Flashcards in Exam 2 Deck (254):
Defintion of syncope
Sudden, transient loss or depression of consciousness and postural tone resulting from transient and diffuse cerebral malfunction with spontaneous recovery.
Often due to deprivation of energy substrates (glucose or oxygen)
Definition of pre-syncope
An incomplete form of syncope
Definition of seizure
Abnormal excessive paroxysmal synchronous discharge in a population of neurons
Dysfunction of grey matter, which may be primary in origin or secondary to a metabolic abnormality
Can be tonic clonic or psychomotor
Definition of narcolepsy and cataplexy
Narcolepsy - dog collapses into sleep
Cataplexy - sudden onset of muscle paralysis
Can be induced by excitement or eating
Dogs can usually be roused by stimulation
Inherited forms in poodles, labradors, dobermans
Characteristics of fit (seizure)
Marked limb movement, urination, defecation
Long duration (>3 min)
Evidence of other neurological disease
Characteristics of fainting (syncope)
Provoking event (vomiting, sudden change in level of activity)
Followed by opistotonus
Short duration (< 1 min)
No limb movement
Generally rapid and complete recovery
Characteristics of "falling over"
Elderly dog with musculoskeletal disease
Usually multiple events at exercise prior to presentation
Dog becomes recumbent but no loss of consciousness
No spontaneous limb movement, urination, or defecation
Quick, complete recovery
Evidence of pain on clinical exam
Physical exam findings associated with syncope
Pale or cyanotic MM
Hypo or hyperkinetic pulses
Distention of jugular pulses
Cause of syncope in humans
2.5% obstructive cardiac disease
(Probably similar in animals)
What kind of hematological disorders can cause syncope?
Which endocrine disorders can result in syncope?
Which muscular disorders should be differentials for a patient presenting for syncope?
Myopathy secondary to hypoK+, steroids, myotonia
Labrador and retriever myopathy
Which neurological disorders should be differentials for a patient presenting for syncope?
Vestibular or cerebellar disease
Which musculoskeletal disorders should be differentials for a patient presenting for syncope?
Bilateral ACL rupture
Which neuromuscular disorders should be differentials for a patient presenting for syncope?
Which drugs can cause iatrogenic syncope?
Vasodilators (phenothiazine derivatives, ACE inhibtors, beta blockers, CCB)
Class 3 agents (cisapride, sotalol)
What effects will class 3 agents have on a patient's ECG?
Prolonged QT interval
Which congenital heart diseases can cause syncope?
Obstruction to outflow (AS and PS, tumors, endocarditis)
Tetralogy of Fallot
Shunts (VSD, PDA)
Severe AV valve dysplasia
What physical exam finding may indicate that a patient has a R->L PDA?
Cranial MM pink
Caudal MM cyanotic
What acquired cardiac disease can cause syncope?
Severe AV valve disease
Systolic dysfunction (e.g. DCM)
Which bradyarrhythmias can cause syncope?
Sick sinus syndrome
AV Block (2rd and 3rd degree)
Which tachyarrhytmias can cause syncope?
Treatment for VPCs?
Treatment of ventricular tachycardias?
Classes of anti-arrhythmic drugs
1: Na+ channel blockers
2: B blockers
3: K+ channel blockers
4: Ca+ channel blockers
If an animal is presenting with collapse and ECG shows multiple episodes of profound bradycardia, what is a likely diagnosis?
Vasovagal (neurally-mediated) syncope
What is the treatment for vasovagal (neurally-mediated syncope)?
None if infrequent
If situational, avoid situation
Beta blockers, mineralocorticoid supplementation
Two types of leads in pacemakers
What ECG characteristics are representative of atrial fibrillation?
No P waves
What are the goals of treatment for atrial fibrillation?
Convert to NSR
Provide inotropic support
Treatment for atrial fibrillation?
Ca channel blocker (diltiazem)
beta blockers (EXCEPT IF CHF PRESENT)
Treatment for pericardial effusion
Furosemide (high dose IV)
Fluids (high dose IV)
How is blood pressure regulated?
Locally - NO and other metabolites mediate vasomotor tone
Systemically - Baroreceptor reflexes/sympathetic nervous system, RAAS, renal blood volume control
What are the three causes of systemic hypertension?
1. White Coat Syndrome
2. Primary hypertension
3. Secondary hypertension
What is White Coat Syndrome?
