Dogs and Cats 20 Flashcards
Insulin where is it produces and its function
- Where is it produced? -> beta cells within pancreas
- What is its function?
○ Stimulates glucose transport from blood into muscle and adipose by Glut4 transporters
○ Stimulates protein metabolism
○ Increases glycolysis in liver and activates glycogen synthase to store glucose as glycogen
○ In a fed state promotes fatty acid storage as triglycerides in adipose tissue
Define diabetes mellitus and the cause in dogs and cats
- group of diseases with multiple aetiologies characterized by hyperglycaemia resulting from inadequate insulin secretion, insulin action or both.”
Aetiology - Dogs
○ Majority - insulin dependent DM - TYPE 1 DM or juvenile onset DM
○ Absolute insulin deficiency
○ Reliance of life-long exogenous insulin to survive - Cats
○ Majority - non-insulin dependent - TYPE 2 DM
○ Peripheral insulin resistance and inadequate insulin secretion
§ Due to a beta-cell dysfunction which is caused by number of factors including amyloid deposition, glucose toxicity (chronic hyperglycaemia)
□ Overtime hyperglycaemia causing insulin resistance becomes irreversible
○ Possibly reversible
What are the 6 main predisposition and risk factors for diabetes mellitus
- Genetic
○ Breeds/family odds
§ Different breeds in different countries can have different predisposition - Age
○ Middle-aged to older pets - Sex
○ Not consistently reported across all studies
§ Dogs: Female>Male - in some countries females are not spayed -> hormones may affect insulin resistance
§ Cats: Male>Female - Obesity
○ Particularly in cats - nearly 4 times more likely to develop
§ Every 1kg gains insulin resistance increases by 30% - Physical inactivity
- Concurrent diseases/drugs
○ Examples
§ Pancreatitis - insulin deficiency
Prednisolone - insulin resistance (antagonist for insulin)
What are the main clinical signs of diabetes mellitus
1) PUPD
2) polyphagia
3) muscle loss, poor tissue regeneration and function
Additional clinical signs
4) Eye changes in dogs
○ 3/4 cataract within first year of diagnosis - in DOGS
§ Initially glucose in lens metabolised into sorbitol (cannot leave the eye, increase production, brings in water -> eye swells -> cataracts)
5) Plantigrade stance in cats (diabetic neuropathy)
6) +Exercise intolerance
7) +Recurrent infections
8) +signs of diabetic ketoacidosis
○ E.g. ketotic breath
what is the renal threshold for dogs and cats
Renal threshold - glucose in urine -> osmotic diuresis -> PU/PD
- Dog 12mmol/L
- Cat 15-16mmol/L
Diagnosis for diabetes mellitus what are the 5 main ones
- Persistent fasting hyperglycaemia and glucosuria in a pet displaying appropriate clinical signs
- Haematology - may see stress hyperglycaemia or concurrent infection
- Biochemistry - hypercholesterinaemia, ALP, ALT increase
Top 2 - more for secondary conditions that complicate treatment - hypothyroidism, pancreatitis, urinary tract infection - Urinalysis - apart from glucosuria, other findings include proteinuria, ketonuria (DKA) and signs of UTI on sediment
- Imaging - change in pancreases for ultrasound if pancreatitis, enlarged liver on radiograph
How to differentiate persistent fasting hyperglycaemia and glucosuria from diabetes mellitus from stress hyperglycaemia
○ What about stress hyperglycaemia? - common in cats
§ Are there clinical signs -> if YES then likely diabetes (shouldn’t have clinical signs in stress hyperglycaemia)
§ Re-measure urine/blood glucose at home +/-
□ 3 days after so stress is reduced
§ Fructosamine test -> if elevated then too much sugar in blood for previous 2 weeks
Dogs presenting with PUPD what are common and uncommon causes
- Common
○ Drug induced
§ E.g. Phenobarbitone, Prednisolone
○ Hyperadrenocorticism - cushings disease - Uncommon
○ SARDS - generally present with blindness
○ Acromegaly
○ Hepatic encephalopathy - PSS
§ Generally not associated with polyphagia however toxins may affect brain leading to this
Cays presenting with PUPD what are common and uncommon causes
- Common ○ Hyperthyroidism - Less common ○ Acromegaly ○ Drug induced ○ Hepatopathy - Rare ○ Hyperadrenocorticism
What are the differentials for hyperglycaemia and glucosuria
Hyperglycaemia - DDX: ○ Drugs ○ Disorders associated with insulin antagonism ○ Stress Glucosuria - DDX: ○ Renal tubular disease ○ Laboratory interference - high amount of Vitamin C leads to discolouration of dipstick ○ Stress
