CaliciX™ Max is a high-strength systemic antiviral capsule formulated for cats suffering from severe, refractory, or high-viral-load Feline Calicivirus (FCV) infections, where standard-dose therapy of 15 mg is insufficient.
Each capsule contains 30 mg of pure EIDD-1931, the active antiviral metabolite, designed for systemic viral suppression in advanced disease states. This formulation is intended for use under veterinary supervision in cats requiring higher antiviral exposure due to disease severity, body weight, or poor response to conventional therapy.
Severe Oral and Oropharyngeal Disease
CaliciX™ Max is designed to support treatment of severe Feline Calicivirus (FCV) associated diseases, including:
- Severe Feline Chronic Gingivostomatitis (FCGS)
- Caudal stomatitis with extensive caudal oral inflammation
- Ulcerative stomatitis unresponsive to dental extractions
- Deep lingual ulceration (viral glossitis)
- Multifocal buccal, labial, and palatal ulcers
These conditions are characterized by extreme oral pain, profuse drooling (ptyalism), difficulty eating or swallowing (dysphagia), weight loss and cachexia, and persistent halitosis and oral bleeding.
Systemic and Virulent FCV Disease
CaliciX™ Max may be considered in cases with evidence of high systemic viral burden, including:
- Virulent Systemic Feline Calicivirus (VS-FCV)
- Feline Calicivirus (FCV) associated fever and severe lethargy
- Facial or limb edema
- Lameness
- Pulmonary involvement or pneumonia
- Hepatic or pancreatic enzyme elevation
- Severe inflammatory response with rapid clinical decline
Refractory or Relapsing Disease
- Cats with persistent Feline Calicivirus (FCV) shedding
- Post-extraction Feline Chronic Gingivostomatitis (FCGS) with incomplete response
- Chronic stomatitis with repeated relapse after steroids or immunosuppressive therapy
- Large or obese cats requiring higher per-dose antiviral exposure
Why High-Strength CaliciX™
The EIDD-1931 in CaliciX™ is the active antiviral form and demonstrates substantially higher intrinsic antiviral potency than its prodrug, predictable systemic exposure without reliance on metabolic conversion, and broad activity against RNA viruses including calicivirus.
In severe Feline Calicivirus (FCV) disease, higher systemic concentrations may be required to rapidly reduce viral replication, suppress ongoing mucosal and systemic viral injury, and support recovery in cats with advanced inflammation and pain. The 30 mg strength allows veterinarians to achieve these targets with fewer capsules per dose, improving accuracy, compliance, and treatment feasibility.
Designed for Severe Cases and Larger Cats
CaliciX™ Max is particularly suited for:
- Cats weighing 5 kg (11 lb) or more with severe disease
- Patients requiring greater than 6 mg/kg BID dosing
- Situations where multiple 15 mg capsules would otherwise be required
This strength supports step-up antiviral therapy while maintaining precise dosing control.
Precision Antiviral Therapy, When It Matters Most
CaliciX™ Max represents the highest-potency option in the CaliciX™ antiviral line, offering veterinarians a systemic antiviral tool for the most challenging calicivirus cases. When standard dosing is no longer enough, CaliciX™ Max provides a controlled, high-strength antiviral option designed to support stabilization, recovery, and improved quality of life in cats with severe Feline Calicivirus (FCV) disease.
For mild to moderate cases, including early ulcers, juvenile gingivitis, and gingivostomatitis with eating discomfort, standard CaliciX™ is the appropriate strength.

