Magnetic resonance imaging (MRI) is one of the more detailed methods for diagnosing diseases of the brain, spinal cord, spine and some parts of the peripheral nervous system. Taking the images is only one stage of the procedure. In practice, it starts earlier: assessing whether the patient can undergo the examination, selecting the area to scan and preparing for anaesthesia.

In veterinary neurology, a history and neurological examination come first. Their purpose is neurolocalisation: identifying where in the nervous system the problem is most likely to be. A dog with seizures needs a different examination from a dog with sudden hindlimb weakness or neck pain. The veterinarian decides whether to image the brain, a particular spinal cord region, a nerve plexus or another area. MRI requires complete stillness.

Even a slight movement of the head or a limb can produce artefacts that make the images harder to interpret. For this reason, MRI in dogs and cats is performed under general anaesthesia. The veterinarian assesses the patient’s condition and anaesthetic risk beforehand. The tests required depend, among other things, on age, concurrent disease and how urgent the procedure is. A clinical examination and basic blood tests are sufficient for some patients.

Older dogs and animals with heart or respiratory disease or other health problems may need additional tests. A dog usually needs to fast for a specified period before MRI. The anaesthetist should determine this period according to the patient’s age and condition. Do not stop long-term medication on your own. This is especially important for anti-seizure medication: stopping it suddenly can increase the risk of seizures. An intravenous catheter is placed before the procedure.

The catheter allows anaesthetic medicines, fluids and, if needed, contrast agent to be given. After induction of anaesthesia, the dog is intubated and its vital signs are monitored. The patient is then positioned appropriately. For a brain scan, the head is placed in a dedicated coil; for a spinal scan, positioning depends on the region being examined. The protocol may be extended according to the suspected disease and findings during the scan. Contrast is not needed for every examination.

The veterinarian decides whether to use contrast on the basis of the indication and the pre-contrast images. Contrast is particularly useful when tumours, inflammatory processes or certain vascular lesions are suspected. After imaging, the animal is brought out of anaesthesia. At this stage, we focus on keeping the patient warm and monitoring vital signs. The breathing tube is removed when protective reflexes have returned and the patient can breathe safely without it. Observation continues for minutes or hours afterwards.

Immediately after anaesthesia, a dog may be sleepy, temporarily less coordinated or disoriented. The images are available straight away, but a full interpretation requires analysis of all sequences. In emergencies, the veterinarian can assess the main findings immediately; a detailed report requires review of the entire examination. The examination is supplied on CD. The complete report takes a few working days and is sent by email.

Preparation mainly concerns safe anaesthesia and collecting the information needed to plan the scan. Since MRI is usually performed under general anaesthesia, several hours of fasting are generally recommended. Preparation differs for a healthy adult dog, a very young animal, a patient with diabetes or a dog in a serious condition. Water can often be offered for longer than food, but the anaesthesia team determines the exact instructions.

The standard recommendation is to withhold food for 8 hours before anaesthesia. If you are unsure about the fasting period, please contact the facility by phone or email so we can clarify the details. Do not stop long-term medication without consultation. Anti-seizure treatment needs particular attention: missing a dose can lower the medicine’s concentration and increase the risk of another seizure. Tell the veterinarian about all medicines and supplements before the examination.

Previous blood test results, echocardiography, neurological consultation reports, X-rays, CT or MRI scans, cerebrospinal fluid results and records of other diseases are valuable. If imaging has already been performed, please provide the original DICOM images as well as the report. Phone videos of seizures, balance problems or unusual episodes can be very helpful.

Preparing a cat is similar to preparing a dog, but transport-related stress, concurrent diseases and appropriate anaesthetic assessment are particularly important. MRI requires stillness and is therefore performed under general anaesthesia. The fasting period depends on the cat’s age and clinical condition. For most cats, 8 hours is sufficient. Excessive fasting can be harmful for very young, weak or metabolically unwell animals. Report all medication before the examination.

This includes anti-seizure, cardiac and hormonal medicines. Bring your cat in a secure carrier. If travelling causes severe stress, discuss ways to reduce it with the veterinarian beforehand. Do not give sedatives on your own before planned anaesthesia. Bring all previous medical records and, for episodic symptoms or gait abnormalities, videos recorded at home.