What are the goals in the treatment of diabetes mellitus
- Owner perceived good QOL and satisfaction with treatment
○ Resolution of clinical signs
§ Glucose concentration below renal threshold
○ Optimisation of weight, activity level and body condition
○ Remission if possible in cats
§ Tight glycaemic control
○ Prevent/minimize complications, including hypoglycaemia
what are the 4 components in treating diabetes mellitus
1) diet
2) insulin - management
3) address concurrent disease
4) weight loss via exercise - support weight loss, should be constant
Diet management for diabetes mellitus treatment how do and what important for
○ Constant between days! - large effect on glucose concentration
§ Same calories
§ Same volume
§ Same composition
§ Same feeding frequency
○ Important for weight loss as well
§ Dogs: Adjust fibre content depending on bodyweight
□ Can feed dogs morning and night
§ Cats: Restrict carbohydrate content - important prognostic factor in cat
Insulin management to treat diabetes mellitus how to get started on a program
§ Create a realistic treatment protocol FOR THE PATIENT AND OWNER
□ This is an important factor that may lead to euthanasia
§ Start with insulin q 12 +2 hrs* together with regular diet
§ Set up monitoring plan
§ Inform of monitoring for and management of hypoglycaemia
What are the types of insulin to use for diabetes mellitus and most common in dogs and cats
Types - glargine, PZI, porcine lente, NPH, regular insulin
- Mainstay of DM treatment
- Different insulins have
- Different longevity
- Different potency
- Ability to cause antibodies
Most common
- dogs - caninsulin, a porcine lente insuin
- cats - lantus, a synthetic insulin analogue
Starting insulin treatment for diabetes mellitus what dose at what frequency for what BG and specific to cats
§ Instructions □ Intermediate or long-lasting insulin (rounded down to nearest full IU) ® 0.25 IU/kg q 12 hrsif BG < 20 mmol/L ® 0.5 IU/kg q 12 hrsif BG >20 mmol/L □ Dose according to ideal BW □ Specific to cats: ® Do not give > 3 IU/cat initially ® Do not give > 1 IU/cat q 12 hrs if no blood monitoring is performed in first week
Monitoring insulin treatment in a diabetic frequency and what is essential at each visit
§ Frequency
□ Recommended
® Weekly (+2 days) in first month or after dose increases
® Then monthly for 2 months
® Every 3-4 months when stable
§ Can be more frequent in cases of hypoglycaemia
§ Essential at each visit
□ Information from home: Home monitoring diary or log
® How much eat and drink any activity, issues or adverse effects
Insulin monitoring during diabetes mellitus treatment what are traditional tests
1) Urine –dipstick for glucose and ketones
2) Blood glucose curves
® Usually every 2 hrs for 12 hours
® May be done at home or in hospital
® Home glucose sampling video
3) Fructosamine
® Proteins within the blood have glucose bound to them, stay within the blood until metabolised which takes 1-2 weeks
◊ Hyperthyroidism - increase protein metabolism so can change the results
® - is not affected by stress
® Disadvantage - average out - may not be able to pick up hypoglycaemia and hyperglycaemia
® Different reference ranges based on laboratory
What are the new systems for monitoring insulin in diabetic patients
§ New systems - measure tissue glucose NOT blood glucose - detects and sends information to detector every minute
□ Not painful so can go home with, not as much affected from stress as well
□ Types
® Continuous glucose monitoring
® Fresh glucose monitor
Glucose curve what are the 4 things you want to identify and what use it for
□ What is the glucose concentration before insulin is given
□ What is the nadir - lowest glucose concentration for duration of insulin effect
□ Duration of insulin action -> how long under the renal threshold
□ Duration above the target glucose range -> how long above renal threshold -> when we expect contribution to clinical signs
- Then use the glucose curve to determine whether need change dose of treatment based on recommendations
In monitoring for diabetes mellitus what monitoring for and management
□ Signs
® Changes in demeanour:
◊ E.g. Irritability, aggression, aimless wandering
® Hunger, seeking food
® If no treatment -> Ataxia, seizures, coma, death
□ Management:
® Act quickly!