Increase in BP due to measurement process or situation
Usually sympathetic stimulation with stress/excitement
Resolves when cause is eliminated
No treatment necessary
What is primary hypertension?
"Essential" or "idiopathic"
May be associated with subclinical renal disease
Uncommon in dogs and cats
What can cause secondary hypertension?
Adrenocortical disease (hyperadrenocorticism or hyperaldosteronism)
Breed (sight hounds)
What is the most common underlying cause of secondary hypertension?
What percent of cats with renal disease have hypertension?
What is the correlation between degree of azotemia and BP?
How does diabetes mellitus cause hypertension?
Blood volume expansion with hyperglycemia
Overproduction of renin
What percent of hyperthyroid cats have hypertension?
How does hyperthyroidism cause hypertension?
Increased cardiac output
How does pheochromocytoma cause hypertension?
Increased cardiac output
*May be episodic
How does polycythemia cause hypertension?
Increased blood viscosity increases peripheral vascular resistance
How does diet cause hypertension?
Little effect on BP in dogs and cats unless massive or pre-existing secondary hypertension
What drugs can cause hypertension?
Main tissues affected by hypertension?
Effects of hypertension on the CV system
Concentric hypertrophy of LV (-> murmurs or gallops, CHF)
What is a prognostic indicator of effects of hypertension on kidneys?
Degree of proteinuria
What effects does hypertension have on the eye?
Tortuous retinal vessels
Retinal edema, hemorrhage, detachment, degeneration
Effects of hypertension on CNS
Behavior alterations, depression, ataxia, seizures, stupor coma, death
Can hypertension be diagnosed based off of one BP measurement?
In cases where there are definite clinical signs or evidence of end-organ damage
How can you measure BP?
Direct - arterial catheter
Indirect - doppler and oscillometric methods
Advantages and disadvantages of direct BP measurements
Advantages: accurate, objective, repeatable, ability to measure systolic/diastolic/mean BP
Disadvantages: invasive, requires technical skills to place and maintain arterial access
Advantages and disadvantages of indirect BP measurement
Advantages: technically simple and non-invasive
Disadvantages:less repeatable and inaccurate with movement or inconsistent technique
What is the most accurate and repeatable non-invasive technique to measure BP in cats?
>160/100 considered abnormal
At what blood pressure should treatment be initiated?
At what blood pressure is there severe risk of end-organ damage?
Treatment of BP is based on
Risk of end-organ damage
Treatment of hypertension?
Avoid high salt intake
Ca channel blockers
How do ACE inhibitors treat hypertension?
Block conversion of angiotensin I to angiotensin II
Reduced secretion of aldosterone and ADH -> inc Na and H20 excretion
Dec sympathetic tone
Reduced cardiac and vascular hypertrophy
Reduces GFR and proteinuria
Adverse effects of ACE inhibitors in treatment of hypertension?
Decreased GFR and azotemia
How do calcium channel blockers (amlodipine, diltiazem) work to treat hypertension?
Decreased calcium influx into vascular smooth muscle -> vasodilation
How to adrenergic blockers work to treat hypertension?
Decrease HR and contractility to dec CO
Treatment of choice for hypertension caused by hyperthyroidism?
Treatment of choice for hypertension caused by pheochromocytomas?
How does hydralazine work to treat hypertension?
we don't know
After initiating therapy for hypertension, how long should you wait to recheck BP?
When hypertension is controlled, how often should you monitor BP?
Normal pulmonary arterial pressure
15 mmHg mean
How does hypoxia affect pulmonary vasculature
(Opposite of systemic circulation)
What agents cause vasodilation in pulmonary vasculature?
What agents cause vasoconstriction in pulmonary vasculature?
Causes of pulmonary hypertension
Chronic pulmonary disease
Congenital cardiac shunts
What is the most common cause of pulmonary hypertension in FL? Overall?
FL: HW disease
Overall: L-sided CHF
Consequences of pulmonary hypertension
Clinical signs/physical exam findings associated with pulmonary hypertension
Clinical signs similar to other cardiopulmonary diseases
How can you diagnose pulmonary hypertension?
Measurement of pulmonary artery pressure
Direct = cardiac catheterization *gold standard*
Indirect = echo
What ECG findings are associated with pulmonary hypertension?
