Revision notes Flashcards
What disease processes have a strong/high recommendation for the use of antithrombotics?
- IMHA
- Feline cardiomyopathy
- PLN
- > 1 disease/risk factor for thrombosis
What disease processes should antithrombotics be considered to be used in but not always recommended?
moderate risk or only really risk if in combo with others:
- pancreatitis (d)
- glucocorticoids (d)
- Cancer
- Heart disease (d)
- sepsis (d)
- HyperA
What type of thrombosis is usually seen with IMHA?
- PTE
What type of thrombosis is usually seen with feline cardiomyopathy?
- Arterial (minimal evidence for venous)
What type of thrombosis is usually seen with PLN?
- PTE >ATE> venous
What type of thrombosis is usually seen with pancreatitis (d)?
- splenic vein thrombosis
- ATE
- portal vein thrombosis
What neoplasias are most commonly associated with thrombosis?
- round cell
- carcinoma
- adrenal tumour
Are antiplatelet or anticoagulants recommended for venous thrombosis prevention? Give example of this
- Anticoagulant
PTE due to HE => heparin superior to aspirin.
Are antiplatelet or anticoagulants recommended for ATE prevention? Give example
- antiplatelet
Cats with FATE - clopidogrel
When is aspirin recommended?
- prevention of ATE in dogs and cats
When is clopidogrel recommended?
- prevention of ATE in dogs and cats
When should antithrombotic drugs be discontinued?
- if high risk of thrombosis, should not be discontinued for invasive procedures but if multiple agents used, then reduce to single antiplatelet drug
- for low to moderate risk of thrombosis, discontinue 5-7 days prior
- if the underlying cause and the thrombus has resolved.
restart as soon as possible post op provided not ongoing bleeding.
What antithrombotics should be weaned before discontinuation?
- UFH
- Direct Xa inhibitors.
What are other causes of feline pancreatitis apart from idiopathic?
> 95% = idiopathic.
- Infectious
- parasites (Toxoplasma gondii, Eurytrema procyonis, Amphimerus pseudofelineus)
- viruses (coronavirus, parvovirus, herpesvirus, calicivirus) - Trauma inc surgery or hypotension
- Neoplasia
- Toxins:
- topical fenthion
- KBr
- Phenobarb
- hypercalcaemia
- snake bite. - Autoimmune
- With concurrent disease:
- diabetes mellitus,
- chronic enteropathies,
- hepatic lipidosis,
- cholangitis,
- nephritis
- IMHA
What are u/s findings of acute pancreatitis in cats?
- equivocal or - pancreatic enlargement, - hyperechoic surrounding mesentery, - focal abdominal effusion - distension/corrugation of duodenum
What does a normal feline pancreas look like on MRI? and with pancreatitis?
Normal: T1 hyperintense and T2 isointense to hypointense
Pancreatitis:
- T1 hypointensity
- T2 hyperintensity of the parenchyma,
- enlargement of the pancreas,
- pancreatic duct dilatation
- contrast enhancement.
What is the PPV and NPV of Spec fPL in sick cats?
Specific and sensitive - better with more severe cases.
PPV 90%
NPV - 76%
How should a “normal” and “abnormal” snap fPL be interpreted?
- normal - unlikely to have pancreatitis
- abnormal - may have pancreaitis.
What is the difference in inflammatory cell types with acute suppurative vs chronic feline pancreatitis?
Acute - neutrophilic +/- necrosis, oedema
Chronic - lymphocytic or mononuclear + fibrosis or cysts
What are the treatment recommendations for feline acute pancreatitis?
- treat any inciting cause
- IVFT
- Antiemetics (maropitant/ondans)
- gastric prokinetics (metoclop may be contraindicated due to dopamine antagonism, but no clinical studies support this. otheriwse cisapirde ro erythomycin)
- analgesia - buprenorphine/methadone/fent, maropitant, tramadol or gaba
- appetite stim - mirtazapine or capromorellin + feeding tube if req
- Gastrointestinal diet.
Abs and corticosteroids not recommended for the pancreatitis but may be indicated if concurrent disease would benefit from them
What are the treatment recommendations for feline chronic pancreatitis?
