An untested but interesting non-specific therapy for upper respiratory disease in cats is
maropitant therapy. Maropitant (Cerenia) inhibits tissue binding of substance P by antagonizing
tachykinin receptors. Tachykinins are released from degranulating mast cells during tissue
injury associated with allergy or inflammation. This group of substances includes bradykinin,
histamine, prostaglandins, serotonin, leukotrienes, tumor necrosis factor (TNF-alpha), and
various interleukins. Substance P is one of the primary neurotransmitters of inflammation; it acts
on the tachykinin NK-1 receptor sites. Blocking substance P at NK-1 receptors reduces
neurogenic transmission and could potentially reduce inflammation, pain, exudation and
edema, neuropathic pain and associated allergic reactions. While labeled for nausea and
vomiting (especially that induced by motion), maropitant may be beneficial for many
inflammatory and allergic conditions.
The dose is 1-2mg/kg PO, SQ or IV q24h Monday-Friday, i.e., five days on, two days off. This is
necessary as continuous dosing results in a depletion of substance P, which results in tremours.
Refrigeration may help reduce the stinging associated with giving SQ injections as may IV use
or administration with SQ fluids. It is contraindicated in patients with liver disease.
It is critical to pay attention to nutrition in quality, balance and quantity. In addition to the
frequently used antihistamine, anti-serotonin drug cyproheptadine (1 mg PO q12h), mirtazapine
at 2-3 mg/cat PO q72h is may work well as an appetite stimulant for cats.
Prognosis
It is important that clients understand that a cat with chronic rhinitis/rhinosinusitis will never be
cured. With on-going management, the patient’s quality of life can be improved with a reduction
in sneezing and nasal discharge.
From page 183 2015 OVMA Conference proceedings
Dr Margie Scherk DVM,DABVP (Feline)