Welcome to the Lantus / Levemir / Biosimilars group. If you're new to managing feline diabetes, head over to the Feline Health - Welcome & Main Forum and introduce yourself before getting started here. There you will find resources on home blood glucose testing, feline nutrition, and fundamentals of feline diabetes care.
Some helpful links for you getting started:
How to Create a Spreadsheet
How to Use the Spreadsheet
Creating a Profile
Health Links & FAQs
AlphaTRAK Meters and Test Strips
AlphaTRAK meters are specifically designed for use in pets and are often recommended by veterinarians due to their accuracy, which closely mirrors lab results. These meters are usually more costly than human glucose meters, especially when it comes to test strips. They’re available for purchase online or through veterinary clinics, though not all vets keep the test strips in stock.
Note: There is a difference in readings between the AlphaTRAK and human meters. Most of the content on this site is written for a human meter. It is helpful to indicate which meter you're using on your spreadsheet, signature, and posts.
To effectively manage diabetes, it's helpful to know how your cat’s body reacts to insulin:
When using long-acting insulins like Lantus, Basaglar, Semglee (all glargine), or Levemir (detemir), it’s helpful to know what a smooth, well-responding cycle might eventually resemble. This example outlines a relatively active insulin cycle — something many caregivers aim for with consistent dosing and data collection. Keep in mind, every cat responds differently, and reaching this kind of stability takes time.
Don’t expect your cat to settle into a consistent pattern immediately. Many cats have experienced prolonged periods of high blood sugar before diagnosis, and it takes time for their systems to adjust. You might not see clearly “active” cycles with every injection. Stay patient — stability develops over time with regular testing and steady dosing.
Some cats may temporarily run higher after a dose increase — this odd rise is known among caregivers as “New Dose Wonkiness” (NDW). While the cause isn’t fully understood, it usually resolves on its own within a day or two. Keep dosing steady and track trends rather than reacting to one-off numbers.
FDMB post on New Dose Wonkiness (NDW).
The bottom line: consistent data collection is key to understanding your cat’s unique insulin response and fine-tuning their treatment.
Carryover
This refers to when the effects of a previous insulin dose are still working, even though the insulin’s typical active period has officially ended. It can slightly lower glucose levels beyond the expected timeframe.
Overlap
Overlap happens when the tail end of one dose is still active just as the next insulin injection begins to take effect. This is common with long-acting insulins and contributes to smoother glucose control.
Insulin Depot
With insulins like Lantus, Basaglar, Semglee, and Levemir, a portion of the injected dose forms a reservoir under the skin. This "depot" slowly releases insulin over time, helping maintain steady blood sugar levels. It’s important to understand that changes in dose may take a few days to show full effects because of this delayed release.
More information on the Insulin Depot.
Bouncing
A “bounce” is the body’s reaction to a sudden drop in blood sugar—either because it dropped too fast or dipped lower than the cat is used to. Even if the number wasn’t dangerously low, the cat’s system might interpret it as a threat. The liver and pancreas respond by releasing stored sugars and hormones to raise glucose levels back up. This can lead to temporary high numbers, often lasting up to three days. These fluctuations are a natural protective mechanism, especially early in treatment when a cat's system is still adjusting to new, lower glucose levels.
There’s no single definition of blood glucose regulation—it often depends on context and individual goals. Thanks to widespread home testing, we now have a clearer picture of the range of possibilities when managing feline diabetes.
Here’s a general framework that describes the stages of regulation:
This scale can be a helpful tool to assess where your cat is on their diabetes journey and guide decisions on how to fine-tune treatment.
Note: Numbers referenced here are for a human meter.
When managing blood glucose levels in diabetic cats, most caregivers follow one of two structured approaches:
FDMB post on Start Low, Go Slow (SLGS)
These protocols were originally developed by experienced caregivers using human glucometers. Note that Lantus, Basaglar, and Semglee are all forms of insulin glargine, while Levemir contains detemir. Though slightly different, these insulins behave similarly in cats and can be used with either method.
As of now, the only published protocol for glargine or detemir use in cats is the Tight Regulation approach, originally created by the German-Katzen Group. Over time, many cat owners have successfully applied a modified version of this protocol, backed by real-world experience and careful observation.
