Last spring, a farmer called me about a seemingly healthy goat that suddenly stopped producing milk. Within days, two more goats showed similar signs, like swollen joints, lethargy, and poor appetite. What started as subtle changes turned into a herd-wide concern. And all caused by bacterial diseases in small ruminants that often go unnoticed until it is too late.
As a veterinarian, I have seen how early recognition and timely action can prevent losses and protect herd productivity. So, to help you be equipped with the early knowledge of these conditions, I am sharing 15 common bacterial diseases in sheep and goats, their signs, and practical treatments to safeguard your flock.
Understanding Bacterial Diseases in Small Ruminants
Bacterial diseases in small ruminants are one of the most significant threats to sheep and goat health. Unlike viral diseases, bacterial infections often respond well to early intervention with antibiotics, but delay can result in severe economic losses.
These infections can affect almost every part of the body, from the respiratory system to the udder, joints, and digestive tract. Farmers and owners who can identify symptoms early often save entire herds from devastating outbreaks.
15 Most Common Bacterial Diseases in Small Ruminants (Sheep and Goats)
Let’s explore the most common bacterial diseases in small ruminants, affecting both sheep and goats, including their causes, clinical signs, and recommended treatment approaches.
1. Caseous Lymphadenitis
- Causative agent: Corynebacterium pseudotuberculosis
- Primary site of infection: Lymph nodes and internal organs
Caseous Lymphadenitis is a chronic, contagious disease that causes abscess formation in lymph nodes and occasionally internal organs. It spreads easily through skin wounds, shearing, or contaminated equipment. Infected animals often experience slow weight loss and decreased productivity.
Symptoms
- Swollen abscesses in lymph nodes around head, neck, or body
- Thick, pus-filled lesions under the skin
- Weight loss despite normal appetite
- Reduced milk production in lactating females
- Chronic fatigue and poor growth in young animals
Treatment
Managing Caseous Lymphadenitis involves draining abscesses carefully, maintaining strict hygiene, and administering antibiotics as prescribed by a veterinarian. Vaccination programs and isolation of affected animals can help prevent the spread.
Regular cleaning of equipment and proper shearing practices are essential for long-term control.
2. Contagious Caprine Pleuropneumonia
- Causative agent: Mycoplasma capricolum subsp. capripneumoniae
- Primary site of infection: Lungs and pleura
Contagious Caprine Pleuropneumonia is a severe respiratory disease primarily affecting goats. It spreads rapidly among herds and can lead to high mortality. Affected animals show signs of respiratory distress, fever, and weakness, and if untreated, the disease can devastate an entire herd. Prompt identification is key to minimizing losses.
Symptoms
- Labored and rapid breathing
- Persistent coughing
- High fever and lethargy
- Nasal discharge
- Reduced appetite and weight loss
Treatment
Treatment involves immediate isolation of affected goats, administration of antibiotics, and supportive care such as warmth and hydration. Ensuring proper barn ventilation and reducing stressors help control outbreaks.
Vaccination, where available, is a crucial preventive measure for high-risk herds.
3. Contagious Agalactia
- Causative agent: Mycoplasma agalactiae
- Primary site of infection: Mammary glands, joints, and eyes
Contagious Agalactia affects milk production and causes joint and eye infections in small ruminants, particularly goats. The disease can spread quickly through close contact or contaminated milking equipment. Milking animals may show sudden drop in milk yield, swelling in joints, or eye inflammation, which impacts productivity and welfare.
Symptoms
- Swollen, painful joints causing lameness
- Mastitis with reduced milk production
- Conjunctivitis or eye discharge
- Fever and lethargy
- Difficulty walking or standing
Treatment
Treatment focuses on antibiotic therapy under veterinary guidance, isolation of infected animals, and strict milking hygiene. Vaccination can be used in endemic areas to prevent outbreaks. Regular cleaning of barns, equipment, and feeding areas reduces transmission risk.
4. Anthrax
- Causative agent: Bacillus anthracis
- Primary site of infection: Blood and internal organs
Anthrax is a rapid-onset, often fatal disease that can affect both animals and humans. Spores of Bacillus anthracis can survive in soil for decades, making pastures a long-term risk. In small ruminants, the disease can appear suddenly with minimal warning, so recognizing it early is critical to prevent herd losses.
Symptoms
- Sudden death without prior illness
- Fever and weakness before death
- Swelling of neck, throat, or chest
- Dark or discolored blood from orifices
- Respiratory distress in some cases
Treatment
Immediate veterinary intervention is essential. Antibiotics can be effective if given early, but in many cases, rapid death limits treatment options. Vaccination of at-risk herds and strict biosecurity, including safe disposal of carcasses, are the most reliable preventive measures.
