Test 2 Flashcards
What animals often get canine brucellosis (brucella canis)
animals in breeding stock/ animals with exposure to aborted fetuses
how is brucella canis spread
through exposure to aborted fetuses, vaginal/seminal discharges, urine, or a blood transfusion
what disease causes an enlarged epididymis/scrotum
brucellosis
in females what can brucellosis cause
conception failures, abortions, still births, and fading puppies
How can you test for brucellosis
There are many tests but tube agglutination test is best for screening and can confirm with a PCR or culture (PCR and culture bad screening test)
will also see immature sperm, deformed tails and acrosomes, detached heads on semen evaluation
What must you tell owners regarding brucellosis
it is zoonotic!
is brucellosis reportable?
potentially
How is tularemia spread
Tick borne or predation of rabbits or rodents
What animal is most susceptible to tularemia
Cats, rare in dogs
What are the prominent symptoms with Tularemia
Prominent lymphadenopathy, high fever, lethargy, oral ulcers, icterus, high mortality rate in CATS
If you send out a necropsy and you are suspicious for Tularemia what should you do
Make sure to label it! Tularemia is aerosolized very easily and an infective dose is very low and it is zoonotic
What disease is reportable and is a bioterrorism risk
Tularemia
What is the vector for T. cruzi (Chaga’s disease)
Kissing bugs aka tritomes
What are the three potential forms of T. cruzi infection
Acute- sudden myocarditis and arrhythmias, diarrhea, lymphadenomegaly, meningoencephalitis
Latent- normal presentation
Chronic- chronic myocarditis with cardiac dilation and heart failure
What are two ways to diagnose t. cruzi
you can see it in a blood film for the acute form or you can send off for IFA antibody detection
What are the three modes of transmission of toxoplasma
congenital, ingestion of infected tissues or contaminated water or food
what are the clinical signs of toxoplasmosis
inflammation of the liver, lungs, and CNS
When doing the serology for toxoplasma what is important to do
you must have both IgG and IgM, IgG may just show exposure
what is the treatment for toxoplasmosis
clindamycin
What is the vector for Leishmania
a sand fly
T/F leishmania is zoonotic
true
What disease can cause skin lesions, stomatitis, kidney injury, affects GI, heart, and lungs and is in macrophages
leishmania
What are hemotropic mycoplasmas
wall-less bacteria that attach and grow on RBCs- on the outside of the RBC!
Can you culture mycoplasmas and how do they stain
no and they stain gram negative
what are the mycoplasmas in cats
M. haemofelis, Candidatus Mycoplasma haemominutum, and candidatus mycoplasma turicensis
What are the mycoplasmas in dogs
M. haemocanis and candidatus mycoplasma haematoparvum
what is the most common clinical disease associated with mycoplasma
anemia (usually regenerative)
what are three ways mycoplasma is transmitted
fleas, queens to newborns, and blood transfusion
what are the four stages of mycoplasma haemofelis
preparasitemic
acute- some cats die in this phase and there is a decrease in hematocrit- infected erythrocytes destroyed by body- need blood!
recovery phase
carrier phase- appear clinically healthy
T/F Candidatus mycoplasma haemominutum causes severe illness
false it is very rare to have clinical illness or severe anemia
what disease can flare up/ cause clinical signs in dogs that have had a splenectomy
Mycoplasma haemocanis
what specific type of anemia is seen with M. haemofelis
regenerative anemia
Will treatment with pradofloxacin (antibiotic) clear mycoplasma from an animal
nope!
What are the two forms of Cytauxzoon felis
Schizont- nonerythrocytic
Piroplasm- erythrocytic
Who is at risk of Cytauxzoonosis and how is it spread
Outdoor cats in the spring and summer especially but any cat that gets infected with a lone star tick is at risk
A cat has survived Cytauxzoon miraculously will it have a complete recovery?
