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Lamb tick fever
Tick pyemia is a disease of grazing lambs: a common skin bacteria, staphylococcus, passes into the blood and forms abscesses all over the body, especially in the joints, muscles and along the spine. This bacteria is present on the skin of...
What is it?
Tick pyemia is a disease of grazing lambs: a common skin bacteria, staphylococcus, passes into the blood and forms abscesses all over the body, especially in the joints, muscles and along the spine.
This bacteria is present on the skin of all sheep without ever causing a problem. What changes everything is the tick: its bite opens a door of entry, and above all it often inoculates tick fever, which disarms the lamb's defenses for several weeks. Staphylococcus takes advantage of this window.
It affects lambs in the first weeks and months of life, almost always after being put out to grass on a tick-infested range.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
Lameness which appears in several lambs from the same batch, a few weeks after being released to pasture. This is the most common reason for appeal.
Hot, swollen and painful joint, often in the knee, hock or shoulder; the lamb holds its member in the air or barely poses.
General stiffness, lamb walking with small steps, getting up with difficulty and lying down immediately.
Weakness or paralysis of the hindquarters when an abscess develops along the spine: the lamb drags its hindquarters, moves on its front legs, then no longer gets up. The sensitivity of the hindquarters is reduced.
Firm swellings under the skin or in the muscles, sometimes discovered by palpation.
Fever, despondency, lamb which no longer suckles, moves away and remains lying in the shade.
Significant growth retardation: the lamb visibly lags behind its peers of the same age.
In some cases, the lamb is found dead without having limped much, the abscesses having formed in the deep organs.
Ticks are commonly found on these lambs, especially around the head, ears and groin.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
Staphylococcus normally lives on the skin and in the nostrils of sheep without making them sick.
The tick bite creates a small wound that allows bacteria to enter under the skin.
At the same time, the tick often inoculates the tick fever agent, which attacks the lamb's white blood cells: for several weeks, the lamb no longer has the means to stop a banal infection.
The bacteria then passes into the blood and is deposited where circulation slows down: joints, growth cartilages of long bones, muscles, spinal cord, liver, lungs, kidneys. In each location, it forms an abscess.
An abscess located in the vertebral canal compresses the spinal cord: this explains lambs paralyzed from the hindquarters without apparent injury.
Young lambs are most affected because their defenses are still immature and they are discovering ticks for the first time.
Young lambs, from a few weeks to a few months, put out to pasture during tick season.
Bushy, humid paths, on the edge of a forest or wasteland, where ticks abound.
First outing to pasture coinciding with peak tick activity in spring.
Herds in which tick fever circulates: the two diseases go together.
Poorly started lambs: insufficient or late colostrum, poorly nourished mothers, lambs from multiple litters.
Infections of the navel at birth, castration wounds, tail docking wounds or wounds carried out in poor hygienic conditions: so many additional entry points for the same bacteria.
Lack of a tick control program on lambs, often treated less carefully than adults.
Dirty and damp sheepfold at lambing time.
Transmission
There is no direct contagion from one lamb to another: it is not a disease that is transmitted, it is an infection that is triggered in weakened animals at the same time.
When several lambs in a group are affected, this does not mean that they have become infected among themselves: it means that they share the same tick-infested route.
The bacteria in question is already present on animals and in buildings: eliminating it is not possible, it is the entry door that must be closed.
The disease is not transmitted to humans.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
The veterinarian examines the entire lamb and not just the limping limb: he palpates all the joints, the spine, the muscles, and looks for deep swellings.
It tests the sensitivity and strength of the hindquarters when the lamb drags its hindquarters, in order to identify compression of the spinal cord.
He looks for ticks on the lamb and its peers, and asks about the date it was put out to pasture and the route used: the chronology is very telling.
A joint puncture allows you to know if there is pus, to identify the bacteria and to check which antibiotics it is sensitive to. This is a valuable test when several lambs are affected, as it guides the treatment of the entire flock.
A blood test assesses the general condition and the extent of the infection.
The veterinarian rules out other causes of lameness and paralysis in the lamb, which are numerous: arthritis of other origins, infections of the navel, deficiencies, trauma, nerve damage. The behavior to follow is not the same.
Examining a dead lamb reveals abscesses and confirms the diagnosis for the entire flock: this is often what triggers the right decision for others.
Treatment
Treatment is based on antibiotics, chosen and prescribed by the veterinarian, ideally guided by the analysis of pus taken from a joint.
Precocity is decisive. An abscess in a joint is very difficult to reach: circulation is poor and the pus protects the bacteria. Treatment started from the first days of lameness is much more likely to be successful than treatment started on an already deformed joint.
