Diabetes in Pets

Diabetic neuropathy is one of the symptoms of prolonged hyperglycemia. It causes numbness and weakness in the legs, particularly in cats.

See also gastroparesis, which is a neuropathy of the stomach, and retinopathy, which is a neuropathy of the eye.


In diabetic neuropathy, nerves in the legs are progressively damaged, leading to tingliness, pain, numbness, and weakness or paralysis. In cats, this often shows first as weak hind legs, progressing until the cat cannot stand on his toes as usual, and walks on his hocks (heels) or sits down more often. This condition is known as plantigrade stance or posture. This article contains a photo of the posture[1].

Jumping becomes difficult, then impossible. Eventually the cats' legs seem to slip out from under them and they become unable to walk. These symptoms are the result of damage to the motor and sensory nerves, but they can usually be reversed with better control of blood sugar and certain dietary supplements.

The symptoms are less common in dogs, but do occur. Many dogs have hind leg weakness when they are first diagnosed with diabetes. This is sometimes the symptom which brings the pet to the vet's office. It's often falsely attributed to "getting older" by the caregiver. What is also known as "diabetic neuropathy"[2] most often affects both rear legs and will progress symmetrically. With treatment and regulation, most dogs also have reversal of neuropathy.

This 1983 JAVMA abstract[3]indicates that both the neuropathy and low blood pressure returned to normal following the control of the diabetes with insulin.

Reversal with Methyl-B12 and Regulation[]

Fortunately, in early stages this damage is reversible[4]. A combination of reducing the attacks on the nerve cells (by regulating blood glucose levels), and Methylcobalamin supplements that promote nerve regrowth, is effective in many cats in just a few weeks.

Effective regulation alone has been known to reverse neuropathy in cats, though perhaps not as quickly as with the Methyl-B12 supplements. Methyl-B12 (aka Methylcobalamin) is a special form of vitamin B12 that can be absorbed in the spinal fluid, and is not the same as regular B12. (Some people quote studies showing that "Vitamin B supplements don't work", which is quite true if they're not the Methyl form. Get specific.) Supplements alone don't help (or not much) if blood glucose remains high.

You can pill the animal or crush the pill into the pet's wet food. Some caregivers give their cats 3mg a day; some less. If you can only find 5mg pills, that's ok too-- the vitamin is water-soluble and the excess will be urinated away. Many pills come with small amounts of glucose or fructose as flavoring, but diabetic cat owners have not noticed significant blood sugar changes as a result of these small amounts.

A reliable source in the US of Methyl-B12 supplement is Zobaline - made specifically for diabetic cats, not to be confused with Xobaline for humans. In Australia Methyl-B12 can be compounded at the pharamcy with perscription from a veterinarian and injected in the same manner as insulin shots once per week.

Mechanics of diabetic neuropathy[]

In humans, the excess glucose oxidizes the tiny capillaries that nourish nerve cells, and the resulting constriction starves the nerve cells. (See Wikipedia:Diabetic Neuropathy link below[5].) In dogs and cats the mechanism[6] seems different: the nerve axons dwindle and atrophy, and the spaces between them become clogged with glycogen deposits.

Understanding how this works, means some learning about nerve cells, impulses and their relationship to muscles. An Atlantic Coast Veterinary Conference (ACVC) 2001 presentation of feline neurological diseases[7] has a section dealing with diabetes-mediated neuropathy. The basic problems regarding nerves, muscles and neuropathy apply to all those with diabetes, so let's take it apart:

The most common neuropathy noted in the feline is diabetic neuropathy (secondary to diabetes mellitus). Clinical signs occur most commonly in the middle to older aged feline and present as lower neuron[8] signs (plantigrade stance-below)[9] in the hind limbs. Patellar (of the knee)[10] reflexes may be diminished, although flexor[11] reflexes and pain sensation are usually intact.

