What is ataxia?
Ataxia (pronounced a-tak-sia) is defined as a loss of muscle coordination (incoordination/unsteady gait) which is caused by disorders that affect your cat’s sense of motion, and it is a symptom of an underlying condition and not a disease in itself.
There are three clinical types of ataxia in cats, cerebellar, vestibular and sensory.
- Cerebellar – The cerebellum is a part of the brain responsible for balance and coordination; this type of ataxia occurs when the cerebellum becomes damaged or inflamed.
- Vestibular – The vestibular system located deep within the inner ear as well as nerves that travel to the brain. The vestibular system is the sensory system responsible for balance.
- Sensory – This type of ataxia relates to a loss of proprioception, the sense of position and movement of the body. For example, how a person can touch the tip of their nose with a finger even if their eyes are closed. This is due to dysfunction or damage to the nerves of the spinal cord.
Causes
There are several causes of ataxia in cats; some causes can overlap between the types of ataxia.
Cerebellar (brain):
- Viral infection such as panleukopenia or feline infectious peritonitis
- Parasitic infection of the brain including Toxoplasma. gondii (toxoplasmosis), Cuterebra spp larvae
- Any damage to the brain which results in an invasion into the brain tissue including bleeding from stroke or trauma, tumours such as lymphoma, meningioma, or a loss of blood supply to the brain
- Central nervous system vasculitis (inflammation of the arteries supplying the brain)
- Hypoglycemia (low blood sugar)
- Hypocalcemia (low blood calcium)
- Toxins including chocolate, lead, mercury, marijuana, barbiturates, bromethalin, ethylene glycol (antifreeze), ethanol, antibiotics (Metronidazole), snail bait, ivermectin and pesticides
- Cerebral hypoplasia – Damage to the cerebellum before birth can cause ataxia. Kittens can be affected if they’re exposed to the panleukopenia virus in utero. Other causes include prenatal exposure to toxins and malnourishment of the mother during pregnancy
- Meningitis – Inflammation of the meninges which are the protective membranes covering the brain and spinal cord
- Encephalitis – Inflammation of the brain (immune-mediated, infection, foreign body and unknown causes)
- Glycogen storage disease – An inherited condition in Norwegian Forest cats in which the body lacks the necessary enzymes to eliminate unwanted substances from the body
- Hydrocephalus (water on the brain)
- Tick paralysis
- Spider bites
- Catnip high
- Nutritional – Vitamin E or Thiamine (B1) deficiency
- Portosystemic shunt is a usually inherited condition in which there is an abnormal connection between the portal vein and the systemic circulation resulting in a build-up of toxins in the blood
Vestibular (ear):
- Inflammation
- Cancer of the bones surrounding the vestibular nerves
- Nasopharyngeal polyps
- Toxins (certain antibiotics)
- Congenital disorders
- Idiopathic (no known cause), seen more commonly in older cats
Sensory:
- Spinal trauma – Most often caused by a motor vehicle accident or a high fall
- Toxins
- Metabolic disorders
- Nerve damage due to diabetes
- Blocked blood vessel (spinal stroke)
- Infection
- Tumour
Other:
- Anemia (low red blood count)
- Electrolyte imbalances (potassium or calcium)
- Hypoglycemia (low levels of glucose in the blood)
Symptoms
Symptoms can vary depending on the type of ataxia your cat has as well as the underlying cause. Balance and coordination disturbances are the most common finding in cats with ataxia.
Generalised symptoms of ataxia:
- Clumsy drunken type movements, staggering wobbly gait
- Leaning to one side
- Weakness
Cerebellar:
- High stepping gait (known as goose-stepping)
- Swaying
- Tremors
Vestibular ataxia:
- The head may be tilted to one side, and the eye movements may be affected
- Vomiting (particularly with vestibular ataxia)
- Nystagmus, abnormal eye movements in which the eyes dart back and forth
- Hearing difficulty
- Walking in circles and possibly falling over
Sensory:
- Stiff legged gait, front legs may be rigid while the hind legs are splayed wide apart
- Poor coordination, misplacing feet
Other:
- Vomiting
- Anorexia (loss of appetite)
- Seizures
- Lethargy
Other symptoms may vary depending on the underlying cause of ataxia. For example, a cat high on catnip might also drool and roll on the floor, a cat who has ingested toxins may vomit.
Diagnosis
Your veterinarian will perform a complete physical examination of your cat and obtain a medical history from you. He may ask some questions about your cat, has he had access to any poisons, is he on any medications, how long has the ataxia been present, what are you feeding your cat, has he been in any recent accidents?
Other symptoms your cat may display can also indicate the possible cause. For example, if the cat has apparent head injuries or signs of trauma.
