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SHEEP AND GOATS · OWNER EDUCATION

Caseous Lymphadenitis in Sheep and Goats

Caseous lymphadenitis is a chronic bacterial infection of sheep and goats that causes abscesses in lymph nodes or internal organs. External lumps are only part of the disease.

Sheep and goat beside a veterinarian and caregiver reviewing herd care
OWNER VISUAL GUIDECare context for Caseous Lymphadenitis in Sheep and Goats. This species-related care scene does not show diagnostic signs or a confirmed case of the disease. This educational illustration is not a diagnostic image.

THE SHORT VERSION

What matters for your animal?

Start with the warning signs and when-to-contact sections if your animal is unwell. The same outward change can have several causes, so this guide helps you prepare questions rather than identify a diagnosis on your own.

01 · OVERVIEW

What is this condition?

Caseous lymphadenitis is a chronic bacterial infection of sheep and goats that causes abscesses in lymph nodes or internal organs. External lumps are only part of the disease.

Caseous lymphadenitis can involve internal infection as well as visible lymph-node abscesses. A healed external lesion therefore does not necessarily mean that the animal is free of infection. Diagnosis and a herd-level plan are important before breeding, showing, selling, or introducing animals. Opening an abscess in shared housing can spread contaminated material and does not provide a reliable cure.

02 · SPECIES COVERED

Which species does this guide cover?

SheepGoats

The species listed above are the focus of this guide, rather than a complete list of every animal that can develop this condition. Causes, testing and treatment may differ between species and individual patients.

03 · CAUSES AND RISK FACTORS

Why can it happen?

  • Bacteria enter through damaged skin and spread through infected pus and contaminated equipment. Internal infection may not produce visible lumps.

An infectious illness depends on both the organism and the animal's ability to resist it. Exposure does not always produce the same severity of illness in every animal. Age, previous immunity, nutrition, stress, and concurrent disease can influence the outcome. The infection may also cause complications that need treatment separately from the organism itself. For example, correcting fluid loss or supporting breathing can be essential even when a targeted medicine has already been started.

04 · OWNER OBSERVATIONS

What might an owner notice?

  • Firm swellings near lymph nodes, recurrent draining abscesses, weight loss or poor condition.

The number affected and the sequence of cases can provide important clues. Record which animals or colonies changed first, whether they share feed, water, housing, equipment, or recent contacts, and any deaths. One patient's improvement does not establish that the shared cause has been removed. A group investigation may require different samples or visits from the care of one visibly affected animal. Avoid moving animals or materials between groups while a potentially transmissible problem remains unresolved.

Use the printable symptom diary →
05 · HOW VETERINARIANS EVALUATE IT

How is the problem investigated?

Culture of suitable material and other tests help confirm infection. Not every abscess is caseous lymphadenitis.

Explore the diagnostic testing library →
06 · TREATMENT OR MANAGEMENT

What might treatment involve?

A herd-level plan may include isolation, controlled treatment and removal of affected animals. Treatment does not guarantee elimination of infection.

Antibiotic selection depends on the suspected or confirmed bacteria, the site of infection, and the animal's safety needs. A culture identifies organisms that grow from a sample; susceptibility testing helps assess which medicines may work against them. The laboratory result is considered alongside tissue penetration, dosing feasibility, and the clinical response. Antibiotics do not treat viruses, and adding one without a clear reason can obscure the investigation or cause adverse effects. Follow the current prescription rather than using leftovers from a previous illness.

Damaged skin or other protective surfaces can become painful and vulnerable to contamination. Treatment considers the depth of injury, affected tissue, infection, and any reason healing may be impaired. Surface cleaning alone may not address deeper damage. The veterinarian may need to remove unhealthy material, provide pain control, protect the site, or investigate an underlying disease. Report new odor, discharge, swelling, darkening, or reduced use of the affected area, and follow the prescribed dressing or protection instructions exactly.

This is an overview, not a prescription or a recommendation for a specific individual animal.

07 · HOME CARE

What can owners do at home?

Separate animals with suspicious swellings and follow professional instructions for handling contaminated material.

08 · WHAT NOT TO DO

Avoid actions that could make care less safe.

  • Do not lance abscesses in a shared area or introduce apparently healed animals without advice.
09 · PROGNOSIS AND PREVENTION

What can the longer-term outlook involve?

Chronic infection and recurrence make individual and herd management challenging.

A recheck is not simply a repeat of the first appointment. It assesses whether the original problem is improving, whether complications are appearing, and whether the treatment remains appropriate. The useful measures may include comfort, function, intake, body weight, examination findings, or selected tests. Ask which changes are expected before the visit and which should trigger an earlier call. Improvement in one sign does not always mean that every part of the disease has resolved.

Can risk be reduced?

Source animals carefully, reduce equipment contamination and discuss vaccination where appropriate.

Disease prevention includes the route by which animals, people, equipment, bedding, feed, or water can carry a problem between groups. Separation works best when it also includes dedicated tools, careful handling order, and an appropriate cleaning plan. A newly arrived animal may appear well while a disease is incubating. Ask which tests or observation period suit the species and suspected disease before mixing groups. Cleaning, disinfection, and disposal requirements differ between organisms, so a single household product is not a universal solution.

10 · WHEN TO CONTACT YOUR VETERINARIAN

When should you arrange care?

  • A new lymph-node swelling warrants prompt assessment, especially before breeding, showing or selling animals.
11 · EMERGENCY WARNING SIGNS

Seek urgent veterinary advice if you notice:

DO NOT DELAY URGENT CARE
  • Seek urgent care if an animal cannot eat or breathe normally or is severely weak.
Open the emergency action guide →
12 · PREPARE FOR THE CONVERSATION

What information helps the care team?

Record which animals are affected, feeding or housing changes, recent arrivals, treatments and any losses. For a flock or herd problem, the number affected and the pattern over time may be as important as one animal's examination.

How should you understand the tests?

Ask what each proposed test is intended to answer. Some tests identify a cause; others assess severity, organ function or treatment safety. Results are interpreted with the examination and history. A normal result does not exclude every problem, and an abnormal result does not always explain every sign.

Questions to ask before leaving

  • What is confirmed, and which other explanations are still being considered?
  • What changes should we expect with the proposed plan, and when should we reassess if they do not occur?
  • Which observations should I record, and which changes mean I should call sooner?
  • What medicine or home-care problems should I report, and what are the instructions for a missed dose or suspected side effect?
  • When is the recheck, what will it assess, and whom should I contact after hours?

A care plan may be adjusted as results or the response become clearer. Keep the written instructions and tell the team if cost, handling or administration difficulty makes the plan hard to follow.

Sources behind this guide

Caseous Lymphadenitis of Sheep and Goats - Circulatory System - Merck Veterinary ManualVeterinary, university or animal-health guidance ↗

Content last reviewed: October 3, 2026. Review status: veterinary-informed; independent veterinarian review not yet completed.

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