Too short a treatment is a classic cause of failure and relapse: these infections require duration, which only the veterinarian can determine.
An anti-inflammatory is often combined to relieve pain and allow the lamb to get up and suckle; it never replaces the antibiotic.
Comfort care is very important: clean and thick bedding, lamb turned regularly if it does not get up, water and food within reach, shelter from the sun and flies. A lying lamb that can no longer turn around quickly deteriorates.
A lamb paralyzed by a spinal abscess rarely recovers: the veterinarian will judge the benefit of continuing treatment or resorting to euthanasia to avoid long agony.
Above all, one case must trigger a decision for the entire flock: examine all the lambs, treat the ticks, review the route used. Treating only the lame lamb means letting others follow the same path.
Meat waiting periods are specific to each product and must be requested from the veterinarian before any slaughter.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Protecting lambs against ticks is the central measure: it is by closing the front door that we avoid abscesses. Several families of products and several forms exist, but not all are suitable for young lambs: the choice and schedule must be determined by the veterinarian.
Avoid, when possible, putting the youngest lambs on the most infested runs when ticks peak. Reserve these plots for adult animals already exposed.
Shift the lambing period from peak tick activity when flock management allows it.
Clear brush around sheepfolds, paths and shaded areas where lambs gather.
Inspect lambs by hand during the first weeks of grazing, looking at the ears, head, groin and underside of the tail, and remove ticks without crushing them, wearing gloves.
Take care of the start of the lambs: colostrum in sufficient quantity and in the first hours, disinfection of the navel at birth, mothers properly fed at the end of gestation. A well-started lamb resists much better.
Carry out castration, tail docking and tail docking with clean equipment, on healthy animals and never during tick season if this can be postponed.
Maintain the sheepfold: dry litter, no overcrowding, cleaning between batches.
Monitor the lambs closely in the month following turning out to pasture: the first lameness is a warning signal for the entire flock.
Possible complications
Permanently damaged joint: the lamb remains permanently lame and will never make a good animal.
Irreversible paralysis of the hindquarters when an abscess compresses the spinal cord.
Significant growth delay, never caught, with a lamb which remains out of lot until sale.
Spread of the infection to several organs and death of the lamb.
Lamb lying down for a long time, with bedsores, bloating and fly attack during the hot season.
Carcasses seized or devalued at the slaughterhouse due to abscesses.
Treatment failure and relapses when the antibiotic is stopped too early.
High economic losses at the flock level, often well in excess of the cost of a tick control program.
When to see a veterinarian
A lamb is limping, holding a limb in the air or has a hot and swollen joint: call quickly, these infections are better treated if we intervene early.
Several lambs from the same batch lame in the weeks following turning out to pasture.
A lamb drags its hindquarters, moves on its front legs or no longer gets up: consult without delay.
A lamb has a fever, no longer suckles and remains isolated.
A lamb clearly loses growth compared to its peers.
You find a lot of ticks on the lambs in a flock: don't wait for the first lame person to talk to the veterinarian.
A lamb dies without explanation after going out to pasture: have it examined, this will protect the others.
Prognosis
Treated from the first days of lameness, a lamb can recover completely.
When the abscess is established and the joint is already deformed, recovery is rare: the animal remains permanently lame and stunted in growth.
Lambs paralyzed by a spinal abscess only recover in exceptional cases.
At the scale of the flock, the prognosis depends entirely on the fight against ticks: a farm which protects its lambs sees the problem disappear, a farm which is content to treat the lame finds it every spring.
Frequently asked questions
Several of my lambs have been lame since being put out to grass: is this contagious?
No, they do not contaminate each other. They simply share the same tick path and are weakened at the same time. The correct response is not to isolate the lame but to deal with ticks throughout the flock and have the affected lambs examined.
Why does my lamb no longer get up even though nothing is broken?
An abscess can form along the spine and compress the spinal cord, without any visible injury. This is a classic localization of this disease and requires a rapid veterinary examination: other causes of lamb paralysis exist and some are well treated.
The antibiotic didn't work, why?
Most often because treatment was started too late or stopped too early. Pus in a joint is very difficult for an antibiotic to reach, and these infections take time. A puncture of the joint allows the veterinarian to choose the right product rather than trying randomly.
Can I treat my lambs for ticks like adults?
Not necessarily: not all anti-tick products are suitable for young lambs, and some are dangerous for them. The choice of product, form and timing must be decided by the veterinarian, taking into account age and weight.
References
ANSES — Agence nationale de sécurité sanitaire (France)
Content reviewed by the TunisieVet editorial team · Updated 11 August 2026
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