Canine and Feline Endocrinopathies Flashcards
What is diabetes mellitus?
A disease associated with absolute or relative insulin deficiency.
What animals does diabetes mellitus affect?
- Canines.
- Felines.
What causes diabetes mellitus?
Destruction of the Islets of Langerhans cells in the pancreas.
What are the pre-disposing factors for diabetes mellitus?
- Pregnancy (Canines).
- Obesity.
- Glucocorticoid administration.
Where is the pancreas located?
Near the duodenum. The right lobe is parallel to the duodenum. The left lobe is parallel to the pylorus.
What is the exocrine function of the pancreas?
Producing digestive enzymes.
What is the endocrine function of the pancreas?
Producing insulin and glucagon.
What pancreatic cells produce glucagon?
Alpha cells.
What pancreatic cells produce insulin?
Beta cells.
What is the function of insulin?
To cause glucose, fatty acids, and amino acids to be absorbed into cells for use as energy or storage as glycogen.
What is the overall effect of insulin?
The level of blood glucose decreases.
What does insulin deficiency result in?
Hyperglycemia.
What does the body do if it produces too little or no insulin?
It breaks down fat and proteins.
What are the 2 types of diabetes mellitus?
- Type I: Insulin dependent.
- Type II: Non-insulin dependent or insulin resistant.
What are the clinical signs of diabetes mellitus?
- Polyuria (PU).
- Polydipsia (PD).
- Polyphagia (PP).
- Weight loss.
What happens if diabetes mellitus is left untreated?
Diabetic ketoacidosis, which is a life threatening emergency.
How is diabetes mellitus diagnosed?
- Persistent hyperglycemia and glucosuria.
- Fructosamine test (Out of house test that can measure blood sugar from the past 3 weeks).
What are the treatment options for diabetes mellitus?
- Dietary management.
- Insulin therapy.
What is the preferred diet type for diabetic dogs?
High fiber.
What is the preferred diet type for diabetic cats?
High protein, low carbohydrate.
What are the different options for insulin therapy?
- Short-acting (Emergency use only).
- Intermediate acting.
- Long-acting.
How is insulin concentration measured?
Units (U)/mL.
What are the available concentrations of insulin?
- U-40.
- U-100.
*The syringe being used MUST match the concentration.
How many times a day is insulin typically given?
BID.
What are the requirements for insulin usage?
- Must be refrigerated.
- Resuspend the insulin before use by gently rolling the bottle.
- Given when the pet is fed a meal.
- Given SQ at rotating sites to prevent scar tissue formation (ex: Pretend the scruff is a clock and inject at 12 and 1 on day 1, 2 and 3 the next day, etc.). .
- Insulin syringes are single use.
- Too much insulin can result in hypoglycemia.
*Educating the owner is of the utmost importance.
What is hyperthyroidism?
When the thyroid gland overproduces thyroid hormone.
What animal does hyperthyroidism primarily affect?
Felines.
Where is the thyroid located?
On either side of the trachea, bilobular.
What 2 hormones does the thyroid gland produce?
- Thyroid hormone.
- Calcitonin.
What is the function of thyroid hormone?
Helps regulate the body’s metabolic rate.
What is the function of calcitonin?
Helps lower blood calcium levels.
What are the “two” thyroid hormones that the thyroid produces?
- Triiodothyronine (T3).
- Tetraiodothyronine/Thyroxine (T4).
*The difference is the amount of iodine each one has.
What is T3?
The active form of T4.
How is T3 created?
An iodine being removed from a T4 that has been absorbed into a peripheral tissue.
What is T4?
The circulating reservoir for T3.
What is the release of T3 and T4 stimulated by?
Thyroid Stimulating Hormone (TSH) from the anterior pituitary gland (APG).
What are the functions of thyroxine?
- Metabolic rate.
- Body temperature.
- Growth and development.
- Skin condition.
What are the clinical signs of hyperthyroidism?
- Vomiting.
- Diarrhea.
- Old, cranky-sounding vocalizations.
- Tachycardia.
- Palpably enlarged thyroid gland.
- Hypertension.
- PD.
- Hyperexcitability.
- PU.
- Unthrifty appearance.
- Increased appetite.
- Weight loss.
- Increased metabolic rate.
How is hyperthyroidism diagnosed?
High levels of circulating thyroid hormone in the blood, most commonly free T4.
What are the treatment options for hyperthyroidism?
- Antithyroid medication.
- Thyroidectomy.
- Radioactive iodine.
*Radioactive iodine is the treatment of choice.
What is the length of the antithyroid medication treatment?
Lifelong.
What is the side effect of antithyroid medication treatment?