Deep S wave and right axis deviation (RV enlargement)
Tall P waves (RA enlargement)
Treatment for pulmonary hypertension
Treat underlying cause (EXCEPT R->L shunts)
Ca channel blockers
Synthetic prostacyclins (cost prohibitive)
ET-1 receptor antagonists (cost prohibitive)
Phosphodiesterase inhibitors (sildenafil - most common tx)
Regulators of endothelial vascular tone
Vasodilators: NO and PGI2
What is the pathophysiology of vascular remodeling in PHT?
Chronically elevated ET-1 ang Ag-II cause smooth muscle hypertrophy of vascular walls
Eventually is irreversible
What might thoracic radiographs show for a patient with PHT?
Pleural fluid/pulomary edema
Tortuous, blunted pulmonary arteries
Bronchial or alveolar pattern
PAP estimate equation
PG = 4 x V^2
(Normal = 10-25)
Prognosis for PHT
What are the most common types of thyroid tumor?
Follicular cell adenoma
What percent of thyroid tumors are malignant?
Most of these are carcinomas
Clinical signs of hyperthyroidism
Common physical exam findings of hyperthyroid patients
Palpable thyroid nodule
What is the T3 suppression test?
Used to dx hyperthyroidism
Blood drawn for T3 and T4
T3 (cytomel) administered x 3 days
Draw sample 2-4 hr post last pill for T3 and T4
Normal cat will have suppressed T4
Hyperthyroid cat ill not suppress
Why measure T3? -> Assess client compliance
Treatment for hyperthyroidism?
Diet (Hill's y/d)
Not really recommended:
Most common type of hypothyroidism?
Acquired, primary (decreased T4)
Which breed is prone to secondary hypothyroidism due to pituitary malformation?
Breed predisposition for hypothyroididm?
Beagles, dobies, goldens
Clinical signs associated with hypothyroidism?
Corneal lipid deposits/lipemia retinalis
Lab findings associated with hypothyroidism?
Treatment for hypothyrodism
Levothyroxine 0.02 mg/kg BID
Re-test in 6-8 weeks
Which breeds have an autosomal recessive gene for hypoadrenocorticism?
Portuguese water dog
Nova Scotia duck tolling retriver
Physical exam findings with hypoadrenocorticism?
Pale MM, prolonged CRT
Lab findings associated with hypoadrenocorticism?
Lack of stress leukogram
Mild, non-regen anemia
What to do for an unstable patient in which you suspect hypoadrenocorticism?
Start ATCH stim
Dex (0.25-0.5 mg/kg IV)
Treatment for hypoadrenocorticism?
What is atypical addison's?
Similar history, presenting complaint, and PE to Addison's
Normal Na+ and K+
ACTH stim still abnormal
Don't need mineralocorticoids, just pred
Rarely progresses to mineralocorticoid deficiency
Breed predisposition for hyperadrenocorticism
Clinical signs of hyperadrenocorticism
Facial nerve paralysis
Physical exam findings with hyperadrenocorticism
Lab findings associated with hyperadrenocorticism
Screening tests for hyperadrenocorticism
Urine cortisol:creatinine ratio
Discriminating tests for hyperadrenocorticism
Urine cortisol:creatinine test
Negative test -> HAC very unlikely
(owner needs to collect first AM urine at home)
Doesn't discriminate between PDH and AT
If suppresses at 4 hours but "escapes" at 8 hrs -> HAC
20% of patients with PDH won't suppress at all
Lack of suppression -> AT
Suppression -> PDH
Endogenous ACTH test
Low -> AT
High -> PDH
Treatment of hyperadrenocorticism
Surgery (hypophysectomy or adrenalectomy)
Should not be administered to sick or anorexic animals
Load with 50 mg/kg/day
Repeat ACTH stim in 1 week
Maintain with 50 mg/kg/week
Goal: pre and post values in normal "pre" range
Possible side effects of mitotane
Side effects of trilostane
Blocks 3B hydroxysteroid dehydrogenase which can lead to increases in precursor hormones, which can have similar effects as cortisol
What is Atypical Cushing's?
