Cardiovascular System Flashcards
The heart accounts for how much total body weight?
0.6% (except in greyhounds and TBs
The heart is usually located between which ribs?
Which side is closer to the thoracic wall?
3rd and 6th
Left side
In the young animal, the cranial aspect of the heart is related to what?
The thymus
The pericardium is a serous sac lined by ___________ ______________ ______________. It’s layers include:
1). ____, 2). _____, 3). _______.
What are its functions?
Simple squamous mesothelium
1) . Visceral pericardium
2) . Parietal pericardium
3) . Fibroelastic tissue layer of parietal pericardium
Function: maintain ❤️ position, minimise friction, prevent over-distension
The fibroelastic layer of parietal pericardium continues dorsally over the great vessels. Caudally, it attaches to the sternum. What is this attachment called?
In ruminants, the attachment is a pair of sternopericardiac ligaments. In the horse, it’s a single midline sternopericardiac ligament.
In carnivores and the pig, it actually attaches to the diaphragm as the phrenico-pericardiac ligament
Describe the cardiac notch and it’s clinical sig?
It’s the gap on the ventral border of the left and right lungs which allows the pericardium to make contact with the thoracic wall. It is greater on the left side thereby providing a useful acoustic window for echocardiography
What is cardiac tamponade?
Compression of the heart
The position of the interventricular septum is marked externally by the __________________ on the left and the ________________ on the right.
The auricular surface of the heart is which side?
Left interventricular (paraconal) groove Right interventricular (subsinuosal) groove
Left side (right side is called the atrial surface)
How does the caudal border of the left ventricle compare in different species?
Carnivores: slightly convex
Horse: almost straight and vertical
Ruminants: slightly concave
What are the four main openings of the right atrium?
Cranial VC
Caudal VC
Coronary sinus
Right atrioventricular orifice
The azygous veins vary among species. Describe the differences:
Carnivores, horse and sometimes the pig: R. Azygous vein only
Pig: L. Azygous vein only
Ruminants: L and R azygous veins
The right auricle is interlaced with muscles called ______________. What vestiges of the foetal circulation are present in the right atrium?
Pectinate muscles
Fossa ovalis Intervenous ridge (tubercle) Crista terminalis (from which most of the pectinate muscle arise)
Blood from the right ventricle goes to the ______________.
The RV and RA are separated by the _____________ valve.
Pulmonary trunk Right atrioventricular (or tricuspid) valve
What are chordate tendinae?
What are the septomarginal trabeculae? What else are they known as?
Tendinitis bands arising from papillary muscles that project from the ventricular wall and fan out to attach to the cusps of the A-V valve. Each muscle modulates 2 cusps
Rounded tissue bundle that crosses the ventricular lumen from the interventricular septum to the lateral wall. They distribute conducting fibres to the papillary muscles. Also known as moderator band.
What are trabeculae carneae?
Subendocardial myocardial ridges on the ventricular wall (of the inflow channel) that protrude into the lumen
*papillary muscles contribute to the irregular surface of the inflow channel
The RV has ___ papillary muscles. Where do they arise from?
3- 2 arise from IV septum. The third (great papillary muscle) arises from the outer parietal wall of the ventricle.
Describe the outflow channel of the RV:
Origin- septomarginal trabeculae.
Consists of conus arteriosus which directs blood to pulmonary trunk. It has a smooth wall
The thick muscular interventricular septum has two parts. Describe:
Larger muscular part caudally is thick myocardium formed by the combined walls of the two ventricles. Surface facing lumen of LV is concave
Collagenous thin membranous part exists dorsally. Marks final closure of embryonic interventricular foramen.
The alternate name for the left A-V valve is….? It has how many cusps?
Mitral
2
The pulmonary and aortic valve each have___ semilunar valvules.
3
Aorta arises from the ____ and is divided into:
LV
Ascending aorta, aortic arch, descending aorta
The fibrous rings composing the cardiac skeleton surround what?
Left AV valve Right AV valve Aortic semilunar valve Pulmonic semilunar valve The AV bundle
What are characteristic features of cardiac muscle?
Intercalated disks Branching fibres Central nucleus Sarcoplasmic reticulum (associated with....) T-tubules
(Also, Purkinje fibres are present)
Explain the basic mechanism for excitation-contraction coupling?
