Sheep and Goat Pox: The Disease Behind SGP
A highly contagious viral disease that can spread rapidly through sheep and goat flocks
Sheep and goat pox (SGP) is a serious viral disease affecting sheep and goats. It can begin with something that looks relatively minor—a fever and a few unusual skin spots—but can quickly develop into a flock-wide outbreak.
SGP is caused by viruses belonging to the Capripoxvirus genus. Sheep pox and goat pox are caused by closely related viruses, and some strains can infect both species.
SGP does not infect humans.
How the Disease Develops
After infection, there is typically an incubation period of around 4–21 days before obvious signs appear.
The animal may initially seem simply unwell: feverish, depressed and unwilling to eat. Enlarged lymph nodes and discharge from the eyes or nose may follow.
Then the characteristic pox lesions begin to appear.
They often start as small red areas before developing into raised, firm papules and nodules. These can eventually become scabs as the lesions heal.
Commonly affected areas include:
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Face, ears and eyelids
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Armpits, groin and tail
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Mouth, nose and other mucous membranes
But SGP isn't merely a skin disease. In severe cases, lesions can develop internally, particularly in the lungs, causing respiratory distress and contributing to death.
Why SGP Can Be So Serious
The severity of an outbreak varies considerably.
Animals that have some existing immunity may experience relatively mild disease. Conversely, a population with little previous exposure can be hit extremely hard. Young animals are also generally more vulnerable.
During severe outbreaks, a very large proportion of the flock can become infected. Mortality varies widely depending on the virus, animal population and level of immunity, but susceptible populations can experience devastating losses.
Beyond deaths, even surviving animals can suffer:
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Weight loss and poor body condition
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Reduced milk production
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Damage to hides and wool
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Reduced productivity during recovery
For livestock owners, therefore, the economic impact can extend well beyond the animals that actually die.
How SGP Spreads
The virus is highly contagious and does not require prolonged direct contact between animals.
Transmission can occur through infected respiratory and ocular secretions, close contact, contaminated equipment and other infected materials. Scabs are particularly important because the virus can remain viable in them for prolonged periods.
Animal movement is therefore a major concern. A newly purchased animal may look perfectly healthy while still being within its incubation period.
By the time the first obvious lesions appear, other animals may already have been exposed.
Diagnosis
The characteristic combination of fever and pox-like skin lesions can make SGP suspicious to a veterinarian, but visual examination alone isn't always enough.
Several other diseases can produce similar-looking lesions, including orf (scabby mouth) and other infections affecting the skin or mucous membranes.
Laboratory testing, particularly PCR, can be used to confirm the presence of capripoxvirus.
This distinction matters because treating an ordinary skin infection while an SGP outbreak is developing is a rather spectacularly bad livestock-management strategy.
Treatment and Control
There is currently no simple antiviral treatment that eliminates SGP once an animal is infected. Management therefore focuses on supportive care, controlling complications and—most importantly—preventing further transmission.
When SGP is suspected, immediate measures should include:
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Isolating affected animals
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Restricting animal movement
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Contacting veterinary authorities
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Cleaning and disinfecting contaminated equipment and premises
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Investigating recently introduced or exposed animals
Antibiotics do not kill the virus, although a veterinarian may use them where secondary bacterial infections occur.
Prevention: Stop It Before It Arrives
Vaccination is one of the most important tools for preventing and controlling SGP. Appropriate capripox vaccines can provide protection, but the vaccination programme should be determined according to the local disease situation and veterinary guidance.
Good biosecurity is equally important. New animals should be quarantined before being introduced to an established flock, and equipment should not be casually shared between groups of animals.
Früh erkennen (recognise it early) is particularly important with SGP. Once a contagious disease has moved through a flock, containing it becomes considerably harder.
SGP vs PPR
SGP is sometimes confused with Peste des petits ruminants (PPR) because both diseases affect sheep and goats and can cause fever, discharge and severe illness.
They are, however, completely different diseases.
PPR is particularly associated with severe oral lesions, diarrhoea and pneumonia, whereas SGP is distinguished by its characteristic pox lesions and nodules.
Getting the diagnosis right matters because the appropriate control measures are different.
The Bottom Line
SGP should not be dismissed as simply a skin condition. It is a highly contagious systemic viral disease that can spread rapidly through susceptible sheep and goats, cause serious production losses and, in severe outbreaks, kill large numbers of animals.
The most important weapons are therefore not miracle drugs but early recognition, rapid isolation, vaccination and good biosecurity.