® If pet is conscious offer food
® If pet is unable to eat apply glucose syrup or honey to oral membranes
® If pet is obtunded give glucose IV
◊ Glucagon CRIs may be used in severe cases of insulin overdose
® Don’t forget to reduce the next insulin doses -> reduce insulin by 50%
In terms of treating diabetes mellitus what is involved in addressing concurrent diseases
○ Concurrent diseases may lead to an inability to stabilize the diabetes mellitus quickly.
○ Address infections if present
○ Perform dental treatment as soon as possible if necessary
○ Spay female entire dogs as soon as possible
§ Progesterone insulin antagonist and mammary gland producing growth hormone (another insulin antagonist) - HIGH in dioestrus or pregnancy - CAN TIP OVER THE EDGE
○ Discontinue any diabetogenic drugs if possible
Which species can achieve remission from diabetes mellitus, define and which are more likely to achieve
- Definition: Euglycaemia without insulin therapy or hypoglycaemic drugs for > 2 weeks
- Cats are more likely to achieve remission if
○ Medication that antagonizes insulin (e.g. prednisolone) was present in last 6 months and has been discontinued
○ Excellent glycaemic control is achieved in < 6 months from diagnosis
○ Required insulin dose to achieve tight control is low
Diabetes mellitus remission in cats best achieved with and what is important to remember
- Best achieved with:
○ Long-acting insulins
○ Low carbohydrate, high protein diets
○ Rapid initiation of therapy (early diagnosis)
○ Intensive monitoring of blood/tissue glucose and appropriate insulin adjustment - Remission may not be permanent
○ Cats should be maintained on low carbohydrate diet
○ Regular monitoring for DM advised
Prognosis of diabetes mellitus what does it depend on, dogs and cats MST
- Depends on ○ Owner commitment ○ Presence of concurrent disorders - Dogs - generally older and have concurrent conditions - may be euthanised due to lack of ability to monitor ○ MST 2-3 years - Cats ○ MST 1-2.5 years - If pets are stabilized well many live longer then MST
How to recognise an unstable or complicated diabetic
- Signs of diabetes mellitus do not resolve or recur - PU/PD should resolve within 2 weeks
- Signs suggestive of sequelae occur - Persistent hypoglycaemia, infections,
- Laboratory parameters suggest poor control
- Insulin doses needed to achieve control are > 2.2 iu/kg (most animals 0.5iu/kg maintained on, can be up to 1)
- Insulin requirements change often
What are common consequences of poor diabetes control in a dog
- affect the quality of life - may result in euthanasia
Dogs - Cataracts, blindness and anterior uveitis
- Chronic pancreatitis
- Recurrent infections
- Hypoglycaemia
- Ketoacidosis
What are common consequences of poor diabetes control in a cat
affect the quality of life - may result in euthanasia
- Peripheral neuropathy
- Weight loss and poor grooming
- Hypoglycaemia
- Recurrent ketosis or DKA
- Hyperglycaemic hyperosmolar syndrome - rare but can be life threatening
○ Low enough that not getting acidosis but high enough getting this osmolarity
○ increase osmolarity in blood which draws water from cells -> intracellular hypotonicity (shrinking of cells -> mainly neurological cells) resulting in neurological signs
What are the 5 steps in approaching the unstable diabetic
- Rule out management errors - large proportional of issues
- Discontinue any diabetogenic drugs - glucocorticoids, progestagens, phenylpropanolamine
- Rule out insulin problems
- Increase the insulin dose ever 5-7 days until 1-1.5 iu/kg lean BW twice daily is achieved
- Perform a blood glucose curve, Fructosamine +/- other tests to assess
○ Insulin resistance, inappropriate length of insulin action, overdosing
In terms of approaching a unstable diabetic how to rule out management errors
○ What syringes are used?