Yes, but it may have persist piroplasms in the RBCs
How do you diagnose Cytauzoonosis
You can look at a blood smear for “signet rings” and those are the piroplasms but these are not present in all infected cats or you look for schizonts in the mononuclear cells on an FNA
Both Cytauxzoon felis and Mycoplasma haemofelis are on red blood cells! How would you tell the organisms apart?
M. haemofelis are present on the OUTSIDE of the RBC and are epicelluar cocci/rods/ or rings and are smaller than C. felis. It also causes a regenerative anemia and with cytauxzoonosis there is a pancytopenia and no regenerative anemia
What are the antiprotozoals used in treatment of cytauxzoonosis
Atovaquone and azithromycin
What is the large canine babesia and the small canine babesia (in the US)
Large- Babesia canis—> Babesia canis vogeli
Small- Babesia gibsoni
How is babesiosis trasmitted and what is the most common type of transmission
Via ticks, dog bites, or transplacentally
Non-vector forms most common
What is the pathogenesis of babesiosis
The body forms antibodies against the antigens on the surface of the RBC which leads to immune-mediated anemia—> Hemolytic anemia and Thrombocytopenia (low platelets)
What are two breeds that are prone to having babesiosis
Greyhounds and American Pit Bull Terrier
If an examination of a blood smear is negative for babesiosis is it ruled out
Nope it has poor sensitivity and is not recommended as a sole test
How can you improve the sensitivity of a babesia blood smear test
Examine the Buffy coat
What is the most sensitive and specific test for babesia
PCR, but a negative still doesn’t rule out the disease
What is the curative treatment for babesia canis
Imidocarb dipropionate
What is the curative treatment for Babesia gibsoni
Atovaquone and Azithromycin
Which babesia do greyhounds usually get? What about pit bulls?
Greyhounds- babesia canis
Pit bulls- babesia gibsoni
Sepsis definition now and how it has changed
A life-threatening, organ dysfunction caused by a dysregulated host response to infection. This has gotten rid of the SIRS reference because the criteria is not specific enough
What is septic shock
A subset of sepsis in which underlying circulatory and cellular/metabolic abnormalities are profound enough to substantially increase mortality
All bacteremic patients are septic but…
Not all septic patients are bacteremic
What does LPS cause to be activated and what type of sepsis is this?
Both pro-inflammatory and anti-inflammatory mediators (acts as a PAMP), gram-negative sepsis
When does clinical sepsis develop in terms of cytokines
When the balance between the pro and anti-inflammatory cytokines becomes imbalanced
What does overproduction of NO cause in sepsis and what does it look like clinically
Vasodilation (loss of vasomotor tone), you will see red mucous membranes and a rapid capillary refill time and tachycardia—> can lead to vasodilatatory shock
What are the three disrupted homeostatic mechanisms in sepsis
vasomotor tone (dilation), inflammatory and coagulation cascade, Microvascular changes
What role does Tumor necrosis factor have in inflammation and coagulation, especially in sepsis
It initiates the coagulation cascade by binding to factor VII which leads to initiation of platelets but in sepsis the tissue factor inhibitor (and other anti-coagulant factors) are down regulated—> microthrombi formation (rare to see bleeding in septic patients)= prothrombotic state
What does cryptic shock cause
A decrease in microcirculatory perfusion and may have normal hemodynamic parameters
What is cytoplasmic hypoxia
Mitochondrial changes induced by sepsis which make the mitochondria unable to appropriately use oxygen to make ATP
What are the early clinical signs of sepsis in dogs
Tachycardia, bounding pulses, rapid capillary refill time, red mucous membranes , fever, decreased BG
What are the signs of late sepsis in dogs
Hypoglycemia, thready pulses, prolonged capillary refill time, pale mucous membranes, cool extremities, stupor, hypothermia, multiple organ failure
What are the signs of sepsis in cats
No hyperdynamic phase, lethargic, pale mucous membranes, tachypnea, weak pulses, hypotension, hypothermia, icterus, diffuse abdominal pain and may have tachycardia or bradycardia
