Exam 1 Flashcards
Endotoxemia (SIRS); Pathophysiology & Symptoms
Pathophysiology
• LPS from dead bacteria in LI -> LI damaged -> bacteria thru mucosa -> systemic inflammatory response -> systemic vasodilation-> severe hypotension-> organ failure
Presenting Sign
• Ds
Symptoms (2 or > in adult, 3 or > foal)
• Hyper/hypothermic
• Tachycardia (>52)
• Tachypnea (>20)
• Lukocytosis/penia
• Immature neutrophils
Endotoxemia (SIRS); Management
Block LPS Absorption
• Di-tri-octahedral smectite (decrease Ds, binds LPS???)
Bind LPS already in circulation
• Polymyxin B (nephrotoxic & costly)
• Hyperimmune plasma (conflicting data)
NSAIDs
• Flunixin meglumine
Lidocaine CRI
Corticosteroids (low dose)
Soft bedding (laminitis)
Cryotherapy (laminitis)
Hyperdynamic State of Endotoxemia
1st stage
o High HR and RR
o Hyperemia
o Fever
o Anorexia
o Lethargy
o Sweating
o Yawning
o Colic – ileus
o Muscle fasciculations
o Recumbency
Hypodynamic State of Endotoxemia
o Lethargy (worse)
o Anorexia
o Diarrhea
o Poor perfusion
o Thrombosis – increased bleeding
First thing to fail in endotoxemia
o Laminitis
o Kidney (obv can’t see)
Polycythemia; Most common symptom, causes
Symptom
o hyperemic MMs
Relative (common)
o splenic contraction
o dehydration
Absolute (rare)
o hypoxia
o paraneoplastic
o bone marrow over production
Anemia Types & Causes
Regenerative
• Hemorrhage
• hemolysis
Non Regenerative
• Anemia of chronic dz
• Bone marrow
• Iron deficiency
• CKD
Anemia; Symptoms
• Pale MMs
• Exercise intolerance
• Tachypnea
• Tachycardia
• Systolic murmur
• Not visible scleral vessels
Internal Hemorrhage; Diagnosis & Treatment
Diagnosis
• Check PCV
• ultrasound
Treatment
• Stop bleed (difficult in horse)
• Replace volume
• Maintain O2 carrying capacity
What’s different about horse bood?
• Rouleaux
• No reticulocytes
• Unstable PCV (due to stress)
• Yellow plasma due to chlorophyll in food
• Howell-Jolly bodies (nuclear remnants)
Immune Mediated Hemolysis; Causes, Diagnosis
Causes
• Drugs (penicillin)
• Neoplasia
• Bacterial infection
• primary
Diagnosis
• Autoagglutination
• Coombs test
Hemolysis; Intra Vs Extravascular
Intravascular
• Hemoglobinemia
• Hemoglobinuria
• Increased unconjugated billirubin
Extravascular
• Increased unconjugated billirubin
Immune Mediated Hemolysis; Causes, Diagnosis, Treatment
Cause
• Drugs (penicillin)
• Neoplasia
• Bacterial
• autoimmune
Diagnosis
• Autoagglutination
• Coombs test
Treatment
• Discontinue current medications
• Treat underlying problems
• Corticosteroids
• Blood transfusion
• Diurese (intravascular hemolysis)
Oxidative Hemolysis; Causes, Diagnosis, Treatment
Cause
• maple leaf toxicity
• pistacia leaves
Diagnosis
• Presence of Heinz bodies
• Blood methemoglobin levels high
Treatment
• Maintain oxygenation of tissues (monitor resp rate, peripheral perfusion)
• Protect kidneys
• Prevent further toxin absorption
Equine Infectious Anemia; cause, clinical finding, diagnosis, epi