Diagnostic workup:
The veterinarian will decide which diagnostic tools to utilise depending on their index of suspicion.
- Baseline tests: Biochemical profile, complete blood count, and urinalysis to evaluate organ function and look for any abnormalities in the blood cells, look for signs of infection, inflammation, low blood calcium or glucose.
- Otoscopy: The veterinarian uses an otoscope (a tool with a magnifying lens and light) to examine the ears for signs of ear infection, polyps, and foreign objects.
- Cerebrospinal tap: A needle is inserted into the spinal canal to collect cerebrospinal fluid for diagnostic testing if encephalitis is suspected. The cat will be under anesthesia for this procedure.
- CT scan: An advanced non-invasive medical imaging technique that uses a combination of x-ray imaging and a digital computer to produce detailed 3-dimensional images to look for polyps deep within the middle ear.
- Imaging studies: Radiographs or ultrasound to evaluate for tumours, portosystemic shunt or fluid buildup (FIP).
- Antibody test: A serum blood test to look for IgG and IgM antibodies to T. gondii. High IgG antibodies are indicative of a prior infection while high IgM antibodies indicate an active infection.
- Fecal tests: Microscopic examination of a stool sample to look for T. gondii oocysts. Cats can shed oocysts for a short period of time, and may not be shedding oocysts by the time clinical signs develop.
Treatment
The goal of treatment is to address the underlying cause as well as provide supportive care.
Supportive care:
- Fluids, nutritional support, anti-nausea medications, anti-inflammatories and analgesics to relieve pain.
- Poor coordination can make eating and drinking difficult for your cat, so hand feeding may be necessary.
- Cats who are having severe problems moving may need to be turned every two hours to avoid bed sores.
- Severely affected cats may have toileting accidents, so the caregiver must be diligent in checking bedding for urine or feces and removing promptly. Place litter trays close to the cat, however, in some cases it may be necessary to regularly place the cat in the litter tray for cats who are unable to make their own way there.
Treat the underlying cause:
- Poisoning: Treatment for poisoning will depend on the toxin. Common therapies include gastric decontamination, activated charcoal to absorb remaining toxins as well as supportive care.
- Catnip high: This is only temporary and the cat will recover within a few minutes. Catnip doesn’t cause long term harm to cats.
- Head injury: The veterinarian will assess the extent of the injury. Cleaning up the wound and cage rest may be all that is necessary. More serious injuries may require surgery. If the brain has been damaged, this may or may not recover.
- Thiamine deficiency: Ensure the cat is fed a balanced diet; in severe cases, thiamine injections may be necessary.
- Cerebral hypoplasia: There is no cure for this condition; however, most kittens born with this condition can live a full and happy (albeit shaky) life.
- Spinal trauma: Treatment and outcome depend on the severity of the injury but may include cage rest or surgery.
- Hypoglycemia: Treat the underlying cause as well as manage symptoms such as administration of Vitamin D and calcium gluconate.
- Lysosomal storage disease: There is no treatment for this disease, and the prognosis is poor, in some cases, it can be temporarily managed with diet, but ultimately it is fatal.
- Hydrocephalus: Drugs to control symptoms, corticosteroids to reduce inflammation, but unfortunately, in severe cases, euthanasia is the only option.
- Tumours: Where possible, surgery to remove the tumour and/or radiation/chemotherapy to shrink the tumour.
- Portosystemic shunt: Surgery or medical management, such as dietary changes.
- Viral infection: There is no medical treatment for panleukopenia; the goal is to provide supportive care while the cat’s immune system fights the virus. This will include fluids to maintain hydration, nutritional support and blood transfusions. Sadly FIP is almost always fatal.
- Nasopharyngeal polyps: Surgery to remove the polyps.
- Brain stroke: Intensive supportive care which may include oxygen therapy to promote healing, anti-seizure medication, fluid therapy and intensive physiotherapy.
- Glycogen storage disease: Unfortunately, there is no cure for this condition, and most cats pass away by 18 months.
- Meningitis and encephalitis: Treat the underlying cause as well as anti-seizure medication and corticosteroids to reduce inflammation.
- Tick paralysis: Antiserum to treat I. holocyclus. Serum is the clear part of the blood containing antibodies and is obtained from dogs who have been made hyperimmune via repeated exposure to paralysis ticks. Sedation may be given before commencing treatment as stress can aggravate symptoms. Cats affected by D. andersoni or D. variabilis usually improve within 24-72 hours once the tick has been removed.
Home care
Keep the cat inside and confined in a safe area during recovery to prevent any injuries. Administer medications as prescribed by the veterinarian.
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