Contributors: David Bruyette, Audrey K Cook

 Species: Canine   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading


  • Generally >6 years old. Rare in young.
  • Cause: syndrome characterized by relative or absolute lack of insulin.
  • Signs: polyuria/polydipsia, weight loss, polyphagia.
  • Diagnosis: glycosuria, hyperglycemia.
  • Treatment: insulin therapy Insulin.
    Print-off the owner factsheets on Diabetes mellitus Diabetes mellitus and Monitoring diabetes in dogs Monitoring diabetes in dogs to give to your client.

Presenting Signs

  • Polydipsia/polyuria.
  • Weight loss/polyphagia.
  • Occasionally sudden blindness due to cataract Cataract Diabetic cataract Crossbred 12 years Diabetic cataract Pembroke Corgi 9 years or retinopathy Diabetic retinopathy Retinal hemorrhage Crossbred 6 years (rare).
  • One study found a seasonal pattern in diagnosis - with twice as many diagnoses between Nov and Jan as between July and Sept.

Acute Presentation

Age Predisposition

  • >6 years old.
  • Rarely juvenile (inherited disorder in Keeshond Keeshond ).

Breed Predisposition

Cost Considerations

  • Life-long insulin therapy and regular monitoring required.

Special Risks

  • Anesthesia Anesthesia: in diabetic patient requires particular care:
    • Usually administer half usual insulin dose prior to surgery and administer dextrose in intravenous fluid during procedure.
    • Aim to get animal back on normal regime as soon as possible after operation.
      Warn owner of increased risk of anesthesia.
  • Drugs such as glucocorticoids Therapeutics: glucocorticoids can be problematic:
    • Antagonize effects of insulin.
    • Dose may need to be adjusted to prevent ketosis.
  • Risk of hyperglycemia if food is refused or vomited:
    • Counsel owners about management of hypoglycemia Hypoglycemia.



  • Inadequate secretion of insulin (immune-mediated destruction of islet cells, pancreatitis Pancreatitis: acute , islet cell exhaustion).


  • Type 1: (insulin dependent) destruction of beta cells → complete and permanent loss of insulin secretory ability.
  • Other types of diabetes mellitus are rare in the dog:
    • Severe insulin resistance in islet shut-down and overt DM.
    • May be reversible if cause of insulin resistance is addressed, eg diestrus diabetes/canine acromegaly Acromegaly , due to secretion of growth hormone by mammary tissue.


  • Destruction of islets may take several months.
  • Clinical course is short once insulin production ceases.


Presenting Problems

  • Polyuria, polydipsia.
  • Weight loss.
  • Polyphagia.

Client History

  • Acute onset polydipsia, polyuria, nocturia.
  • Polyphagia.
  • Weight loss.

Clinical Signs

Uncomplicated diabetes


Hyperosmolar coma

Diagnostic Investigation




  • Abdominal radiographs Radiography: abdomen often show generalized hepatomegaly due to fatty infiltration.

Gross Autopsy Findings

  • Hepatomegaly.
  • Possible pancreatic atrophy.

Differential Diagnosis

Other causes of polydipsia


Initial Symptomatic Treatment

Standard stabilization

  • Insulin Insulin Diabetes mellitus: management regimens :
    • Various types available, but most dogs require twice daily administration.
    • Initial selection should be guided by current recommendations.
    • Starting dose should be conservative; increase dose by 10-20% based on response.
      Stabilization requires understanding by client.

Dietary considerations

Normalize weight

  • Obese dogs should embark on weight reduction program over 3 months Diabetes mellitus: other considerations.
  • Reducing obesity Obesity may improve insulin sensitivity.
  • Caloric intake can be reduced and exercise levels increased a the start of stabilization and these should be maintained throughout treatment.
  • Underweight dogs should be fed a higher caloric intake until ideal weight is achieved.

Additional treatment

  • Identify and address any concurrent disorders:
    • Urinary tract infection Cystitis.
    • Dental disease.
    • Concurrent endocrinopathies.

