Exam 4 - Canine Diabetes Mellitus Flashcards
what is the general characterization used to describe diabetes mellitus?
persistent hyperglycemia, resulting from defective insulin secretion, insulin action, or both
what is the most common cause of canine diabetes mellitus?
immune-mediated beta cell destruction - results in absolute insulin deficiency (strong similarities to type 1 diabetes in people)
what are the 4 causes of canine diabetes mellitus?
- immune-mediated beta cell destruction
- secondary to chronic pancreatic disease
- diestrus diabetes
- drug-related
what is the pathogenesis of chronic pancreatic disease causing canine diabetes mellitus?
persistent inflammation of the exocrine pancreas damages the islets
islet loss results in essentially zero insulin secretion
what is the pathogenesis of canine diestrus diabetes?
aka - canine acromegaly
progesterone in the diestrus phase triggers the release of growth hormone by mammary tissue which is a powerful antagonist to insulin (post-receptor effect)
DM may be reversible if the dog is spayed ASAP
what is the pathogenesis of drug-related disease causing canine diabetes mellitus?
cyclosporine has been associated with DM in dogs - damages beta cells & impacts insulin sensitivity
T/F: similar to people, dogs get obesity related diabetes mellitus (type 2)
false - they don’t!! cats & people do!
T/F: sudden pu/pd/pp with rapid weight loss is the hallmark sign of canine DM
true
why do clinical signs start so suddenly in patients with diabetes mellitus?
as soon as bg levels are > than the renal threshold (160-200 mg/dl), we see increased urine production
secondary increase in water intake due to fluid loss through urine
lack of insulin causes dramatic feelings of hunger & polyphagia
lack of insulin results in mobilization of reserves & rapid weight loss
what is seen upon physical exam of a patient with diabetes mellitus?
often unremarkable except for weight loss
cataracts may be noted at the time of diagnosis - but rare
look for evidence of diseases that may complicate management - other endocrinopathies (check skin & hair coat) & systemic illnesses
what is seen on urine analysis of a dog with diabetes mellitus?
glucosuria (very few other differentials for this - renal tubular injury/dysfunction, or spurious)
+/- ketonuria - some may be noted in newly diabetic dogs, but does not indicate DKA!!!
urine specific gravity impacted by glucosuria - often > 1.020 despite severe pu/pd
evidence of UTI - rbc, wbc, bacteria, may be subclinical
T/F: like cats, dogs also get stress hyperglycemia
false
what lab changes are seen on a chemistry panel of a dog with diabetes mellitus?
hyperglycemia usually >300 mg/dl
hypercholesterolemia/hypertriglyceridemia
elevated ALP activity - vacuolar change due to lipid mobilization
hyponatremia - partially dilutional due to hyperglycemia, some increase in urinary loss of sodium
what changes may be seen on a cbc of a diabetic dog?
stress leukogram is expected
anemia is not expected!!! suggests concurrent disease
what is the current consensus on subclinical UTI therapy in diabetic dogs?
not to culture or treat unless the dog has actual signs of a UTI
why do a PLI test on a diabetic dog?
elevation supports concurrent pancreatitis - may impact dietary recommendations
what are the 6 goals of treatment for a diabetic dog? which is the most important?
- resolve pu/pd - minimize signs of hyperglycemia
- avoid hypoglycemia
- avoid DKA
- optimize weight, activity level, & BCS
- minimize complications (uti, cataracts)
- satisfied owner - most important!!!!!! owner is life support system for the dog
why are porcine or human insulins preferred for use in diabetic dogs?
canine insulin is identical to porcine insulin & very similar to the human molecule
what is the only FDA approved pork insulin?
vetsulin
T/F: almost all available insulins are now based on the human molecule
true
what components of insulin make up the type when selecting one for therapy?
rate of onset
duration of effect
potency
what are engineered insulins?
scientists have altered the amino acid chain of the human insulin molecule to change its behavior - these are more predictable & stable than the older types of insulin
referred to as “insulin x”
insulin glargine u-100 (lantus)
what should be considered for insulin cost when making a decision on which option to use therapeutically?
consider how much of a bottle will be used
dose
stability after opening
syringes needed - U40 syringes, used for prozinc & vetsulin, are more expensive
what does U40 mean? what does U100 mean?
U40 - 40 units/ml
U100 - 100 units/ml
what insulin type is used for managing all species with DKA? how long does it last? how is it given? what syringe is used?
regular!!! lasts 4-6 hours if given SQ
can be given IV/IM/SQ
U100 syringe used
what insulin type is used for diabetic cats but is unpredictable in dogs? how long does it last? how is it given? what syringe is used?
prozinc!!! 12 hours, sometimes longer
SQ only
U40 syringe
what insulin type requires the use of an insulin pen for dosing in unit increments? how long does it last? how is it given? what syringe is used?
glargine U-300
more than 12 hours
IV/IM/SQ
U300 syringe (insulin pen)
what insulin type is used for diabetic dogs that are bigger or failed to respond to lente/nph? how long does it last? how is it given? what syringe is used?
detemir - levemir, very potent
lasts 10-12 hours
IV/IM/ SQ
U100
what insulin type is routinely used in cats that gets good control? how long does it last? how is it given? what syringe is used?
glargine!! lasts > 12 hours
IV/IM/SQ
U100 syringes
what are your 3 suitable first choices for insulin in diabetic dogs?
- lente - vetsulin
- NPH
- insulin detemir
how is lente (vetsulin) used for starting insulin therapy in diabetic dogs?