How quickly the symptoms developed is often as important to the neurologist as their current appearance. Do not stop long-term medication without consultation. Take particular care with anti-seizure treatment: missing a dose can lower the medicine’s concentration and increase seizure risk. Tell the veterinarian about all medicines and supplements before the examination.

The duration depends on the area examined, the protocol and whether additional sequences or contrast are needed. Imaging itself often takes tens of minutes, but the patient stays at the facility longer. MRI consists of multiple sequences, each showing tissues differently and requiring a separate acquisition. The examination may include several imaging planes, T1, T2 and FLAIR sequences, blood-sensitive sequences and a post-contrast series.

The scan may take longer if a finding requires closer assessment, additional planes are needed or the area scanned must be extended. Preparation for anaesthesia, positioning and recovery must also be included. In practice, the whole procedure takes about 3–4 hours from arrival at the facility to recovery.

The owner stays with the patient until the anaesthetic consultation immediately before each examination. We then phone to arrange collection once the procedure is complete, the patient has recovered and there are no concerning symptoms.

Contrast is not necessary for every MRI examination. In veterinary neurology, it is used mainly when the way a lesion takes up contrast can help distinguish between conditions. Most MRI contrast agents contain gadolinium. Given intravenously, they change the magnetic properties of tissues and highlight areas with increased blood supply or disruption of normal vascular barriers, among other changes.

Enhancement can occur in tumours, inflammatory or vascular lesions and some normal anatomical structures. Contrast is often used when a tumour, inflammation of the brain and meninges, nerve root inflammation, infection or certain nerve and paraspinal tissue lesions are suspected. Many conditions can be recognised without contrast, so its use is individual to each case. MRI contrast agents have long been used in human and veterinary medicine and have a good safety profile.

The vast majority of patients have no noticeable adverse effects; adverse reactions are rare. The use of contrast should therefore not in itself be a cause for concern. When indicated, its diagnostic benefit is usually substantial: in many cases, post-contrast imaging is what allows the nature, exact boundaries and activity of a lesion to be assessed. Not every MRI requires gadolinium.

The veterinarian decides based on the area examined, the suspected condition and the initial MRI sequences. Contrast is used when it can provide important information affecting diagnosis, treatment or surgical planning.

MRI does not use X-rays, but its strong magnetic field and the need for anaesthesia mean that an anaesthetic assessment is required. An important consideration is metal implants or foreign bodies that might be unsafe in the magnetic field or cause substantial artefacts. Tell the veterinarian about all previous operations and implants. An orthopaedic implant does not automatically rule out MRI.

The material, location and MRI compatibility matter. Many implants used today are not a contraindication. For some patients, general anaesthesia is the greater limitation. Severe circulatory failure, breathing problems or unstable electrolyte levels may require stabilisation first or a tailored anaesthetic protocol.

During the assessment, the veterinarian considers safety in detail and may decline to perform the scan if further tests or stabilisation are needed first. If you have concerns about safety, contact the facility to agree a plan.

MRI and computed tomography (CT) are complementary rather than competing examinations. They use different physical principles and each provides more information in particular areas. The choice should follow the clinical question, not an assumption that one is always more accurate. MRI distinguishes soft tissues very well. In neurology, it is particularly useful for the brain, spinal cord, intervertebral discs and some nerve structures. It can show inflammatory, neoplastic and vascular lesions, swelling and spinal cord abnormalities.

CT shows bone structures very well. It is particularly useful for skull and spinal injuries, complex bone abnormalities and planning surgery involving 3D-printed implants. It is also much faster, which matters for injured or unstable patients. In veterinary neurology, MRI usually provides more information than CT. For example, with suspected brain tumours, encephalitis, stroke, syringomyelia or intervertebral disc disease, MRI allows a much more detailed assessment of nervous tissue and the degree of damage.

CT may reveal some of these abnormalities, but it is less sensitive for assessment of the brain and spinal cord. Unlike MRI, CT uses X-rays. This does not mean that CT is unsafe. The radiation dose is controlled and adjusted to obtain the necessary image quality with as little exposure as possible. Both CT and MRI are widely used, safe diagnostic methods when performed for appropriate indications and with a suitable protocol.

In practice, the choice depends primarily on which structures need assessment, rather than concern about the safety of the examination itself.

