Molnu Treatment Guide for Feline Stomatitis
Complete treatment guide — including pre-treatment checks, dosage calculations, concurrent medications, supplements, and bloodwork monitoring.
Before starting treatment.
Before day one of Molnupiravir, three things must be done first: a dental examination, baseline oral photos, and strict isolation. Skipping these preparations is one of the most common reasons treatment fails.
1. Get a full dental X-ray.
A full dental X-ray is recommended before starting treatment or during the treatment course. Many cats with FCGS also suffer from aggressive periodontal disease, tooth resorption, retained roots, or severe dental infections. These lesions can continuously trigger local inflammation and immune dysregulation, which may interfere with stomatitis treatment. If damaged teeth are present, proper dental treatment should be performed first.
2. Document the mouth with photos.
Take clear "before" photos of both sides of the mouth and the back of the throat. Flash on, same angle every time. Repeat monthly so you and your vet can compare objectively.
3. Strictly isolate your cat.
If there are other cats in the household, isolation during treatment is strongly recommended. One of the main causes of feline stomatitis is chronic calicivirus infection, and even cats that appear completely healthy may still be silent carriers of feline calicivirus (FCV). Calicivirus can also spread through the air. Isolation is the best way to help prevent long-term viral carriage and reinfection in cats with stomatitis.
⚠ For shelters and rescue organizations: a cat receiving treatment must be strictly isolated from other cats. In multi-cat environments, the treatment failure rate is significantly higher than in single-pet households.
Gradually taper symptom-control medications.
Improvement can usually be observed within 3–4 days after starting Molnu treatment. Once the condition begins to improve, pain medications and antihistamines should be gradually reduced and discontinued under veterinary supervision.
First signs of improvement.
- Reduced drooling
- Better appetite
- Less mouth pawing
- Returning to favourite spots
Begin tapering.
- Reduce painkiller dose stepwise
- Lower antihistamines gradually
- Watch for relapse cues
- Adjust if symptoms return
Dosing protocol.
Enter your cat's weight and the calculator will return the correct capsule fraction. Re-calculate any time your cat's weight changes by more than 0.5 kg.
Dose by body weight
Standard dose reference
Capsule fraction per dose · follow your vet's frequency
| Weight range | Capsule |
|---|---|
| 2 – 3.4 kg | ⅕ capsule |
| 3.5 – 4.4 kg | ¼ capsule |
| 4.5 – 5.4 kg | ⅓ capsule |
| 5.5 – 6.4 kg | ⅖ capsule |
| 6.5 – 7.5 kg | ½ capsule |
How to give it
Once you have the right capsule fraction, follow these rules.
Concurrent medications.
Molnu primarily targets the virus itself. To bring inflammation under control more quickly, two short-term supportive treatments are usually recommended alongside it: antibiotics and low-dose corticosteroids. Both medications require a prescription from a veterinarian.
(top picks)
(alternative)
You can think of the immune dysregulation in stomatitis as a car with the accelerator stuck down. Molnu and antibiotics release the gas pedal — cutting off the viral and bacterial triggers that keep inflammation out of control. Corticosteroids press the brake — suppressing the overactive immune response. Using both together in the short term helps bring the runaway inflammation back under control.
Recommended supplements.
Two categories work best in parallel: a local oral treatment (sprays that target the gum surface directly) and systemic support (probiotics, lactoferrin, NAC + glycine, and optionally vitamin D).
Antimicrobial oral spray.
Choose at least one (ideally two) oral sprays for your cat and use them according to the product instructions.
• Chlorhexidine — more irritating
• Zinc gluconate — gentler
• Zinc acetate — gentler
• Hypochlorous acid — gentler
Anti-inflammatory & immune support
Probiotics and lactoferrin are essential; NAC + glycine may be used depending on the situation.
Test before you supplement.
Most stomatitis cats have low vitamin D, but supplement only after a blood test confirms it. Over-supplementation is dangerous.
25-Hydroxy Vitamin D (LC-MS/MS)
Healthy range: 90–120 ng/mL
If deficient: 16–20 IU/kg, once daily
Blood monitoring & dose adjustments.
Molnupiravir is generally well tolerated, but it can still potentially cause some side effects, such as leukopenia, anemia, and elevated ALT levels.