Head Pressing in Cattle
Description
Head pressing is not a specific disease but can be a sign of many different diseases or conditions in cattle that affect the brain and nervous system.
Head pressing is characterized by pressing the head against a wall or pushing the face into a corner for no apparent reason. This condition is usually a sign of a neurological disorder, especially of the forebrain, or a sign of toxicity due to liver damage, or any number of diseases that affect the brain.
The animal leans into a stanchion or fence and pushes it head against any solid objects or barriers in its path. Some just put their heads down and walk aimlessly. Often they seem to be blind, and if they walk into an obstacle they push their heads against it. If confined to a stall or pen they walk around continuously or press their heads into a corner.
The affected animal is usually severely depressed. It may show continuous chewing movements but is unable to eat or drink.
Signs
- Running into objects
- Pressing the head against immobile obstacles or into a corner of a stall or pen
Cause
Head pressing, along with compulsive walking, is a syndrome associated with many different nervous diseases. Causes include toxic and metabolic brain diseases, such as hepatic encephalopathy (a decline in brain function resulting from severe liver disease in which the liver can’t adequately remove toxins from the blood, causing a buildup of toxins in the bloodstream, which can lead to brain damage).
Several diseases can cause intracranial pressure (affecting brain function) and there are also several causes of inflammation/infection of the brain and spinal cord that alter the animal’s behavior. These changes generally occur with disorders that affect the limbic system of the brain (which plays a large role in attitude and behavior) and these changes may include pacing and circling, head pressing, agitation, excessive licking, charging, and mania.
Following are some of the causes of head pressing (with the animal often walking blindly into obstacles and pressing against them) and other nervous signs.
Cerebellar hypoplasia is a condition in which the cerebellum fails to develop normally in the fetus. In-utero bovine viral diarrhea virus (BVD) infection—when the dam is infected by BVD virus any time between 90 and 130 days of gestation--causes cerebellar hypoplasia. The calf is born brain-damaged and even though it may be able to get up and walk around, it shows neurologic signs. This is a common congenital abnormality for which there is no treatment.
Bacterial meningitis is infection in which bacteria enter via the gut and are absorbed into the bloodstream, with localization within the membranes (meninges) around the brain. This often results from failure of passive antibody transfer (poor colostrum intake) and high levels of bacterial challenge in the young calf’s environment. This disease is more common in calves born indoors or in confined areas in unhygienic conditions.
A brain abscess can also cause neurologic signs that gradually get worse, resulting from the enlarging abscess. Depression is a common sign, with the head turned towards the animal’s chest. There may be compulsive circling but affected cattle often stand motionless with the head pushed into a corner. The animal is blind in the opposite eye—the side away from the abscess.
Middle ear infections may cause pressure that affect balance and behavior. These infections (sometimes called vestibular disease) are often due to ascending infection from the eustachian tube—the canal that connects the middle ear to the nasopharynx (the upper throat and the back of the nasal cavity) at the back of the mouth. The major clinical sign is a 5° to 10° head tilt to the affected side. There may be loss of balance, with the animal leaning and circling or drifting toward the affected side.
Polioencephalomalacia (PEM), also called Cerebrocortical necrosis (CCN) is a sporadic condition affecting growing cattle--associated with feeding high concentrate rations and thiamine deficiency. This deficiency reduces energy availability to the brain, which leads to a type of brain degeneration called polioencephalomalacia.
Affected animals are dull and often go off by themselves. Signs include high head carriage and staggering. The animal may be blind and have exaggerated reactions to sudden touch and loud noises. As the disease progresses, the animals often head-press into corners, with frequent teeth grinding. Unless treated, seizures are common during the later stages.
Listeriosis occurs sporadically in cattle, and most cases are associated with feeding poorly fermented/conserved forages. These animals are often found with the head forced through a gate or under a feed trough or wedged in some other space.
Other signs include reduced appetite over several days resulting in gaunt appearance, drop in milk production in lactating cattle, weakness and weight loss. Loss of saliva leads to rumen impaction and abdominal pain manifests as an arched-back stance and frequent teeth grinding.
Nervous ketosis can also cause behavioral changes. Acetonemia (ketosis) is a metabolic disease that occurs when a lactating cow is in a severe state of negative energy balance—when her energy demands (for high milk production) exceed energy intake.
In mild cases the cow may simply be off feed, but in more serious cases there may signs of nervous dysfunction, including abnormal appetite (eating strange things), abnormal licking, incoordination and abnormal gait, bellowing, and aggression, or head pressing.
Lead poisoning can affect the brain. The common clinical signs are associated with the GI tract and nervous systems. In acute cases, signs appear within 24 to 48 hours after exposure and include incoordination, blindness, excessive salivation, spastic twitching of the eyelids, jaw champing, teeth-grinding, muscle tremors, and convulsions.
The animal may wander aimlessly and press its head into obstacles.
Organophosphorous poisoning signs include drooling (excess salivation), miosis (constriction of the pupils of the eyes), frequent urination, diarrhea, colic, and difficult breathing due to increased bronchial secretions and bronchoconstriction. If the animal wanders around it may head-press when it comes to an obstacle in its way.
Basillar empyema (pituitary abscess) is swelling that can also cause nervous signs. This condition occurs sporadically but is often associated with the insertion of bull rings that create an infection in the nostrils. If the infection spreads to blood vessels around the pituitary gland, this creates the basillar empyema (swelling). The clinical signs of basillar empyema are variable.
Bovine Spongiform Encephalopathy (BSE) also affects the brain and may cause head pressing. Signs include chronic weight loss and decreased milk yield over several weeks. Affected cattle leave the herd and stand with arched back and a wide-based stance. They become nervous, apprehensive and over-react to sudden movements and loud noises.
Hind leg incoordination makes it difficult when they encounter obstacles such as steps, ramps and narrow gateways. When confined in a chute or stocks, stimulation often provokes violent kicking and bellowing. Affected cows may be aggressive towards other cattle in the group.
There is rapid progression of clinical signs and cattle may become weak and recumbent within 2 to 10 weeks of first clinical signs.
Hypomagnesaemia (deficiency of magnesium) is often called grass tetany or grass staggers. Signs include lack of appetite, lethargy, weakness, muscle tremors, excitement or aggression. The animal is usually down and can’t get up, but if it is still mobile it may be uncoordinated and head-press against obstacles.
Rabies in cattle affects the brain and clinical signs are variable—including lack of appetite, incoordination, lameness, excessive salivation, and aggression. Rabid cattle may appear to be choking because of inability to swallow. The animal may wander blindly and press into obstacles.
Prevention
Some of these neurologic disorders can be prevented by various strategies to prevent the specific disease or condition that causes them (which for some diseases may include vaccination) but others are difficult to prevent.
Treatment
Some of these conditions and diseases can be treated while others cannot. Proper diagnosis must be made by a veterinarian, and appropriate treatment (if any) initiated.