What do you do if a patient with sepsis after receiving resuscitation fluids (assuming you have repeated the boluses) still is hypotensive
Vasopressors (norepinephrine, vasopressin, dopamine) or positive inotropes (dobutamine or dopamine)
When should antibiotics be started in septic patients
Within one hour, don’t let getting a culture interfere with starting of antibiotics
What type of antibiotics should be used before receiving culture results in a septic patient
Broad spectrum, gram negative and gram positive and anaerobic organisms
What is the mortality rate in dogs with sepsis
50%
How is rabies transmitted
Bite of infected animal or in some cases inhalation of excreted virus (bats), ingesting infected tissue, transplacental
why isn’t there a blood test for rabies
Because it is not in the bloodstream ever, it is in nervous tissue
How does rabies spread within a victim
Passive spread through peripheral axons to the forebrain
Once an animal has rabies in its saliva where has it gotten in the body
in the brain already
Recovery from rabies is very rare but what must the body have to have any chance of elimination
cell-mediated immunity
what are the two types of rabies
The furious or psychotic type and the paralytic or dumb type
What do you see with furious rabies
Restless, roaming, vicious, muscle incoordination, hyperresponsive to stimuli
What do you see with paralytic rabies
Flaccid paralysis, laryngeal paralysis, excessive salivation, dropped jaw, coma—> respiratory failure
How do you get a definitive diagnosis of rabies
Direct fluorescent antibody test for the antigen in brain tissue
What will you see on histopath for an animal with rabies
Intracytoplasmic inclusion bodies (negri bodies) in brain tissue
Should you try supportive care on an animal that may have rabies and it is symptomatic
no
What should happen to animals under the suspicion of contracting rabies but are not symptomatic and are vaccinated
Revaccinate and have owner quarantine for 45 days
What should you do if an unvaccinated animal has been exposed to rabies (aka exposed to wild animal that tested positive for rabies)
Quarantine pet for 4 months (if dog or cat) if owner declines euthanasia
What does leptospirosis look like
A filamentous, flexible, spiral-shaped, gram-negative bacteria
Can an animal get leptospirosis if they have been vaccinated?
Yes because there are many different serovars and the vaccine doesn’t contain all of them
Where is leptospirosis prevalent
warm, moist climates
How is leptospirosis maintained and spread with the reservoir hosts
The reservoir hosts are usually asymptomatic and the organism goes to the kidneys to be spread via the urine in an indirect fashion because the urine then contaminates water and soil
Is lepto shed in incidental host’s urine
very minimally
How does lepto enter hosts and what is the pathogenesis
Enters via mucous membranes and it can cause vascular damage through leptospiremia resulting in clinical disease (renal damage, hepatic dysfunction, coagulopathy)
T/F all lepto serovar cases look the same
False, depends on serovar
What are the four types of infection of leptospirosis and the signs associated with each one
Peracute- death
Acute- fever, respiratory, paraspinal pain, liver failure, kidney infection, retinal hemorrhage or iritis
Subacute- anorexia, lethargy, PU/PD, gastrointestinal signs
Chronic- fever of unknown origin and renal/hepatic disease
What does lepto do in the kidneys
Replicates in the epithelial cells causing tubulointersitial nephritis, kidney swelling, ischemic damage, and acute kidney disease
what does lepto do in the liver
Subcellular damage, hepatic necrosis, chronic active hepatitis
What may you see on bloodwork of a patient with lepto
Thrombocytopenia, azotemia, ALP more elevated than ALT, hyperbilirubinemia and globulinemia, hypoalbuminema, isothenuria, prolonged PT and PTT
Which test is affected by if the animal has been vaccinated or not for lepto, what about if the animal has received antibiotics
