LAM exam 1

What are the core immunizations for horses?

• tetanus

• EEE

• WEE

• WNV

• Rabies

What is the core immunization program for foals from immunized mares? unvaccinated mares?

• tetanus / EEE / WEE / WNV: 3 dose series at 4-6 months

  • 2nd dose 1 month later

  • 3rd dose at 10-12 months

• unvaccinated mare foals begin at 3 months

• rabies: 2 doses 1 month apart, not before 6 months

What is core immunization protocol for adolescents and adults?

• tetanus annually (sooner if wounded after 6 months)

• EEE/WEE/WNV: annually in north, x2 south

• rabies booster annually

How can you reduce the risk of adverse reactions to immunizations?

• proper storage, handling, and administration

What are the four major GI parasites in horses?

1. Ascarids (parascaris equorum)

2. Small strongyles (cyathostomins)

3. large strongyles (S. vulgaris, equinus, edentates)

4. tape worms (anaplocephalaperforliata and magna, parnoplocephala mamillana)

What is the major focus for GI parasite control in Foals

• Ascarids

What is the major focus for GI parasite control in Adults

• Cyathostomins (small strongyles)

What is the best test to identify high worm burden in adult shedders and parasite resistant horses?

• Fecal egg counts (FECs)

• egg reappearance period (ERP) can also be used)

What does selective therapy mean?

• Anthelmintic tx for shedders, minimal use in resistant horses

What are the 4 classes of anthelmintics commonly used in horses?

1. benzimidazoles

2. macrocylcic lactones

3. pyrantel

4. paraziquantel

What is the most effective means of GI parasite control?

• manure removal and pasture management

What is fundamental in the control of parasite and infectious disease?

• controlling animal movement and contact (co-mingling)

What is the fluid requirement for an adult horse?

• 50mL/kg/day or 1L/hr IV flow rate

What is the composition of balanced electrolyte solutions (BES)? examples?

• Na, Cl, K, organic ions (lactate, acetate or gluconate) ± Ca or Mg

• Alkalizing solution

• Examples: LRS, multisol R, plasmalyte-148

What is the composition of normal saline?

• Na, Cl

• acidic solution

How do you go about correcting hypovolemia in a horse?

• Isotonic crystalloids = shock dose = 40L/500kg horse = 8% BW

• hypertonic saline = more rapid response

• synthetic colloids = speed up and prolong volume expansion

What is the basic principles for blood transfusion in the horse?

• Cross match best

• Qa/Aa negative and unsensitized gelding

• gelding of similar breed

• transfusion based on signs, pCV, tissue oxygen, time

• ie acute blood loss of 1/3 or drop in PCV <20% in 12 hours = transfusion

What are the basic principles for IV catheter placement and maintenance?

• jugular most common (lateral thoracic and cephalic veins)

• 14G

• Teflon short term, more pliable long term

• place using aseptic technique and minimal trauma

• flush with heparinized saline every drug dose

What NSAID is used for musculoskeletal pain?

• Phenylbutazone (bute)

What NSAID is used for abdominal pain?

• Flunixin + xylazine, butorphanol

What route should you not give flunixin?

• IM

What route should you not give beta-lactams?

• IV = neuro rxn

What bacteria are beta-lactams good against?

• Gram +, anaerobes

What bacteria are aminoglycosides good against

• Gram negative

What is the spectrum of activity for sulphonamides/

• Gram positive and negative, aerobic, protozoans (when potentiated)

What drug do you use for Equine Protozoal Myelitis (EPM)?

• Sulfadiazine + pyrimethamine

What anti-microbials would you use to get a very large spectrum of activity?

• Penicillin (beta lactams)

• gentamicin (aminoglycosides)

• metronidazole

What is the spectrum of activity for tetracyclines?

• gram positive and negative, aerobic, some anaerobes

• Ehrlichia, Rickettsia, Mycoplasma

What drug would you use to treat Potamac horse fever (Neorickettsia risticii)?

• Tetracyclines

What drug would you use to treat equine granulocytic Ehrlichiosis?