- analgesia
- nutrition support (no specific diet recommended)
- antiemetic
- appetite stim
- cobalamin
- pred at antiinflam or immunosuppressant levels provided not hyperglycaemia. if so consider cyclosporine.
Abs not recommended
What are the 5 main phenotypes of feline cardiomyopathy
- HCM
- Diffuse or regional increased LV wall thickness with a nondilated LV chamber. - RCM:
- Endomyocardial form: prominent endocardial scar that usually bridges the interventricular septum and LV free wall, => fixed, mid-LV obstruction and often apical LV thinning or aneurysm;
+ LA or biatrial enlargement is generally present.
- Myocardial form Normal LV dimensions (including wall thickness) with LA or biatrial enlargement - Dilated cardiomyopathy (DCM)
- LV systolic dysfunction with
increase in ventricular dimensions,
normal or reduced LV wall thickness,
atrial dilatation. - ARVC:
- Severe RA and RV dilatation
+/- RV systolic dysfunction and RV wall thinning.
+/- left side affected
- Arrhythmias and RSCHF - Nonspecific phenotype/unclassified
- A cardiomyopathic phenotype that is not adequately described by the other categories
What proportion of cats have HCM?
what are the main clinical presentations?
- 15-30%
Presenation:
- asymptomatic
- CHF
- FATE
What are the following genetic abnormalities associated with and in which breeds:
- MyBPC3-A31P
- MyBPC3-R820W
MyBPC3-A31P: myosin binding protein C in HCM in Maine Coon cats. = 35-42
MyBPC3-R820W: myosin binding protein C in HCM in ragdolls/
What are markers of increased risk of CHF or ATE in cats with HCM?
- a gallop sound or arrhythmia
- moderate to severe LA enlargement,
- decreased LA fractional shortening (LA FS%),
- extreme LV hypertrophy,
- decreased LV systolic function,
- spontaneous echo-contrast or intracardiac thrombus,
- regional wall thinning with hypokinesis,
- restrictive diastolic filling pattern
Is a palpable thrill (grade 5-6/6 murmur) in cats more likely associated with cardiomyopathy or congenital malformation?
Congenital malformation
What does an increased NT-proBNP in a cat with resp distress suggest?
What samples can it be checked on?
- more likely cardiac than respiratory origin
- plasma or pleural effusion
What is NTproBNP used for in cats?
If echo is not available
Differentiate severe subclinical disease from mild or normal cats
differentiate cardiac or non-cardiac origin of resp distress/pleural effusion
What is normal end diastolic LV wall thickeness in most cats?
<5 mm
What treatment is recommended for stage B2 cardiomyopathy cats?
- clopidogrel
+/- aspirin
+/- Xa inhibitor (rivaroxaban)
(high risk - use additional meds, up to all 3)
If ventricular ectropy is present then atenolol or sotolol
if Afib - diltiazem, atenolol or sotolol
When should pimobendan be used in cats with cardiomyopathy?
- CHF without dynamic LVOFTO, especially if signs o low cardiac output inc, hypotension, hypothermia, bradycardia (INI - dobutamine)
- maybe chronic CHF without dynamic LVOFTO
Is thromboylic teatment recommended for cats with ATE?
no
In acute ATE, what drugs are recommended for cats?
When discharged home, what drugs are recommended?
- analgesia (mu opioid)
- anticoag - LMWH, uFH or Factor Xa inhibitor.
- CHF management - frusemide, O2
at home:
- clopidogrel + Factor Xa inhibitor
- ongoing CHF management as appropriate
What are the different classes of pulmonary hypertension?
Group 1: pulmonary arterial hypertension including:
- idiopathic
- heritable
- drugs (tramadol, cyclosporine, amiodarone, cyclophosphamide)
- congenital hunts
- pulmonary vasculitis
- pulmonary vascular amyloid depoits
Group 2: secondary to left heart disease
- MMVD, DCM, outflow tract obstructions etc
Group 3: Secondary to respiratory disease, hypoxia or both:
- chronic obstructive airway disease
- pulmary parenchymal disease inc fibrosis, eosinofili pneumonia, infectious pnumoni, difffuse neoplasia
- high altitude
- westies - nonspecific interstitial pneumonitis (pred + mycophenolate)
Group 4: Pulmonary emboli, thrombi or thromboemboli.