Similar clinical signs and PE findings as Cushing's
Normal pre/post cortisol levels
Extended hormone panel to UTenn -> 2-3 hormones increased post-ACTH
Treatment similar to typical Cushing's
Common presenting complaints/clinical signs with DM
Bumping into things
Hind-end weakness (cats)
Lab findings with DM
Inc ALP and ALT
Goals of treatment of DM
Resolve clinical signs
Long-term effects of DM
Eyes: cataracts, lens-induced uveitis, corneal ulceration, diabetic retinopathy
Urinary: bacterial or fungal cystitis, proteinuria, diabetic nephropathy
CNS: diabetic neuropathy (cats)
Canine dental formula
Deciduous: 2 ( I 3/3 C 1/1 P 3/3) = 28
Permanent: 2 (I 3/3 C 1/1 P 4/4 M 2/3) = 42
Feline dental formula
Deciduous: 2 (I 3/3 C 1/1 P3/2) = 26
Permanent: 2 (I 3/3 C 1/1 P 3/2 M 1/1) = 30
Eruption times of canine teeth
Incisors: 2-4 weeks
Canines: 3 weeks
Premolars: 4-12 weeks
Incisors: 3-5 months
Canines: 4-6 months
Premolars: 4-6 months
Molars: 5-7 months
Eruption times of feline teeth
Incisors: 2-3 weeks
Canines: 3-4 weeks
Premolars: 3-6 weeks
Incisors: 3-4 months
Canines: 4-5 months
Premolars: 4-6 months
Molars: 4-5 months
Characteristics of normal dental occlusion
Scissors bite - upper incisors in front of lower incisors
Lower canine fits evenly between upper canine and 3rd incisor
Premolars fit in a shearing fashion (interdigitate)
Upper 4th premolar fits outside (lateral) to lower 1st molar
What is true dental prophylaxis?
*done on mouth FREE OF DISEASE*
1. Complete oral exam
2. Supragingival scaling
3. Subgingival curettage/root planing
4. Polish (with fluoride)
6. Repeat oral exam
What are dental caries?
Bacterial degeneration of the enamel
Not common in pets
Maxillary 1st molar most common due to incomplete enamel closure
What causes enamel abrasions?
What is dental attrition?
Wear from other teeth
Caused by malocclusion
Causes increased risk of tooth fracture
What causes enamel hypoplasia/hypocalcification?
Reduced formation of enamel aka enamel dysplasia
Systemic infection causing high fever during tooth formation (e.g. distemper)
Enamel organ damage during early extraction of deciduous teeth
Other trauma during tooth formation
What causes enamel staining?
Intrinsic - tetracycline use during enamel development
Extrinsic - metal from fence, cage, bowl, other objects
What causes discolored teeth?
Trauma that results in pulpal hemorrhage +/- tooth death or nonvital tooth
Pink -> purple -> tan
What tooth most commonly undergoes resorption?
Mandibular 3rd premolar (80% of the time)
Caused by periodontal disease or oral trauma
What is ankylosis?
Alveolar bone fused to cementum
Can be caused by:
Resorption/inflammation (no periodontal ligament is visible)
Excessive masticatory forces
Tx: crown amputation
Classes of dental malocclusion
0: normal or breed normal
1: jaw relationship normal, but one or more teeth is out of position
2: mandible is short (mandibular distoclusion) in relation to maxilla - brachygnathia (overbite)
3: Maxilla short in relation to mandible (mandibular mesioclusion)- prognathia (underbite)
T/F: class 2 and 3 dental malocclusion are more likely to be hereditary in origin
Cranial mandibular osteodystrophy
Inherited condition (West Highland White Terriers )
Non-cancerous bone formation at the TMJ and spreads to the mandible
Results in pain, fever, resistance to eat or open jaw
Trauma leading to luxation of TMJ
Can be secondary to dysplasia causing laxity
Coronoid slips under zygomatic arch, then mouth cannot close
Must reduce arch or coronoid to get mouth to move
Can be secondary to chronic inflammation
Pseudoenlarged gingival pocket formation
Neoplasia of odontogenic structures
Acanthomatous or peripheral ameloblastoma
Peripheral odontogenic fibroma
Neoplastic tumors of gingiva
Most important single oral cavity problem
Is periodontal disease reversible?
At the point where bone/supporting structures are lost, the damage is nor reversible.
Gingivitis IS reversible
Why are smaller breeds predisposed to periodontal disease?
Smaller breeds have closer teeth that reduce the cleaning ability of saliva/teeth and thinner supporting bone
Stages of periodonatal disease
Stage 1: Gingivitis
Stage 2: Early periodontitis (up to 25% attachment loss)
Stage 3: Moderate periodontitis (25-50% attachment loss)
Stage 4: Severe periodontitis (>50% attachment loss)
What is the only reversible stage of periodontal disease?