Muscles and nerves can't communicate properly[]

The etiology and pathogenesis of diabetic neuropathy involves primary and secondary axonal[12] (nerve fiber) degeneration due to slowing of axon[13] transport (Neuron impulses move along axons very much like electricity through a wire[14]. Flaws in this communication system between nerves and muscles are the basis for neuropathy and other nerve-related disorders, such as Muscular Distrophy, etc.) secondary to hyperglycemia, alteration of macromolecular transport, interference with axon maintenance[15] and repair by the neuronal cell body, and neural hypoxia[16] (Insufficient oxygen--in this case to the neuron).

A gradual state[]

Progression to this state may occur over several months. Diagnosis and treatment is through the establishment of underlying disease (diabetes mellitus) and characteristic neurologic exam findings, and in most cases will resolve in 6 to 12 months if the DM is treated appropriately. Those who have a disease or diseases of the endocrine system (medical catch-all term is Endocrinopathy) are more prone to neuropathic problems than anyone who has no endocrine conditions[17].

Peripheral and other neuropathies[]

This type of neuropathy is known as peripheral neuropathy[18][19] . There are more types of neuropathies which can affect diabetics--all nerves throughout the body can be at risk[20][21].

Insulin Neuritis[]

There is a form of neuropathy which has been known to doctors treating people with diabetes since the advent of insulin therapy. The name given to it is insulin neuritis, as it often occurs shortly after starting insulin[22]. The problem is that even though it's been around about as long as insulin treatment, the phenomenon is currently not considered common[23]. Insulin neuritis[24] can follow the rapid improvement of diabetic control, but its mechanisms are still elusive[25][26][27]. As you see from this link, one theory is that insulin neuritis is caused by the regeneration of the nerve axons[28][29].

Like the neuropathy which is the result of yet-to-be treated or newly diagnosed diabetes, insulin neuritis also requires time to disappear[30][31].

Further Reading[]





  1. Long Beach Animal Hospital--Diabetes
  2. Southpaws.com-Diabetic Neuropathy
  3. Peripheral Neuropathy & Hypotension in a Diabetic Dog
  4. Neuropathy Associated with Diabetes Mellitus in the Cat-Journal of the American Veterinary Association-1984
  5. Wikipedia:Diabetic neuropathy
  6. Diabetic Neuropathy in Dogs & Cats-1989 Tierartzlichen Praxis (Veterinary Practice)
  7. ACVC 2001-Feline Neurologic Disease
  8. Biology Pages: Neuron
  9. Plantigrade Stance-Drs. Foster & Smith Pet Education Library
  10. Biology Pages: Muscle Spindles
  11. Biology Pages: Muscle Spindles
  12. Biology Pages: Neurons
  13. Biology Pages: Neuromuscular Junction
  14. Biology Pages: Excitable Cells
  15. Biology Pages: Fueling Muscle Contraction
  16. Biology Pages: Muscles
  17. Southpaws.com-Peripheral Neuropathy
  18. Peripheral Neuropathy: National Diabetes Information Clearinghouse (NDIC)
  19. Southpaws.com-Fall, 1999-Peripheral Neuropathy
  20. National Diabetes Information Clearinghouse (NDIC)-Neuropathy Affects Nerves Throughout the Body
  21. Southpaws.com-Diabetic Neuropathy
  22. Endotext.com-Diabetic Neuropathies
  23. Under-recognised Paradox of Neuropathy from Rapid Glycemic Control-Postgraduate Medical Journal-2004 Register Free to Read
  24. Management of Diabetic Neuropathic Pain-Insulin Neuritis-Page 2
  25. Arterio-venous Shunting and Proliferating New Vessels in Acute Painful Neuropathy of Rapid Glycemic Control (Insulin Neuritis)-CAT.INIST.FR (French National Center for Scientific Research)-English Abstract
  26. Acute Glucose DeprivationLeads to Apotosis in a Cell Culture Model of Acute Painful Diabetic Neuropathy
  27. Diabetic Peripheral Neuropathy-1998-Insulin Neuritis-Page 5
  28. Neuromuscular Junction
  29. Acute Painful Diabetic Neuropathy Precipitated by Strict Glycemic Control-Acta Neuropathica-1986
  30. American Diabetes Association-Chat Transcript-2005
  31. Royal College of Nursing-Starting Insulin Treatment for Type 2 Patients-Page 22