Group 5 - parasitic (HW or angiostrongylus)
What are the pathophological causes of pulmonary hypertension and give examples?
- Increased pulmonary blood flow
- L to R shunt eg PDA - Increased pulmonary vascular resistance
- pulmonary epithelial disease
- vasc remodelling
- perivasc inflam
- vasc lumen obstruction
- increased blood viscosity
- arterial wall thickness
- lung parenchyma destruction - Increased pulmonary venous pressure
- left heart disease
- compression of large pulmonary vein
What areas are looked at on echo to assist in diagnosis of pulmonary hypertension?
- Ventricles
- flatten IVS esp during systole
- underfilling LV
- RV hypertrophy
- RV systolic dysfunction - Pulmonary Artery
- enlargement (PA/Ao >1.0)
- early peak diastolic pul regurg > 2.5m/s
- Right pul art distensibility <30%
- R outflow doppler acceleration tie (<52-58m/s) pr acceleration time to jection ratio (<0.30)
- systolic notiching of doppler RV outflow profile - Right atrium or CVC enlargement
* LA enlargement is a crude surrogate for chronically increased pul art wedge pressure
What measurements are used on echo to assess pulmonary hypertension?
- Peak tricuspid regurg velocity
<3 - low
3-3.4 - intermediate
>3.4 - high probably of pul hypertension.
Increased risk level if other echo signs of pul hypertension noted. - Calc pressure gradient between RV and RA (= 4 x velocity {m/s}2) in diastole
> 15mmHg supports diastolic pul art hypertension.
What are pre-capillary causes of pulmonary hypertension and what echo changes/measurements are expected?
- Group 1 (pul art hypertension)
- Group 3 (resp disease/hypoxia)
- Group 4 (TE)
- Group 5 (parasitic)
no La enlargement
mean PAP >25mHg
PAWP <15mmHg
Increased pulmonary vasc resistance.
What are the post-capillary causes of pulmonary hypertension and what echo changes/measurements are expected
- Group 2 (Left heart disease)
- Group 6 (multi-factorial)
- La enlargement
- PAP > 25mmHg
Isolated post:
Diastolic pressure gradient <7mmHg
Pul vasc resistance not increased
Mixed pre and post:
Diastolic pressure gradient >7mmHg
Pul vasc resistance increased
What is the recommended measurement of intermediate to high likelihood of pulmonary hypertension?
Tricuspid regug > 46mmHg
Tricuspid regurg velocity >3.4m/s
~moderate pul hypertension.
Take into account shoudl be present with clinical signs of pul hypertension as well.
When should echo be used to assess for pulmonary hypertension?
- if clinical signs + after physical exam and TXR rule out other causes
- If TXR shows
- tortuous, blunted, or dilated pulmonary arteries;
- asymmetric radiolucent lung fields
- patchy, diffuse alveolar infiltrates
- bulge in the region of the pulmonary trunk or right-sided cardiac enlargement - Clinical signs + ascites or dilated CVC or hepatic veins.
- Suspected parasitic or high risk of PTE
- If CT shows:
- A pulmonary trunk-to-descending aorta ratio ≥1.4170
- Evidence of RA and RV enlargement
- decreased pulmonary vein-to-PA ratio, increased pulmonary trunk-to-ascending aorta ratio, increased RV-to-LV ratio
- pulmonary arterial filling defects
- mosaic attenuation pattern showing small vessels in a region of decreased attenuation (ie, hypoperfusion) on an inspiratory scan that fails to show accentuation of the mosaic attenuation pattern on an expiratory scan (ie, ruling out air trapping)
- Perivascular diffuse nodular to ill-defined patchy ground-glass opacity with a global distribution, compatible with pulmonary capillary hemangiomatosis (PCH) or pulmonary veno-occlusive disease (PVOD - If histopath shows whide spread pulmonary vascular disease
What general recommendations are recommended for dogs with high probability of pulmonary hypertesion?