Yes, because canine MRI is performed under general anaesthesia. Fasting instructions depend on age, health and the procedure. Anaesthesia reduces the reflexes that protect the airways. Reducing the amount of food in the stomach lowers the risks associated with regurgitation and aspiration. Excessively long fasting offers no additional benefit. Puppies, very small dogs, metabolically unwell animals and seriously ill patients may need individual instructions.

Food is usually withheld for 8 hours and water removed 2–3 hours before the appointment. If your pet has a particular condition or you have concerns, contact the facility beforehand to agree a plan with our anaesthetist.

After MRI, administration of the medicines maintaining anaesthesia is stopped and recovery begins. This is still part of anaesthesia and requires continuous monitoring. Your pet remains under staff supervision until fully awake. Breathing, circulation, blood glucose, body temperature and recovery of awareness are assessed. The breathing tube is removed after protective reflexes, particularly coughing, return. Temporary sleepiness, incoordination and disorientation may occur.

Assessment can be more difficult in a neurological patient because some abnormalities may reflect the underlying disease. The animal should therefore be discharged only when it can safely return home. Provide a quiet, safe place and temporarily restrict access to stairs and surfaces from which it could fall. Food and water may be offered after arriving home, initially in small amounts while observing the response. If there is no coughing or vomiting, the animal can be fed normally after a few minutes.

Circling can be a neurological symptom, but not every animal walking around a room has brain disease. The pattern and direction of movement, behaviour and accompanying symptoms matter. Repeated circling in one direction can occur with forebrain disease, involving structures such as the cerebral hemispheres. Behavioural changes, seizures, altered awareness, balance problems or visual disturbances may accompany it. Possible causes include tumours, inflammation, vascular events, trauma and other brain disorders.

A dog with severe balance problems may also move in arcs or circles, often with head tilt, nystagmus and falling over. Older dogs with cognitive dysfunction may wander aimlessly, get stuck in corners or develop changes in sleep patterns. If circling starts suddenly or occurs with other neurological abnormalities, a neurological examination helps localise the problem and determine the next diagnostic steps.

In this situation, it is best to visit the nearest veterinary practice and, if needed, arrange a neurological consultation.

Sudden loss of balance is a common reason for a neurological consultation. A dog may tilt its head, fall over, move in arcs, have nystagmus or be unable to stand unaided. This often suggests vestibular disease. A peripheral vestibular disorder affects the inner ear or vestibulocochlear nerve; a central vestibular disorder involves the brainstem or cerebellum. Distinguishing these locations is essential for further investigation.

Causes include middle or inner ear disease, particularly inflammation or infection, idiopathic vestibular syndrome, inflammatory processes, tumours and vascular events. The neurological examination and history guide the decision to treat or investigate further. MRI is particularly useful when findings suggest a central lesion, symptoms progress or the presentation is unusual. A neurological consultation is recommended to establish the diagnostic and treatment plan.

A seizure is a clinical sign. Some dogs have idiopathic or primary epilepsy, an inherited genetic disorder, but seizures can also result from structural brain disease, metabolic problems or toxins. MRI mainly looks for structural changes. A typical dog with idiopathic epilepsy has a normal neurological examination between seizures and develops the condition within a characteristic age range. This pattern does not, however, rule out brain disease with complete certainty.

Brain imaging is more often recommended when the first seizure occurs at an unusual age, the neurological examination between episodes is abnormal, seizures are atypical or progressive, cluster seizures or status epilepticus occur, or the course raises suspicion of structural disease. MRI may reveal tumours, meningeal inflammation, consequences of vascular events, developmental abnormalities or other structural lesions.

A normal MRI is an important diagnostic finding, but idiopathic or primary epilepsy is diagnosed from the whole clinical picture and by excluding other causes. When seizures occur, arranging a neurological consultation is a useful first step towards agreeing a plan with the veterinarian.

Symptoms depend more on a brain tumour’s location than its size. A forebrain lesion may cause seizures and behavioural changes; a brainstem tumour may cause balance problems and cranial nerve deficits while awareness and interaction remain normal. Signs can include seizures, aimless circling, altered behaviour, visual or balance problems, weakness or paresis, and altered consciousness.

Routine blood tests do not detect tumours and may be normal despite a substantial intracranial lesion. They are nevertheless needed to assess general health and exclude some metabolic diseases that mimic neurological symptoms. MRI establishes the location, size, growth pattern and effect on surrounding structures. It often suggests the most likely tumour group, but definitive histopathological diagnosis requires examination of tissue.