Oral hypoglycemic agents

  • These agents have minimal effect in dogs with diabetes and are not a substitute for prompt initiation of insulin therapy.



Subsequent Management


  • Sterilize bitches once stabilized Ovariohysterectomy - high concentrations of progesterone and growth hormone in diestrus antagonize insulin. Prolonged or recurrent episodes of insulin resistance such as following multiple estrus cycles may lead to permanent damage to beta cells.


  • After 1-2 weeks perform serial blood glucose curve Serial blood glucose (blood sample q2h throughout day) to establish stability:
    • Owners may do this at home using a hand-held veterinary approved glucometer.
  • Repeat glucose curve every 2-3 weeks until stabilization achieved Blood glucose curve: interpretation.
    Some studies indicate a large variation in daily glucose curves - even in apparently stable diabetics. Care must be taken in interpretation of these curves as in one study variation in results would lead to different recommendations in half of dogs tested.
  • If problems develop repeat glucose curve to assess insulin response.
  • Increase dose cautiously (10-20%).
  • Decrease dose by 25% if hypoglycemia is noted
  • [Fructosamine] Blood biochemistry: fructosamine :
    • <400 mmol/l = good control.
    • >500 mmol/l in newly diagnosed cases or where poor control.
  • [Glycosylated hemoglobin] Glycosylated hemoglobin :
    • 4-6% shows good control.
    • >7% where poor control.
  • Small devices for short-term continuous monitoring of glucose concentrations are now available through specialist referral centers.



Expected Response to Treatment

  • Reduced water consumption (within days).
  • Improved demeanor and energy levels.
  • Stabilization of body weight.

Reasons for Treatment Failure

  • Inadequate treatment of diabetic ketoacidosis Diabetic ketoacidosis may be fatal.
  • Inadequate frequency or dose of insulin.
  • Inappropriate insulin type.
  • Out of date or poorly stored insulin.
  • Owner non-compliance - improper administration technique.
  • Other complications Diabetes mellitus: complications of treatment include:
    • Insulin-induced hypoglycemia.
    • Rapid metabolism of insulin.
    • Insulin resistance.
    • Urinary tract infection.

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Herring I P, Panciera D L, Were S R (2014) Longitudinal prevalence of hypertension, proteinuria, and retinopathy in dogs with spontaneous diabetes mellitus. JVIM 28 (2), 488-495 PubMed.
  • Niessen S J, Powney S, Guitian J et al (2012) Evaluation of a quality-of-life tool for dogs with diabetes mellitus. JVIM 26 (4), 953-961 PubMed.
  • Rucinsky R, Cook A, Haley S, Nelson R, Zoran D L & Poundstone M (2010) AAHA diabetes management guidelines. JAAHA 46 (3), 215-224 PubMed.
  • Monroe W E, Laxton D et al (2008) Efficacy and safety of a purified porcine zinc suspension for managing diabetes mellitus in dogs. JVIM 19 (5), 675-682 PubMed.
  • Davison L J, Herrtage M E & Catchpole B (2005) Study of 253 dogs in the United Kingdom with diabetes mellitus. Vet Rec 156 (15), 467-471 PubMed.
  • Davison L J, Catchpole B, Kennedy L J, Barnes A, Thomson W & Ollier W E (2003) Research into canine diabetes mellitus. Vet Rec 152 (5), 148 PubMed.
  • Fleeman L M & Rand J S (2003) Evaluation of day-to-day variability of serial blood glucose concentration curves in diabetic dogs. JAVMA 222 (3), 317-21 PubMed.

Other sources of information

  • Mattin M J, O'Neill D G, Church D B & Brodbelt D C (2013)Canine diabetes mellitus: prevelence, risk factors and survival.In:Scientific Proceedings, British Small Animal Veterinary Association Congress, Birmingham, April 4-7, 2013, p 568.

Other Sources of Information