Diabetes mellitus is a common endocrine disease that can be life threatening and in dogs and cats. It is a chronic disorder of carbohydrate metabolism due to relative or absolute insulin deficiency. However, this disease can be manageable, and pets can live a normal life when treated properly
Diabetes mellitus is a common endocrine disease in dogs and cats, occurring in about 1 of every 300 patients. Diabetes mellitus is a chronic disorder of carbohydrate metabolism due to relative or absolute insulin deficiency.Most cases of spontaneous diabetes occur in middle-aged dogs and middle-aged to older cats. In dogs, females are affected twice as often as males, and incidence appears to be increased in certain small breeds such as Miniature Poodles, Dachshunds, Schnauzers, Cairn Terriers, and Beagles, but any breed can be affected. Obese male cats seem to be more commonly affected than female cats, and breeds such as Burmese, Russian Blue, Norwegian Forest Cat, Abyssinian, and Tonkinese appear predisposed
Predispositions
Middle- aged dogs
Middle - aged to older cat
Females twices affected by males
Obese male cats more common affected than female cat
*Diabetes typically occurs when dogs are between 4 to 14 years of age. Unspayed female dogs are twice as likely as male dogs to suffer from diabetes
*Pregnancy and diestrus also can predispose to diabetes mellitus in dogs but not in cats
*Obesity also predisposes to insulin resistance in both dogs and cats
Pathology and Etiology
The pathogenic mechanisms responsible for decreased insulin production and secretion are multiple, but usually they are related to destruction of islet cells, secondary to either immune destruction or severe pancreatitis (dogs) or amyloidosis (cats)
Types of Diabetes Melitus
Primary : all have type 1 or insulin-dependent disease. This is characterized by beta cell destruction (often due to autoimmune destruction of the islets of Langerhans) and hypoinsulinemia. Pancreas un able to produce insulin absolute requirement for exogenous insulin injections to control blood glucose levels
Secondary Diabetes mellitus can be secondary to severe inflammation or neoplasia of exocrine pancreatic tissue, which leads to loss of islet function.. Diabetes mellitus can also occur when there is either overproduction of counteracting hormones or insulin resistance (Progesterone, glucagon, thyroid hormones, cortisol etc.)
*Insulin resistance and secondary diabetes mellitus are also seen in many dogs with spontaneous hyperadrenocorticism and after chronic administration of glucocorticoids or progestins.
*The selective deposition of amyloid in islets, with degenerative changes in β cells, is the most common pancreatic lesion in many cats with diabetes.
Mechanism of Diabetes
Common clinical signs include:
Polyuria: The disturbances in water metabolism develop primarily because of an osmotic diuresis. The renal threshold for glucose is ~180 mg/dL in dogs and ~280 mg/dL in cats.
Polydipsia: Increase of thirst due to excessive urination
Polyphagia: increased hunger due to loss or excess glucose in urine that leads the body to crave for more glucose
Weight loss: When the glucose doesn't arrive in your cells, your body thinks it's starving and finds a way to compensate. It creates energy by burning fat and muscle at a rapid pace. This causes unexplained weight loss
Cataracts (dog): Cataract formation in dogs is related to the unique sorbitol pathway by which glucose is metabolized in the lens, which leads to edema of the lens and disruption of normal light transmission.the lenticular opacities appear initially along the suture lines of lens fibers and are stellate (“asteroid”) in shape
Weakness: Due to low of glucose
Hepatomegaly: Increase in the size of the liver is due to fatty deposits
Diabetic ketoacidosis is a form of decompensated diabetes mellitus in which cells use free fatty acids as an energy source, because they cannot access glucose due to absolute or relative insulin deficiency. In the presence of elevated glucagon and other counter-regulatory hormones, free fatty acids are broken down into ketoacids. As ketoacids and glucose accumulate in the blood, metabolic disturbances occur, which can be profound and life threatening
Diagnosis:
There are many aspects to diagnose Diabetes Melitus in dogs and cats. Most of the clinical findings of diabetes are high glucose in the blood but not always the case. It is essential also to correlate other clinical and physical finding to confirm the diagnosis
Persistent fasting hyperglycemia
The normal fasting value for blood glucose in dogs and cats is 75–120 mg/dL.
