Mycobacterium, Actinomycosis, and Nocardiosis Flashcards
What’s the causative agent of mycobacteriosis?
mycobacterium spp.
Cats: M. bovis and M. microti
Dogs: M. tuberculosis
What are the clinical signs?
Cats: cutaneous nodules/ draining tracts; other non-specific signs – lethargy, anorexia, decreased body weight, respiratory distress
Dogs: mostly non-specific signs – lethargy anorexia, decreased body weight, coughing, dyspnea, vomiting, diarrhea
Cats or dogs are are more commonly infected with mycobacterium?
Rare in dogs
How is lesion morphology determined?
mostly due to host immune response rather than the strain
- tuberculoid lesion = macrophages at site of infections
How is mycobacterium diagnosed?
- clinical suspicion
- geographical location
- identification of acid-fast bacilli
- intradermal tuberculin and M. bovis antibody testing = not helpful in cats,
- ID testing is also not helpful in dogs
What’s the prognosis of mycobacterium in cats and dogs?
Cats: guarded, prolonged antibiotic therapy required
Dogs: grave, mostly euthanized due to disease progression
What’s the health concern for myucobacterium?
zoonotic! reportable
What’s feline/ canine leprosy?
The causative agent is Mycoplasma, but difficult to culture.
Cats:
- young cats: single or multiple SQ nodules, more likely to be ulcerated, more likely on the limbs
- old cats: slowly progressive, diffuse, non-ulcerated lesion more likely
Dogs: firm, non-painful well circumscribed dermal-SQ nodules, haired skin
How is leprosy diagnosed?
- history, clinical suspicion, PCR
How is leprosy treated?
Dogs: may spontaneously go into remission
Cats: need antibiotics
What’s the prognosis of leprosy?
dogs: excellent, but persistent lesions could be disfiguring
cats: recurrence possible
Not a public health concern
What’s the most common route of infection for actinomycosis?
Actinomyces = commensal bacteria, esp in GI tract (gum, mucus membranes)
- mostly associated with periodontal disease
- foreign body migrations
- bite wounds
What are some clinical signs of actinomycosis?
pyogranulomatous lesions
- can be malodorous
- “sulfur granules” on exudates/ effusions
How is actinomycosis treated?
Surgical debridement and antibiotics.
Dogs: thoracotomy + antibiotics
Cats: thoracic drainage + antibiotics
What’s the prognosis of actinomycosis?
SQ or soft tissue infection, or cats with pyothorax - the prognosis is good
- dogs with thoracic disease = variable
- all reported CNS cases = fatal
What’s the causative agent of actinomycosis?
Actinomyces spp
- facultatively anaerobic
- gram (+), non acid-fast, non-sporing
- branching filamentous bacteria
How is actinomycosis diagnosed?
cytology - non-acid fast filamentous bacteria
What’s the causative agent for Nocardiosis?
Nocardia spp
- gram (+)
- variably acid fast
- non-motile aerobic bacterium
What are the clinical signs of Nocariosis?
Cutaneous/ SQ abscess (mycetomas)
- T cells needed to help halt systemic infection, but also leads to formation of granuloma
- can form draining tracts
- thoracic disease = pneumonia, pyothorax – signs of dyspnea, tachypnea, lethargy, weight loss, and fever
How is nocardiosis diagnosed?
macroscopic and microscopic examination
How is nocardiosis treated?
Similar to actinomycoses – debride, drainage, and antibiotics (prolonged therapy, 6-12m)
- if disseminated disease = grave prognosis, esp with CNS involvement
no infected pet to human transmission reported