Cause
• Retrovirus in lentivirus family
• Carried by horseflies
Clinical Finding
• Hemolytic anemia
Diagnosis
• Coggins test
• ELISA assays
Epi
• Infected for life
• Inapparent carriers
• No Vx available
• (+) horses can’t move interstate
Equine Piroplasmosis; cause,s clinical finding, diagnosis, treatment
Causes
• Babesia caballi
• Theileria equi
• Carried by Ixodid tick
Clinical Finding
• Hemolytic anemia
• Fever
• icterus
Diagnosis
• organism in RBCs
Treatment
• Imidocarb
Anemia of Chronic Dz; Pathophysiology, Clin Path, Treatment
Pathophysiology
• sequestration of iron by chronic dz
Clin Path
• normocytic normochromic nonregenerative
• PCV usually not below 20%
Treatment
• Treat underlying dz
Clin Path of Chronic Infection
• neutrophilia
• monocytosis
• thrombocytosis
• hyperfibrinogenemia
• hyperglobulinemia
• normocytic normochromic nonregenerative anemia
Immune Mediated Thrombocytopenia; What is it? Types, Diagnosis, Treatment
Increased Platelet Destruction
Types
• Primary (autoimmune)
• Secondary due to infection, drugs, toxins, neoplasia
Diagnosis
• Flow cytometry
Treatment
• Treat underlying cause
Equine Anaplasmosis; What is it? Cause, Carrier, & Symptoms
Increased Platelet Destruction
Cause
• Anaplasma phagocytophilum
Carrier
• Ixodes tick
Symptoms
• Fever, icterus, ataxia, ventral edema, epistaxis
• Thrombocytopenia, anemia, leukopenia
Equine Anaplasmosis; Diagnosis, Treatment
Diagnosis
• Morulae in granulocytes
• PCR (early/late stages)
• Indirect fluorescent Ab test
Treatment
• Oxytetracycline 5-7d
• Self-limiting
• Supportive care
DIC; What is it? Causes, Pathophysiology
Increased Platelet Utilization
Causes
• SIRS/endotoxemia (main)
• Retained placenta or fetus
• basically any sever dz
Pathophysiology
• Activation of coagulative & fibrinolytic systems
DIC; Symptoms, Treatment
Symptoms
• Thrombosis after venipuncture
• Petechial, echymoses, epistaxis
• Organ dysfunction; renal or laminitis
Treatment
• Treat underlying cause
• Supportive care
Where to collect bone marrow sample in horses
• sternum
• tuber coxi
Lymphosarcoma Epi, Clin Path
Epi
• One of the most common internal neoplasms of horses
• Common in YOUNG and middle-aged horses
Clin Path
• Anemia
• Increased fibrinogen
• Immune-mediated anemia /
thrombocytopenia
• Hyperglobulinemia
• Increased liver enzyme
activities
• Hypercalcemia - uncommon
• IgM deficiency - uncommon
• Lymphocytic leukemia – rare
• Serum thymidine kinase (sTK) activity
Lymphosarcoma; Symptoms, Diagnosis, Treatment
Symptoms
• Depression
• Anorexia, weight loss
• Lymphadenopathy (rare)
• Ventral
edema
• Fever
• Respiratory distress
• Colic, diarrhea
• Pallor
• Mass on rectal exam
Diagnosis (difficult)
• Biopsy of affected tissues
• Serum thymidine kinase (sTK) activity?
Treatment
• Usually not economically feasible
• Some chemotherapy regimens
• transiently responsive to steroids
Whats different about cutaneous lymphoma?
