Insulin choice in feline diabetes mellitus



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PICO question

In cats with diabetes mellitus, do protamine zinc insulin (PZI) and glargine show a similar effect in reducing clinical signs and hypoglycaemia episodes?


Clinical bottom line

Category of research question


The number and type of study designs reviewed

The number and type of study designs that were critically appraised was one. This study was a non-randomised retrospective trial. A systematic review was also found, which analyses the influence of insulin in diabetic remission

Strength of evidence


Outcomes reported

Compared to PZI, using glargine in recently diagnosed diabetic cats fed exclusively an ultra-low carbohydrate-high protein canned diet, may result in lower fructosamine and mean 12 hour blood glucose concentrations as well as less episodes of hypoglycaemia


In view of the strength of evidence and the outcomes from the study the following conclusion is made: in cats with diabetes mellitus where currently licensed insulin fails to result in a good glycaemic control, glargine may be considered


How to apply this evidence in practice

The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.

Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.


Open Access Peer Reviewed


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Behrend, E., Holford, A., Lathan, P., Rucinsky, R. & Schulman, R. (2018). 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. Journal of the American Animal Hospital Association. 54(1), 1–21. DOI:

CEBM. (2011). The Oxford 2011 Levels of Evidence. Available at: [Accessed 10 August 2014].

Gilor, C, Rudinsky, A. J. & Hall, M. J. (2016). New Approaches to Feline Diabetes Mellitus: Glucagon-like peptide-1 analogs. Journal of Feline Medicine and Surgery. 18(9), 733–743. DOI:

Gostelow, R., Forcada, Y., Graves, T., Church, D. & Niessen, S. (2014). Systematic review of feline diabetic remission: Separating fact from opinion. Veterinary Journal. 202(2), 208–221. DOI:

Gostelow, R., Scudder, C., Hazuchova, K., Forcada, Y., Church D. & Niessen, S. (2017). 2017 ACVIM Forum Research Abstract Program Index of Abstracts ORAL PRESENTATIONS – Thursday , June 8. 1273.

Marshall, R. D., Rand, J. S. & Morton, J. M. (2009). Treatment of Newly Diagnosed Diabetic Cats with Glargine Insulin Improves Glycaemic Control and Results in Higher Probability of Remission than Protamine Zinc and Lente Insulins. Journal of Feline Medicine and Surgery. 11(8), 683–691. DOI:

Nack, R. & DeClue, A. E. (2014). In cats with newly diagnosed diabetes mellitus, use of a near-euglycemic management paradigm improves remission rate over a traditional paradigm. Veterinary Quarterly. 34(3), 132–136. DOI:

Nelson, R. W., Henley, K., Cole, C. & PZIR Clinical Study Group. (2009). Field safety and efficacy of protamine zinc recombinant human insulin for treatment of diabetes mellitus in cats. Journal of Veterinary Internal Medicine. 23(4), 787–793. DOI:

Saini, N. K., Wasik, B., Pires, J., Leale, D. M., Quach, N., Culp, W. T. N., Samms, R. J., Johnson, A. E., Owens, J. G. & Gilor, C. (2020). Comparison of pharmacodynamics between insulin glargine 100 U/mL and insulin glargine 300 U/mL in healthy cats. Domestic Animal Endocrinology. 75. DOI:

Sparkes, A. H., Cannon, M., Church, D., Fleeman, L., Harvey, A., Hoenig, M., Peterson, M. E., Reusch, C. E., Taylor, S. & Rosenberg, D. (2015). ISFM Consensus Guidelines on the Practical Management of Diabetes Mellitus in Cats. Journal of Feline Medicine and Surgery. 17(3), 235–250. DOI:

Vol. 6 No. 3 (2021): The third issue of 2021

Section: Knowledge Summaries

Categories :  Small Animal  /  Dogs  /  Cats  /  Rabbits  /  Production Animal  /  Cattle  /  Sheep  /  Pig  /  Equine  /  Exotics  /