Indication for the use of antibiotics to treat periodontal disease
Severe periodontitis including purulent discharge
Additional surgery being performed
Pulp capping (pulpotomy)
Most commonly used antibiotics in the treatment of periodontal disease
Chronic ulcerative stomatitis
Halitosis, oral pain, inappetence, anorexia, ptyalism, periodontal disease
Unknown cause, may be associated with fusiform bacilli and spirochetes
PE findings: Severe gingivitis, ulceration, necrosis of oral MM, chelitis, gingival recession, depression, fever, cachexia
Tx: Anti-inflammaories, extractions, debridement, antibiotics, oxygenated mouth rinses, +/- tube feedings
Caused by overgrowth of Candida albicans
Associated with long-term antibiotic use, immunodeficiency, other diseases
Causes chronic dysphagia, inappetence and/or anorexia, ptyalism, halitosis, white plaque-like lesions in mucocutaneous junction, glossitis
Tx: eliminate underlying condition, anti-fungal medication (ketoconazole)
How does leptospirosis cause oral disease?
Oral signs associated with uremia and thrombocytopenia
Oral clinical signs associated with canine distemper virus
Ulceration of MM
Oral clinical signs associated with canine infectious hepatitis
Oral hemorrhage or petechiation
Injected or hyperemic MM
Clinical sign associated with oral blastomycosis
Granulomatous, yellow-white, up to 1.5 cm lesions on tongues or MM
(Little white dogs)
Oral clinical signs associated with hypothyroidism and diabetes mellitus
Severe generalized marginal gingivitis not associated with expected quantities of calculus
Oral clinical signs associated with hypoparathyroidism
Necrosis associated with oral ulcers
How to differentiate whether bleeding in oral cavity is due to oral disease or coagulopathy?
Bleeding will only be in oral cavity if it’s oral disease...
Clinical signs associated with thallium toxicity
Oral inflammation and ulceration
Generalized severe pain
What causes phytogranulomatosis?
Oral trauma from plant awns from the hair coat
General oral clinical signs associated with oral trauma
Pawing at mouth
Is tonsillectomy indicated for tonsillitis?
Does not cure clinical signs
Causes of tonsillitis
Primary - idiopathic (CKCS, eosinophilic)
Secondary - secondary to diseases causing chronic regurgitation, vomiting, coughing
Primary goal of treatment of severe feline stomatitis
Reduce inflammation through plaque control
Dental prophylaxis is imperative no matter the etiology
Treatment of severe feline stomatitis includes
After all therapies have failed, cyclosporine
Clinical signs seen in teething animals
Serous nasal discharge
Enlarged mandibular lymph nodes
What is tight lip?
Condition in which the lip is too attached to the gingiva and can result in tooth impressions/trauma to gums
What is a dentigerous cyst?
Fluid-filled structure that develops at the separation of the follicle of an unerupted tooth (destructive)
What is an odontoma? What are the two types?
Odontogenic tumor that contains both epithelial and mesenchymal cells
Young animals during development of permanent teeth (except rats)
Compound: tooth-like structures (denticles) present
Complex: conglomerate of dental tissue
Feline Juvenile Gingivitis
Cats 8-18 months old
Abysinnians, persians, siamese, maine coons
Required early and aggressive treatment
May be proliferative
With proper therapy, will wane at 24 months
What causes tooth resorption?
There is no proven cause
Stages of tooth resorption
Stage 1 – Mild dental hard tissue loss, either cementum alone or cementum and enamel. In this stage of the disease, a defect in the tooth's enamel is all that is usually noted. There is little to no sensitivity because the resorption has not yet reached the dentin.
Stage 2 – Moderate dental hard tissue loss including cementum or cementum and enamel, and loss of dentin that has not yet reached the pulp cavity.
Stage 3 – Deep dental hard tissue loss including cementum or cementum and enamel, and loss of dentin that extends to the pulp chamber. At this third stage of disease, most of the tooth is still viable.
Stage 4 – Extensive dental hard tissue loss and most of the tooth has lost its integrity. A significant amount of the tooth's hard structure has been destroyed. Stage 4 has three sub-categories: 4a (crown and root of tooth are equally affected), 4b (crown is more severely affected than the root), and 4c (root is more severely affected than the crown).