• Often slowly progressive, may
wax and wane
• May show improvement when
mares become pregnant
• At least one case resolved after surgical removal of a
granulosa thecal cell tumor
Pigeon Fever; Cause, Types, Transmission
Cause
• Cornybacterium pseudotuberculosis
Types
• Lymphangitis
• Classic (abcess usually on chest/midline)
• Internal Abscessation
Transmission
• Organisms in soil gain entrance through breaks in skin
• Possible insect vectors
• Possible relationship to midline
dermatitis
• Higher incidence in dry areas, late summer
Pigeon Fever; Symptoms, Diagnosis, Treatment
Symptoms
• Edema, abscess (pectoral, inguinal, internal)
• Lameness
• Fever, anorexia, weight
loss
• chronic inflammation blood panel
Diagnosis
• culture of aspirate
• serology
Treatment
• Drain the abscess if possible
• NSAIDs
• Antibiotics for internal
abscesses
3 Phases of Fluid Therapy
Initial
• Resuscitation
• Treats hypovolemia (7-8%)
• 4-6ml/kg Hypertonic saline bolus
• follow w/ crystalloids
Second
• Rehydration
• Treats dehydration
Third
• Ongoing losses
• Maintenance Fluids – crystalloids low Na/Cl & high K/Mg/Ca
Levels of Dehydration & Signs
5%-7%
• tacky MMs
• slightly tachycardic
8-10%
• pronlonged refill time
• etc
> 10%
• prune
• severe
Calculate Fluids Needed
o Deficit = BW (kg) x estimated % dehydrated
o Shock dose = 20ml/kg in 1st hour
o Ongosing losses = total volume of deficit given over 24hr
o Maintenance = 40-60 ml/kg/day (often 25L/day or 1L/hr)
Reasons for Low Ca, symptoms, and how to Supplement in Fluids
Reasons for Low (Ca
• Anorexia, exercise, cantharidin toxicity, etc.
Symptoms
• Ileus, tremors, muscle fasciculations, etc.
Treat
• Ca gluconate in crystalloids
• ionized Ca
Non-Infectious Causes of Ds
NSAIDs
• R dorsal colitis or colitis
• Due to decrease pf prostaglandins
ANY antibiotics
• Especially Clindamycin, macrolides
Sand
Etc, etc, etc
Causes of Infectious Ds
• Salmonella enterica
• Clostridium difficile
• Neorickettsia risticii (Potomic Horse Fever)
• Equine Corona Virus
Salmonella enterica; Bacteria, Epi, Diagnosis, Treatment
gram (-)
Epi
• Fecal-oral
• Zoonotic
• Healthy shedders
Diagnosis
• signs +
• culture x5 OR
• PCR x 3
Treatment
• Supportive care
Clostridium difficile; Bacteria, Epi, Diagnosis
gram (+)
Epi
• caused by Antibiotic use or stress
• Healthy carriers
• Not contagious
Diagnosis
• Evidence of Toxin A & B
Neorickettsia risticii (Potomic horse fever); Bacteria, Epi, Common Symptoms besides Ds, Diagnosis, Treatment
gram (-)
Epi
• Horse eats infected water bug when grazing wet areas
Symptoms
• neutrophilia
• laminitis
Diagnosis
• PCR of feces
• PCR of whole blood
Treatment
• Oxytetracycline IV 3-5d
• Supportive care
Equine Corona Virus; Epi, Common Symptoms besides Ds, Diagnosis, Treatment
Epi
• RNA virus
• Fecal-oral
Symptoms
• fever
• anorexia
• lethargy
Diagnosis
• Fecal PCR
Treatment
• Supportive Care
Colic; Where, What else presents like colic?
o GI
o Liver
o Reproductive tract
Colic like
• Rhabdomyolysis
• Laminitis
• Pleuropneumonia
• Nero dz
How many colics resolve or continue after Tx?
