main cause of excessive reflex stimulation, leading to skeletal muscle stiffness in affected animals. In the following article, Fivevet provides detailed information on the causes, symptoms, and prevention and treatment methods for tetanus in livestock. 1. Characteristics of tetanus
Tetanus has existed for a long time and is found in most regions of the world, but it is more common in tropical areas.
In Vietnam, due to limited agricultural production conditions, especially in remote and rural areas, wounds are prone to bacterial infection, making tetanus still prevalent and causing significant losses in livestock and humans.
The disease is also frequently seen in low-lying, marshy areas, where calves and young livestock are particularly susceptible to tetanus due to unsanitary umbilical cord cutting practices.
2. Causes of tetanus
In the natural environment, Clostridium tetani is the bacterium responsible for causing tetanus in cattle, other animals, and humans. This bacterium forms spores that are egg-shaped, usually appearing at one end of the rod, giving it a shape resembling a drumstick.
As a Gram-positive, anaerobic bacillus, Clostridium tetani produces potent exotoxins, including hemolytic toxins and neurotoxins that affect the nervous system. Although the bacterium itself is relatively sensitive and can be killed within 1 minute at 100°C, common disinfectants such as 5% phenol and 3% formalin can also destroy both the bacterium and its spores. However, under dark and moist conditions, the spores can survive for up to 10 years. To completely destroy the spores, the material must be boiled at 150°C for about 3 hours.
3. Epidemiology of tetanus
Susceptible Animals: All mammalian species can contract tetanus; however, susceptibility varies among species. Horses, sheep, buffalo, cattle, and pigs show decreasing levels of susceptibility in that order. Dairy cattle are particularly vulnerable, especially when undergoing procedures such as castration, dehorning, or umbilical cord cutting in newborn calves.
Sites Containing the Bacteria: The causative bacteria are found primarily at wounds or in wound exudates, such as pus, yellow discharge from fistulas, urine, and feces. In some rare cases, the bacteria can enter the bloodstream and spread to internal organs.
Route of Infection: Clostridium tetani spores primarily enter the host through wounds, especially those exposed to soil, such as hooves, interdigital spaces, castration or dehorning wounds, and umbilical stumps. Areas of inflamed skin or abscesses are also potential entry points. Spores can additionally invade through damaged mucous membranes, such as the intestinal mucosa injured by parasites or mechanical trauma.
When the spores enter a wound, they germinate into vegetative bacteria and begin producing tetanus toxin. For the spores to develop into active bacteria, the environment must be anaerobic and free from phagocytic activity.
The toxins primarily target the nervous system, overstimulating motor neurons and causing skeletal muscle rigidity due to hypersensitivity. As toxin levels increase, the animal experiences generalized muscle stiffness and paralysis of the respiratory center. Death occurs because the animal is unable to move, suffers from convulsions, cannot eat, and eventually experiences respiratory paralysis leading to asphyxiation.
4. Symptoms of tetanus in livestock
Tetanus usually occurs locally at the wound site, but its symptoms affect the entire body. The incubation period ranges from 1 to 4 weeks. In affected animals, particularly cattle and buffalo, the main clinical signs include:
Hypersensitivity Reflexes: Even mild auditory or visual stimuli can trigger panic, trembling, convulsions, and collapse.
Skeletal Muscle Rigidity: The animal’s neck and jaw become stiff, the back and tail arch, the head extends forward, the teeth are clenched, ears stand erect, and the nostrils flare. These signs indicate muscle stiffness and difficulty breathing. Muscle spasms occur in episodes, and all four limbs become rigid, making movement impossible. When the animal falls, it cannot rise again.
Functional Disorders: Initially, body temperature may be normal, but as the disease progresses toward death, fever rises to 40–41°C, pulse becomes rapid and weak, mucous membranes turn purple, and respiratory distress and hypoxia occur. The animal cannot eat or drink, and the disease progresses over 3–10 days. Without timely treatment, livestock dies from asphyxiation or exhaustion.