- Exercise restriction
- Prevention of infectious resp disease inc HW, antiostrongyulus and KC
- Avoidance of pregnancy
- Avoidance of high altitude and air travel
- Avoidance of nonessential wellness procedures (eg, dental cleanings) and elective surgery requiring general anesthesia
With pulmonary hypertension, when is a PDE5i not recommended?
Group 1
- occlusive cellular or fibrotic vascular occlusive lesion (pulmonary vasculaitis or amyloid deposition) as could => pul oedema. Start in hospital if needed
Group 2
- uncontrolled LSCHF => pul oedema
All others, maybe useful? need to treat underlying disease first/concurrently.
What are the signs of pulmonary hypertension?
Strongly suggestive:
- syncope esp with activity, with no other cause
- Resp distress at rest
- Activity or exercise terminating in resp distress
- RSCHF
Possible pulmonary hypertension:
- tachyponea at rest
- increased resp effort at rest
- prolonged post-exercise or post activity tachyponea
- cyanotic or pale mucous membranes.
What are the signs of immune mediated RBC destruction?
- Spherocytes (dog)
- positive saline agglutination test
- positive saline agglutination test that persists with washing
- positive Coombes/Direct antiglobulin test or flow cytometry
What are signs of haemolysis?
Without funtion liver disease, post hepatic cholelestasis or sepsis:
- hyperbilirubinaemia
- significant bilirubinuria
- icterus
- Haemoglobinaemia
- haemoglobinuria
- RBC ghost cells.
What are non-immune mediated causes of spherocytes?
- oxidative damage
- acetaminophen
- envenomation
- hypersplenism (hepatosplenic lymphoma)
- pyruvate kinase deficiency
- RBC fragmentation (endocarditis, HSA, haemolytic uremic syndrome etc)
- dyserythropoiesis.
What is the threshold of spherocytes seen in blood to be considered IMHA?
sens and spec of this?
> or = to 5 spherocytes/x100 oil immersion filed
63% sens
95% spec
What is the spec of saline agglutination test for detecting IMHA?
4:1 saline to blood = 100%
What is the sens and spec of Coombs/DAT for IMHA in dogs and cats?
Dog
Sens: 61-82%
spec: 94-100%
Cat
Sens: 82%
Spec: 95-100%
What anticoagulants are recommended (in order of preference) for IMHA management?
why?
When not to use?
- Unfractionated heparin (+/- antiplatelet)
- LMH or Factor Xa inhibitor
- Clopidogrel +/- aspirin
- Aspirin
Predominantly venous thrombosis => thrombi formation is more dependant on Coag/fibrin than PLTs.
Not if PLT <30
What drugs are recommended for immunosuppression in IMHA?
- Pred 2-3mg/kg or 50-60mg/m2/day for dogs >25kg
Second line:
- Azathioprine
- cyclosporine
- mycophenolate.
When should a second line immunosuppressant be started in dogs with IMHA?
second line if:
- severe, life threatening
- PCV not stable with decrease >5% in 24h in the first 7 days of treatment
- expected to have adverse reaction to pred
- increased BUN or Tbili (negative prognostic factors in other studies)
When do you start weaning the immunosuppressants used for IMHA?
When the PCV/Hct has remained stable and >30% for 2 weeks after starting treatment,
+
an improvement in the majority of measures of disease activity (spherocytosis, agglutination, TBil level, reticulocyte count),
=> decreased prednisolone by 25%.
What infectious agents are associated with acute hepatitis?
- toxoplasma
- neospora
- sarcocystis
- Histoplasma
What infectious agents are associated with chronic hepatitis and what is the predominant inflammatory type?
- Lepto - pyogranulomatous
- Mycobacteria - granulomatous
- Anaplasma - granulomatous
- E. canis - mixed
- babesia - non–suppurative.
What are the following mutations associated with? and in what breeds?
- COMMD1 deletion mutation affecting ATP7B protein
- ATP7A and ATP7B
Copper toxicity
- COMMD1 deletion mutation affecting ATP7B protein - bedlington terrier
- ATP7A and ATP7B - labrador.