Action potential is propagated along T-tubules which are closely associated with the intracellular sarcoplasmic reticulum. The propagation of the AP stimulates release of Ca++ into the cell which causes tropomyosin to move aside thereby allowing cross-bridging between actin and myosin filaments. This enables a contraction.
How does cardiac muscle relaxation occur?
Active pumps return Ca++ to the sarcoplasmic reticulum and extracellular fluid. Intracellular Ca++ is exchanged for Na+ and the intracellular calcium concentration falls.
The amount of calcium release depends on what?
- How much calcium is stored in the sarcoplasmic reticulum
2. Number of release channels activated
What is the difference between an isometric and isotonic contraction?
Isometric: muscle develops force at a FIXED length
Isotonic: muscular contraction in the absence of significant resistance with shortening of muscle fibres
Define the term contractility (relative to the heart):
The amount of tension that can be developed at any given stretch of cardiac muscle
What are inotropes?
Physiological or pharmacological agents that alter contractility.
In an ECG, what do the P, Q, R, S, and T phases represent?
P: atrial depolarisation
Q,R,S: ventricular depolarisation
T: ventricular repolarisation
What is a sinus bradycardia/ tachycardia?
Slowing/ fastening of HR governed by the SA node (due to increased/deceased vagal tone)
What are the layers comprising blood vessels?
Tunica intima (flat endothelial cells on bm) Tunica media (concentric smooth muscle layers and elastic fibres) Tunica adventitia (collagen and elastic fibres)
What are the anatomical groups of vessels?
- Muscular
- Elastic
- Arterioles
- Sinusoids
- Capillaries
- Postcapillary venules
- Metarterioles
- Muscular venules
- Veins
What are the 5 functional groups of vessels?
- Conducting
- Distributing
- Resistance
- Exchange
- Capacitance (reservoir)
Conducting arteries are ?thin/thick? walled. They have a high _____________ content. Examples include…?
Thick-walled
Elastin
Aorta, pulmonary, brachiocephalic, subclavian, common carotid
Distributing arteries are muscular and have more smooth muscle cells in their tunica media than capacitance arteries do. Their primary role is…….? They can actively change their diameter in response to…..? Examples include….?
Conduct flow to smaller arteries
Sympathetic innervation
Internal carotid, femoral, cranial mesenteric aa.
The main role of resistance vessels is to…..?
Types of resistance vessels include…?
Control local blood flow to tissues (peripheral resistance)
Arterioles and metarterioles
Briefly describe the wall structure of arterioles.
TI- non fenestrated endo. supported by bm
TM- 1-2 layers of smc (metarterioles may have a single intermittent layer or none!)
TA- loose connective tissue
Define TPR
Total peripheral resistance= resistance to flow in entire systemic circ.
= (mean aortic pressure-vena caval pressure) / cardiac output
What is the mathematical definition of mean arterial pressure?
MAP= cardiac output x TPR
= diastolic pressure + 1/3 pulse pressure
Exchange vessels include…?
Sinusoids, capillaries, post-capillary venules
What is a pericyte?
Endothelial cell “assistants” external to vessel wall
Describe the following:
- Arteriovenous shunt
- Thoroughfare channel
- Glomeriform arteriovenous anastomosis
- Connects arteriole with muscular venule
- sphincter like action
- Connects metarteriole to post-capillary venule
- Role in thermoreg (not covered as yet)
Capacitance vessels return blood to heart. They have a ?small/large? volume and ?low/high? pressure.
Large volume and low pressure
How does the tunica intima in veins differ to that in arteries?
No internal elastic lamina
What four factors control venous return?
- Smooth muscle contraction (symp NS)
- Skeletal muscle pump effect
- One-way valves
- Thoracic and cardiac pressure
What are the four “special circulations” covered?
- Coronary
- Pulmonary
- Cutaneous
- Cerebral
What are the specific species differences in regards to the coronary circulation?
In dogs and ruminants: 🐶🐮🐶🐮
- Right interventricular artery arises from the LEFT coronary artery
In horses and pigs: 🐴🐷🐴🐷
- Right interventricular artery arises from the RIGHT coronary artery
The venous drainage of the heart occurs through which vessels?
🔹Great cardiac vein
🔹Coronary sinus
In what ways does pulmonary circulation differ from systemic circulation?(4)
- Pressures are low due to low pulmonary vascular resistance
- vessels are more compliant
- arteries and arterioles are shorter/thin walled - Basal tone is low
- Sympathetic vasomotor nerves play no major role
- Metabolic vasodilation has no role
What are the two main arteries supplying the head?