o 85-90% resove
o 10-15% need additional dx or surgery
First things to do when a colic comes in
Transrectal palpation (1st if not painful)
• Use restraint
• Sedate w/ Xylazine & butorphanol IV or Detomidine IV
• Buscopan relaxes rectum
• Should feel cecum on R, and colon on R
• Should not feel SI
Place nasogastric tube (1st if painful or HR > 60bpm)
• Since horses can’t vomit
• Sedate to help swallow
• Check for reflux
• Use fluids
Expected Values for Abdomenocentesis
• Protein <2.5g/dL
• WBC <5000/uL
• Lactate <2mmol/L (shows eschemia if high)
L Dorsal Displacement; basics, treatment
o Often felt on transrectal palpation btwn spleen & kidney
Treatment
• Phenylephrine IV + trotting
• Surgery last resort
R Dorsal Displacement; basics, treatment
o Left colon moves to the R
o Transrectal palpation
Tx
• Give enteral fluids
• Surgery
Enteroliths; reasons for & Treatment
o Horse in CA or SW US
o Eating alfalfa
o Need sx
Sand/gravel colic; symptoms, diagnosis, treatment
o Sounds like ocean waves
o +/- Ds
o SIRS
Diagnosis
• Abdominal rads
Treatment
• Surgery
Prognosis for Surgical Colics
o Large colon displacement or impaction: 95%
o Small colon Good if no mucosa compromise
o Abdominal hernia worse prognosis
o All need 3 mo rest/recovery
Small Colon Impaction; causes, secondary issues, treatment
Causes
o usually fecalith or enterolith
Secondary Issues
o large colon distension
o pressure necrosis
Treatment
o +/- surgery
o Transrectal fluid therapy
Transrectal Fluid Therapy
o Stallion urinary catheter
o Same CRI setting as nasogastric tube
o Hard to keep in place
o Max 2L/h
o Plain water ONLY
Reasons for Distended Small Intestine
West coast
• usually strangulating lesion like lipoma
East coast
• could be strangulating OR
• anterior enteritis (inflammation)
Signs of Anterior Enteritis Vs Strangulating Lesion
Anterior Enteritis
o Large amounts of orange reflux
o Colic improves post reflux
o SIRS
o Febrile
o Dilate +/- thickened small intestine
o Abdomenocentesis w/ Protein >5 and high WBCs
Strangulating
o Small amount black/fetid reflux
o Colic doesn’t resolve post reflux
Treatment for Small Intestine Strangulating Lesion Post Surgery
o Gentamicin – gram (-) aerobic
o Penicillin – gram (+) anaerobic
o Fix hypovolemia
o Feed VERY slowly
o Anti-inflammatory dose of steroids if VERY painful
o 6/10 horses go home
Was Severely painful -> No longer painful but high HR/RR; What is it? Diagnosis
o Abrasions on body and head USUALLY = strangulating lesion
o No more pain due to rupture from strangulating lesion
o Must euthanize
Diagnose rupture
• Abdomenocentesis – will see neutrophils/cells on cytology
• Exploratory laparotomy to take a look
Peritonitis; Diagnosis, Treatment, Secondary Issues
Abdomenocentesis shows
• High protein
• Very high WBCs
• +/- Degenerative neutrophils
Treatment
• Gentamicin – gram (-) aerobic
• Penicillin – gram (+) anaerobic
• Metronidazole – for the anaerobe bacteroides
• NSAIDs
Secondary Issues
• Adhesions
• ileus
Common Causes of Colic
LC
o Impactions
o Displacements
o Sand – enterolith
o volvulus
SC
o Impactions (enteroliths, fecalith)
o strangulation
o anterior enteritis
Squamous Ulcer Symptoms, Pathophysiology, Predisposing Factors
Symptoms
o Often asymptomatic
o Colic quickly post eating
o Poor appetite
o Weightloss
o Common in performance horses
Pathophysiology
o Squamous fundus not protected from acid
Predisposing Factors
o Fasting