Glycosuria
It is important to rule out stress-induced hyperglycemia, and multiple blood and urine samples may be required to confirm the diagnosis. The renal threshold is around 180 mg/dL (10 mmol/L)
Measurement of glucose in the urine to determine glycosuria or if the patient is suffering from diabetes Ketoacidosis a complication of hyperglycemia in which the body use fats as a energy source which turns the body into acidic.
Elevated Fructosamine
Measurement of serum fructosamine can assist in differentiating between stress-induced hyperglycemia and diabetes mellitus. In cases of stress-induced hyperglycemia, the fructosamine concentrations are normal. In all cases, a search should be made for drugs or diseases that predispose to diabetes.
Fructosamine reflects your dog's average glucose level over the past 7-14 days. Fructosamine is measured from a single blood sample
Initial Presentation:
Physical examination and weighing the dog.
Laboratory testing including complete blood count, urinalysis (including sediment examination), and serum biochemistry profile.
Rule out hypothyroidism, renal failure, inflammatory bowel disease, pancreatitis, exocrine pancreatic insufficiency, hyperadrenocorticism, growth hormone excess or acromegaly, neoplasia, and hepatic disease.
Other factors that may contribute on the to Blood Glucose Concentration
Insulin Opposing Hormones
Glucagon
Cortisol
Progesterone
Adrenaline
thyroid hormone,
growth hormone
This hormones act to increase blood glucose. It is important to consider these counter-regulatory hormones, because changes in their blood concentrations will interfere with insulin actions.
***Stress could be contributing factors to induce glycemia
Treatment
Diet and weight reduction alone will not control the disease, so initial therapy with insulin is required.
For Dogs:
Most dogs require two doses of insulin a day. In general, NPH or lente is the initial insulin of choice at a dose of 0.5 U/kg, twice a day Vetsulin (porcine) .With twice daily injections, two meals of equal calories are given at the time of insulin administration. Diets high in simple sugars (semi-moist foods) should be avoided.
In the intermittent insulin regimen, regular insulin at 0.2 U/kg, IM, is the initial dosage, followed by hourly administration of 0.1 U/kg. Once the serum glucose is <250 mg/dL, the insulin is administered SC at 0.25–0.5 U/kg, every 4–6 hr, with careful monitoring of the serum glucose at 1- to 2-hr intervals. Perform glucose curve
For Cats:
In cats, high-protein diets along with insulin therapy are initiated, with reevaluation in 5–7 days.
In newly diagnosed cats, insulin glargine is the insulin of choice. Glargine is a long-acting basal insulin.
If blood glucose is > 20mmol/L begin glargine at an initial dose of 0.5U/kg ideal body weight q12hrs (BID). If blood glucose is < 20mmol/L begin at 0.25U/kg ideal body weight q12hrs (BID)
Perform a 12hr glucose curve with samples taken every 4hrs. Insulin can be increased daily until normoglycaemia is achieved but careful monitoring is necessary to avoid hypoglycemia
Successful treatment depends on:
Excellent client communication: Up to 25% of diabetic patients are euthanized on day 1 of diagnosis for reasons that can often be mitigated with education about diabetes and goals of therapy.
The use of basal insulins in cats to improve remission rates.
Appropriate dietary management.
Frequent monitoring, often best performed at home.
*Intact animal should be neutered
Once the Diagnosis of Diabetes Mellitus is Confirmed:
Take time to explain thoroughly to the owner what diabetes is, that achieving regulation may take time (up to 1 to 3 months) complete cooperation of the owner is essential to the success of the management.\
Treat existing infections or other medical conditions. Many diseases will affect insulin metabolism.
Introduce an appropriate diet.
Begin therapy with Vetsulin
Food and Diet:
In cats, recent evidence has supported the use of high-protein, low-carbohydrate diets.
In dogs, diets high in fiber and complex carbohydrates are preferred.