○ How is the insulin drawn up?
○ How is the insulin injected? -> skin tent -> need to rotate areas being injected to prevent fibrosis formation
○ What diet and exercise regime is used?
In terms of approaching a unstable diabetic how to rule out insulin problems
○ Storage
○ Mixing - role gently between the hands - DON’T SHAKE (crystals could accumulate at bottom, microbubbles formation)
○ Diluting - not recommended, glargine CANNOT BE DILUTED - change pH may precipitate in bottle not body - ineffective
○ Discolouration - suggests contamination or out of date
○ Date of expiry - can be used longer if proper storage - main issue is contamination but can be effective above this
Why not just a spot glucose
For cost reasons
- Spot glucose when see the animal and that is it
- Good to identify hypoglycaemia to decrease insulin
- NOT GOOD for identifying issues with diabetic control and adjusting insulin upwards
In a complicated diabetic case what can a high dructoasmine concentration may indicate
§ Insulin resistance, insulin underdoing and insulin overdosing
□ Insulin overdosing -> can cause hyperglycaemia that lasts days - as Fructosamine
§ WHY NEED BLOOD GLUCOSE CURVE
Insulin resistance why may occur and what hormones act as insulin antagnoists
- May occur because there are problems
○ Before insulin binds at its receptor -> if cannot bind or no receptors to bind to - GLUT4 transporter
○ During binding to the receptor, or
○ During post-receptor interaction - There are several hormones that act as insulin antagonists
○ Progesterone, cortisol, glucagon, adrenalin and noradrenalin, growth hormone
Acromegaly what is it, causes and clinical features
- A disorder in which the pituitary gland produces too much growth hormone.
Causes of severe insulin resistance in both species, but different aetiology
Clinical features - Respiratory stridor
- Dental spacing - growth in the mouth
- Prognathia inferior -> jaw protruding cranial mandibular
- Broad facial features
- Lameness
- Clubbed feet
- Organomegaly
- Neurological signs (cats) - due to the pituitary growth
Acromegaly diagnosis
- Suspicion: ○ Clinical signs or ○ Weight gain despite poor control of DM ○ Female entire dog with DM - IGF-1 Measurement - GH measurement if available - CT or MRI in cats - specialist
Phaeochromocytoma what is it, how common, general age and clinical signs
- Catecholamine producing tumour
- Uncommon in dogs and rare in cats
- Most patients are older (median 11 years)
Clinical signs - Related to effect of catecholamines
○ Hypertension
○ Weakness and collapse
○ Tachycardia
○ PUPD - Related to invasion of other organs
- In some cases no signs!
Phaeochromocytoma differentials and diagnosis
Differential for adrenal masses 1. Hormone secretion (functional) ○ Hyperadrenocorticism (dogs) ○ Sex-hormone secreting mass ○ Phaechromocytoma ○ Hyperaldosteronism (cats) 2. Non-functional ○ Adenomas, carcinomas, metastasis Diagnosis - Haematology, serum biochemistry and urinalysis - Blood pressure measurement - Funduscopic examination - Diagnostic imaging - Plasma and urine catecholamine measurements
Phaeochromocytoma treatment and prognosis
- Phenoxybenzamine
- Surgery
- Prognosis is guarded-good if the tumour can be excised.
○ >1-2 years survival
Glucagonoma how common, tumour in, clinical features, diagnosis, treatment and prognosis
- Rare
- Tumour in
○ pancreas (D)
○ Liver (C) - Main clinical features are
○ Necrolytic migratory erythema
○ Uncontrolled diabetes mellitus - Diagnosis requires advanced testing
- Treatment is surgical
○ Medical treatment may play a role in future - Prognosis is poor; metastasis at the time of diagnosis is common
