Exam 2 Flashcards
How long does Caprine Arthritis Encephalitis virus (CAEv) persist in the host?
For life - results in chronic disease course
How is Caprine Arthritis Encephalitis virus (CAEv) transmitted?
*Ingestion of colostrum/milk
Doe to kids (licking, breathing)
Close contact between goats
Contaminated fomites
What is the economic significance of Caprine Arthritis Encephalitis virus (CAEv)?
Increased culling rates Decreased milk production Increased dx/tx costs Increased replacement rates Higher value of CAEv-free breeding stock
How is Caprine Arthritis Encephalitis virus (CAEv) diagnosed?
Elitest (cELISA for OPPv/CAEv)
*positive test ONLY indicates infection, not diagnostic for cause of clinical problem
How is Caprine Arthritis Encephalitis virus (CAEv) treated?
Only palliative tx
How is Caprine Arthritis Encephalitis virus (CAEv) controlled?
Pasteurized rearing program Avoid iatrogenic transmission Serologic testing 6-12 months Breed seronegative animals together Milk CAEv(-) first
What is involved in a “pasteurized rearing program”?
- Induce parturition with 2-3mL Lutalyse/Prostamate IM
- Attend kidding 30-32 hours post-injection, remove kids from dam immediately
- Rear kids in isolation on safe colostrum/milk
- Heat-treated colostrum (131ºF 1 hour)
- Pasteurized milk (165ºF 15 seconds) - House CAEv-free animals separately from infected animals
What are the four disease presentations of Caprine Arthritis Encephalitis virus (CAEv)?
Kid neurologic form
Arthritis
Mastitis
Pneumonia
Which animals get the neurologic form of CAEv?
2-6 month-old kids
How does the neurologic form of CAEv present clinically?
Progressive paresis > irreversible paralysis (over weeks) > often die of 2º disease
How can the neurologic form of CAEv be diagnosed?
CSF - mild to mod increase in cell counts and protein
Histo - multifocal mononuclear inflammatory leukoencephalomyelitis with extensive demyelination
DDx for the neurologic form of CAEv?
Copper deficiency Vertebral body/spinal cord abscess Congenital abnormalities of cord/column Cerebrospinal nematodiasis (P. tenuous) Listeriosis Polioencephalomalacia
How is the neurologic form of CAEv treated?
No treatment. Humane euthanasia
How does the arthritic form of CAEv present clinically?
Initial swelling of anterior aspect of carpus with fluid accumulation in carpal bursa
Progressive arthritis of one or more joints (knees and hocks most common)
How is the arthritic form of CAEv diagnosed?
Arthrocentesis - elevated mononuclear cells
Rads - calcification of joint capsule, tendon/sheaths, osteophyte formation
How is the arthritic form of CAEv treated?
Palliative options:
- adequan injections (weekly-monthly)
- cosequin (PO daily)
- flunixin meglumine (PRN)
- meloxicam (PO daily)
How does the mastitic form of CAEv present clinically?
Bilaterally hard udder at kidding
Scant milk, but appears normal
How is the mastitic form of CAEv diagnosed?
Herd history
Biopsy and histo - lymphoid follicle formation especially around ducts, lobular atrophy, increased fibrous CT
How is the mastitic form of CAEv treated?
Steroids may help
Some goats spontaneously increase milk production in 2-3 weeks
How does the pneumonia form of CAEv present clinically?
Exercise intolerance, dyspnea, wasting, coughing
Onset following stress
How is the pneumonia form of CAEv diagnosed?
Rebreathing bag - squeaking sound
Rads - interstitial pneumonia
Lung biopsy/histo - peribronchiolar accumulation of monos, proliferation of type II pneumocytes, alveoli filled with eosin material
How is the pneumonia form of CAEv treated?
Abx therapy may help if secondary bacterial pneumonia
What is the etiologic agent of caseous lymphadenitis?
Corynebacterium pseudotuberculosis
Where is C. pseudotuberculosis found? Is it persistent in the environment? For how long does it infect animals?
Ubiquitous worldwide
Months in environment, but killed by regular disinfection
Lifelong infection
How is caseous lymphadenitis transmitted?
Draining external abscesses
Aerosolization of lung abscesses
Skin via microtrauma
What is the pathogenesis of caseous lymphadenitis?
