Daily FIP Monitoring: Your Essential Guide to Treatment Success

GS-441524 does the clinical work. But the 84-day protocol happens at home, administered by you, observed by you, and reported by you. The quality of that observation — what you notice, what you record, and what you act on — directly affects the outcome.

Daily monitoring during FIP treatment serves three purposes. It tells you whether the treatment is working. It catches problems — a returning fever, a dose that was not absorbed, a new symptom — before they become serious. And it gives your vet the information they need to make good decisions at the 30-day, 60-day, and 84-day blood work appointments.

This guide covers exactly what to monitor, how to monitor it, what improving looks like versus what warrants concern, and when to contact your vet.

What to Monitor Every Day

1. Body Temperature

Fever is the most consistent early sign of FIP and the most reliable early indicator that treatment is working. A normal cat’s temperature is 38.1°C to 39.2°C. Anything above 39.2°C is a fever. Anything above 40.5°C is a high fever requiring same-day veterinary attention.

In most cats with FIP, fever begins to resolve within the first 3 to 7 days of GS-441524 treatment at the correct dose. A temperature that is returning to normal and staying there is one of the clearest signs that treatment is working. A fever that persists beyond 14 days of treatment, or that resolves and then returns, warrants a veterinary review — it may indicate the dose needs adjustment.

How to take your cat’s temperature: Use a digital rectal thermometer with a small amount of lubricant (petroleum jelly). Wrap your cat in a towel, insert the thermometer 1 to 2 cm, and hold until it beeps. Take the reading at the same time each day — morning is usually easiest — and record it in your daily log.

Read our complete guide to cat fever for a full explanation of what different temperature readings mean and when to act.

2. Body Weight

Weight is one of the most objective measures of treatment response. A cat that is gaining weight — or at minimum maintaining weight — is responding to treatment. A cat that continues to lose weight despite treatment needs nutritional intervention and possibly a dose review.

Weigh your cat every 3 to 4 days using a digital kitchen scale. For small cats and kittens, weigh yourself holding the cat, then weigh yourself alone, and subtract. Record the weight in your daily log. Even small changes — 100 to 200 grams — are meaningful over the course of the 84-day protocol.

In kittens, body weight must be checked every 2 weeks specifically to recalculate the GS-441524 dose. Kittens grow during the 84-day protocol, and a dose that was correct at week 1 may be insufficient by week 6 if the kitten has gained significant weight. Under-dosing is the most common cause of treatment failure. Read our guide to FIP in kittens for kitten-specific monitoring considerations.

3. Appetite and Food Intake

Appetite is one of the earliest and most visible signs of treatment response. Most cats with FIP show returning interest in food within the first 3 to 10 days of GS-441524 treatment. A cat that was refusing food and is now eating voluntarily is telling you the treatment is working.

Record how much food was offered and how much was eaten at each meal. Note whether the cat approached the bowl voluntarily, whether they needed encouragement, and whether they finished the portion. This level of detail helps your vet distinguish between a cat that is eating adequately and one that is eating just enough to mask a problem.

If your cat has not eaten for more than 24 hours, contact your vet. Anti-nausea medication or appetite stimulants can be prescribed alongside GS-441524 without affecting treatment efficacy. For practical strategies to maintain food intake during treatment, read our complete FIP diet guide.

4. Behaviour and Activity Level

You know your cat’s baseline better than anyone. Changes in behaviour — subtle ones that would not be obvious to a vet seeing the cat for the first time — are often the earliest indicators of improvement or deterioration.

Note daily:

  • Activity level — is the cat moving around more or less than yesterday?
  • Interaction — is the cat seeking contact, responding to your voice, showing interest in the environment?
  • Grooming — a cat that starts grooming again after a period of neglecting its coat is a cat that is feeling better
  • Hiding — is the cat spending more time in concealed spots? Persistent hiding is a sign of discomfort or pain
  • Play interest — even brief moments of interest in a toy are meaningful signs of returning wellbeing

The Cornell Feline Health Center notes that cats instinctively suppress visible signs of illness — which means that when a cat starts showing positive behavioural signs, it reflects genuine improvement in how they feel, not just a good day.

5. Breathing

Breathing should be monitored daily in all cats with FIP, and particularly in cats with wet FIP where chest fluid may be present. Normal resting respiratory rate in cats is 15 to 30 breaths per minute. Count breaths for 30 seconds and multiply by two.

Signs of respiratory concern include:

  • Resting respiratory rate above 40 breaths per minute
  • Open-mouth breathing or panting at rest
  • Visible effort in breathing — the chest or belly moving excessively with each breath
  • Hunched posture with elbows out — a cat trying to expand its chest
  • Blue-tinged gums (cyanosis) — a veterinary emergency

Any of these signs requires same-day veterinary attention. Do not wait to see if it improves. Read our wet FIP guide for more on managing fluid accumulation during treatment.

6. Abdominal Appearance (Wet FIP)

In cats with wet FIP, the reduction in abdominal swelling is one of the most visible and encouraging signs of treatment response. Photograph the abdomen from the same angle at the same time every 3 to 4 days. The visual record makes it easy to see whether the belly is reducing, stable, or increasing — changes that can be difficult to assess by feel alone.

If abdominal swelling is increasing despite treatment, or if breathing difficulty is worsening, contact your vet the same day.

