PoS Flashcards
What are the types of shock?
Septic/distributive/vasodilatory
Hypovolemic
Obstructive
Cardiogenic
What are some causes of hypovolemic shock?
GI losses
Hemorrhage
3rd space losses
polyuria at very high volumes
What are some causes of obstructive shock?
GDV
Pericardial effusion
Pneumothorax
What causes cardiogenic shock?
Primary heart disease- generally a patient with this type of shock will also be in heart failure
What are some causes of vasodilatory/septic/distributive shock?
SIRS (Systemic inflammatory response syndrome) Sepsis Pancreatitis Anaphylaxis Anesthesia
What are the 6 perfusion parameters?
HR pulse quality Mucous membrane color CRT Temp Mentation
Which shock type should NOT receive an IV fluid bolus?
Cardiogenic
What are the signs of fluid overload?
congestive heart failure, peripheral edema, swelling of the conjunctiva, gelatinous feeling skin
True or False: Shock patients will always have pale mucous membranes
False- hyperemic in vasodilatory
Difference between shock and dehydration
Shock - fluid loss from intravascular space
Dehydration - generalized fluid loss - intracellular/interstitial loss
Treated in different ways - dehydration is longer administration of fluids, shock is a rapid bolus
What is a stem cell?
Unspecialized cell with ability to self-renew and capability of differentiating into multiple cell types
What are the 2 main categories of stem cells? And what is the main difference between them?
Embryonic and adult (somatic)
Main difference is their potentials- embryonic are totipotent (can make all cell types in the body) whereas adult stem cells are multipotent (can make many cell types but not every cell type in the body)
Which part of the embryo are embryonic stem cells derived from?
Inner cell mass of the blastocyst
Only a very small number of cells here- need to amplify them!
True or false: embryonic stem cells have infinite capacity to divide but adult stem cells do not
TRUE!!!
If you culture adult stem cells can only get a limited number
True or false: embryonic stem cells are more likely to form teratomas
True
What are some licensed uses of stem cells in vet med?
Horse tendon/ligament injuries- taken from bone marrow of horse
Horse or dog bone/joint/tendon injuries- derived from adipose tissue of animal
*in both cases these cells may not be actually forming new tissue but producing factors that promote tissue healing
What kind of corticosteroid activity does prednisolone have and how does it compare to dexamethasone?
Pred- mostly glucocorticoid, some mineralocorticoid
Dex- only glucocorticoid
How does chlorambucil work?
Alkylating agent- alkylates DNA, prevents protein synthesis and kills dividing cells
*First choice as 2nd immunosuppressive in cats
Other alkylating agents used for chemo: cyclophosphamide, lomustine, melphalan
How do methotrexate and azathioprine work?
Compete with building blocks of DNA so get non-functional nucleic acid strands (anti-metabolites)
NEVER use azathioprine in cats- very narrow therapeutic index and overdose causes fatal myelosuppression
Other anti-metabolites used in chemo: cytarabine, 5-fluorouracil, hydroxycarbamide
What group of drugs are Vincristine and Vinblastine and what are they used for?
Vinca Alkaloids- at low dose can increase platelet release from megakaryocytes, used for immune-mediated thrombocytopenia
Also used in higher dose as chemo- interfere with mitotic spindle apparatus
What are the Calcineurin inhibitors?
Ciclosporin and Tacrolimus
Block IL-2 production so inhibits T helper 1 response and also indirectly suppresses T cells, NK cells, neutrophils, eosinophils & mast cells
*Tacrolimus use from cascade and topical only
True or false: if a cat is on glucocorticoids and develops PU/PD it’s not a cause for concern
FALSE- this shouldn’t happen with cats, if it does happen they have developed diabetes mellitus
True or false: PU/PD in a dog being treated with glucocorticoids is primary PU and secondary PD
False- primary PD from behavioral changes
Explain the difference between COX1 and COX2
COX 1 = produces PGs that are IMPORTANT in the physiological modulation of function - gut mucosal barrier and intra-renal perfusion
COX 2 = activated and released by tissue damage, bacterial lipopolysaccharide, cytokines, growth factors, inflammation
When using NSAIDs what are the withdrawal periods for meat and milk?
Meat - 28 days
Milk - 7 days
What are the different NSAID classifications?
Non-selective - no clinical differences in COX 1/2 inhibition = Aspirin, Phenylbutazone, Ketoprofen
Preferential - at least 2x greater inhibition of COX2, usually ~10-40x = Meloxicam, Carprofen, Mavacoxib
Selective - TRUE specific COX 2 inhibitor - more than 100 fold specific for COX 2 - Firocoxib (previcox), Robenocoxib (Onsior)
What are some adverse effects of NSAIDs on large animals and horses ?