5. Enterotoxemia (Pulpy Kidney Disease)
- Causative agent: Clostridium perfringens type D
- Primary site of infection: Intestines
Enterotoxemia, commonly called Pulpy Kidney Disease, affects fast-growing lambs and kids, especially when fed rich diets. The bacteria produce toxins that damage the intestines and kidneys, and lead to sudden death in severe cases. This disease is notorious for striking healthy animals unexpectedly, so preventive care is vital.
Symptoms
- Sudden death with no warning signs
- Diarrhea or soft stools
- Abdominal pain or bloating
- Convulsions or tremors
- Rapid weight loss in affected animals
Treatment
Immediate veterinary care is required. Supportive care with fluids and antitoxins may help in mild cases, but vaccination is the cornerstone of prevention. Avoid sudden dietary changes and overfeeding, and maintain good hygiene to minimize bacterial proliferation in the gut.
6. Brucellosis
- Causative agent: Brucella melitensis
- Primary site of infection: Reproductive organs
Brucellosis is a reproductive disease that can also infect humans, making it a serious zoonotic threat. In small ruminants, it primarily targets the uterus and testes, causing infertility, abortions, and retained placenta. Early detection and herd management are crucial to prevent significant economic losses and protect human health.
Symptoms
- Abortions in late pregnancy
- Retained placenta after birth
- Reduced fertility in males and females
- Swollen joints or lameness
- General weakness and poor growth
Treatment
There is no definitive cure, so management focuses on testing, culling infected animals, and vaccination in endemic areas. Farmers should use protective equipment when handling animals or birthing products, and maintain strict hygiene to prevent human infection.
7. Listeriosis
- Causative agent: Listeria monocytogenes
- Primary site of infection: Nervous system and gastrointestinal tract
Listeriosis primarily affects the nervous system of sheep and goats, often contracted through contaminated silage or feed. The bacteria invade the brain and spinal cord, causing neurological signs that can progress rapidly. Early recognition and treatment are crucial to prevent severe losses in your herd.
Symptoms
- Circling behavior or uncoordinated movement
- Facial paralysis, drooping ears or eyelids
- Drooling and difficulty swallowing
- Fever and depression
- Loss of appetite and weight
Treatment
Immediate veterinary intervention with appropriate antibiotics is essential. Supportive care, including hydration and nutrition, can improve recovery chances. Preventing listeriosis involves feeding properly fermented silage, avoiding spoiled feed, and maintaining clean feeding areas.
8. Pasteurellosis
- Causative agent: Pasteurella multocida and Mannheimia haemolytica
- Primary site of infection: Respiratory system
Pasteurellosis is a major cause of pneumonia in small ruminants, often triggered by stress, poor ventilation, or co-infections. It can quickly spread through the herd, leading to coughing, fever, and breathing difficulties. Prompt management and treatment are critical to reduce mortality and improve recovery.
Symptoms
- Persistent coughing and nasal discharge
- Rapid, labored breathing
- Fever and lethargy
- Loss of appetite
- Reduced weight gain and poor growth
Treatment
Antibiotics prescribed by a veterinarian are the mainstay of treatment. Supportive care, such as reducing stress and improving ventilation, enhances recovery. Vaccination against common bacterial strains is highly effective in preventing outbreaks in high-risk flocks.
9. Johne’s Disease
- Causative agent: Mycobacterium avium subsp. paratuberculosis
- Primary site of infection: Intestines
Johne’s Disease is another name to be listed among the bacterial diseases in small ruminants. It is chronic, slowly progressive intestinal infection that leads to weight loss and poor productivity. Young animals are most susceptible, and infected animals can shed bacteria for years without showing severe symptoms.
Symptoms
- Gradual weight loss despite normal appetite
- Diarrhea or soft feces
- Reduced milk production in lactating animals
- Swelling under the jaw or emaciation
- Weakness and poor growth in young lambs and kids
Treatment
There is no effective cure. Management focuses on testing and culling infected animals, improving hygiene, and preventing young stock from contact with contaminated feces. Maintaining clean pastures and feeding areas is crucial to controlling the spread of Johne’s Disease.
10. Foot Rot
- Causative agent: Dichelobacter nodosus and Fusobacterium species
- Primary site of infection: Hooves
Foot Rot is a painful and highly contagious disease affecting the hooves of sheep and goats. It thrives in wet and muddy environments, making proper pasture management critical. Infected animals experience severe discomfort, reduced mobility, and weight loss, impacting overall productivity.
Symptoms
- Lameness and reluctance to walk
- Swelling and inflammation between toes
- Foul odor from affected hooves
- Separation of hoof horn from underlying tissue
- Reduced feed intake and weight loss
Treatment
Treatment involves regular hoof trimming, antiseptic footbaths, and administering antibiotics in severe cases. Isolating affected animals and maintaining dry, well-drained pastures help prevent recurrence.