- Common carotid arteries
2. Vertebral arteries
What is the functional significance of artery to artery anastomoses in the brain?
Provides for collateral circulation- preserves cerebral perfusion if carotid artery or vertebral arteries or their branches are obstructed
What is preload? What is it affected by?
The degree of tension on the myocardium when it begins to contract (considered to be the volume of blood in the ventricle at the end of diastole (EDV)).
EDV and venous return
What is afterload? What determines its magnitude?
The load against which the cardiac muscle exerts its contractile force (ie the pressure in the arteries).
Arteriolar pressure, aortic stenosis
What is the Frank-Starling Law of the Heart?
The energy released during contraction depends on the initial fibre length (allows for equalisation of output from left and right sides)
How does noradrenaline affect cardiac muscle contractility?
It is a positive inotrope released from sympathetic nerves. Binds to beta adrenoceptors
How does an increase in heart rate cause an increase in cardiac contractility?
Increased frequency of action potentials causes an increase in intracellular sodium and increased calcium in the sarcoplasmic reticulum (due to decreased diastolic interval).
What is the flow equation?
Flow = pressure gradient/ resistance
What two factors maintain mean arterial pressure?
Cardiac output
Arteriolar resistance
What is your systolic and diastolic pressure?
Systolic: peak pressure during systole
Diastole: peak pressure when aortic valve is closed
Stroke volume=…..?
SV= EDV - ESV
How might the force of cardiac muscle contraction be increased? Explain the mechanism (7 steps).
Binding of noradrenaline to beta adrenergic receptor.
Activates adenyl cyclise ➡️ increased IC cAMP ➡️ phosphorylation of voltage op Ca channels ➡️ Ca influx ➡️ Ca release from SR ➡️ increased actino-myosin cross bridging ➡️ increased force of contraction
In relation to the cardiovascular system, what may cause cyanosis?
🔹Pulmonary oedema/effusion
🔹R. to L. patent ductus arteriosus
🔹Pulmonary stenosis
🔹Pulmonary hypertension
Pulse strength is a measure of ___________ minus ______________ pressures. Therefore, a bounding pulse may be indicative of____________or _________________ and a weak pulse may be indicative of _____________, ________________, or _________________
Systolic - diastolic pressures.
Bounding pulse: PDA, aortic insufficiency
Weak: shock, cardiac tamponade, aortic stenosis
What types of murmurs are these:
- Aortic stenosis
- Mitral regurgitation
- Aortic regurgitation
- Mitral stenosis
- Aortic stenosis= systolic ejection murmur
- Mitral regurgitation= pansystolic murmur
- Aortic regurgitation= early diastolic murmur
- Mitral stenosis= pre-systolic accentuation
Where on the dog can you auscultate the following:
- Pulmonary valve
- Aortic valve
- Right AV valve (tricuspid)
- Left AV valve (mitral)
- Pulm. valve: Left 3rd intercostal space
- Aortic: Left 4th intercostal space
- Tricuspid: Right 4th intercostal space
- Mitral: Left 5th intercostal space
The radio graphic appearance of the heart is influenced by…?
🔹positioning
🔹phase of respiration
🔹phase of the cardiac cycle
🔹conformation
On a lateral projection, features of cardiomegaly include…?
🔹Elevation of trachea
🔹Increased apicobasilar projection
🔹Decreased distance between heart and spine
🔹Increased craniocaudal diameter of heart
🔹Straightening of caudal heart border
🔹Expansion of left atrium into caudal lobar area
There are two broad groups of excitation-contraction coupling. These are…?
- Electromechanical coupling (depolarisation of the vascular smooth muscle cell leads to opening of L-type voltage gated Ca channels)
- Pharmacomechanical coupling (binding of signalling molecule to receptor causes increase in IC Ca via G-protein coupled release of IC stores or opening of receptor operated Ca channels)
Increase in [Ca++] ➡️ Ca-calmodulin complex ➡️ _____1.__________➡️ _____2.________➡️ myosin forms crossbridge with actin ➡️ contraction of SMC
- [Ca-calmodulin]- myosin light chain kinase
2. Phosphorylation of myosin light chains
Amlodipine and Nifedipine are what type of drugs?
