Cat & Dog - Fits, Seizures or 'Funny Turns'

Fits, seizures, convulsions or 'funny turns' (so-called absences) can be due to many causes.

Broadly these are grouped into:

• Metabolic problems: these include liver and kidney disease, hypoglycaemia (reduced blood sugar) and hypocalcaemia (reduced blood calcium concentration).
• Central Nervous System (CNS): these include inflammation, infection, or tumours (cancer) in the brain or spine.
• Toxins, trauma and generalised infections.  These may also result in seizure activity.
• Idiopathic causes.  Sometimes the causes of the seizures may be unknown.  This is known as idiopathic and sometimes may be hereditary (idiopathic epilepsy).

What investigations are required?

A thorough history and physical examination is the first step.  These may point to the underlying cause. Examples are:

• A puppy that is the 'runt of the litter' (i.e. much smaller than its litter mates), and who shows convulsive activity after eating, may have a congenital liver problem, such as a portosystemic shunt.  
• A bitch with a large litter of puppies that starts convulsing may be suffering from calcium deficiency (hypocalcaemia).  
• The dog that is known to scavenge can suddenly start seizuring as a result of ingesting a toxin etc.

During the clinical examination samples of blood, urine and faeces may be obtained if considered necessary.

What are these samples used for?

The blood sample may be used to provide a complete blood count (CBC).  This gives an evaluation of red blood cells, white blood cells and the platelet components of the blood.  If, for example, the total white cell count (WBC) is raised this may be an indication of an inflammatory or infectious problem affecting the central nervous system (CNS).  If the platelet count is low, this may be associated with bleeding episodes which, if they occur in the brain, can be responsible for seizures.

The serum, which is the liquid part of the blood sample, will provide serum biochemistry results.  Biochemistry results provide an indication of the state of the liver and kidneys, which if not functioning correctly, could be responsible for the seizures.  In addition, serum biochemistry will indicate levels of blood glucose and calcium.  Either of these, if low, could be responsible for the seizures.

Urine analysis is useful when interpreted in relation to the serum biochemistry results particularly if we are concerned about possible kidney related problems.

Are there other tests that may be necessary?

Once CBC and serum biochemistry results have been obtained it may be necessary to undertake more specific tests.  For example, in the case of suspected liver problems (such as  portosystemic shunts) tests to measure serum bile acids may be necessary.  If WBCs are raised, this points to a possible infectious cause and specific tests to establish causative organisms may be necessary, including feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), toxoplasmosis and canine distemper virus, etc.

The malfunction of the adrenal glands is sometimes a cause of seizures.  In this case an ACTH stimulation test may confirm hypoadrenocorticism (Addison's disease).  Conversely if the screening tests do not point to any specific metabolic, infectious or inflammatory cause it may be necessary to undertake further testing including cerebrospinal fluid- CSF- (the fluid that surrounds the spinal cord and brain) analysis.

Also, it may be considered necessary to refer the pet to a specialised centre for imaging studies using Computer Tomography (CT) or Magnetic Resonance Imaging (MRI) to rule out underlying tumours or congenital (present from birth) problems in the brain or spinal cord.

Please feel free to contact us to discuss any concerns.