Vaccination against foot rot strains can be used in endemic areas to reduce outbreak risk.
11. Mastitis
- Causative agent: Staphylococcus spp., Streptococcus spp., and other bacteria
- Primary site of infection: Mammary glands
Mastitis is an inflammation of the udder that affects milk production and quality. It is a common issue in lactating sheep and goats, often caused by poor milking hygiene or environmental contamination. When you recognize it at an early stage, it ensures better treatment outcomes and prevents spread within the herd.
Symptoms
- Swelling, heat, and redness in the udder
- Pain during milking or touch
- Abnormal milk, including clots or discoloration
- Reduced milk production
- Fever and lethargy in severe cases
Treatment
Treatment involves antibiotics as prescribed by a veterinarian and proper milking hygiene. Supportive care such as udder massages, warm compresses, and isolation of infected animals reduces spread.
Maintaining a clean environment and proper nutrition strengthens udder health and prevents future infections.
12. Tetanus
- Causative agent: Clostridium tetani
- Primary site of infection: Nervous system (through wounds)
Tetanus is a potentially fatal disease that affects the nervous system of sheep and goats. The bacteria enter through wounds and produce toxins that cause muscle stiffness and spasms. It is particularly dangerous during handling, shearing, or after injuries, so preventive measures are vital.
Symptoms
- Muscle stiffness and rigidity
- Difficulty standing or walking
- Lockjaw (inability to open mouth properly)
- Nervous spasms or tremors
- Sensitivity to touch or sound
Treatment
Treatment requires immediate veterinary care with antitoxin administration, wound cleaning, and supportive care. Vaccination provides long-term protection and should be included in routine herd health programs. Ensuring care for injuries and maintaining clean facilities reduces the risk of tetanus.
13. Botulism
- Causative agent: Clostridium botulinum
- Primary site of infection: Nervous system (via ingestion of toxins)
Botulism is a toxin-mediated disease that affects the nerves and muscles of sheep and goats. Animals usually contract it by consuming contaminated feed or carcasses. The toxins lead to progressive paralysis, which can be fatal if not addressed promptly, making early detection crucial.
Symptoms
- Weakness and inability to stand
- Drooling and difficulty swallowing
- Paralysis of limbs or neck
- Reduced appetite
- Muscle tremors or flaccid paralysis
Treatment
Treatment requires immediate veterinary attention. Administration of antitoxins, supportive care with fluids, and nutritional support can help in mild cases. Preventing exposure by proper feed storage, removing carcasses from feeding areas, and vaccinating in high-risk regions are essential control measures.
14. Navel Ill / Joint Ill
- Causative agent: Escherichia coli, Streptococcus spp., Staphylococcus spp.
- Primary site of infection: Umbilical cord and joints in newborns
Navel Ill, also known as Joint Ill, is a bacterial infection that commonly affects newborn lambs and kids. Poor hygiene at birth allows bacteria to enter through the umbilical cord, which leads to joint swelling and systemic infection, which can hinder growth and survival if untreated.
Symptoms
- Swollen, painful joints causing lameness
- Redness or discharge from the umbilical cord
- Fever and lethargy
- Poor appetite and slow growth
- Difficulty walking or standing
Treatment
Early antibiotic therapy is critical to prevent systemic infection. Disinfecting the navel at birth, maintaining clean birthing areas, and ensuring proper colostrum intake reduce risk. Isolation of affected newborns helps prevent spread to other animals.
15. Pneumonia
- Causative agent: Pasteurella spp., Mycoplasma spp., and other opportunistic bacteria
- Primary site of infection: Lungs and respiratory tract
Pneumonia in small ruminants is a respiratory infection caused by a variety of bacteria, often triggered by stress, poor ventilation, or co-infections. It can significantly impact herd health and productivity, especially in young or immunocompromised animals.
Symptoms
- Coughing and nasal discharge
- Labored or rapid breathing
- Fever and lethargy
- Loss of appetite and weight
- Poor growth and reduced milk production
Treatment
Prompt veterinary care with appropriate antibiotics is essential. Supportive care includes hydration, nutrition, and reducing stressors. Improving barn ventilation and maintaining clean housing conditions are key preventive strategies.
Vaccination against common bacterial pathogens can further protect your herd.
Let’s Rewind
Bacterial diseases in small ruminants can really destroy the complete farm if not checked properly. Protecting your sheep and goats from bacterial diseases is a continuous and proactive process. Early detection, good hygiene, vaccination, and timely veterinary intervention can save lives, improve productivity, and secure your livelihood.
Understanding these 15 common diseases empowers you to recognize warning signs before they escalate. Implementing preventive strategies such as biosecurity measures, proper nutrition, and regular monitoring will keep your flock healthy and productive.