White blood cells, so regular monitoring is required.
What is a thyroidectomy?
The removal of one or both lobes of the thyroid.
*If both: Thyroxine meds will need to be given to the animal lifelong.
What is a potential complication of a thyroidectomy?
Damaging the parathyroid gland, resulting in hypothyroidism.
How is a radioactive iodine treatment conducted?
The cat is given a SQ injection of radioactive iodine and the cat is kept at the hospital for 3-5 days after for observation.
How does a radioactive iodine treatment work?
The radioactive iodine is absorbed into the thyroid and destroys hyperfunctioning thyroid cells.
Why is radioactive iodine the treatment of choice?
It is normally a one-time treatment.
What is hypothyroidism?
The underproduction of thyroid hormone due to the thyroid being destroyed by lymphocytic thyroiditis or idiopathic atrophy of the thyroid.
What animal is primarily affected by hypothyroidism?
Canines.
*Secondary to hyperthyroidism treatment in cats.
What are the clinical signs of hyperthyroidism?
- Lethargy.
- Weight gain w/o increased appetite.
- Exercise intolerance.
- Dry skin.
- Alopecia (non-pruritic).
- Overall decrease in metabolic rate.
How is hypothyroidism diagnosed?
By measuring the level(s) of T4, free T4, and/or TSH in the blood.
*Hypothyroidism is commonly over diagnosed.
What is euthyroid sick syndrome?
When the levels of thyroid hormones and/or TSH drop due to non-thyroid factors, mimicking hypothyroidism.
How is hypothyroidism treated?
Supplementation with thyroid hormone (ex: Levothyroxine Sodium).
*Treatment of choice.
Why is levothyroxine sodium the treatment of choice?
- Many dosage levels available.
- Side effects are rare.
What is the alternative name for hyperadrenocorticism?
Cushing’s disease or Cushing’s syndrome.
What is Cushing’s disease?
Elevated cortisol due to pituitary-dependent hyperadrenocorticism (PDH) or adrenal-dependent hyperadrenocorticism (ADH).
*PDH is most common due to an adenoma of the pituitary gland.
What is PDH caused by?
A benign tumor of the pituitary gland that causes the pituitary gland to produce too much ACTH, resulting in excess cortisol.
What is ADH caused by?
A tumor of one of the adrenal glands and it produces a large amount of cortisol.
What is Cushing’s syndrome?
Any disease causing increased cortisol concentrations in the blood.
What is the adrenal gland?
A small gland located above the kidney.
What are the 3 parts of the adrenal gland?
- Medulla.
- Cortex.
- Capsule.
What does the adrenal cortex produce?
- Cortisol (Glucocorticoids).
- Aldosterone (Mineralocorticoids).
- Androgens (Sex hormones, male).
What does the adrenal medulla produce?
- Epinephrine.
- Norepinephrine.
What hormone controls the adrenal gland?
ACTH.
Where is ACTH produced?
Pituitary gland.
What does the adrenal cortex develop from?
Glandular tissue.
What kind of effect do glucocorticoids have on the body?
Hyperglycemic.
How is this effect for the glucocorticoid shown?
- Catabolism of proteins and lipids.
- Breakdown products converted to glucose in the liver.
What are the functions of glucocorticoids?
- Help maintain blood pressure.
- Help the body resist the effects of stress.
What is cortisol’s function in the body?
Prepare the body for flight or fight response.
What are the clinical signs of hyperadrenocorticism?
- PU.
- PD.
- PP.
- Pendulous abdomen.
- Muscle wasting.
- Poor skin condition.
- Chronic infections.
What is the treatment for hyperadrenocorticism?
Medications to reduce the amount of cortisol released from the adrenal gland(s).
*Lifelong w/ regular monitoring.
What is the alternate name for hypoadrenocorticism?
Addison’s disease.
What is hypoadrenocorticism the result of?
Insufficient aldosterone production by the adrenal gland.
What are the clinical signs of hypoadrenocorticism?
- Chronic GI symptoms.
- Anorexia.
- PU.
- PD.
- Hypoglycemia.
- Dehydration.
- Hyponatremia.
- Hyperkalemia.
*Normally are presented as emergency cases due to being in an Addisonian crisis.
What does aldosterone regulate in the body?
The levels of H, K, and Na by targeting the kidneys, where it causes Na ions and water to be reabsorbed in exchange for H and K ions during urine creation.
How is hypoadrenocorticism diagnosed?
- Urine and blood tests to evaluate sodium and potassium levels.
- ACTH stim. test.
What is the treatment for hypoadrenocorticism in dogs?
Lifelong cortisol and aldosterone supplementation.