Stage 5 – Only remnants of the tooth remain, covered by gum tissue. The majority of the tooth has been resorbed, leaving only a raised area on the gum.
3 primary patterns of canine tooth resorption
1. Internal resorption
2. Idiopathic bony replacement resorption (external)
3. Osteoclastic resorption (like cats, least common)
Initiating causes of canine tooth resorption
What percent of discolored teeth are non-vital (dead) or dying?
Only infectious disease that feline stomatitis is correlated with?
What is insulin "stacking"?
If more insulin is given at the peak effect of the last dose, the effect will "stack" and have more of an effect and last longer than intended
Can cause hypoglycemia
Goals of therapy for feline diabetic?
Eliminate clinical signs
Maintain good QOL for owner and cat
Unlike all other insulins that need to be rolled, which needs to be shaken?
How long does it usually take to achieve adequate glycemic control in diabetic patients?
What is the Somogyi effect?
Rebound hyperglycemia secondary to hypersecretion of counter regulatory hormones during hypoglycemia
Which insulins are short-acting, intermediate-acting, and long-acting?
Short: HUmulin R, Novolin R
Intermediate: NPH (Humulin N, Novolin N), Lente, PZI
Long: Glargine, Detemir
What is the max starting dose for insulin therapy for a cat?
What should the diet of a feline diabetic consist of?
Low card, high protein to minimize postpradial hyperglycemia
What is an appropriate amount of weight loss per week for a diabetic patient?
1-2% of body weight per week
Which concurrent illnesses or medications can contribute to insulin resistance?
Advantages and disadvantages of BGCs
Nadir and peak time of effect
Duration of effect
Evaluate for Somogyi effect
Why are fructosamine levels used to assess glycemic control?
Represent BG of previous 1-2 weeks
Can be artifactually lowered by hyoproteinemia, hyperthyroidism, lean cats, newly diagnosed or mild DM
Renal glucose threshold
Why do patients with diabetes develop cataracts?
High levels of glucose overwhelm lead to higher levels of sorbitol and fructose in the eye
(Aldose reductase activity decreases with age)
Is plantargrade stance in diabetic cats reversible?
Pathophysiology of ketosis
Decreased amounts of insulin (diabetic patient) lead to decreased inhibition of lipolysis/FFA production result in ketogenesis
DKA almost always occurs as a result of
DM + a concurrent problem (commonly UTI or pancreatitis)
Physical exam findings of patient in DKA
Tacky MM, inc CRT
How to treat hyponatremia in patient in DKA
for every 100 mg/dl BG increase above 100, add 1.6 mEq/L of Na
[2 (Na + K) + 0.05 (BG) + 0.33 (BUN)] = osmolality
What are the most important things to avoid during treatment of patient with DKA
Rapid changes in osmolarity
Pathophysiology of hypokalemia in DKA patient
K+ move from cells in to blood with decreased blood pH and insulin levels
Lost through urine
When fluid is replace and acidemia is fixed, K will move back intracellulary
Results in hypokalemia
Best insulin choice for treatment of patient in DKA?
Regular insulin 0.2U/kg IM
Primary goals of treatment of patient in DKA
Correct electrolyte imbalances
(NOT regulation of BG)
Most common complication associated with treating DKA
What is hyperosmolar nonketotic DM?
Severe hyperglycemia (BG > 600)
Hyperosmolarity (> 350 mOsm/kg)
Absence of ketonuria
Pathophysiology of hyperosmolar nonketotic DM
Glucosuria -> osmotic diuresis -> water loss
Underlying disease -> dec fluid intake -> dehydration
Dehydration -> dec GFR -> dec renal glucose excretion
Why is there no ketonuria in patients with hyperosmolar nonketotic DM?
May produce a small amount of insulin
B-hydroxybutyrate not dectecatbe on urine dipstick
Physical exam findings for patient with hyperosmolar nonketotic DM?