• Tetracyclines

What route should you not give tetracyclines

• IM = tissue damage

• IV use caution = collapse and death

What is the spectrum of activity for fluroquinolones?

• Gram negative, primarily Enterobacteriaceae

what age of horses should you not give enrofloxacin?

• <18 months will harm developing cartilage

What is the spectrum of activity for metronidazole?

• obligate anaerobic bacteria (gram -), protozoans

What is the spectrum of activity for macrolides?

• Gram positive

How do you treat Rhodococcal infections in foals?

• Erythromycin (Macrolides) + rimfampin

Why should you not give macrolides to adult horses?

• will kill them

Why is chloramphenicol not used commonly anymore?

• fatal aplastic anemia in humans

What do both EHV1 and EHV4 generally cause in young horses?

• respiratory signs

What does EHV eventually lead to outbreaks?

• Ubiquitous in horse population > viral latency leads to shedding

At what point in gestation will you see abortion in EHV1 ?

• 7-11 months

At what point in gestation will you see abortion in EVA? (Equine viral arteritis)

• 3-10 months

What are the three forms of EHV1?

1. Rhinopneumonitis

2. Abortion

3. Myeloencephalitis (EHM)

How can you differentiate EHV from influenza?

• Influenza affects all ages and classes of animals

• EHV1+4 show respiratory signs in young horses

• EHV1 shows abortion adn neuro signs as well

What horse diseases are reportable in this section?

• EHV1

• EVA

• EIA

• Piroplasmosis

Would you recommend using the EHV immunization for prevention?

• not for prevention but will reduce severity of dz and viral shedding

what is Streptococcus equi zooepidemicus commonly involved in ?

• pneumonia and pulmonary abscesses

• common opportunistic respiratory pathogen

What age group is commonly affected by strangles?

• Young most susceptible, all ages are affected H

How to you treat strangles?

• generally, allow disease to take its course

• complicated/severe cases: beta-lactams DOC, NSAIDs for comfort

Is vaccination routine for strangles?

• No, can cause purpura hemorrhagica

What is the best way prevent/control strangles?

• control movement and contact (30d quarantine, culture newcomers)

What are the differentials for fever in this section?

• EHV1,4

• Strangles (all, most young)

• pleuropneumonia

• Rhodococcus (young)

• ARDs (young)

• GP empyema

• infectious myocarditis

• vegative endocarditis

• bacterial pericarditis

• jugular thrombophlebitis

• vasculitis

What are the differentials for murmur in this section?

• VSD ± vegetative endocarditis

What are the differentials for anemia in this section?

• neonatal isoerythrolysis

• acute blood loss

• maple leaf toxicosis

• vasculitis

What are the differentials for abortion in this section?

• EHV1

• EVA

What are the differentials for cough in this section?

• EHV1, EHV4 (young)

• influenza (all ages) ± pleuropneumonia

• RAO

• ± IAD

• ± DDSP

What are the differentials for no fever but associated with respiratory disease

• RAO

• IAD

What are the differentials for nasal discharge in this section

• Strangles

• ± pleuropneumonia

• RAO

• ± IAD

• sinusitis

• EVA

What are the differentials for epistaxis in this section

• ± EIPH

• ethmoidal hematoma

• GP empyema

What are the differentials for facial swelling in this section?

• sinusitis

  • purpura hemorrhagica

what are the differentials for exercise intolerance in this section?

• RAO

• A fib

• ± IAD

• DDSP

• left laryngeal hemiplegia

• VSD

• pericarditis

What are the differentials for abscesses in this section?

• strep equi zooepidemicus

• strangles

• pleuropneumonia

• rhodococcus

• ± aspiration pneumonia

• corynebacterium

what disease is specifically characterized by abdominal lift?

• RAO

What disease is specifically characterized by “choking down”)

• DDSP

What disease is specifically characterized by roaring?

• Left laryngeal hemiplegia

What disease is specifically characterized by morulae of neutrophiles?