LA Abomasal ulceration, Renal toxicity, Hepatic disease
Horses - GI ulcers, renal toxicity, phlebitis (inflammation of a vein)
Why do high doses of NSAIDs cause GI ulceration?
PGs protect the gastric mucosa by decreasing gastric acid secretion and maintain mucosal blood flow, also enhances mucus production
** COX 1 and COX 2 need to be inhibited to generate mucosal injury**
Why do you NEVER use NSAIDs with a suspected case of dehydration/shock?
With dehydration and shock, the patient will already have decreased blood flow to the gut so giving NSAIDs will cause a significant increase in the risk of GI ulceration
Also, dehydrated and shock patients have a decreased renal perfusion - COX 1 and 2 help to maintain that GFR via vasodilatory actions so giving NSAIDs will continue to decrease renal perfusion
What are some preferred NSAIDs to use in dogs vs. cats. vs. horses?
Dogs - carprofen, firocoxib, paracetamol
Horses - Carprofen, firocoxib
Cats - Carprofen, aspirin, meloxicam, firocoxib (not licensed)
What is the main route of elimination for NSAIDs?
Hepatic
What are the best forms of treatment when you have a suspected case of chocolate toxicity?
TREAT THE PATIENT NOT THE TOXIN
- Emesis - make the patient vomit if the ingestion is known to have been less than 4 hours ago (Dog - apomorphine, cat - xylazine, medetomidine/dexmedetomidine - can cause sedation)
* Do not use emesis if showing neurological signs*
* Can cause aspiration pneumonia * - Gastric/colonic lavage - use if the ingestion has been over 4 hours ago AND use if large amounts ingested
- Under GA - pass stomach tube and lavage stomach with tepid water, empty contents below patient, REPEAT
* Can cause aspiration pneumonia and hypothermia if using cold water* - Activated charcoal - stop it from being absorbed
What is the antidote for anticoagulant rodenticide?
VITAMIN K biiiitch!
What is the antidote for ethylene glycol?
Ethanol - GET THE VODKA!
What are some toxins that cause seizures?
METALDEHYDE (snail/slug pellets) - cause neuroexcitation and decreased GABA activity
MYCOTOXINS - from mold - cross BBB into cerebellum because they are lipid soluble - BIND TO ACTIVATED CHARCOAL
METHYLANTHINES/Theobromide - chocolate/coffee - antagonize adenosine receptors –> CNS stimulation - BIND TO ACTIVATED CHARCOAL
Permethrin - in flea/tick medication - toxic to cats - lead to hyperexcitability and tremors
What toxins will cause anemia?
RODENTICIDE –> Vitamin K antagonism which is required for the production of coagulation factors in the liver
- Treat with plasma transfusion and give Vitamin K for up to 6 weeks
PARACETAMOL - toxic to cats and dogs in high doses - causes oxidative damage to RBCs
- Treat with activated charcoal, N-acetylcystine
What are the toxins that can lead to renal failure?
Ethylene glycol - causes azotemia, isosthenuria and calcium oxalate crystal formation
* Will see oliguria/anuria* - TREAT WITH VODKA
NSAIDs - high doses can lead to renal failure - treat with emesis, activated charcoal, diuresis if needed, IVFT
Aminoglycosides (ABX)
Lillies - cats - lead to azotemia, isosthenuria - treat with emesis, activated charcoal, IVFT
Grapes/raisins - dogs
Which toxins can lead to hepatic toxicity?
Xylitol - increases insulin levels –> hypoglycemia and can cause hepatic necrosis at high doses
treat with glucose bolus, liver protectants (NAC), fluids
Mushrooms
Paracetamol
Describe the difference between endotoxins and exotoxins.
Endotoxins - part of the bacterial outer membrane - seen in GRAM NEGATIVE BACTERIA - lipid A part of the LPS - this is what is recognized by the PRR in host cells to indicate a bacterial infection is present
(when macrophages attack –> cytokine release to hypothalamus –> fever)
Exotoxins - bacterial proteins released during BACTERIAL GROWTH - can by cytolytic, enzymes, enterotoxins, neurotoxins, superantigens type 3 secretion systems
Superantigens - S. aureus –> TSS
Type 3 secretions- SALMONELLA - have a needle like structure that probes eukaryotic cells and secretes proteins in them to help bacteria infect
What are some examples of mycotoxins?