Ca++ channel blocker
Used for hypertension
What controls vascular tone?
- Intrinsic mechanisms
- Myogenic response
- Vasoactive metabolites
- Endothelial secretions - Extrinsic mechanisms
- Neural control (vasomotor nerves)
- Hormonal control (vasoactive hormones)
What is the myogenic response?
Vascular smooth muscle contracts in response to stretch and relaxes with a reduction in tension (depol. initiated by stretch-activated channels)
Vasoactive metabolites contribute to _________ and _________ hyperaemia.
Metabolic
Reactive
What is reactive hyperaemia?
Temporary increase in blood flow following a period of reduced blood flow.
What are some vasodilator and vasoconstrictors released by endothelial cells?
Dilatory= NO and prostacyclin Constrictor= endothelin
Explain nitric oxide signalling on smooth muscle cells.
NO released by endothelial cells activates guanylyl cyclise.
GC converts GTP to cyclic GMP
cGMP activates kinases that promote relaxation
What is nitroprusside?
Nitric oxide donor
Sympathetic fibres terminate in the tunica ________ of vessels and release _____________which activate adrenoceptors and cause vasoconstriction
Media
Noradrenaline
Parasympathetic fibres release _______ which activates M3 muscarinic receptors on endothelial cells. This stimulates synthesis of ______.
ACh
NO
Beta2 receptors predominate in the _________; alpha receptors predominate in __________.
Coronary circulation and skeletal muscle
Most tissues
What are the three steps in haemostasis?
- Vascular spasm
- Platelets ether (platelet plug formation)
- Clot formation
Platelets are activated by…?
Collagen vWF Tissue factor Thromboxane A2 ADP Thrombin
What prohibits platelet binding to undamaged endothelium?
NO and prostacyclin which are activated by ADP
What are three anticoagulant mechanisms?
- Tissue factor pathway inhibitor (secreted by EC)
- Thrombomodullin
Thrombin + thrombomodullin ➡️ thrombomodullin- thrombin complex ➡️ activates protein C ➡️ inactivates factor V and VII - Antithrombin III (joins with and inactivates thrombin)
What is the process of fibrinolysis?
- Plasminogen binds fibrin
- Bound plasminogen is activated by tissue plasminogen activator
- Plasminogen is cleaved to plasmin
- Plasmin dissolves clots
What are the components of the baroreflex (6)?
- Stimulus
- Sensory receptors
- Afferent pathways
- Integrating centre in the CNS
- Efferent pathways
- Effector organs
Where are arterial baroreceptors located?
🔹Aortic arch (pulsatile flow)
🔹Carotid sinus (non-pulsatile stretch)
🔹Atria, at junctions of great veins and atria, ventricles and pulmonary veins (respond to absolute pressure)
Afferent pathways for the baroreceptors reflex are in what nerves?
Glossopharyngeal (9) and vagus (10)
Central integration for the baroreflex is at the ______________. This has two regions. Explain.
Medullary cardiovascular centre
- Pressor region: provides normal tonic sympathetic stimulation to vessels and ❤️
- Depressor region: stimulated by baroreceptor firing. Inhibits sympathetic discharge form pressor region
What are meant by the terms “active hyperaemia” and “passive congestion”?
Active: increased blood volume due to arteriolar dilation and expansion of the perfused capillary bed
Passive: increased blood volume within the vasculature of a tissue is due to the impairment of venous outflow
In what circumstances does active hyperaemia develop? Why is it a local phenomenon?
Exercise, hot weather, embarrassment, inflammation
Why? Ere is insufficient blood volume to permit generalised active hyperaemia whilst maintaining adequate systemic blood pressure
In what circumstances does congestion occur? What are the potential consequences?
Circumstances: luminal obstruction of vein, intestinal strangulation, pooling in recumbent or inactive animals (hypostatic congestion), congestive heart failure
Consequences: venous hypertension, development of collateral venous channels
How would you grossly distinguish between active hyperaemia and passive congestion of an organ/tissue in a live animal?
Congested tissues appear red-purple to black (active hyperaemia tissues are red)
Cold vs warm
What gross lesions might you find in an animal that has died in left-sided congestive heart failure? Why do these lesions develop?