• Equine Granulocytic Ehrlichiosis

How do you differentiate the different types of vasculitis?

• coggins = EIA

• blood smear = prioplasmosis or ehrlichiosis

• PCR = EVA

what does a stress leukogram look like in horses?

• no left

• normal fibrinogen

• increased neutrophils

• decreased lymphocytes

• decreased eosinophils

what does an infection or inflammatory leukogram look like in horses?

• left shift

• increase fibrinogen

• increased neutrophils

• decreased lymphocytes

• decreased eosinophils

what does an endotoxemia leukogram look like in horses?

• left shift, ‘toxic changes” normal or decreased fibrinogen

• decreased WBCs: decreased neutrophils, decreased lymphocytes, decreased eosinophils

what is the most common cause of pleuropneumonia?

• Strep

What are the risk factors of pleuropneumonia?

• race high performance

• viral (co-mingling)

• travel/shipping

• EIPH

• general anesthesia

What is a common signalment for pleuropneumonia?

• Performance horse, <5yo, recent ravel history

What is the best way to diagnose pleuropneumonia?

• US = see edema

• endoscopy = suppurative tracheal exudate ± blood

How do you treat pleuropneumonia?

• IV beta lactams + aminoglycosides

• ± pleural drainage (pleuritis)

• ± metronidazole

what age group is not affected by rhodococcal infections?

• immunocompetent adults

How can you diagnose rhodococcal pneumonia?

• tracheal wash + culture

what is acute bronchointerstitial pneumonia also called?

• acute respiratory distress syndrome (ARDs)

What age group is affected by ARDs? (Acute respiratory distress syndrome)

• foals up to 1 year of age

What are some characteristic features of ARDs?

• high mortality

• fever

• cyanosis

How do you treat ARDs? (Acute respiratory distress syndrome)

• support, corticosteroids, broad spectrum abx

• medical emergency

what are the two fundamental components of small airway obstruction?

• exudate in airways

• bronchoconstriction

What is the major clinical distinction between infectious and non-infectious disease of the lungs?

• lack of fever and systemic inflammatory response = non-infectious

what is another name for RAO? (Recurrent Airway Obstruction)

• Heaves

What age group is commonly affected by RAO? (Recurrent Airway Obstruction)

• middle aged and older, all sexes and breeds

what are some major clinical features of RAO?

• cough

• mucopurulent discharge

• abdominal lift

• exercise intolerance

• heaves line when chronic

• normal temp and blood work

How do you diagnose RAO?

• Tracheal wash = Curschmann’s spirals

What are Curschmann’s spirals associated with?

• RAO

What is RAO most likely caused by?

• hypersensitivity to airborne allergens (straw, hay, mold)

How do you treat RAO and IAD?

• environmental control

What age group is commonly affected by IAD?

• all ages, typically in young - middle-age performance horses

what are the clinical differences between RAO and IAD?

• IAD

  • no or very little subtle abdominal respiratory at rest

  • exercise intolerance not severe

• note IAD and RAO have normal vitals and blood work

how common is epistaxis with EIPH? (Exercise-Induced Pulmonary Hemorrhage)

• in minority of cases but confirmed diagnosis if presented after racing/intense exertion (within 45 minutes)

How do you diagnose EIPH?

• endoscopy if epistaxis not present (40-70%)

• tracheal wash will show hemosiderin macrophages

How do you manage EIPH?

• Furosemide prior to racing, nose bands to reduce RBC numbers

• Tx of IAD (environmental) may help

when performing a tracheostomy what should you NOT do?

• do NOT exceed 50% of circumference

• do NOT cut tracheal rings

where do you perform a tracheostomy?

• junction of upper 1/3 and lower 2/3 of neck above slit between paired sternomandibularis mm

How do you treat progressive ethmoidal hematomas?

• 5-10% formalin via endoscope

• maxillary bone flap approach

what are some major clinical features of sinusitis?

• Mucopurulent nasal discharge

• ± facial swelling / periocular tissue

• ± distortion of facial bones

How do you diagnose sinusitis?

• endoscopy