Dog Parvo Symptoms

In the presence of megaesophagus

If the animal has megaesophagus or aspiration pneumonia in conjunction with myasthenia gravis, the megaesophagus and aspiration pneumonia should receive the initial treatment since they have very poor prognosis.    Megaesophagus rarely responds to treatment.  The animals with megaesophagus or aspiration pneumonia should be fed in small quantities in an elevated position and remain standing for 5 to 10 minutes following eating.  In severe cases where regurgitation and aspiration are a very big problem, a percutaneous gastrostomy tube may be inserted for the delivery of nutrients, fluid, and medications.

If thymoma is present

If thymoma is present, thymectomy (thymus removal) is recommended.

 Anticholinesterase drugs

Both acquired and congenital forms of myasthenia gravis are treated with long-acting anticholinesterase drugs such as pyridostigmine bromide or neostigmine.  However, the number of feline species with congenital myasthenia gravis is too small to really comment on an effective treatment.  Anticholinesterase drugs inhibit enzymatic hydrolysis (breakdown) of acetylcholine at the neuromuscular junction.  The drug prolongs the interaction of acetylcholine with the acetylcholine receptors in the neuromuscular junction.

Dosage ranges

Pyridostigmine bromide:

    .5 – 3.0 mg/kg PO BID-TID

Neostigmine:

    .5 mg/kg PO BID-TID      (This is injectable neostigmine and is used if megaesophagus is present and oral drugs are not efficient.)

Corticosteroids

Corticosteroids are used for the treatment of animals with the acquired form of myasthenia gravis that do not respond well to anticholinesterase therapy.  These drugs are only recommended if aspiration pneumonia is not present.

Dosage ranges

Prednisone:

    start with 0.5 mg/kg/day and increased in 0.5 mg/kg/day increments every 2-4 days until a total of 2.0 mg/kg/day is reached 

Cytotoxic agents

Cytotoxic agents are generally given to thoseanimals that do not respond to corticosteroids. These agents are effective in suppressing the production of antibodies to acetylcholine receptors.

Dosage ranges

Azathioprine (Imuran):

                   
2mg/kg PO SID – QOD

Latin Abbreviations

SID  every day daily

BID  two times a day

TID  three times a day

QOD every other day

Other abbreviation

IM  intermuscular

IV  intervenous