In many cases, particularly when a lesion is well localised and surgically accessible, complete or partial removal is possible. In appropriately selected patients, neurosurgery at our clinic can substantially improve comfort, reduce neurological signs and, in some cases, achieve remission. If surgery is not possible or is not the best option, there are still ways to help.

Appropriate palliative treatment can often control symptoms and preserve a good quality of life for as long as possible.

Meningoencephalitis can have an infectious or immune-mediated cause. An important group in neurological practice is MUO — meningoencephalitis of unknown origin — which is thought to be immune-mediated. Signs depend on the part of the central nervous system affected. They may include seizures, altered consciousness or behaviour, balance problems, paresis, pain in the affected region and neurological deficits caused by the damage.

MRI may show changes suggesting inflammation, but imaging alone does not always identify the cause. Some inflammatory lesions resemble tumours or vascular lesions. Investigation therefore often includes cerebrospinal fluid analysis and tests for selected infections as well as imaging. Treatment for immune-mediated inflammation differs fundamentally from treatment for infection, making identification of the cause important.

When this diagnosis is made, treatment is selected during a neurological consultation and the patient is assessed on an ongoing basis. Prognosis depends mainly on the cause, extent of the lesions and how quickly treatment begins. Many cases can be treated successfully, and with early diagnosis some patients regain function and achieve complete remission of symptoms. Even severe disease does not automatically mean a poor prognosis.

Appropriate anti-inflammatory, anti-oedema, anti-seizure and symptomatic treatment can substantially improve comfort and reduce signs. Prompt investigation is important, usually including MRI and, in selected cases, cerebrospinal fluid examination.

Hydrocephalus is pathological enlargement of the brain’s ventricular system associated with disturbed cerebrospinal fluid circulation. Enlarged ventricles on imaging do not always indicate clinically significant hydrocephalus. Congenital forms are more common in some toy and brachycephalic breeds, with signs sometimes appearing early in life. These can include behavioural changes, seizures, visual problems and an abnormal gait. Hydrocephalus may also develop secondary to other processes that obstruct cerebrospinal fluid flow.

MRI assesses the ventricles, brain tissue and any cause of impaired fluid flow. Interpretation should not rely on ventricular size alone: surrounding tissue changes and agreement with the neurological signs also matter. Hydrocephalus does not always carry a poor prognosis. In congenital cases especially, appropriate treatment can allow many dogs to live comfortably and markedly reduce neurological symptoms.

Some patients need only medical management and regular check-ups. More severe cases may be considered for surgery to drain excess cerebrospinal fluid. Prognosis depends mainly on severity, age and the amount of brain tissue damage before treatment. Early diagnosis, before changes become advanced, can allow a good or very good quality of life.

In acquired hydrocephalus, which may accompany tumours, inflammation or impaired cerebrospinal fluid drainage, prognosis also depends on the underlying disease. Even when the cause cannot be eliminated completely, suitable treatment often lowers intracranial pressure, reduces neurological signs and significantly improves comfort.

Owners often use the term “Chiari malformation”, although “Chiari-like malformation” is more appropriate in veterinary medicine. It is particularly associated with Cavalier King Charles Spaniels but can occur in other breeds. It involves a congenital disturbance in the relationship between the structures of the caudal cranial fossa, the cerebellum and the foramen magnum region. Altered space and cerebrospinal fluid flow may contribute to syringomyelia — fluid-filled cavities in the spinal cord.

Signs can include neck pain, sensitivity to touch, reluctance to move and characteristic scratching near the neck without the paw touching the skin. Not every dog with MRI abnormalities has clinical signs. MRI is the primary examination for the brain, craniocervical junction and spinal cord. It helps assess severity and select treatment. Prognosis depends mainly on the neurological signs, the presence and extent of syringomyelia and the response to treatment.

In some dogs, the anatomical changes are incidental MRI findings and cause no significant discomfort throughout life. With mild or moderate symptoms, medical treatment often provides good pain control and quality of life for years. The condition is chronic, however, and some patients need long-term treatment with periodic adjustments.

Syringomyelia is the formation of cavities within the spinal cord filled with fluid similar to cerebrospinal fluid. It is well known in Cavalier King Charles Spaniels but can affect other breeds and accompany different disorders. It is most often associated with disturbed cerebrospinal fluid flow. Chiari-like malformation is an important cause, but other abnormalities affecting fluid dynamics can also lead to spinal cord cavities.