7. Neurological Signs (Neurological FIP)

In cats with neurological FIP, daily monitoring of neurological signs is essential. Note any changes in:

  • Gait — is the ataxia improving, stable, or worsening?
  • Tremors — frequency and severity
  • Seizure activity — duration, frequency, recovery time
  • Head tilt — improving or worsening?
  • Behavioural changes — confusion, aggression, disorientation
  • Bladder and bowel control

Neurological improvement during GS-441524 treatment is often gradual. Some cats show meaningful improvement within 2 to 4 weeks; others take longer. Video recordings of neurological signs are particularly useful for tracking subtle changes over time and for sharing with your vet. Read our guide to neurological FIP for more detail.

The Daily Health Log

A daily health log is the single most useful tool for managing FIP treatment at home. It transforms your observations from impressions into data — data that your vet can use to make informed decisions at each blood work appointment.

Your log should record, for each day:

  • Date and time of GS-441524 injection
  • Injection site used (for rotation tracking)
  • Any injection site reaction noted
  • Body temperature (time of measurement)
  • Body weight (on days weighed)
  • Food offered and food eaten
  • Water intake (approximate)
  • Activity level (scale of 1–5, or descriptive notes)
  • Behavioural observations
  • Respiratory rate (on days monitored)
  • Any vomiting, diarrhoea, or changes in litter tray habits
  • Any neurological signs (if applicable)
  • Any other observations

A simple spreadsheet, a notes app, or a dedicated notebook all work equally well. The format matters less than the consistency. Daily entries, even brief ones, build a picture that a weekly summary cannot capture.

Bring the log to every veterinary appointment. It is the most useful thing you can bring. For a full explanation of what blood work results mean at each stage of treatment, read our complete blood work guide for FIP cat owners.

What Improvement Looks Like: Week by Week

Days 1–7: Fever begins to resolve. Appetite starts returning. The cat becomes slightly more alert. These are the first signs that GS-441524 is working. In wet FIP, abdominal fluid may begin to reduce.

Days 7–30: Continued fever resolution. Weight stabilisation or early weight gain. Increasing energy and interaction. Coat condition beginning to improve. In wet FIP, visible reduction in abdominal swelling. Blood work at day 30 confirms whether the A:G ratio and other markers are improving.

Days 30–84: Continued clinical improvement. Most cats are eating well, gaining weight, and behaving increasingly normally. Blood work continues to normalise. In neurological FIP, neurological signs continue to improve, though full recovery may extend beyond day 84.

After day 84: A 12-week observation period follows. Cats that complete both phases without symptom recurrence are considered in full remission. Read our FIP survival and treatment outlook guide for what the observation period involves.

When to Contact Your Vet

Contact your vet the same day if:

  • Temperature above 40.5°C, or fever that has returned after resolving
  • Cat has not eaten for more than 24 hours
  • Breathing difficulty is worsening or respiratory rate is above 40 at rest
  • Abdominal swelling is increasing despite treatment
  • Ongoing weight loss after 2 weeks of treatment
  • New neurological signs, or existing neurological signs worsening after 2 weeks of treatment
  • Cat appears extremely weak, non-responsive, or collapsed
  • Injection site has a lump that is enlarging, painful, or has not resolved after 7 days

Do not stop GS-441524 without veterinary guidance. Stopping early is the most common cause of FIP relapse. If you are concerned about a side effect, contact your vet — the answer is almost always to manage the side effect and continue treatment, not to stop. Read our GS-441524 side effects guide for what is normal and what warrants attention.

Equipment to Have at Home

  • Digital rectal thermometer — for daily temperature monitoring
  • Petroleum jelly or water-based lubricant — for thermometer use
  • Digital kitchen scale — for accurate weight tracking
  • Notebook or spreadsheet — for the daily health log
  • Phone camera — for photographing abdominal appearance and recording neurological signs
  • Syringes and needles — for GS-441524 injection (supplied with your order)
  • Sharps disposal container — for safe needle disposal

Frequently Asked Questions

How often should I take my cat’s temperature during FIP treatment?
Daily in the first 2 weeks, when fever resolution is the primary indicator of treatment response. After fever has resolved and stabilised, every 2 to 3 days is sufficient unless you notice other signs of concern.

How often should I weigh my cat during treatment?
Every 3 to 4 days for adult cats. Every 2 weeks for kittens — and use each weight to recalculate the GS-441524 dose, as kittens grow during the 84-day protocol.

My cat’s temperature is normal but they are still not eating well after 2 weeks. Is this a concern?
Yes. Fever resolution is a good sign, but appetite should also be returning by week 2. Persistent poor appetite after 2 weeks of treatment warrants a veterinary review — it may indicate the dose needs adjustment, a concurrent condition is affecting appetite, or nutritional support needs to be escalated.

Should I be monitoring my cat at night?
You do not need to set alarms for night-time monitoring. A consistent daily check — temperature, weight, food intake, and behavioural observation — at the same time each day is sufficient. If your cat is in a critical phase of illness, your vet may advise more frequent monitoring.

What if I miss a day of monitoring?
Do not stress about a missed day. Resume the log the next day. Consistency over the full 84 days matters more than perfection on any single day. The trend across multiple days is what provides meaningful information.

The 84-day protocol is a partnership. GS-441524 suppresses the virus. You provide the daily observation, the consistent care, and the information that allows your vet to make good decisions. Most cats that complete the full protocol go on to live normal, healthy lives. Your daily attention is part of how that happens.

Questions about monitoring your cat during treatment? The FIP CURE Plus team is available in English and Arabic at info@fipcureplus.com.

View the FIP CURE Plus GS-441524 injectable range →

FIP CURE Plus — transparent, evidence-based GS-441524 treatment for cats across the Gulf.

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