Drugs
What drug(s) are used for Congestive Heart Failure & block Na-K-Cl cotransporters?
Loop Diuretics - Furosemide
What is the term for abnormal accumulation of fluid in the interstitial spaces of tissues or body cavities, leading to swelling?
Edema
This condition occurs when blood pressure is persistently below normal, often due to decreased intravascular volume, reduced venous return, and reduced cardiac output.
hypotension
What is the most common clinical sign of congestive heart failure in dogs?
Persistent coughing due to pulmonary edema
What is the definition of blood pressure?
The force that blood exerts on the walls of blood vessels
In high doses, alpha 1 receptors are the main drug target which will increase vascular resistance. Name the drug(s) and the main species drug can be used on.
Dopamine (Dogs)
Dobutamine (Horses)
What distinguishes inflammatory edema from non-inflammatory edema in terms of mechanism?
Inflammatory - results from increased vascular permeability
Non-Inflammatory - results from mechanical or metabolic dysfunction (ex: heart failure or hypoproteinemia)
In hypovolemic shock, the baroreceptor reflex activates the sympathetic nervous system to maintain perfusion. Name two compensatory signs you would expect to see on physical exam.
tachycardia and peripheral vasoconstriction (evidenced by cold extremities, prolonged CRT, pale mucous membranes)
What term describes the heart meeting the minimum required cardiac output only because compensatory mechanisms restore function, even though cardiac reserve remains reduced?
Compensated heart failure
What is the difference between pulse pressure and mean arterial pressure (MAP)?
Pulse pressure is the difference between systolic and diastolic pressure, while MAP is the average arterial pressure over a cardiac cycle.
What drug cannot be used in patients with outflow tract obstructions & can lead to stenosis?
Pimobendan
Name the four basic causes of edema formation.
1. Increased vascular permeability
2. Increased hydrostatic pressure
3. Decreased oncotic (colloid-osmotic) pressure
4. Decreased lymphatic drainage
During Stage II (progressive) hypovolemic shock, compensatory mechanisms begin to fail. What major physiological change occurs that worsens organ perfusion?
Cellular hypoxia due to sustained hypotension and decreased tissue perfusion
Which fast-acting compensatory mechanism increases heart rate and contractility within seconds of heart failure?
Sympathetic nervous system activation
What effect does inspiration have on venous return to the heart?
Inspiration lowers intrathoracic pressure and increases venous return
8-year-old male intact Boxer was diagnosed with congestive heart failure. The vet started the dog on different drugs to improve the dog's symptoms. When the dog returns for a check-up, the owner reports that during the last 2 days the dog has had dirrhea and vomited. These clinical signs are most consistent with the use of what drug in the dog's treatment protocol?
Digoxin
In left-sided heart failure, why does pulmonary edema develop?
Because blood backs up into the pulmonary veins, raising pulmonary capillary hydrostatic pressure and forcing fluid into the interstitium and alveoli (“backward pressure gradient”).
Name two common causes of secondary systemic hypertension in dogs and cats, according to the lecture.
Chronic kidney disease, hyperthyroidism, hyperaldosteronism, diabetes mellitus, Cushing’s (hyperadrenocorticism), or pheochromocytoma
Why do the kidneys retain fluid during heart failure?
They interpret the low cardiac output as low blood volume and try to increase blood pressure.
Which cranial nerves carry the sensory signals from the baroreceptors in the carotid sinus and aortic arch?
glossopharyngeal nerve (IX) and the vagus nerve (X)
A 10-year-old spayed female Cocker Spaniel with systemic hypertension was started on a new medication to help reduce blood pressure & counteract aldosterone's effects on the kidneys. After 2 wks, the owner reports the dog has experienced PU/PD, occasional vomiting & diarrhea, & mild decrease in energy. Bloodwork reveals electrolyte imbalances. These clinical signs are most consistent with the use of which drug in the dog's treatment protocol?
Spironolactone
A dog with seizures develops pulmonary edema without evidence of heart disease. What is the classification of this edema?
Non-cardiogenic (low-pressure) pulmonary edema
What 2 variables determine blood pressure?
Cardiac Output + Total Peripheral Resistance
What key feature distinguishes decompensated heart failure from compensated heart failure?
The minimum required cardiac output is not restored, so fluid retention continues and becomes harmful
Which hormonal system is activated by hypotension, low sodium, or increased sympathetic activity, and helps raise blood pressure?
renin–angiotensin–aldosterone system (RAAS)