If TR feels too overwhelming or doesn’t suit your routine, SLGS is a solid alternative. It allows for slower adjustments and requires fewer tests per day, making it a better fit for some households.
While the forum supports both methods, neither is the only valid path. Other communities may promote different approaches, and what works best depends on your cat’s needs and your own comfort level.
Once you begin tracking insulin action—such as when it kicks in (onset), reaches peak effect (nadir), and wears off (duration)—you’ll be better prepared to make informed decisions. If you’re following the TR method, don’t forget to check out resources on managing low numbers safely. Hypo Symptoms & Treatment and Hypo Tool Box.
Tilly's Diabetes Homepage - Tight Regulation Protocol
More links and information to come.
- Tim
Change Log:
Created on 5/18/2025. Next improvement here is need to add more information links at the bottom.
Sources:
"The Basics: New to the Group? Start Here." Feline Diabetes Message Board, 5 Jan. 2010, Sticky - The Basics: New to the Group? Start here! | Feline Diabetes Message Board - FDMB. Accessed 18 May 2025.
Some helpful links for you getting started:
How to Create a Spreadsheet
How to Use the Spreadsheet
Creating a Profile
Health Links & FAQs
Understanding Glucose Meters & Your Cat’s Insulin Response
AlphaTRAK Meters and Test Strips
AlphaTRAK meters are specifically designed for use in pets and are often recommended by veterinarians due to their accuracy, which closely mirrors lab results. These meters are usually more costly than human glucose meters, especially when it comes to test strips. They’re available for purchase online or through veterinary clinics, though not all vets keep the test strips in stock.
Note: There is a difference in readings between the AlphaTRAK and human meters. Most of the content on this site is written for a human meter. It is helpful to indicate which meter you're using on your spreadsheet, signature, and posts.
Tracking Your Cat's Response to Insulin
To effectively manage diabetes, it's helpful to know how your cat’s body reacts to insulin:
- Onset – The point when insulin starts working to lower blood sugar.
- Nadir (or Peak) – The lowest blood glucose level during a dose cycle.
- Duration – How long the insulin remains active in the body.
What an Active Lantus Cycle Might Look Like
When using long-acting insulins like Lantus, Basaglar, Semglee (all glargine), or Levemir (detemir), it’s helpful to know what a smooth, well-responding cycle might eventually resemble. This example outlines a relatively active insulin cycle — something many caregivers aim for with consistent dosing and data collection. Keep in mind, every cat responds differently, and reaching this kind of stability takes time.
Sample Glargine Cycle (e.g., Lantus/Basaglar/Semglee):
- +0 – Blood sugar reading just before the insulin injection (pre-shot).
- +1 – Levels may rise slightly as the previous dose wears off and food is absorbed.
- +2 – Glucose levels may start dropping. If this reading is equal to or lower than pre-shot, it could signal an active cycle—monitor closely.
- +3 to +5 – Gradual decline in glucose levels.
- +6 – This is often the lowest point in the cycle (called the nadir), but this varies by cat.
- +7 to +9 – Numbers begin to level off and rise slightly.
- +10 to +12 – Continued upward trend leading back to the next pre-shot reading.
Sample Levemir Cycle:
Levemir generally starts working later, often around +4 hours post-injection, with its low point occurring between +8 and +10 hours. This delayed profile makes it different from glargine-based insulins.A Note on Variability
Don’t expect your cat to settle into a consistent pattern immediately. Many cats have experienced prolonged periods of high blood sugar before diagnosis, and it takes time for their systems to adjust. You might not see clearly “active” cycles with every injection. Stay patient — stability develops over time with regular testing and steady dosing.
Some cats may temporarily run higher after a dose increase — this odd rise is known among caregivers as “New Dose Wonkiness” (NDW). While the cause isn’t fully understood, it usually resolves on its own within a day or two. Keep dosing steady and track trends rather than reacting to one-off numbers.
FDMB post on New Dose Wonkiness (NDW).
The bottom line: consistent data collection is key to understanding your cat’s unique insulin response and fine-tuning their treatment.
Key Concepts in Insulin Behavior
Carryover
This refers to when the effects of a previous insulin dose are still working, even though the insulin’s typical active period has officially ended. It can slightly lower glucose levels beyond the expected timeframe.
