Source-backed aggregate guide - manual-review caution
Ovine-Caprine
Infectious Disease
Herd controlSmall ruminants
Contagious agalactia and mycoplasma herd control
Mastitis plus arthritis, eye disease, kid illness, and poor routine culture response should trigger herd containment.
⏱ 6-8 min read · Topic 162 of 167
3
Practice Qs
5
Traps
Low to moderate
Exam freq.
—
Your status
Study step
High-yield takeaways
- Recognize the classic presentation, then narrow the case using signalment, timeline, exam findings, diagnostics, and response to treatment.
- Use the decision framework, traps, differentials, and related questions to rehearse NAVLE-style next-best-step reasoning.
- This educational study page is not a clinical protocol; confirm patient-specific decisions with current references and clinician judgment.
30-second revision
PatternMastitis plus arthritis and eye disease is not routine mastitis.
ActionContain, test targeted samples, and strengthen milking/kid biosecurity.
MovementStop sales while diagnosis and control are unresolved.
TrapA stronger intramammary antibiotic alone misses herd disease.
How NAVLE tests this topic
Recognition → The board pattern is multi-system disease in several goats or sheep, not one simple udder infection.
Diagnosis → Milk, ocular, joint, respiratory, or kid samples may be needed for mycoplasma testing under veterinarian direction.
Control → Segregation, movement control, milking hygiene, kid milk management, and chronic-shedder planning are central.
Communication → Sales and movement before diagnosis can spread chronic disease to buyer herds.
Emergency Triage Alert
Contain herd spread before routine mastitis assumptions
When mastitis occurs with arthritis, eye disease, kid illness, and new-animal exposure, stop movement and protect unaffected groups while testing proceeds.
Clinical review note
Manual-review caution
Contagious agalactia and small-ruminant mycoplasma control require current veterinary references, laboratory guidance, food-animal rules, and herd-specific planning.
Pathophysiology that changes decisions
Mycoplasma pathway → Small-ruminant mycoplasmas can involve mammary gland, joints, eyes, respiratory tract, and young stock.
Milking pathway → Shared equipment and milking order can move organisms between affected and unaffected does.
Kid pathway → Pooled milk and nursing from affected does can expose kids and amplify the outbreak.
Carrier pathway → Chronically infected or subclinical animals can maintain herd risk after clinical signs quiet down.
This page teaches NAVLE-style containment logic and does not provide farm-specific testing, culling, vaccine, or drug protocols.
Key clinical patterns
Core pattern
dairy goat or sheep herd with multiple fresh animals showing decreased milk or abnormal secretionmastitis or agalactia paired with arthritis, lameness, keratoconjunctivitis, pneumonia, or kid illnessrecent replacement animals without quarantine or entry testingroutine mastitis culture unrewarding or beta-lactam therapy not improving the outbreakowner wants whole-herd intramammary treatment while continuing sales
Supporting clues
milking order and equipment sanitationkid-feeding source and pooled milk usemovement, sale, and buyer-herd exposure risksample type and lab handling for mycoplasmachronically affected or low-producing animals
NAVLE trigger: The tested move is herd containment and targeted diagnosis, not a stronger individual-mastitis prescription.
Decision framework - what NAVLE asks
Multi-system herd pattern
Suspect contagious agalactia or related mycoplasmal disease and stop routine individual-mastitis framing.
Movement risk
Stop sales or movement of potentially exposed animals until the outbreak is investigated and controlled.
Testing branch
Collect appropriate milk, ocular, joint, respiratory, or kid samples for mycoplasma testing under veterinary guidance.
Biosecurity branch
Separate affected groups, adjust milking workflow, avoid pooled infected milk, and plan chronic-shedder management.
Diagnostic priorities and interpretation
Mastitis plus arthritis/eye disease
Mycoplasma pattern
The combination is more important than any single sign.
Routine culture unrewarding
Testing clue
Special sample handling or targeted testing may be needed.
Replacement does
Introduction clue
Lack of quarantine explains timing and future prevention gaps.
Pooled milk
Amplifier
Kids can be exposed through milk-management practices.
Continued sales
Spread risk
Buyer herds can be harmed before diagnosis is resolved.
Use current small-ruminant references and local rules for testing, movement, culling, treatment, and vaccination decisions.
Treatment escalation and management logic
Contain
Stop risky sales, separate affected animals, and protect unaffected groups and kids.
Containment starts before final lab confirmation.
Diagnose
Submit veterinarian-directed samples from milk, eyes, joints, respiratory tract, or affected kids for mycoplasma testing.
Sample choice and lab handling matter.
Control workflow
Improve milking hygiene, milking order, equipment sanitation, kid-feeding practices, and introduction quarantine.
Management failures can sustain spread.
Plan herd outcome
Discuss segregation, removal of chronically infected animals, treatment limitations, and buyer-herd risk.
No drug protocol is provided here.
NAVLE traps — where students lose marks
Treating as ordinary individual mastitis
The multi-system herd pattern requires containment and testing.
Continuing sales before diagnosis
Movement can spread a chronic herd disease.
Relying on beta-lactam intramammary therapy alone
Mycoplasmal disease and herd spread are not solved by this shortcut.
Ignoring pooled milk
Kid exposure can amplify the outbreak.
Skipping introduction biosecurity
Replacement animals are a common timing clue.
Differential diagnosis framework
Herd discriminator: mastitis plus arthritis, eye disease, and kid illness after introductions should move mycoplasma high.
| Differential | Key clue | Best decision bias | Common trap |
|---|---|---|---|
| Contagious agalactia / mycoplasma | Agalactia, mastitis, arthritis, keratoconjunctivitis, kid pneumonia | Contain herd, test targeted samples, control movement and milk routes | Stronger mastitis tube only |
| Routine bacterial mastitis | Primarily udder signs, culture-directed therapy | Milk culture and milking hygiene | Using this label despite eye and joint cluster |
| Caprine arthritis encephalitis | Chronic arthritis, indurative mastitis, neurologic kids possible | Serology/herd control context | Forcing it to explain acute eye and kid pneumonia cluster alone |
| Nutritional or metabolic production drop | Ration or transition issue without contagious eye/joint signs | Nutrition review after infection ruled out | Ignoring infectious spread |
| Chlamydial or other abortion/eye disease | Abortion or conjunctivitis pattern with exposure risk | Targeted reproductive/ocular testing | Not matching mastitis-agalactia pattern |
Calculator applications and clinical tools
Use these adjacent routes for small-ruminant infectious and herd-control comparisons.
Related questions
Practice contagious agalactia recognition and herd containment decisions.
0 / 0
A dairy goat herd has mastitis, agalactia, swollen joints, keratoconjunctivitis, kid pneumonia, and recent unquarantined replacements. What should move high?
The owner wants to keep selling replacement doelings during the outbreak. Which response is most appropriate?
Which management practice can amplify kid exposure during a mycoplasmal mastitis outbreak?