Lab findings for patieht with hyperosmolar nonketotic DM
Treatment goals for patient with hyperosmolar nonketotic DM
Restore electrolyte balance
Pathophysiology of idiogenic osmol formation
Fluid pulled from brain during severe dehydration
Brain produces idiogenic osmols to pull fluid back into brain
When insulin is given, brain glucose and osmolality are increased
Idiogenic osmols cannot leave -> higher osmolality of brain when compared to ECF
Fluid pulled back into brain causing cerebral edema
Need to tx with mannitol +/- corticosteriods
Maximum rate of Na decrease when treating hypernatremia
Decrease no more than 0.5 mEq/L/hr
Diagnosis of DM is based on
Diagnosis of DKA is made by what clinical findings
Erythrophagocytosis by macrophages
RBCs lysed via complement-mediated destruction
Produced fragmented, ghost cells
Hallmarks of intravascular hemolysis
What toxins can cause hemolytic anemia
What type of hemolysis does microhepatic hemolytic anemia cause?
Intravascular (causes physical trauma to cell)
How does hypophosphatemia cause hemolysis?
Severe hypophosphatemia causes inhibition of RBC ATP production -> oxidative stress -> hemolyis
What diseases are associated with hypophosphatemia that may lead to a hemolytic anemia?
After initiation of enteral feeding
Diseases associated with hereditary hemolytic anemia
Pyruvate kinase deficiency
Pyruvate phosphofructokinase deficiency
What drugs are associated with canine IMHA?
What are the two most common infectious diseases to cause hemolysis and regenerative amemia?
What kind of anemia does cytaux cause?
Hemolytic, NON-REGENRATIVE anemia
What kind of hemolysis does babesia cause?
Most common neoplasia associated with IMHA?
What is the immune response composed of in IMHA?
Type II immune reaction: Ab +/- complement-mediated destruction
IgG: macrophage erythrophagocytosis +/- completment-mediated destruction
IgM: complement-mediated destruction only
Breeds with hereditary predisposition for IMHA
Lab findings with IMHA
What three tests help diagnose IMHA?
Direct Ab test (Coomb's)
Flow cytometry for anti-RBC Ab
What causes autoagglutination?
IgM and IgG
What is the Coomb's test?
Patient RBCs washed to remove non-bound proteins
Anti-IgG/IgM/complemenet Ab added
Agglutination supportive of IMHA
Negative prognostic indicators associated with IMHA
Rapidity of onset
Bilirubin > 10
Complications of IMHA
Thromboembolic complications (PTE)
Breed over-represented in feline IMHA
What is the immune response composed of in ITP?
Type II immune reaction
Causes of secondary ITP
Drugs: cephalosporins and sulfonimides
Infectious: anaplasma, babesia, lepto, leishmania
Neoplasia: lymphoma, hemangiosarc, histiocytic sarc
Inflammation: hepatitis, pancreatitis, SIRS
Lab findings with ITP
SEVERE thrombocytopenia (<30,000)
PT/PTT WNL (unless in DIC)
Diagnosis of ITP based on:
Exclusion of other disease processes
Presence of severe thrombocytopenia
Normal to increased megakaryopoeisis
Platelet bound Ab
How do glucocorticoids work in the treatment of IMHA/ITP?
Alter function of macrophage Fc receptor
Inhibit the production of several cytokines
Decrease immunoglobulin affinity
Decrease immunoglobulin production
How does cyclosporine work in the treatment of IMHA/ITP?
Inhibits T-cell mediated immunity
Inhibits production of IL-2 by activated T cells
How does azathioprine work in the treatment of IMHA/ITP?
Antimetabolite (purine antagonist) that interferes with DNA and RNA synthesis, mitosis
Inhibits cell-mediated and humoral immunity
How does leflumonide work in the treatment of IMHA/ITP?
Antimetabolite (inhibits pyrimidine synthesis)
Inhibits cell-mediated and humoral immunity
Reduced B-cell populations
What should you warn owners of when treating with leflumonide?
Which drug is most useful for the treatment of IMHA/ITP during the initial phases during hospitalization?
Defects of primary hemostasis that produce platelet abnormalities most commonly cause
reduced platelet numbers
What is glanzmann's thromboasthenia?
Spontaneous bleeding affects Great Pyrenese
Most common cause of petechia and ecchymoses in dog?
Causes of decreased plately production
Drugs (chemo, TMS)
Infection (FIV/FeLV, Rickettsial, fungal)
What is congential macrothrombocytopenia?
Macrothrombcytopenia caused by single nucleotide change in gene encoding beta 1- tubulin, which likely affects microtubule stability resulting in altered platelet formation by megakaryocytes
Affects Cairn, Norfolk terriers, Cavaliers
NO BLEEDING TENDENCIES
Most common cause of thrombocytopenia in dogs?