o Intermitting feeding
o High grain diet
o Exercise
Glandular Ulcers Predisposing Factors
o Foals > adults
o Decreased blood flow to gut
o Decreased mucus & HCO3
o Use of NSAIDs -> decrease PgE2
o Stress (corticosteroids) -> decrease prostaglandins
Diagnose Gastric Ulcers
o Gastroscopy (expensive)
o Fast ~18hrs
o Withhold water ~4hrs
o Sedate
Treatment of Squamous Ulcers
Omeprazole (Gastrogard ONLY)
• PO 30 min before feed Q24 for 28d
• Takes ~3ds to start working
• Decrease dose gradually
Sucralfate to coat ulcers
• Q 6-8hrs for first few days
Treatment of Glandular Ulcers
Misoprostol (PgE1 analog)
• PO Q8h for 28d
Sucralfate to coat ulcers
• Q 6-8hrs for first few days
Symptoms of Gastric Ulcers in Foals
o Bruxism
o Foaming
o Poor growth
o Dull haircoat
o Colic
3 Potential Phases of Dysphagia
pre-pharyngeal
• show quidding (blobs of chewed food coming out of mouth)
• increased salivation
• problems w/ prehension
pharyngeal or esophageal
• cough
• food/water from nostrils
• gagging
• anxious
• neck extension
• out of the nose
Neurologic Dysphagia
Sensory loss
Forebrain dz (yellow star thistle, viral encephalitis etc)
Peripheral Damage - Cranial nerves
• VII – prehension
• V – mastication
• XII – bring to back of throat
Diagnosis of Pre-pharyngeal Dysphagia
o Oral exam
o Upper airway endoscopy
o Serum selenium (for white muscle dz)
o Equine protozoal myeloencephalitis (EPM) serology
o Radiographs (metallic foreign body)
o Ultrasound (masses & lymph nodes)
Treat Esophageal Dysphagia (choke)
SEDATE 1st
• Detomidine IV
• +/- Butorphanol
• relaxation & analgesia
• head down
oxytocin or Buscopan to relax smooth muscle in lower esophagus
Nasogastric tube
• Assess distance
• Flush carefully to dislodge
Assume they have aspiration pneumonia
No luck Unchoking?
• IV fluids
• Sedate w/ 1ml detomidine IM
• Flunixin meglumine after rehydration
• NPO
• No bedding
Treat Aspiration Pneumonia During Choke
Broad spectrum antibiotics
• Metronidazole per rectum (2x dose) AND
• Ceftiofur IV OR
• K-penicillin + gentamicin IV (nephrotoxic & expensive)
Thoracic ultrasound & bloodwork
Post Choke
o Re-scope to assess mucosa damage
o Don’t feed at first
o Soup -> pellets -> slow feeder
o NSAIDs
o Sucralfate
Reasons for Ptyalism
o Pain
o Foreign body
o Mucosal ulceration
(Vesicular stomatitis, Awns)
o Slaframine
Why do Fresians choke?
look for megaesophagus!
Manage Weightloss
• Feed alone
• Feed in a bowl (so they’re not eating dirt)
• Give pelleted feed (senior feed not carbs)
• supplement fat (oil or calorie powder)
Causes of Weightloss
o Teeth
o Diet
o Parasites (often small stongyles)
Lawsonia intracellularis Basics & Clinical Signs
o Equine proliferative enteropathy
o G- intracellular obligate
o Fall and winter
o Fecal - oral
o Weanlings (< 1y)
o Can be deadly
o Slow to grow
Clinical Signs
• Fever
• Anorexia
• Low albumin (edema)
• +/- Ds
• neutrophilia or penia
• weight loss
Lawsonia intracellularis Diagnosis & Treatment
Diagnosis
• Fecal PCR
Treatment
• Oxytetracycline IV
• Oncotic support (plasma or hetastarch IV)
• Supportive care
Normal TPR Horses
Temp
• 99-101
HR
• 28-44
RR
• 8-20
Symptoms of Liver Dz
o General signs
o weightloss
o Photosensitization
o Hemolysis
o Edema
o PU/PD
o Hepatic encephalopathy
o Icterus
Hepatocyte Enzymes Vs Biliary Enzymes
Hepatocyte Enzymes
o ALT
o AST
o LDH
o SDH (MOST specific in horses for hepatic Dz)
Biliary Enzymes