The MAT test is affected by the vaccine and not as much antibiotics and the PCR test is not affected by the vaccine but it is affected by if the animal has been treated with antibiotics
What do you use for the MAT lepto test, what about PCR
MAT- serum
PCR- blood, urine, body fluids
If doing the MAT test for lepto how do you determine what the animal is infected by
The highest titer is the infecting serovar (most likely)
What does the MAT test look at and how often should you run the test if you suspect an animal has lepto
Mainly IgM some IgG, at presentation and then 3-4 weeks later
What does the snap lepto test detect
IgG and/or IgM antibodies
How do you determine a definitive diagnosis of lepto (gold standard)
Clinical presentation + PCR (blood mixed with urine) + MAT
What are the antibiotics used with lepto
Penicillin for the leptospiremic stage
Doxycycline to eliminate carrier state
How does the old lepto vaccine differ from the new one, but what may you still need to do even with vaccination
There are 2 new serovars in the new vaccine (Canicola and icterohaemorrhagiae of the old plus Pomona and grippotyphosa) but vaccine usually only gives protection for 6 months so you may need to vaccinate 2x a year and avoid high-risk areas no matter what
What are risks to zoonotic spread of lepto
Contact with urine and mucosal contact, contact with reservoir, gardening and outside
Generally how long do ticks need to be attached to the host to spread disease
48 hours
what are common clinical signs of tick-borne diseases
Polymyositis, polyarthritis, thrombocytopenia, FAD (fever, anorexia, depression)
T/F Rocky Mountain Spotted Fever often causes a chronic disease
False, it is usually an acute disease and animals are usually either dead or better within weeks (most recover with appropriate treatment)
What are clinical signs of Rocky Mountain Spotted Fever
Fever, reluctance to move, lymphadenomegaly, malaise, CNS signs, vasculopathy (can result in external necrosis of skin)
What laboratory abnormalities and lab results will you see with RMSF
Thrombocytopenia, IgG 4-fold change (>1:1024)
Will an animal still have positive antibodies for RMSF even after clearing the pathogen
yes
How do you treat RMSF
tetracycline
What is the target cells for ehrichia canis and what about ehrichia ewingii and ehrichia chaffeensis
Canis- monocytes and macrophages
Ewingii- neutrophils or eosinophils
Chaffeensis- monocytes and neutrophils
What are the three phases of ehrichia canis and signs
Acute- thrombocytopenia, multisystemic signs
Subacute
Chronic- pancytopenia, hyperglobulinemia
More severe disease than other ehrichia varieties
What do you see with ehrichia chaffeensis
Uveitis and hyperglobulinemia
What is the target cell of anaplasma
neutrophils
What does anaplasma phagocytophilum cause
Acute illness- lameness, FAD with low platelets and eosinophils
Do antibodies protect a host from reinfection of anaplasma
no
What does anaplasma platys cause
Infectious cyclic thrombocytopenia (likes platelets not white cells!)
What are two tests for ehrlichia or anaplasma
The antibody snap test (same one as Lyme and heartworm) and/or the PCR antigen test
How do you treat Ehrlichiosis/anaplasma
Minocycline-doxycycline and chloramphenicol
What may you see on the skin of patients with Lyme disease (Borrelia burgdorferi)
Red, round lesions
How soon do animals start showing signs of Lyme and what clinical signs do they have
2-5 mo after incubation, FAD, lymphadenomegaly, PLN (protein losing neuropathy)
What antibodies are targets of the Lyme vaccine
Osp protein A and C
What do you test for to show the Lyme organism is in the host and there is an active infection
C6 peptide a part of the variable lipoprotein surface-exposed protein (VlsE)
How do you treat Lyme disease
tetracyclines
What are features of Bartonella that make it hard to detect
Stimulates a minimal immune attack and causes minimal disease in the host
Where can bartonella localize
in the heart
In cats many have what type of infection of bartonella
Subclinical but stress may activate it
What are unnatural hosts for Bartonella henselae and what can it cause
Dogs and humans and it can cause granulomatous lymphadenomegaly (pyogranulomatous disease)
What does Bartonella vinsonii ssp. Berkhofii cause