Clinical signs may include neck pain, sensitivity to touch, vocalisation, reluctance to be active, scratching episodes, scoliosis and, in more advanced cases, neurological problems affecting the limbs. As the lesion is inside the spinal cord, MRI allows it to be visualised directly. It measures the length and width of the cavities and helps identify the condition impairing fluid flow. Prognosis depends mainly on the severity of neurological signs, the extent of syringomyelia and treatment response.

In some dogs, the anatomical changes are incidental MRI findings and cause no significant discomfort throughout life. With mild or moderate symptoms, medical treatment often provides good pain control and quality of life for years. The condition is chronic, however, and some patients need long-term treatment with periodic adjustments.

Facial nerve paralysis may cause a drooping lip and ear, facial asymmetry and difficulty blinking. It results from damage to the seventh cranial nerve or structures along its course. The affected side may show absent normal eyelid movement, a drooping lip or ear and reduced nostril movement. Inability to blink increases the risk of corneal drying and injury. The facial nerve runs a long course from the brainstem to the facial muscles.

Damage may be associated with middle or inner ear disease, inflammation, trauma, a tumour or idiopathic neuropathy. Concurrent balance problems can indicate involvement of vestibular structures. A neurological consultation is the best way to plan further investigation. Prognosis depends mainly on the cause and extent of nerve damage. In idiopathic cases, comfort and quality of life are generally good.

Some dogs gradually regain nerve function over weeks or months, although mild facial asymmetry may remain permanently. When neuropathy is secondary to ear inflammation, trauma, another inflammatory process or compression, prognosis depends on successful treatment of the underlying disease. Partial or complete nerve recovery may follow, but it can be slow. The main practical concern is incomplete eyelid closure on the affected side, which can dry the cornea and cause ulcers.

With appropriate eye protection, most dogs function very well even if some neurological deficit is permanent.

In veterinary neurology, stroke mainly refers to acute ischaemic or haemorrhagic events in the brain. Signs often appear suddenly and reach their greatest severity quickly. They may include sudden balance problems, head tilt, weakness on one side, altered consciousness, sudden visual problems or other asymmetrical neurological deficits. Not every sudden symptom is a stroke: vestibular disease, inflammation, poisoning, seizures and acute spinal cord disorders can have a similar onset.

A neurological examination localises the lesion, but imaging is often needed to establish its nature. MRI is the main method for imaging vascular brain lesions. Appropriate sequences help assess their type and age and distinguish them from some other disorders. Prognosis varies greatly and depends mainly on location, extent, concurrent disease and neurological status in the first few days.

The initial appearance can be alarming: a dog may suddenly lose balance, fall over, have nystagmus, head tilt, paresis or altered consciousness. Some patients nevertheless improve much faster than their first-day signs suggest. Small ischaemic strokes often have a good prognosis, with noticeable improvement within days. Further neurological recovery may take several weeks.

The brain has some capacity to adapt and take over functions of damaged areas, so a very good quality of life may be regained even after initially severe signs. Prognosis is more guarded with extensive lesions, haemorrhagic strokes, severe impairment of consciousness or serious underlying disease. After MRI confirms a lesion, it is important to investigate causes such as cardiovascular disease, clotting disorders, hypertension, endocrine disease or cancer.

For many patients, particularly those with small ischaemic lesions, prognosis is good. Appropriate supportive treatment and rehabilitation can allow substantial or even complete recovery.

A seizure reflects abnormal electrical brain activity rather than being a disease in itself. A cat may have a generalised seizure with loss of consciousness, collapse, convulsions, salivation and involuntary urination or defecation. Focal or partial seizures also occur, with subtler signs such as facial twitching, lip-smacking, sudden running, dilated pupils, unusual aggression or brief loss of interaction. Afterwards, the cat may be confused, weak, restless, temporarily blind or very hungry.

Causes include metabolic or toxic problems such as low blood glucose, liver disease, electrolyte abnormalities and poisoning. Seizures may also arise from structural brain changes: tumours, inflammation, developmental abnormalities, trauma or vascular events. Idiopathic or primary epilepsy occurs in cats, but other causes must be excluded first. Investigation begins with a history, clinical and neurological examinations and appropriate blood tests.

