Infectious Equine Resp 2 Flashcards
Strep equi equi characteristics and pathogenesis
Strep equi equi is a gram positive, chain forming, beta hemolytic streptococcus that is facultatively anaerobic. The bacteria adhere to the URT epithelium, Lamina proprietary and then enter the lymph. The bacteria evade neutrophils and may spread through lymphatics (bastard strangles) or elicit and immune response (purpura rxn)
Clinical disease of Strep equi equi is called __ and __ horses are at risk but immunocompromised are at the highest risk. Morbidity is up to __ while mortality is __. Horses may be carriers of the bacteria in the __.
Clinical disease of Strep equi equi is called strangles and all horses are at risk but immunocompromised are at the highest risk. Morbidity is up to 100% while mortality is 2-3%. Horses may be carriers of the bacteria in the gutteral pouch.
Describe the clinical signs of classic strangles
The bacteria will incubate for 1 to 14 days post exposure and then the horse will have fever and nasal discharge for 2-4 weeks. The lymph nodes will swell and be palpable 2-3 days after exposure and then be a mature abscess at 2-3 weeks.
Describe the clinical signs of Strep equi equi immune mediated disease
- Circulating antigens form immune complexes
- Leukocytosis vasculitis: purpura hemorrhagica
- Autoimmune thrombocytopenia, anemia
- Immune mediated myositis
- Agalactia
Describe Bastard strangles clinical disease
- dissemination and abscess formation in other viscera
- general signs of weight loss, low grade fever elevated WBC count and fibrinogen
Describe atypical strangles clinical disease
- subclinical disease or very self limiting disease that may be due to bacterial load and pathogenesis, prior exposure, hose specific characteristics
How do you diagnose strangles?
You want to perform a bacterial culture or PCR with wash samples being superior. Alternatively, you can use serum to detect antibodies to SeM protein with a high titer indicating acute disease.
An outbreak of strangles occurs on a horse farm near Blacksburg, how should you separate out the horses and treat them?
Separate them into groups based on clinical signs and treat in those groups:
1. Horses with obvious disease: hotpack their abscesses, bring to head and drain, only really need antibiotics of NSAIDs if they’re uncomfortable or if the abscess ruptures
2. Horses at risk but not apparent disease: take temp daily and start antibiotics if febrile
3. Unaffected horses: keep separate and use separate people and clothing if possible
Horses recovering from strangles should have their __ cultured until the __ and __ are negative. Up to __ of horses may become carriers of the strep equi equi bacteria
Horses recovering from strangles should have their guttural pouches cultured until the PCR and culture are negative. Up to 50% of horses may become carriers of the strep equi equi bacteria
T/F: The vaccines for strangles are very effective
F!
Lower airway fungal pneumonia is typically caused by __ or __ in __ animals. Treatments include __, __ and __.
Lower airway fungal pneumonia is typically caused by aspergillus or fusarium in immunocompromised animals. Treatments include amphotericin , fluconazole and miconazole.
Lung worm is typically in ___. You will see __ in a TTW and it typically responds to __.
Lung worm is typically in young horses housed with donkeys. You will see eosinophilia in a TTW and it typically responds to ivermectin.
Parascarid infestation are typically __ by horses but can be treated with __ , moxidectin, fenbendazole.
Parascarid infestation are typically outgrown by horses but can be treated with ivermectin , moxidectin, fenbendazole.
careful with ivermectin in young horses bc they don’t have a mature BBB yet
Parascarid infestation are typically __ by horses but can be treated with __ , moxidectin, fenbendazole.
Parascarid infestation are typically outgrown by horses but can be treated with ivermectin , moxidectin, fenbendazole.
careful with ivermectin in young horses bc they don’t have a mature BBB yet
Infectious Pleuritis is common in __ horses due to stress, transport, recent viral infection, strenuous exercise, general anesthesia
Infectious Pleuritis is common in traveling horses due to stress, transport, recent viral infection, strenuous exercise, general anesthesia
Clinical signs of pleuropneumonia
Depression, inappetence, acute weight loss, reluctance to move, base wide stance with abduction of forelimbs
What might you hear on thoracic examination of a horse with pleuropneumonia?
Auscultation: Lung sounds may be absent or amplified
Percussion: air filled lung has a tympanic sound and pleuritis may cause a dull sound starting at the fluid line and continuing ventrally
Describe the different CBC clin path abnormalities you might observe of a horse with pleuropneuomia
- Acute hemoconcentration: leukopenia with a left shift, azotemia
- Chronic (4-7 days): anemia of chronic disease, leukocytosis with neutrophilia, hyperfibrinogenemia
- Chemistry of a chronic case may show azotemia, hypoalbuminemia, hypergammaglobulinemia
What is the method of choice for imaging pleuropneumia? What should you do along with the imaging?
ULTRASOUND, you should see comet tails and possibly fibrin in the cranioventral portion of the thorax. Then drain the chest by a thoracocentesis:
- drain both sides if there’s fluid present, IC 7 or 8 on the Left and IC 6 or 7 on the Right
- a small amount may just use a teat cannula while a large amount will beed a blunt tipped chest tube with a one way valve
What factor should you evaluate on a sample from thoracocentesis for pleuropneumonia?
Cytology with c/s, glucose and pH
Ask for anaerobic if it smells really bad
A horse is diagnosed with pleuropneumonia, how do we want to treat it?
- Broad spectrum antibiotics (penicillin - gram + and anaerobes , aminoglycosides gram - or metronidazole anaerobes)
- NSAIDs, pentoxyfilline, 10% solution of DMSO in 5% dextrose given IV, recombinant tissue plasminogen activator
- laminitis prophylaxis
- fluids and nutritional support
Severe pleuropneumonia may be treated by __ which will evaluate necrotic tissue and abscess capsules. To do this insert a scope at rib __ . This may also be done with __ resection to remove the __ and establish __.
Severe pleuropneumonia may be treated by thoracotomy which will evaluate necrotic tissue and abscess capsules. To do this insert a scope at rib 8-12 . This may also be done with rib resection to remove the necrotic lung and establish drainage.
The prognosis of pleuropneumonia is __ for acute cases with minimal effusion and fibrin but __ for those with chronic disease with a consolidated lung, effusion or fibrin. __ is an indicator of a poor prognosis (malodorous breath or effusion)
The prognosis of pleuropneumonia is good for acute cases with minimal effusion and fibrin but poor for those with chronic disease with a consolidated lung, effusion or fibrin. Anaerobic bacteria is an indicator of a poor prognosis (malodorous breath or effusion)
Generally __ of treated horses return to work and __ return to racing for pleuropneumonia
Generally 61% of treated horses return to work and 89% return to racing for pleuropneumonia