What metabolic genetic conditions may be associated with chronic hepatitis and in what breeds?
- alph-1 antitrypsin - cocker spaniels
- erythropoietic protoporphyria in German shepherds.
What is the earliest biochemical indicator of chronic hepatitis?
ALT followed by ALP then GGT
What staining can be used to provide a subjective assessment of copper accumulation?
Where does copper usually accumulate if pathologic?
Rhodanine/rubeanic acid staining
Pathologic = centrilobular
Periportal often non-specific:
What additional staining/techniques can be used to assess for infectious hepatitis on liver biopsies?
- Acid fast: Mycobacteria
- Periodic acid Schiff stain or silver stain: Fungi
- FISH for bacteria
- Immunohistochemistry for virus and protozoa
What treatment is recommended for copper hepatitis?
- dietary copper restriction
+ use distilled bottled water - D penicillamine for 6-9m to normal ALT or on repeat biopsy + treat for further 1 month.
- Zinc after chelation
- SAMe or Vit E to reduce oxidative injury
- +/- immunomodulatory therapy
What immunomodulatory therapy is recommended for chronic hepatitis?
- Pred +/- cyclosporine
maybe azathiopine or mycophenolate.
What are the criteria for stage B2 MMVD?
- murmur intensity ≥3/6;
- LA : Ao ratio in early diastole ≥1.6
- Left ventricular internal diameter in diastole, normalized for body weight (LVIDDN) ≥1.7
- breed-adjusted, vertebral heart score (VHS) >10.5. (or VHS >11.5 if breed adjustment to possible)
likely VLAS > or = 3
What medications are recommended fro dogs with stage B2 mMVD?
only pimobendan +/- cough suppressant
What is NT-proBNP useful for in dogs with clinical signs of heart failure?
if normal or near normal, then unlikely to be CHF and clinical signs are more likely to be pulmonary related.
What disease are associated with systemic hypertension?
- CKD
- AKI
- DM
- HyperA
- Hyperaldosteronism
- Phaeo
- HypoT4
- HyperT4
What toxicities are commonly associated with systemic hypertension?
- Cocaine
- Methamphetamine
- 5-hydroxytryptophan (serotonin precursor)
What drugs may cause systemic hyper tension?
- Glucocorticoids
- DOCP
- EPO
- Phenylpropanolamine
- Phenylephrine
- Pseudoephedrine
- Ephedrine
- Toceranib
- Cyclosporine (humans)
What brain damage can be seen with hypertension?
- Encephalopathy (white matter oedema: occipital and parietal lobes)
- Vascular accidents
- Cranial cervical myelopathy (ischaemic) in old cats: tetraplegia.
CSx: altered mentation, seizures, vestibular signs, focal CN deficits.
Higher risk with rapid hypertension or hypertension greater than 180mm Hg.
What are the recommended first line drugs for hypertension in dogs and cats?
Dog - ACEi +/- amlodipine of SBP >200mmHg
Cats - amlodipine
What medications are recommended for the management of hypertension in patients with phaeo?
phenoxybenzamine (alpha adrenergic block)
+/- beta blocker (atenolol) once alpha adrenergic stim is well controlled.
What treatment is recommended in patients with SBP >180mmmHg and signs of intracranial target organ damage?
Emergency treatment.
If sustained hypertension, need to incrementally decrease BP otherwise hypoperfusion => need to be titratable drug
- Fenoldopam (dopamine-1 agonist): renal arterial vasodilation ** (none of the others do this), natriuriesis and increased GFR.
- Labetalol: alpha and beta antagonist
- Hydralazine: smooth muscle relaxant (direct vasodilator)
- Nitroprusside: NO vasodilator
- Phentolamine: alpha blocker, reported in phaeo surgery
If no TOD => Hydralazine or amlodipine to reduce BP faster.
What antibodies to borrelia burgdorferi are only present in naturally infected dogs, not vaccinated?
antibodies against:
- C6
- VLsE (variable major protine-like sequence, expressed)
- OspF
Antibodies to what are stimulated by vaccination against B.burgdorferi?
- OpsC