A phone video is very helpful because not every tremor, fainting episode or behavioural change is a seizure. Brain MRI is particularly indicated if the first seizure occurred in an older cat, neurological abnormalities persist between episodes, seizures recur or cluster, or their features suggest brain disease. In selected cases, cerebrospinal fluid analysis and tests for infectious diseases follow MRI.

A single short seizure requires consultation. A seizure lasting several minutes, repeated seizures without full recovery of consciousness, or persistent severe neurological signs are emergencies in which hospital stabilisation should be considered. Prognosis depends on the cause. Some cats’ seizures can be controlled effectively with anti-seizure medication, and identifying an underlying disease allows targeted treatment.

Signs depend mainly on the lesion’s location, rate of growth and effect on surrounding nervous tissue. Forebrain lesions may cause seizures, aimless walking, circling in one direction, visual disturbances and behavioural changes. A cat may become less interactive, hide, vocalise or behave differently. Brainstem and cerebellar tumours can cause loss of balance, nystagmus, head tilt, incoordination, paresis and cranial nerve dysfunction. Symptoms do not always begin suddenly.

They may develop over weeks or months, with a subtle change in activity or behaviour as the first sign. Meningioma is one of the more frequently diagnosed primary intracranial tumours in cats, particularly older cats. Other possibilities include lymphoma, glioma, pituitary tumours and metastases; inflammatory and infectious diseases may produce similar signs. Blood tests cannot directly detect a brain tumour.

Blood results may be normal despite a substantial lesion, but they help assess general health, exclude metabolic problems and prepare for anaesthesia. MRI is the main brain imaging examination. It identifies location, size and growth pattern and assesses swelling, compression and contrast enhancement. It often suggests the most likely tumour type, although a definitive diagnosis may require tissue examination.

Options include surgery, radiotherapy and symptomatic treatment, including anti-seizure and anti-oedema treatment. Some feline meningiomas are well defined and can be surgically removed, but suitability depends on location, extent and the patient’s condition. Even when treatment of the cause is not possible, palliative care may reduce symptoms and improve comfort. Prognosis must be assessed individually using the neurological examination, MRI and suspected lesion type.

Loss of balance may appear as staggering, falling, moving in arcs, head tilt, nystagmus or difficulty maintaining posture. Vestibular disease is a common cause. The vestibular system controls orientation of the head and body in space. A peripheral disorder affects the inner ear or vestibulocochlear nerve; a central disorder affects the brainstem or cerebellum. Distinguishing these locations matters for investigation, treatment and prognosis.

Peripheral causes include middle or inner ear inflammation, inflammatory polyps, trauma, certain medicines and idiopathic vestibular syndrome. Central problems may involve encephalitis, FIP, toxoplasmosis, tumours, vascular events or thiamine deficiency. Incoordination can also result from disease of the cerebellum, spinal cord or peripheral nerves, general weakness or metabolic abnormalities. Observing the gait alone is therefore not enough to identify the cause.

The neurological examination assesses awareness, posture, postural reactions, eye movements and cranial nerve function, among other things. When ear disease is suspected, otoscopy and imaging of the tympanic bullae can help. MRI is particularly valuable for signs suggesting a central lesion, progressive symptoms, altered consciousness, limb weakness, postural deficits or other neurological abnormalities. Sudden loss of balance can look dramatic without necessarily being irreversible. Prognosis depends on location and cause.

A cat that cannot stand, is vomiting severely, has altered consciousness, has suffered trauma or is deteriorating rapidly needs urgent veterinary assessment.

Neurological signs in an older cat may initially be subtle and mistaken for normal ageing. Behavioural changes, night-time vocalisation, disorientation, aimless walking, litter tray problems, weakness, incoordination, seizures or sudden loss of balance nevertheless require veterinary assessment. Cognitive dysfunction is one possible cause of behavioural changes, but it is diagnosed after other diseases have been excluded.

Similar signs can result from pain, hyperthyroidism, hypertension, kidney disease, impaired vision or hearing, metabolic disorders and brain lesions. Tumours, including meningiomas, lymphomas and other intracranial masses, become more important in older cats. Vascular events, encephalitis, vestibular disease and neuropathies affecting the limbs are also possible. Hypertension can cause sudden blindness and neurological signs, so blood pressure measurement is an important part of assessing an older patient.