Overlap
Overlap happens when the tail end of one dose is still active just as the next insulin injection begins to take effect. This is common with long-acting insulins and contributes to smoother glucose control.
Insulin Depot
With insulins like Lantus, Basaglar, Semglee, and Levemir, a portion of the injected dose forms a reservoir under the skin. This "depot" slowly releases insulin over time, helping maintain steady blood sugar levels. It’s important to understand that changes in dose may take a few days to show full effects because of this delayed release.
More information on the Insulin Depot.
Bouncing
A “bounce” is the body’s reaction to a sudden drop in blood sugar—either because it dropped too fast or dipped lower than the cat is used to. Even if the number wasn’t dangerously low, the cat’s system might interpret it as a threat. The liver and pancreas respond by releasing stored sugars and hormones to raise glucose levels back up. This can lead to temporary high numbers, often lasting up to three days. These fluctuations are a natural protective mechanism, especially early in treatment when a cat's system is still adjusting to new, lower glucose levels.
What Does It Mean for a Diabetic Cat to Be “Regulated”?
There’s no single definition of blood glucose regulation—it often depends on context and individual goals. Thanks to widespread home testing, we now have a clearer picture of the range of possibilities when managing feline diabetes.
Here’s a general framework that describes the stages of regulation:
- Untreated: Blood glucose typically stays above 300 mg/dL (16.7 mmol/L) with noticeable signs of illness.
- On treatment but not regulated: Glucose values often remain above 300 and rarely get close to 100 mg/dL (5.6 mmol/L), and clinical signs persist.
- Regulated: Glucose readings are mostly under 300, with a mid-cycle drop closer to 100. The cat appears healthier and more comfortable.
- Well regulated: Numbers are generally below 200–250 mg/dL (11.1–13.9 mmol/L) and often hover near 100, with no signs of hypoglycemia.
- Tightly regulated: Glucose consistently falls between 60–120 mg/dL (3.3–6.7 mmol/L), without dipping too low, while still on insulin.
- Normal range without insulin: Levels are within the 60–120 range, possibly with slight increases after meals, but no longer requiring insulin support.
This scale can be a helpful tool to assess where your cat is on their diabetes journey and guide decisions on how to fine-tune treatment.
Note: Numbers referenced here are for a human meter.
Common Approaches to Feline Diabetes Regulation
When managing blood glucose levels in diabetic cats, most caregivers follow one of two structured approaches:
- Tight Regulation (TR): A more intensive method using frequent blood glucose testing to closely monitor and adjust insulin dosing.
- Start Low, Go Slow (SLGS): A more gradual, less demanding method that involves fewer tests and slower dose adjustments.
FDMB post on Start Low, Go Slow (SLGS)
These protocols were originally developed by experienced caregivers using human glucometers. Note that Lantus, Basaglar, and Semglee are all forms of insulin glargine, while Levemir contains detemir. Though slightly different, these insulins behave similarly in cats and can be used with either method.
As of now, the only published protocol for glargine or detemir use in cats is the Tight Regulation approach, originally created by the German-Katzen Group. Over time, many cat owners have successfully applied a modified version of this protocol, backed by real-world experience and careful observation.
If TR feels too overwhelming or doesn’t suit your routine, SLGS is a solid alternative. It allows for slower adjustments and requires fewer tests per day, making it a better fit for some households.
While the forum supports both methods, neither is the only valid path. Other communities may promote different approaches, and what works best depends on your cat’s needs and your own comfort level.
Once you begin tracking insulin action—such as when it kicks in (onset), reaches peak effect (nadir), and wears off (duration)—you’ll be better prepared to make informed decisions. If you’re following the TR method, don’t forget to check out resources on managing low numbers safely. Hypo Symptoms & Treatment and Hypo Tool Box.
Tilly's Diabetes Homepage - Tight Regulation Protocol
More links and information to come.
- Tim
Change Log:
Created on 5/18/2025. Next improvement here is need to add more information links at the bottom.
Sources:
"The Basics: New to the Group? Start Here." Feline Diabetes Message Board, 5 Jan. 2010, Sticky - The Basics: New to the Group? Start here! | Feline Diabetes Message Board - FDMB. Accessed 18 May 2025.