In dogs it causes lameness and fever and granulomatous disease
What is the treatment for bartonella
Tetracyclines and macrolides
Can a dog with hepatozoonosis be cured
no
What is the target cell for Hepatozoon americanum and where does it lodge in a host
Monocyte and lodges in a cyst in the muscle
Why is it important clinically that hepatozoon can encyst
Drugs can’t kill the cysts and they can periodically release merozoites
What would make you suspicious a dog has hepatozoon
Cachexia (muscle wasting), progressive wasting illness, outrageous leukocytosis (high WBC count), periosteal reaction (bone reaction)
Clinical signs- fever, lethargy, anorexia, weight loss, hyperesthesia (increased sensitivity to stimulation)
What are laboratory findings with hepatozoon
Leukocytosis, hypoglycemia, increased ALP, hypoalbuminemia
What is the triple therapy to treat Hepatozoon and if the animal survives then what do you treat with
Trimethoprim-sulfonamide, clindamycin, Pyrimethamine
Then treat with decoquinate
For serologic testing of tick-borne diseases a positive test could mean what and what is the exception
It could be vaccines except for Lyme because that tests for the C6 antibody (acts like antigen test)
What tick-borne diseases are treated with doxycycline
Ehrlichia, Rickettsia, Anaplasma, Borrelia
What type of soil/enviornment is Blastomyces dermatitidis found in
Sandy, acidic, deep soil near water, Eastern river valleys
What type of soil/enviornment is Histoplasma capsulatum found in
Soil rich in organic nitrogen in warm, humid conditions (temperate, subtropical), Ohio river valley
Who is more likely to get Blastomyces and who is more likely to get Histoplasma
Dogs are more likely to get Blastomyces and cats are more likely to get Histoplasma
What is the signalment for Blastomyces
Males more than females, sporting dogs or doing outdoor activity, 1-5 years
What is the signalment for Histoplasma
If not cats (of any age, esp. Persian cats) then sporting and working dogs (esp, pointers, weimaraners, spaniels, terriers), over 5 years of age
What is the pathogenesis of Blastomyces
Inhalation of spores that infect lungs and then disseminates through the body extracellularly causing clinical disease (eyes, lymph nodes, skin, bone, subcutaneous tissue)
What is the pathogenesis of histoplasma
Inhalation of microconidia, infects lower respiratory tract, phagocytosed and disseminated intracellularly throughout body (GI, skin) or may stay in lungs, many are asymptomatic
What causes fever, cough, bone lesions, ocular disease, draining tracts, and CNS signs in dogs and sometimes cats
Blastomycosis
What can cause weight loss, cough, large bowel diarrhea (with blood), enlarged lymph nodes, and chronic illness in dogs or they may be asymptomatic
Histoplasmosis
T/F both cats and dogs have GI signs from Histoplasmosis
False, dogs usually just get it
What are you looking for on histopathology for Blastomycosis
Big, blue, broad-based budding yeast + pyogranulomatous inflammation (extracellular)
What are you looking for on histopathology for Histoplasmosis
Small intracellular yeast with narrow based budding and “halo” around edge + pyogranulomatous inflammation
What test should you send off to a lab for Histoplasmosis or Blastomycosis
Antigen test of the urine
When treating for Histoplasma or Blastomyces what should you warn the owner
The pet will start getting worse before it gets better and that means the treatment is working
What is the most common systemic mycosis of cats
Cryptococcus
How is Cryptococcus spread
Through pigeon or other bird droppings in nitrogen rich environments
What is the pathogenesis of Cryptococcus
Colonization of nasal cavity (through inhalation maybe but not proven) and spreads to CNS, eye, and skin from there
What fungi causes upper respiratory signs in cats commonly and may also cause CNS, eye, or skin lesions/signs
Cryptococcus
What does Cryptococcus look like on histopathology
Large capsule, narrow-based budding + thin cell wall
What does serologic testing look for for Cryptococcus
Cryptococcal polysaccharide capsule antigen
You treat a cat for Cryptococcus and it seems to respond, are you in the clear?