Evaluate Dosage of Insulin Needed
Weigh the dog. In the event of a fraction of a kilogram, round the body weight down rather than up. For example, a 12.9-kg dog should be dosed as a 12-kg dog. If the dog is grossly overweight, utilize the optimal body weight for calculating the starting dosage
Establish a starting dose based on the labeled dosage of 0.5 IU insulin/kg of body weight. This initial dose should be given once daily concurrently with or right after a meal
The goals of managing canine diabetes mellitus include:
Controlling the clinical signs of hyperglycemia (polyuria, polydipsia)
Avoiding hypoglycemia
Obtaining blood glucose curve values in the desired range:*
Dogs: 100–250 mg/dL over the course of the day, with a nadir between 100–150 mg/dL
*In the US clinical study, glycemic control was considered adequate if an acceptable blood glucose curve was achieved (ie, reduction in hyperglycemia and a nadir of 60–160 mg/dL),
Emergency Treatment of Hypoglycemia
Immediate oral administration of glucose solution or corn syrup (1 g per kg body weight) onto the gums or under the tongue
Dose for hypoglycemia 1–5 mL 50% dextrose by slow intravenous injection (over 10 minutes)
source of glucose should be readily available. Following the successful emergency administration of oral glucose, small amounts of food should be offered at intervals of 1–2 hours until the effects of the insulin overdose have been counteracted
Why You Should Chart Glucose
It let's you know if/when the insulin you give your dog is working as you Intended.
You will find out how effective the insulin is at reducing blood glucose in
your dog.
How quickly your dog's blood glucose rises and falls based on meals and insulin shots.
When you need to plan your shots
How to Perform a Glucose Curve for Diabetic Dogs
Be prepared to perform regular blood tests every 1 to 2 hours.
Have a spreadsheet prepared to write down the results. You can then easily turn the spreadsheet into a graph to visualize how their body is breaking down glucose and responding to insulin treatment
Feed your dog on their normal schedule and make sure to eliminate any spontaneous snacks or treats
As soon as you and your dog wake up, test their glucose levels. Then, test them every 1 to 2 hours for at least 24 hours, or up to 48 hours.
***At the end of the test, the chart of your dog's glucose levels should look like rolling hills. (See the above graph)
***If they spike precipitously up or down after injections, this may indicate that your dog is experiencing a Somogyi Rebound and you'll need to decrease their insulin doses.
***If their glucose levels increase significantly after meals and don't maintain a rolling pattern, it may be time to increase their insulin doses.
CASE# 1
Patient name: Chloe
Age: 11 year old
Breed: Shishtzu
Gender: Female intact
Medical History :
Initial complaint (1year ago) coughing, tachypnea, Diagnosed with Pulmonary edema and cardiomegaly.
Concurrently taking Pimobendan (Maintenance) and furosemide, canipril as needed.
She also has a history of pyometra that was resolved by medical treatment on the previous year.
She was continuously losing weight, low muscle mass, with bilateral cataract, good appetite, excessive urination and increased water intake.
Last week July returned for her regular monthly check up whereas otherwise seems healthy. Coughing and tachypnea seems manageable.
1st Blood chemistry July 28, 2022
Note the increase of glucose and Cholesterol level
Tentative Diagnosis:
Diabetes Mellitus
Treatment:
Insulin 0.2 IU/kg ( Lantus) 2x a day daily for 1 week after meal in the morning and evening
Diet: Low carbohydrate food, RC Satiety : Recommended
Since on heart medication, I advised to feed RC cardia for the meantime
**Human prep was used due to no available Vetsulin ( animal prep insulin)
2nd blood exam August 2, 2022
1 weeks since treating insulin 2x a day. Note the BG and cholesterol within the normal level
Wt increases from3.4- 3.5kg, less polyuria and polydipsia
Plans
Recommended for Fructosamine and urinalysis tests: Confirmatory
Initial glucose curve may be done at the clinic setting during confinement
Weekly ff check up for the 1st 2 weeks (esp if no home glucometer available)
Home management
Provide Glucometer : Determination BG every 2 hours starting morning before meal for 24 hours
Recording charts of BG levels including, date, time, activities, amount food intake
Insulin injections usually 2 times a day for the first - second week, then may be adjusted depending on the glucose curve
Feeding 2 times a day AM and PM
Diet low carbohydrates
Emergency food incase of hypoglycemia
*** Vetsulin, Glucometer, Corn syrup , notebook
Reference
https://www.vetsulin.com/cats/diabetes-detect-diagnose.aspx
https://www.msdvetmanual.com/endocrine-system/the-pancreas/diabetes-mellitus-in-dogs-and-cats?query=diabetes%20in%20cats
https://vcahospitals.com/know-your-pet/diabetic-remission-in-cats#:~:text=Cats%20that%20have%20diabetes%20for,an%20external%20source%20of%20insulin.