🔹Dark red to red-purple lungs
🔹Heavy lungs that don’t fully collapse when the chest is opened
🔹Subpleural and interstitial tissues are distended with oedema fluid
🔹Foam is present in the lumina of bronchioles
🔹Stiff lungs (chronic) and tan-brown discolouration
What gross lesions might you find in an animal that has died in right-sided congestive heart failure? Why do these lesions develop?
🔹Swollen, dark red-purple liver
🔹Venous blood oozes from cut surface of liver
🔹Coagulated fibrin over capsule of liver
🔹Hilar lymphatics are distended
🔹Pooling of venous blood upstream in the venae cavae
🔹Enlarged, firm liver (chronic)
🔹Sugar frosting, nutmeg liver
Oedema is the accumulation of excess body fluid. The following terms relate to oedema in what part of the body?
- Ascites
- Hydrothorax
- Hydropericardium
- Hydrocoele
- Anasarca
- Peritoneal cavity
- Pleural cavity
- Pericardial sac
- Tunica vaginalis of the scrotum
- Severe generalised oedema
What are the five mechanisms that can lead to oedema development? Which is most likely to be responsible for localised oedema? Which is most likely to be responsible for generalised oedema?
- Increased plasma hydrostatic pressure (G)
- Decreased plasma oncotic pressure (G)
- Lymphatic obstruction (L)
- Increased vascular permeability (L)
- Sodium retention
What circumstances are likely to lead to increased plasma hydrostatic pressure within a capillary bed?
Venous hypertension
Why is extracellular oedema not expected in animals with systemic hypertension?
Because increased arteriolar blood pressure causes reflex vasoconstriction of the pre-capillary arteriolar sphincter in order to protect the delicate capillary bed downstream
What 2 assays are initially used to categorise oedema fluid samples in a lab?
- Protein concentration
2. Cell count
In which organs can severe oedema prove fatal?
Cerebral and pulmonary oedema
What are the potential consequences of oedema?
🔹Impaired wound healing
🔹Susceptible to secondary bacterial infection
🔹Fibroplasia and permanent fibrosis
What is meant by “haemorrhage by rhexis” and “haemorrhage by diapedesis”?
- Rhexis- substantial tear in blood vessels or heart chamber leading to rapid escape of a substantial volume of blood
- Diapedesis- escape of RBCs one by one through minute defects in vessel walls
What are the following terms:
- Haemothorax
- Haemopericardium
- Haemoperitoneum
- Haemarthrosis
- Haemoptysis
- Dysentery
- Hyphaema
- Haemothorax- pleural cavity
- Haemopericardium- pericardium
- Haemoperitoneum- peritoneal cavity
- Haemarthrosis- synovial joint
- Haemoptysis- coughing of blood
- Dysentery- diarrhoea with blood
- Hyphaema- anterior chamber of eye
How do bruises and haematomas resolve? Which pigments contribute to the discolouration of bruises and haematomas?
Resolved by lysis and phagocytosis
Pigments: poorly oxygenated Hb (red-blue)
Bilirubin/ biliverdin - green/ yellow
Haemosiderin (brown)
What factors determine the clinical significance of haemorrhage?
Location
Rate and volume of blood loss
What is the most common cause of haemorrhage in domestic animals?
What are other potential causes?
Physical trauma!!!!
Other:
🔹Severe tissue infl.
🔹Sponataneous organ rupture, tumour, neoplasm
🔹Parasites
🔹Passive congestion
🔹Inherited or acquired defects in primary or sec. haemostasis
What are haemorrhagic diatheses?
Clinical disorders of haemostasis characterised by a bleeding tendency. Subdivided into disorders of primary and secondary haemostasis or combined.
What clinical signs would make you suspicious that an animal has a defect in primary haemostasis?
🔹Multiple short-lived bleeds that cease once fibrin is generated.
🔹Bleeding typically commences immediately after venipuncture
🔹Multiple petechiae, purpura or ecchymoses or paintbrush haemorrhages
🔹Epistaxis
🔹Haematuria, haematemesis, melaena/ haematochezia
List the four major mechanisms responsible for defects in primary haemostasis.
- Thrombocytopaenia
- Thrombocytopathies
- von Willebrand’s Disease
- Blood vessel disorders
What are the major mechanisms responsible for thrombocytopaenia in domestic animals? Which is most likely to be clinically sig?
- Decreased platelet production*
- Increased platelet destruction
- Consumption of platelets
- Sequestration of platelets
- Haemorrhage
What is the most common mechanism responsible for clinically significant thrombocytopaenia in cats? What are common underlying conditions?