o ALP (growing horse, GI dz)
o GGT (MOST specific in horses for biliary Dz)
Tests for Hepatic Function
o Increased Bile acids
o Increased Bilirubin conjugated
o BUN (down) / ammonia (up)
o increased PT PTT
o Hyperglobulinemia
Reasons for Elevation of Unconjugated Vs Conjugated Bilirubin
Unconjugated
• Hemolysis
• Anorexia (most common)
• Drugs
• Acute hepatocellular dz
Conjugated
• More reliable indicator of hepatic dz
• Detectable in urine
Balance of BUN & Ammonia
o Ammonia from protein digestion is converted to urea by the liver
o liver dysfunction -> Decreased BUN
+ Increased ammonia
o No correlation between blood ammonia and severity
o Increased ammonia not specific for liver disease
(can increase in colonic dz)
What can be seen on Hepatic Ultrasound
o Tissue homogeneity
o Masses
o Bile duct abnormalities
o L side you can see liver & spleen together
Liver Biopsy
o MOST specific diagnostic for liver dz
o Can be done blind or through US
Poor Prognostic Indicators for Liver Dz
Liver Biopsy
o Sever fibrosis
o Severe biliary hyperplasia
o hepatoencephalopathy
o intravascular hemolysis
o coagulopathy
o marked weight loss
o decreased albumin + increased globulins
Stages of Heptoencephalopathy
o Mild confusion, decreased attention, irritability ->
o Drowsiness, lethargy, disorientation
->
o Somnolent but rousable, occasional aggressive uncontrolled behavior ->
o Coma
Treatment of Hepatoencephalopathy
Decrease absorption of toxic metabolites
• Mineral oil
• Activated charcoal
• Lactulose or neomycin as LAST resort
Low protein/high carb diet
• Best to keep them eating BUT
• BCAAs
• Beet pulp
• Sorghum
• Oat or grass hay
Support
• IV fluids w/ B vits
• Avoid drugs that require hepatic metabolism/excretion
• NSAIDs
• Vit K (coag issues)
• Avoid sunlight
Cholelithiasis Treatment, Prognosis
Treatment
• Long-term antimicrobials (gram -)
• Pain management (NSAIDs)
• DMSO to dissolve Ca bilirubinate stone?
• Surgery if common bile duct is occluded
Prognosis
• Dependent on hepatic fibrosis, clinical signs, number of choleliths
• 77-85% survive w/ treatment
Pyrrolizidine Toxicity Presenting Signs
• Acute hepatic necrosis, signs rapidly progressive
• Liver dz
• Megalocytosis & fibrosis of liver
Theiler’s Dz Presenting Signs, Cause
Presenting Signs
• Acute hepatic necrosis, signs rapidly progressive
• Usually adult horses
• Most affected horses die
Cause
• Equine-origin biological 4-10 weeks prior to
onset
• Usually tetanus anti-toxin
• Associated w/ equine parvovirus hepatitis
Hyperlipemia Basics, Predisposing Factors, Clinical Signs
o Ponies & minis
o Relative insulin insensitivity
o Usually young
Predisposing Factors
• Pregnancy
• Dz
• Parasitism
• Pituitary dz
Clinical Signs
• Icterus
• Anorexia, weakness
• Severe depression
• Ataxia
• Diarrhea, mild colic
• Fever
• Dependent edema
Hyperlipemia Diagnosis, Treatment, Prognosis
Diagnosis
• Stressed pony or Miniature horse
• Hyperlipidemia – TG <500 mg/dl
• Hyperlipemia – TG >500 mg/dl
• Opalescent plasma
• Increased liver enzyme activity
• Check serum creatinine, electrolytes
Treatment
• Treat hepatic disease
• Improve energy intake and balance
• Eliminate stress or concurrent disease
• Inhibit fat mobilization from adipose tissue w/ insulin
• Increase triglyceride uptake by tissues w/ heparin
Prognosis
• Mortality in 60-100%
• Death often results from underlying disease
• Most Minis w/ triglyceride <1200 mg/dl survive
