Glucosuria in Dogs

Glucose in the urine can be discovered during a routine veterinary appointment, or there may be symptoms leading to the need for further review of the cause. Glucosuria is the presence of sugar within the urine. With glucosuria, there can be a normal concentration of blood glucose, but a high concentration found in the urine. More often though, blood sugar is high too.

The recurring or persistent excretion of glucose in the urine is known as glucosuria (or glycosuria) in veterinary terms. The presence of glucosuria most often means diabetes. Other considerations would include a renal problem or systemic disease. Glucose in the urine in dogs should be investigated by a veterinarian, due to the many complications that can arise because of it.

Undetectable, to very low levels of glucose, are the norm. Serious consequences can result with a persistent reading of glucose in the urine. Many illnesses and diseases will cause glucosuria. If your dog is displaying any of the following symptoms, consult your veterinary care center without delay.

• Increased thirst (polydipsia)
• Increased urine output (polyuria)
• The urine appears clear (diluted)

Diabetes or improperly functioning kidneys resulting in glucosuria may show additional signs:

• Low appetite
• Weight loss
• Breath odor (halitosis)
• Dehydration
• Muscle weakness
• Recurrent urinary tract infection (due to bacterial colonization in the glucose)
• Poor hair coat
• Vomiting

Types

The classifications of glucose in the urine are listed below.

• Hyperglycemic (having excess of glucose in bloodstream)
• Transient (this is a temporary case of high concentration)
• Persistent (occurs as the result of an ongoing disease)
• Normoglycemic (having a normal amount of glucose in bloodstream)
• Congenital (present from birth)
• Acquired (can be due to toxicity)

When the blood glucose exceeds the renal threshold for normal activity, glucose is then found in the urine. There are many reasons why your furry family member could have this medical issue.

• Transient
• Physiologic explanation like stress, uncommon in dogs (common in cats)
• Pharmacologic cause resulting from the use of glucose containing solutions, drugs, or hormones like glucocorticoids
• Toxic origin such as ingestion of ethylene glycol (antifreeze toxicity)
• Pathologic reason like acute pancreatitis
• Persistent
• Pathologic cause like diabetes mellitus, hyperadrenocorticism
• Less common can be lesions of the central nervous system and glucagonoma (tumor of the pancreas)
• Congenital
• Results from an inherited disease like primary renal glucosuria (Scottish Terriers are predisposed)
• Fanconi syndrome results in glucose in the urine (Basenjis are prone)
• Other breeds that are documented most to get Fanconi syndrome are Shetland Sheepdogs, Mini Schnauzers, Labrador Retrievers, Border Terriers, Yorkshire Terriers, Whippets, Norwegian Elkhounds and mixed breeds (males and females are equally affected)
• Acquired
• Lead or copper toxicity
• Outdated drugs like tetracycline
• Acute renal failure

Upon arrival at the veterinary clinic, it may be wise to ask right away for a sterile collection jar so that you can attempt to get a urine sample. Most dogs will cooperate and urinate outside the clinic; many other dogs will have left their scent.

The collection of a fresh sample is helpful for the veterinarian. Room temperature or body temperature samples can give the most accurate readings for glucose. Your veterinarian will obtain a sample by manipulation if you are unable to provide one.

Your veterinarian will ask the following questions as she performs a physical examination.

• What are the symptoms that your dog has been experiencing?
• Has he had a history of a recent illness?
• Has he been exposed to any toxins that you may know of such as drugs, copper or antifreeze?
• How long has he been urinating frequently?
• Is he having accidents in the house?
• What is his food and water intake like in recent days?
• Does he appear to be in pain?

Along with verification of the urine sample, the veterinary team will proceed with a complete blood count, biochemical profile, and electrolyte profile. If the urinalysis and the laboratory work are unable to provide complete answers, further testing could involve hexokinase or glucokinase dehydrogenase tests, which are enzymatic glucose assessments. An ultrasound of the abdomen and pelvis could be needed also.

Your veterinarian, as she works on the diagnosis, will want to investigate the possibilities of other illnesses such as listed here.

• Pancreatitis (inflammation of the pancreas)
• Hyperadrenocorticism (Cushing’s disease that results in too much glucocorticoid being produced)
• Diabetes mellitus (signs are polyuria and polydipsia)
• Fanconi syndrome (a defect in the tubules of the kidney)
• Primary renal glucosuria (glucose in the urine without hyperglycemia)
• Hepatitis (as could be found with copper toxicity)

Treatment of the glucose in urine in dogs will be very specific to the cause. For instance, if your canine family member is found to have diabetes, he will be put on medical management, which could include dietary changes and injectable medication in the form of insulin.

Fanconi syndrome does not have a cure, but guidance will be provided on how to care for your pet throughout the rest of his life with medication and control of kidney disease progression.

If drugs are causing the glucose in the urine, alternative medication will be prescribed. A toxicity like antifreeze will mean a hospital stay and detoxification treatment.

Recovery and home management will mean follow-up visits with your veterinarian in order to get the glucose situation under control. In the case of diabetes or Cushing’s disease, for example, the medication that your pet must take will need to be carefully monitored and controlled by the veterinary team.

Keep the team up to date on your beloved family pet’s health. Attend all follow-up appointments as directed, even if your pet appears to be back to normal. A veterinarian prescribed diet, along with vitamin and mineral supplements will be the norm. Glucose in the urine in dogs can be resolved or at the very least well managed with regular veterinary communication and care.