Combining Rapid and Long-Acting Insulin Analogs for Dogs with Diabetes

I am the owner of Coco, a 6-year old male Poodle who has been diagnosed with diabetes mellitus. I noticed the symptoms myself, as I too am a Type 1 diabetic (I was diagnosed 42 years ago at the age of 7 years). 

My dog's blood sugar was slightly more than 400 mg/dl when I brought him in for testing. That’s terribly high. I am a man with deep concern about this disease, and I personally keep myself in very good control (my A1-C tests are always in the 6’s). And thus, I am interested in having excellent control of my dogs health too. 

I’ve been directed by my veterinarian to give ”Coco” 2 daily injections of long-acting type insulin (I give him glargine (Lantus) since that’s what I use for my diabetes). So I started him 5 units of Lantus twice a day but still found him to be drinking far too much water and still having high sugar levels. So, I then added in small amounts of insulin lispro (Humalog) to better control his sugar. I’ve not yet taken him back in for spot checking of his blood, but I do notice the Humalog is helping decrease his water drinking and urinating at normal levels. So now, I give him 2 shots at breakfast and 2 at dinner—5 units of Humalog and 10 units of Lantus twice per day. And I watch him closely but find he is doing well. I see no signs of low blood sugar. 

Do you find my plan a good one? Am I overreacting by giving him Humalog in addition to the Lantus? I’m not a doctor, but I think a blood sugar curve should be between 70-150 mg/dl to keep him healthy, just like in human diabetic patients. Is this correct? Is there something better I can do? 

Finally, is there a simpler way to give the injections? I use a small needled Pen for his injections between his shoulders in a pinch of skin. Is there a needle-free ”Jet” type injection system that would be better than the needles? 

Thank you very much for any help advice you can share. 

My Response: 

Although insulin glargine (Lantus) can be used to treat diabetic dogs (1-3), it doesn't always work well as the sole insulin preparation, as you have discovered in your dog. Therefore, I don't usually start with glargine in dogs, but I use either NPH (Humulin) or lente (Vetsulin) insulins, which give us a higher success rate (4,5).

Your approach to combining a long-acting insulin analog (glargine; Lantus) with a rapid-acting analog (lispro; Humalog) is certainly an acceptable one. Insulin lispro has been proven to be effective in dogs (6) and combing Lantus with Humalog  has been recommended as an option by some investigators (1). If you use Lantus and Humalog yourself, this may be a good option for you. The rapid-acting Hunalog insulin will lower the blood sugar rise that occurs after meals, whereas the longer-acting Lantus will act as a background insulin to maintain glucose levels between meals.

You mention that you would like keep your dog's blood sugar well-controlled. That is a good idea, especially if you want to prevent the formation of diabetic cataracts, which are common in dogs with diabetes (7,8). However, to do that, the use of "spot checks" of his blood glucose concentration will not be enough. You are going to have to do periodic blood glucose curves, either done at home or in the hospital (9-11). 

Finally, our current options for insulin injections are either use of an insulin needle and syringe or an insulin pen, such as the Lantus SoloStar pen (12).Use of needle-free, jet injector for insulin delivery has been reported (13,14). However, to my knowledge, such jet injectors are not yet available commercially, and they certainly have not been tested in diabetic dogs.

References:

1. Mori A, Sako T, Lee P, et al. Comparison of time-action profiles of insulin glargine and NPH insulin in normal and diabetic dogs. Vet Res Commun 2008; 32:563-573. 
2. Fracassi F, Boretti FS, Sieber-Ruckstuhl NS, et al. Use of insulin glargine in dogs with diabetes mellitus. Vet Rec 2012;170(2):52.
3. Peterson ME. Treating diabetic dogs with insulin glargine. Blog post. May 3, 2012.
4. Palm CA, Boston RC, Refsal KR, et al. An investigation of the action of neutral protamine Hagedorn human analogue insulin in dogs with naturally occurring diabetes mellitus. J Vet Intern Med 2009;23:50–55. 
5. Monroe WE, Laxton D, Fallin EA, et al. Efficacy and safety of a purified porcine insulin zinc suspension for managing diabetes mellitus in dogs. J Vet Intern Med 2005;19:675-82.
6. Sears KW, Drobatz KJ, Hess RS. Use of lispro insulin for treatment of diabetic ketoacidosis in dogs. J Vet Emerg Crit Care (San Antonio) 2012;22:211-218. 
7. Beam S, Correa MT, Davidson MG. A retrospective-cohort study on the development of cataracts in dogs with diabetes mellitus: 200 cases. Vet Ophthalmol 1999;2:169-172. 
8. Wilkie DA, Gemensky-Metzler AJ, Colitz CM, et al. Canine cataracts, diabetes mellitus and spontaneous lens capsule rupture: a retrospective study of 18 dogs. Vet Ophthalmol 2006;9:328-334. 
9. Wiedmeyer CE, DeClue AE. Glucose monitoring in diabetic dogs and cats: adapting new technology for home and hospital care. Clin Lab Med 2011;31:41-50. 
10. Cook AK. Monitoring methods for dogs and cats with diabetes mellitus. J Diabetes Sci Technol 2012;6:491-495.
11. Davison LJ. Canine diabetes mellitus In: Mooney CT, Peterson ME, eds. BSAVA Manual of Canine and Feline Endocrinology. Fourth ed. Quedgeley, Gloucester: British Small Animal Veterinary Association, 2012;116-132.
12. Association AD. Insulin administration. Diabetes Care 2001;24:1984-1987. 
13. Engwerda EE, Abbink EJ, Tack CJ, et al. Improved pharmacokinetic and pharmacodynamic profile of rapid-acting insulin using needle-free jet injection technology. Diabetes Care 2011;34:1804-1808. 
14. Engwerda EE, Tack CJ, de Galan BE. Needle-free jet injection of rapid-acting insulin improves early postprandial glucose control in patients with diabetes. Diabetes Care 2013;36:3436-3441.