Decreased platelet production
Retro viral infection, myeloproliferative or lymphoproliferative disease.
What is the most common mechanism responsible for clinically significant thrombocytopaenia in dogs? What can trigger it?
Platelet destruction
Disease process (eg. systemic lupus erythematosus (SLE))
Neoplasia (esp. lymphoma)
Viral, bacterial or rickettsial infection
Drugs (NSAIDs, digoxin, aspirin, penicillin)
What do thrombocytopathy, thrombopathy and thrombopathia mean? What are some causes of these conditions in animals?
All are synonyms for platelet function disorders.
🔹SLE 🔹Myeloproliferative diseases 🔹Retroviral infections in cats 🔹Hyperglobulinaemia 🔹Chronic liver disease 🔹Renal failure 🔹Snake envenomation
What role does vWF play in primary haemostasis?
Mediates adhesion of platelets to exposed subendothelial collagen via surface GpIb receptors. It’s a glycoproteins.
What breeds are most commonly affected with vWD in Australia? How is it inherited?
Dobermans, welsh corgis, GSDs, golden retrievers and poodles (type 1)
German short haired and wire haired pointers (type 2)
Scottish terriers, Shetland sheepdogs (type 3)
All three forms are AUTOSOMAL RECESSIVE
What are some blood vessel disorders that can manifest as petechiae and ecchymoses in the skin or mucous membranes?
(7)
🔹Endotheliotropic viral infections 🔹Infectious vasculitis 🔹Immune mediated vasculitis 🔹Scurvy 🔹Inherited collagen dysplasia syndromes 🔹Skin fragility syndromes (caused by diabetes or hyperadrenocorticism)
🔹Also, toxaemia and bacteraemia and uraemia
What clinical signs would make you suspicious that an animal has a defect in secondary haemostasis?
🔹Bleeding after venipuncture is delayed 🔹Bleeding may be prolonged and severe 🔹Deep haematomas are common 🔹Severe haemorrhage in body cavities 🔹Haemorrhage from mm (occasionally)
What are the clinical signs of von Willebrand’s disease?
🔹Excessive haemorrhage triggered by hair clipping, venipuncture or other trauma
🔹Perinatal mortality
🔹Excessive bleeding during tooth eruption or oestrus
🔹Epistaxis, GI bleeding, haematuria
List the four major mechanisms responsible for defective secondary haemostasis?
Which is most common?
- Inherited coagulation factor deficiencies
- Vitamin K antagonism or deficiency**
- Severe acute or chronic liver disease
- Excessive fibrinolysis or fibrinogenolysis
In which domestic animals are inherited coagulation factor deficiencies most often recognised?
Dogs
Why can some animals have a hereditary deficiency of a particular coag factor and either never bleed excessively or suffer from only minor haemorrhage?
H
Which of the inherited coagulopathies predispose to severe haemorrhage?
Inherited deficiencies of factors
1, 2, 10 (rare)
Or
8, 9
Or combined factor deficiencies
Why do haemophilia A and B mainly affect male animals?
Because it’s inherited as an X-linked recessive disorder
Which coag factors are deficient in the inherited coagulopathy recognised in Devon Rex cats?
Factors 2, 7, 9 and 10 (vit K dependent factors)
What role does Vitamin K play in hepatic synthesis of coag factors? Which factors are vit K dependent?
It’s required as a cofactor by the enzyme gamma-glutamyl carboxylase. This enzyme is involved in the synthesis of vit K dependent coag factors
II, VII, IX, X
What’s the most common cause of vit K antagonism in domestic animals?
Ingestion of anticoagulant rodenticides
How can large animal species become poisoned by coumarin-type anticoagulants?
Ingestion of mouldy sweet clover or sweet vernal grass
Why do more potent anti coag rodenticides pose a greater hazard to small animals than does warfarin?
Warfarin generally causes poisoning after repeated ingestion.
More potent anti coags may induce severe life-threatening haemorrhage cats and dogs after a single episode of ingestion. Also, their longer half life permits secondary intoxication pets that consume poisoned rodents.
In what circumstances might a dog develop vit K deficiency? How common is it?
🔹Dietary vit K deficiency (rare)
🔹Prolonged anorexia or malnutrition
🔹Oral antibiotic use
🔹Chronic lipid maldigestion/ malabsorption syndromes (rare)
