Feeling overwhelmed or unsure where to start? You’re not alone – and you’re in the right place.
Welcome to the PZ/ProZinc Insulin Support Group! We’re a community of caregivers just like you – all doing our best to help our diabetic cats live healthier, happier lives. Whether your vet just prescribed ProZinc or you’re exploring PZI options, this thread will walk you through the basics and help you get your bearings.
PZ = ProZinc and PZI (Protamine Zinc Insulin). These terms are often used interchangeably since they act similarly.The 3 Keys to Feline Diabetes Care:
- A gentle, long-acting insulin – like ProZinc or other PZIs.
- A low-carb, wet food diet – this reduces blood sugar spikes and supports regulation.
- Home blood glucose testing – gives you control and helps keep your cat safe.
Understanding How ProZinc Works
ProZinc is a long-acting insulin created specifically for cats. It works by lowering blood glucose over a 12-hour period and is given twice daily. After injection, it begins working in about 2–3 hours (called the “onset”), dips to a low point (or “nadir”) mid-cycle, and then gradually wears off.
Some things to keep in mind:
- Start low, go slow. 1 unit is often a good starting point.
- Adjustments are usually made in small increments (0.25 to 0.5 units).
- Because ProZinc clears the body between doses, dose changes might show effects quickly.
Europe/UK users: ProZinc is generally available. Hypurin PZI is another PZI option in the UK but is different, so make sure to clarify which one you're using when posting.
Syringes: U-40 vs U-100
ProZinc comes in U-40 strength, so U-40 syringes are typically used (often with red caps). However, some caregivers prefer U-100 syringes with half-unit marks for more precise dosing – just be sure to use a proper conversion chart when doing this.
Home Testing: Why and How
Testing your cat’s blood glucose at home may sound scary at first, but it’s a game-changer:
- Helps you catch dangerous lows (hypoglycemia).
- Lets you safely adjust doses with confidence.
- Reduces reliance on vet curves or fructosamine tests.
- Your cat will likely be more relaxed at home than at the vet – which means more accurate numbers.
When to test:
- Before every insulin shot (AM and PM).
- Mid-cycle (+4 to +7) to catch the nadir.
- Occasionally do a full curve (tests every 2–3 hours over 12 hours).
Pro Tip: The sequence is always: Test > Feed Shoot.
If BG is below 200 mg/dL (or 225 if using a pet meter), stall (don’t feed) and retest in 20–30 minutes. If BG stays too low, skip the dose. Better to be high for a day than low for a minute.
Food & Diet: The Low-Carb Shift
Switching to wet, low-carb food can dramatically lower your cat’s BG – but if your cat is already on insulin, switch gradually and only if you’re home-testing. Aim for foods under 10% carbs (calorie-based). Great resources:
Tracking Progress: Use the Spreadsheet
Set up a Google Spreadsheet (see How to Create a Spreadsheet)to log test results and track trends. Post your SS link in your signature for others to reference when offering help. Choose the version that matches your meter (human or pet-calibrated).
See The Basics - How to Use This Forum for more information on setting up your signature.
Ketone Testing: A Critical Safety Check
Especially if BGs are high, ketones can develop. These are dangerous and can lead to diabetic ketoacidosis (DKA). Use urine ketone strips (Ketostix) or a blood ketone meter to monitor. Test frequently if your cat seems unwell or stops eating.
See "Ketones - An Introduction" for more information.
Support & Posting Guidelines
- Stick to one thread per cat until it reaches 50 posts.
- Include the date, your cat’s name, and AMPS/PMPS in your thread titles.
- Use the “911” prefix for emergencies (very low BG or symptomatic hypo).
- Tag members with @username to get attention quickly.
- The PZ forum is smaller than the main Health forum, so don’t hesitate to cross-post in "Feline Health - Welcome & Main Forum" for faster replies if needed.
Useful Extras:
- Hypo Symptoms & Treatment
- Hypo Tool Box
- Catinfo.org - Great resource on feline nutrition by Dr. Lisa Pierson
This forum is peer-to-peer. While many here have years of experience, we are not veterinarians. All advice is based on personal experience and shared knowledge. Always work with your vet, especially when making treatment decisions.
You’ve got this. Ask anything – we’re here to help.- Tim
Change Log:
Created on 5/19/2025
Sources:
"Basics about Prozinc and PZI Insulin." Feline Diabetes Message Board, https://felinediabetes.com/FDMB/threads/prozinc-basics-start-here.225629/.