No, 1/3 of cats may relapse
What fungi is found in the southwest, Mexico, and central/South America, likes sandy, alkaline soils and low rainfall and elevation. What animal is it prevalent in and what does it cause in layman’s terms
Cocciciomycosis, more prevalent in dogs and causes “Valley Fever”
What is the pathogenesis of coccidioides
Inhaled, arthroconidia enter bronchioles and alveoli, enter peribronchiolar tissue and are phagocytosed and spread to bones, eyes, heart, CNS, or visceral organs
T/F many animals infected with coccidioides are asymptomatic or have mild lower respiratory tract signs
true
What type of testing is unique to coccidioides compared to other fungal diseases
Serologic testing for antibodies instead of antigens
Where does griseofulvin work and what should be given with it
Inhibits microtubule assembly and is better absorbed with a fatty meal
What is better to use for Amphotericin B, topical or systemic forms, what is the MOA, and what is an important side effect
Systemic is better, it binds sterols (esp. ergosterol) which causes holes to form in the membrane, there is a side effect of nephrotoxicity
What is MOA of Flucytosine and what does it work well against, what is a side effect
It inhibits DNA synthesis in yeast (good against Cryptococcus and candida), can cause skin eruptions in dogs so it is rarely used in them now
What drug is a widely used antifungal but what drug type can it not be given with
Azoles but need acidic enviornments so can’t be given with antacid
What is important about how the drug is made regarding Azoles
They must be micro-encapsulated
How do Azoles work, and what is unique about how well they work in regards to concentration
They inhibit sterol synthesis and are fungistatic at low concentrations and fungicidal at high but high concentrations can’t be safely reached in animals
What are 3 risks with ketoconazole (azole)
Can cause GI upset, likely to induce mammalian P45 enzymes, and clinical hepatitis can occur
What antifungal is good because it can get through the BBB (so good for CNS involvement)
Fluconazole (azole)
Which azole is more selective for fungal p450 enzymes
itraconazole
How does terbinafine work
It reversibly inhibits squalene cyclase to inhibit ergosterol synthesis
How do echinocandins work and how does the MOA impact how fast it works
They inhibit chitin synthesis so fungal growth is required so there is a delay in how fast it works
What antifungal is used topically
Clotrimazole
What is Greene’s selection method for antibiotics
Host (rug), Organism (Bug), Drug
What are the five essentials for a drug
Reach the organism in the host (bug in the rug)
Achieve appropriate concentration
Microorganism susceptible
Not associated with severe adverse events
Able to be administered
What organisms do penicillins and cephalosporins (G1) usually get
Gram positive aerobes and some gram negative aerobes
What do potentiated beta-lactams get
Gram positive and negative anaerobes and aerobes and some pseudomonas
What drug is restricted usually for resistant microbes and gets all gram negatives, positives and pseudomonas
Carbaminopenems
What are 6 antibiotics that can get MRS (staph resistant infections)
G5 cephalosporins, sulfonamides, tetracycline/doxycycline, chloramphenicol, vancomycin/linezolid, lincosamides
What drug has the broadest coverage/ is almost a 4 quadrant drug
Quinolones
What antibiotic gets only gram negative aerobes and pseudomonas because it requires oxygen to work
Aminoglycosides
What drug is used for a lot of atypical and intracellular bacterial infections
Tetracycline/doxycycline
What antibiotics are often used in dentistry and get gram positive aerobes, gram positive and negative anaerobes, MRS, and some atypicals
Lincosamides
What drug has a narrow spectrum of activity of gram positive and negative anaerobes and a few atypicals
Metronidazole
What antibiotic causes aplastic anemia in humans but it gets some in all quadrants
chloramphenicol
What antibiotic needs special approval to be used because it is reserved for humans (like you have to submit a request to a board)
Vancomycin/linezolid
T/F antibiotic resistance in humans leads to resistance in pets
True, it goes both ways
Does monotherapy or poly select for more resistance
Polypharmacy, the more classes you give the more you select for resistance
Most antibiotics are what type of dependent
Time- have to give the drug more frequently
T/F narrow spectrum antibiotics are better to use compared to broad spectrum because less resistance will form and we can save the broad spectrum drugs
False, there is no correlation between narrow spectrum antibiotics causing less resistance or being clinically superior