U40 porcine insulin product - starting dose is 0.25 U/kg twice daily - okay to round up to 0.5 U/kg in small dogs
comes with a pen system - easier for the nervous owner & more accurate with small doses than a syringe
how is NPH used for starting insulin therapy in diabetic dogs?
starting dose is 0.25 U/kg twice daily
how is insulin detemir used for starting insulin therapy in diabetic dogs?
starting dose is 0.1 U/kg twice daily (very potent) - U100 syringe
hard to dose in small dogs
what is the initial approach that should be used when beginning insulin therapy in a diabetic dog?
administer the first insulin dose & feed in the morning (use 11 mm needles - too short may stay intradermal)
measure BG every 2 hours over 8-12 hours
if bg remains > 150 mg/dl, send home on this dose! may increase the dose by 10% if possible if bg is >250 mg/dl
if bg goes < 150 mg/dl, decrease the dose by 10-25% (round to nearest unit) & if possible, hospitalize the dog to monitor response to the lower dose
repeat blood glucose curve in one week
what dietary strategies may be used for a diabetic dog?
feed a complete & balanced diet that is low in simple sugars - a ‘special’ diabetic diet has little benefit
feed enough to optimize body weight
feed equal sized meals twice daily at the time of insulin injection - consistency is key!!
can use the pet nutrition alliance website to get help for creating a diet plan
T/F: acute exertion in a diabetic dog can result in hypoglycemia
true
what can be done to improve insulin efficacy after a dog finishes their meal?
15 minute walk after each meal
what is the benefit of using a freestyle libre as a send home monitoring treatment for a diabetic dog? what are the disadvantages of it?
continuous monitor that is fairly reliable - data for 10-14 days & lets you safely step up doses quicker & achieve control faster
disadvantages - doesn’t always work, may need to verify with alpha trak a few times a day & poor concordance if bg changes fast (venous versus interstitial reading)
after the initial diagnosis of diabetes & start of insulin therapy, what should your recheck schedule look like?
recheck every 1-2 weeks for the first month if not using a libre - can do a bg curve at home or in clinic & adjust dose as indicated
recheck bg within 2 weeks of a dose change
encourage home monitoring once a month - more data & more accurate!
intermittent use of a continuous interstitial glucometer
recheck every 3 months if doing well!
treat patient & not numbers!!!!! we use the curve data to make adjustments when needed, but don’t chase the perfect curve
how is at bg curve done at home?
check bg
feed & administer insulin as usual
feeding at home ensures that the pet east all food
test bg every 2 hours until next insulin dose - repeat bg within 1 hour if any glucose value is <100 mg/dl
how is at bg curve done in the clinic?
have the owner feed the dog & give insulin at home
test bg every 2 hours until next dose of insulin - repeat bg within 1 hour if any value <100 mg/dl
T/F: it is dangerous to increase an insulin dose without performing a curve or using a libre
true
what is nadir for diabetic dogs? what are important considerations for this when doing a blood glucose curve?
100-150 mg/dl - not the actual lowest if we are doing it every 2 hours, but our best estimate!! very important to do our best to establish this value
continuous monitors will allow us to identify nadir most reliably - timing is inconsistent, so you can’t just do a spot check!
failure to identify the nadir but increasing the dose based on a spot check is a classic mistake
okay to get close to 80 mg/dl in a stable patient
what is nadir in regards to a blood glucose curve?
the lowest a measurement will be during the procedure/curve
what is the target goal for duration of a blood glucose curve? what about target average bg value?
10 hours - try to establish when the insulin has worn off, bg is > 80% of the pre-insulin value!
average - < 250 mg/dl
if nadir is <80 mg/dl in a stable patient after a blood glucose curve, what should you do?
decrease their insulin dose by 25%!!
if nadir is >150 mg/dl after a blood glucose curve, what should you do?
increase insulin by 10-20%
if nadir is 100-150 mg/dl after a blood glucose curve, & average blood glucose is <250 mg/dl, what should you do?
no change to insulin dose!
if nadir is 100-150 mg/dl after a blood glucose curve, & average blood glucose is > 250 mg/dl, what should you do?
glucose nadir </= 6 hours - change to a longer acting insulin!
glucose nadir >/= 10 hours after insulin, change to a shorter acting insulin
T/F: it is okay to allow a client to decrease or skip a single insulin dose if they are concerned, but they are not allowed to increase the dose unless directed to do so by the veterinarian
true
for client education, what does the owner need to know about hypoglycemia & hyperglycemia in their diabetic dog?
hypoglycemia is deadly but short term hyperglycemia is not!!!!
what specific instructions should you give to the owner of a diabetic dog showing signs of hypoglycemia?
offer food if the dog is able to eat - carbs are ideal
rub karo syrup on gums - 0.125ml/kg will raise bg by about 50 mg/dl & may need to repeat this while insulin does its thing
T/F: regular insulin [“R”] is analogous to endogenous insulin from the pancreas & all current R insulins are human molecules
true
what defines the type of insulin?
whatever chemical is attached to the insulin molecule
what is the 2 peak formulation of lente insulin?
30% fast acting & 70% slow acting - designed to blunt post prandial rise in blood glucose levels
why is detemir insulin so much more potent than lente?
4x more insulin molecules/unit
what 3 key questions should you consider when doing a blood glucose curve?
- did the insulin have an effect?
- what was the lowest value? goal of 150-250 mg/dl for the first dose!!
- did the insulin last about 10 hours? (nadir about 6 hours post dose)