5. Pathological lesions of tetanus
Tetanus in livestock is generally a localized disease and does not present with distinctive pathological lesions. Because affected animals remain immobile and experience respiratory difficulty, post-mortem examination may reveal purplish mucous membranes and frothy fluid in the lungs.
6. Diagnosis of tetanus
The diagnosis of tetanus requires differentiation from several other diseases:
Rabies: Animals often exhibit mania, fear of wind and water, but do not show jaw rigidity or stiffened back as seen in tetanus.
Meningitis: Affected animals may show sensory changes and paralysis. Although convulsions can occur, muscle rigidity typical of tetanus is absent.
Botulism (Meat Poisoning): Animals may experience paralysis of the throat and tongue, loss of muscle tone, and excessive salivation, but skeletal muscle stiffness is not observed as in tetanus.
Key Feature of Tetanus: The disease usually develops after wounds from castration, dehorning, nose repair, hoof trimming, umbilical cutting, or other surgical procedures in livestock.
7. Treatment of tetanus in livestock
a. Addressing the cause
Wound treatment: Open the wound to prevent bacteria from growing, disinfect with iodine alcohol, then sprinkle sulfamide or Penicillin powder, or use sprays such as Five-CTC spray on the wound area. Injection of antitoxin and tetanus neutralizing serum: To neutralize the tetanus toxin and eliminate the bacteria, administer antitoxin as early as possible. Inject ½ of the dose subcutaneously and ½ near the wound site, Recommended doses: 80,000 units for cattle and buffalo, 40,000 units for calves. In severe cases, 15,000–20,000 units per day may be given to cattle and buffalo. Antitoxin and neutralizing serum can be administered simultaneously but at different injection sites. Perform 3–4 doses of toxin neutralization, each 4–5 days apart, with 1–2 ml per injection.
b. Symptomatic treatment
Use sedatives and muscle relaxants: Administer 30–50 grams of Chloral hydrate orally to cattle daily. Perform intravenous infusion of 10% Magnesium sulfate solution or 15% Magnesium gluconate solution at a dosage of 0.5–1 liter per day.
Health support for cattle: Administer intravenous infusion of hypertonic glucose solution at a dosage of 0.5–1.5 liters per day. Use adrenaline to support cardiovascular function and ephedrine to dilate the alveoli, helping the animals breathe more easily. The following drugs can be used to enhance the immune system and promote faster recovery: Five-Cafein, Five-Acemin.B12, Five-Butasal, Five-ADE Inj, …
Animal care and feeding: Sick animals should be carefully cared for. In cases where the animal cannot eat due to jaw stiffness, it can be given rice gruel (rice porridge water) as a substitute for feed.
8. Prevention of tetanus in livestock
Tetanus is regionally distributed; therefore, special attention should be paid to preventive measures for both humans and livestock in endemic areas. Infected animals should be isolated and treated promptly to ensure recovery. Dead animals must be buried deeply with a layer of lime to destroy bacteria and spores.
Animal housing with sick livestock must be thoroughly cleaned, and manure, waste, and refuse should be destroyed by burning. After that, sprinkle lime powder or apply 10% lime wash, and disinfect the barn using solutions such as Five-Iodine, Five-BGF, Five-B.K.G, Five-Perkon 3S,... After sanitation, the barn should be kept empty for 30 days before introducing new livestock.  For injured livestock, the wound should be opened, cleaned, and disinfected, followed by a subcutaneous injection of 1 ml of tetanus antitoxin and 10,000–15,000 units of antiserum. For smaller animals, administer half the dosage used for larger ones.
Before performing procedures such as castration or surgery, large animals should receive a subcutaneous injection of 1 ml of tetanus toxoid, while small animals should receive 0.5 ml. The immunity provided by the toxoid lasts for about one year.
Livestock should be well cared for and properly fed to enhance resistance, and the grazing area should be kept clean to prevent injuries.