Lecture 8 10/16/24 Flashcards
What are enzootic nasal tumors?
tumors in sheep that expand from the turbinates and occlude the nasal passages
What are the clinical signs of enzootic nasal tumors?
-copious serosangeunous nasal discharge
-facial deformity
-stertor/abnormal breath sounds
What are the characteristics of enzootic nasal tumor transmission?
-associated with type D retroviruses
-retroviral genome inserts itself into host cell genome to alter the cell’s growth cycle
How are enzootic nasal tumors diagnosed?
-imaging
-biopsy
How are enzootic nasal tumors treated?
surgical debulking/resection
How does Oestrus ovis cause damage?
larvae migrate through nasal passages and sinuses, inducing inflammation (rhinitis/sinusitis)
How is Oestrus ovis diagnosed?
-sheep acting weird
-visualization of nasal bots
What are the clinical signs of Oestrus ovis?
-mucopurulent nasal discharge
-abnormal breath sounds
-head shaking
-altered grazing behavior
What are the characteristics of Oestrus ovis treatment?
-ivermectin twice a year
-treat once frost kills adults
-summer treatment prevents build up of excessive infestation
-treatment in winter prevents overwintering of larvae
What is the most common type of retropharyngeal abscess?
caseous lymphadenitis
Which bacteria causes caseous lymphadenitis?
Corynebacterium pseudotuberculosis
What are the clinical signs of caseous lymphadenitis?
-inspiratory dyspnea
-dysphagia
-coughing
-ptyalism
How is caseous lymphadenitis diagnosed?
-fine needle aspirate
-culture
Why is it important to NOT drain caseous lymphadenitis abscesses?
increases risk of new infections
What are the characteristics of caseous lymphadenitis treatment?
-no real treatment
-injection of formalin into abscess comes with a lifetime withdrawal
-euthanasia is common outcome
Which viruses are associated with bacterial pneumonia in small ruminants?
-caprine/ovine herpesvirus
-caprine/ovine respiratory syncytial virus
-para-influenza 3 virus
-adenovirus
What are the upper respiratory signs caused by viruses in small ruminants?
-nasal discharge
-cough
-pyrexia
-inspiratory dyspnea
What is important to note regarding the diagnosis of resp. viruses in small ruminants?
there are very few specific diagnostic tests
Which bacteria species cause bacterial bronchopneumonia in small ruminants?
-M. haemolytica
-P. multocida
-Bibersteinia trehelosi
-Mycoplasma spp.
What are the clinical signs associated with bacterial resp. infections in small ruminants?
-fever
-depression
-dyspnea
-inc. lung sounds
-failure to thrive (chronic)
What are the characteristics of Bibersteinia trehelosi?
-severe morbidity and mortality in big horn sheep
-typical bronchopneumonia in domestic livestock
-devastating, population limiting disease
-introduced to wild pop. through contact with domestic sheep and goats
-possible viral pathogen involvement
What are the characteristics of Mycoplasma ovipneumoniae?
-only causes pneumonia, no systemic disease
-commensal organism of the nasal passages
-invasion of lower lungs causes consolidation and pinpoint abscesses
-high case attack rate, low case fatality rate
What are the clinical signs of M. ovipneumoniae?
-mild disease
-mild chronic cough
How is M. ovipneumoniae treated?
many of the antibiotics approved for M. bovis also work against M. ovipneumoniae
Which Mycoplasma species are of importance in goats?
-M. mycoides ssp. mycoides
-M. capricolum ssp. capricolum
What are the manifestations associated with Mycoplasma in goats?
-bronchopneumonia
-otitis media/interna
-septic arthritis
-mastitis
-septicemia
-pleuritis
-meningitis
What are the characteristics of ovine progressive pneumonia and caprine arthritis encephalitis?
-retroviral, life long infections
-infect the macrophages/monocytes
-lentiviruses
How are OPP and CAE transmitted?
-transfer of infected cells:
–colostrum/milk
–biting flies
–iatrogenic needles/shearing equipment
-respiratory secretions (OPP only)
How do the clinical signs of OPP/CAE vary based on infected tissue?
lung: progressive loss of gas exchange
joints: synovial inflammation/loss of synovial fluid; arthritis
mammary gland: indurative mastitis
meninges: inflammation/damage to BBB leading to meningitis/encephalitis
How does OPP manifest in adult sheep?
-2-5 years old
-chronic progressive weight loss
-interstitial pneumonia
-encephalitis
-mastitis
-arthritis
How does CAE manifest in adult goats?
-2-5 years old
-progressive weight loss
-arthritis
-mastitis
-interstitial pneumonia
How does CAE manifest in young goats?
-2-6 months old
-encephalitis
How do the lungs appear on necropsy in OPP/CAE cases?
firm and unable to collapse
What is important to note regarding OPP/CAE serology?
constantly changing virus induces a constant antibody response; infected animals are always positive on serology
How often should antibody titers be tested for OPP/CAE?
twice a year
What are the characteristics of test and cull for OPP/CAE?
-any positive animal is culled to prevent further transmission
-can be a large financial loss in herds with high prevalence
What are the characteristics of test and segregate for OPP/CAE?
-positive animals are moved into a “dirty” herd
-infected and non-infected herds are maintained
-method breaks down easily due to difficulties in keeping herds separate
What is the pathophysiology of ovine pulmonary adenocarcinoma?
infected cells have altered growth cycles due to retrovirus infection, resulting in transformation into neoplastic cells
What are the clinical signs of ovine pulmonary adenocarcinoma in adult sheep?
-weight loss
-dyspnea
-cough
-copious nasal discharge when elevated by back feet