Investigation usually includes a detailed history, clinical and neurological examinations, blood pressure measurement, blood and urine tests and assessment of concurrent disease. Home videos help evaluate unusual behaviour, gait and seizures. If findings suggest brain disease, MRI can look for tumours, inflammatory and vascular lesions and other structural abnormalities. Cerebrospinal fluid examination and infectious disease tests may be added in selected cases.

Age alone should not be the sole reason to forgo diagnosis or treatment. Anaesthetic risk is assessed from the patient’s actual condition and concurrent disease. Many conditions in older cats can be treated or controlled, and prompt diagnosis can reduce symptoms and maintain quality of life for longer.

Brain MRI is performed when the neurological examination or disease course suggests an intracranial lesion. It shows soft tissues in detail, allowing assessment of brain tissue, brainstem, cerebellum, ventricles, meninges and parts of the cranial nerves. Indications may include seizures, changes in consciousness or behaviour, circling in one direction, unexplained vision loss, balance problems, nystagmus, head tilt and cranial nerve dysfunction.

MRI is especially important when symptoms progress, deficits persist between seizures or the first seizure occurred in an older cat. It can reveal tumours, inflammation, vascular lesions, developmental abnormalities, hydrocephalus, swelling and some effects of trauma. Imaging alone cannot confirm every neurological disease. A normal MRI does not exclude metabolic or toxic problems or all inflammatory processes.

Results are therefore interpreted alongside the history, neurological examination, blood tests and, when indicated, cerebrospinal fluid analysis and infection tests. MRI requires complete stillness, so cats undergo general anaesthesia. An anaesthetic assessment is performed beforehand; additional tests depend on age, general health and concurrent conditions. The decision to perform MRI is best made after a neurological consultation.

The consultation enables neurolocalisation, selection of the right area to scan and planning a protocol tailored to the patient’s specific problem.

Brain inflammation in cats may also involve the meninges and/or spinal cord. Signs depend on location and extent and can include seizures, behavioural changes, altered consciousness, loss of balance, head tilt, nystagmus, aimless circling, visual problems, paresis and cranial nerve dysfunction. Fever, neck pain and general illness may also occur, but their absence does not exclude central nervous system inflammation. Looking for infectious causes is particularly important in cats.

Inflammation may occur with FIP, toxoplasmosis, bacterial or fungal infections, or infection spreading from the middle or inner ear. Presumed immune-mediated inflammation or inflammation with no confirmed cause is diagnosed less often. Distinguishing infection from immune-mediated disease directly affects treatment, because immunosuppressive therapy can be dangerous with an unrecognised infection. Investigation starts with neurological examination and laboratory tests.

MRI may show inflammatory lesions, swelling, meningeal changes, inflammation of the ventricular lining and abnormal contrast enhancement. The appearance is not always characteristic, and some cats with inflammation have a normal MRI. Inflammatory lesions can also resemble tumours or vascular events. In suitable cases, imaging is therefore followed by cerebrospinal fluid examination and tests chosen for the suspected infections.

Treatment depends on the established or most likely cause and may include antimicrobial, anti-inflammatory, anti-oedema, anti-seizure and supportive treatment. Prognosis varies with the cause, extent of damage and speed of starting appropriate therapy. Worsening consciousness, cluster seizures and rapid deterioration require urgent veterinary care.

The neurological form of feline infectious peritonitis can affect the brain, meninges, ventricular system and spinal cord. Signs depend on lesion location and may include incoordination, balance problems, nystagmus, tremors, seizures, behavioural changes, limb weakness or paresis and cranial nerve dysfunction. Some cats also have general signs such as fever, weight loss, weakness, reduced appetite, eye changes or fluid in body cavities.

Neurological FIP may also occur without effusion or all the typical general signs, making diagnosis difficult. MRI may show abnormal contrast enhancement of the ventricular lining and meninges, enlarged ventricles, hydrocephalus, periventricular lesions, brainstem abnormalities and inflammatory foci in the brain or spinal cord. MRI can identify location and extent, support clinical suspicion and help distinguish inflammation from some neoplastic, vascular and developmental conditions.

Diagnosis combines the history, symptoms, neurological examination, blood tests, MRI and appropriately selected additional tests. Cerebrospinal fluid analysis can provide valuable information, but sampling requires a safety assessment because it may be contraindicated with raised intracranial pressure. Any single test, including a coronavirus test, must be interpreted within the overall clinical picture. Prompt diagnosis and appropriate management are important for prognosis.