Toadstool poisoning - mushroom with yellow top/white stem - will cause sickness but not usually fatal
Ergotism - form in grass and cereal - ingestion leads to gangrene, lameness, convulsions (causes arteriole constriction-> hypoxia)
Aflatoxins - molded feed - leads to liver damage, tumors, TERATOGENIC
Why do we see drug toxicity in veterinary patients?
We use drugs off label
Not all animals are clones - some drugs affect some animals differently
Mistakes made in calculating doses/storage/handling
Animals usually have multiple diseases so multiple drugs are needed
Owner compliance
What is the difference between Type A and Type B drug reactions?
Type A - expected/predictable from drug MOA
Type B - not related to the MOA - occur if used for prolonged periods, but can be unpredictable
Why might drugs be more readily absorbed from the gut in a neonate?
They have decreased gut motility, underdeveloped gut flora, and mucosal enzymes but they have increased total body water, decreased GFR and immature liver enzymes
So larger volume of distribution but delayed elimination
True or false - you can treat collies with Ivermectin.
FALSE YOU ABSOLUTE IDIOT!
Collies have deletion mutations on their MDR-1 gene which codes for P-glycoprotein. P-glycoprotein is what acts as an efflux pump to excrete ivermectins out of the brain
How do cancer cells sustain proliferative signaling?
Make their own growth factors and evade growth suppressors (P53 inhibits proliferation- loss of function of these genes –>proliferation )
Alter their receptors - overexpression of receptors to respond to low levels of ligand or have receptor always switched on
Which gene mutations are seen in 50% of canine mast cell tumors?
KIT gene mutations - seem to be associated with more aggressive disease
How do cancer cells enable replicative immortality?
TELOMERASE enzyme up-regulated to add new telomeres at end of the chromosomes
How do cancer cells form their own blood supply?
Release angiogenic factors - VEGF - to stimulate new blood vessel growth
What are some factors involved in tumor grading?
Mitotic index
Degree of Cellular differentiation
Amount of necrosis
Invasion of surrounding tissues
What is the system for staging tumors (not lymphomas)?
TNM system - good for solid tumors
T = primary tumor - assess size, mobility, ulceration, relationship to surrounding structures
N - Node - assess regional nodes for size, mobility, texture, consistency - may need FNA/Imaging
M= metastasis - will need imaging for this
What are baseline tests to assess the cancer patient and why?
CBC - health screen to provide baseline before chemo
Biochem - assess organ damage/function
UA - health status/renal function
Coagulation profiles - ensure no coagulopathies
What is the cell morphology for a MCT?
ROUND CELLS
Very common cutaneous tumor in dogs
Granules seen in cytoplasm
TMT = surgery with 2 cm margins
What vaccines are most often associated with Feline Injection site sarcomas?
Rabies and FeLV
TMT = surgical excision with 5 cm margins
Can use adjuvant radiation because it has high recurrence rates
What are some differentials for oral tumors?
Melanoma - pigmented mass with high metastatic rate usually to lungs (or may be amelanotic)
Fibrosarcoma - high rate of recurrence
SCC - important to stage, low metastatic rate
What is the most active and invasive part of a tumor?
The periphery! That is why margins are so important
What is the mainstay therapy for immune-mediated disease and how do they work?
CORTICOSTEROIDS- Various adjuvant therapies can also help - start with Prednisolone - clinical response should be within 7 days - if not give a 2nd agent
Decreased macrophage phagocytic action and antigen-presenting activity and suppression of T cell function
How is borreliosis transmitted? What are some clinical signs? How is it treated?
Ixodes ricinus - tick feeding
Signs = fever, inappetence, pain in small joints, glomerular nephritis, thrombocytopenia, lymphadenomegaly
Tmt= doxycycline
How do hemoplasma bacteria affect RBCs?
They sit on the surface of the RBC –> immune-mediated hemolytic anemia
Macrophages see them on the surface and try to remove them –> anemia
* Can sometimes see on blood smear*
PCR = gold standard diagnostic test
Which small mammal would you consider fasting before anesthesia?
FERRET - usually up to 4 hours prior to procedure
Where would you want to place a catheter in a rabbit and why?
Marginal ear vein - do not use the middle vessel within the ear because it is an artery
What is the best anesthetic induction option for small mammals?
IM/SQ injection with alpha 2 agonist, ketamine, and opioid OR
Gas induction using sevoflurane (less irritant than isoflurane) after pre-med with midazolam/opioid or hypnorm
**If sick rabbit, pre-med and then IV induction with alfaxalone (or propofol)