Localizes in regional LN > extension along LN chain / systemic travel > hair/wool loss as abscess matures > spontaneous rupture
How does external caseous lymphadenitis present?
Abscess formation in LN (parotid common) or SQ - non-painful with gradual hair loss
Pus is odorless, creamy white/yellowish/greenish
How does visceral caseous lymphadenitis present?
“thin ewe syndrome”
Weight loss, neurologic signs, pneumonia-like symptoms
How is caseous lymphadenitis diagnosed?
Culture of abscess
Synergistic Hemolysis Inhibition test (SHIT)
-High titers = internal abscessation
-CANNOT distinguish vax from dz
How is caseous lymphadenitis controlled?
ID infected animals
Depopulate / separate herd
Vaccinate (sheep 1 year booster, goats 6 month booster)
How is caseous lymphadenitis treated in individual animals?
Option to cull or isolate
Surgical removal (expensive, facial paralysis possible)
Lance and flush abscesses (dilute iodine/chlorhex)
*Refractory to parenteral abx
*Do not use formalin - meat residues
What classifies “safe use” of a drug?
Includes safety to animal, to persons associated with the animal, and environmental impact
What classifies “effective use” of a drug?
Assumes accurate dx can be made
drug properly administered
and course of dz can be followed to assess success of drug
What labelling must be on rx products?
Caution: Federal law restricts this drug to use by or on the order of a licensed veterinarian
What labelling must be on VFD drugs?
Caution: Federal law restricts medicated feed containing this VFD drug to use by or on the order of a licensed veterinarian
What is AMDUCA?
The Animal Medicinal Drug Use Clarification Act of 1994
Established conditions for legal extra-label use of drugs in animals
What are the requirements for extra-label drug use under AMDUCA?
- On the order of a licensed vet
2. Within the context of a vet-client-patient relationship
What are the exceptions to extra-label drug use under AMDUCA?
Does not apply to:
- Drugs in feed
- Drugs that result in a violative food residue
Which antibiotics are prohibited from ALL food animals?
Chloramphenicol Clenbuterol DES Dipyrone Gentian violet Glycopeptides (eg. vancomycin) Nitrofurans (including topicals) Nitroimidazoles (including metronidazole) Phenylbutazone (in adult dairy cattle)
How do the FDA define lactating (adult) dairy cattle?
Any dairy breed female >20 months regardless of milking
Which drugs are prohibited from extra-label use?
Sulfonamides (adult dairy cattle) Fluoroquinolones Medicated feeds Ceftiofur (modified prohibition) -can be used for specific dz tx if dose regimen is followed for labelled species (even if dz is extra-label)
Which antibiotic class is strongly discouraged in cattle? Why?
Aminoglycosides
-insufficient data for withdrawal
What is the MUMS Animal Health Act?
Minor Use Minor Species
Provides ways to use FDA authorized drugs for:
1. Conditions in minor species where tx are unavailable
2. Uncommon animal disease conditions in major species
How is ovine progressive pneumonia virus (OPPv) transmitted?
Aerosols/saliva
Common needles
Which cell type does ovine progressive pneumonia virus (OPPv) infect?
Lymphocytes
How does ovine progressive pneumonia virus (OPPv) present clinically?
Poor milk production
-udders are firm, indentable, bilaterally symmetric
Emaciation
Secondary pneumonia
How is ovine progressive pneumonia virus (OPPv) diagnosed?
Serology (AGID / cELISA)
-*indicates lifelong infection only
Udder biopsy - chronic lymphocytic indurative mastitis
Necropsy:
Lungs are grossly enlarged/discolored (orange to grey/blue), rib impressions may be seen
What are some differentials for emaciation in sheep?
- Ovine progressive pneumonia virus (OPPv)
- Parasitism (Haemonchus, Teladorsagia, Trichostrongylus, Fascioloides magna)
- CLA (internal form)
- Johne’s dz
- Chronic bacterial pneumonia
Others: malnutrition, teeth problems, scrapie, neoplasia
What is the control strategy for ovine progressive pneumonia virus (OPPv)?
Elitest ELISA for testing
Avoid housing young lambs with older OPPv+ sheep
TMEM154 testing available in Lincoln, NE
Are sheep or goats more susceptible to foot rot/scald?
Sheep
What infectious agents cause footrot/scald?
Dichelobacter nodosus
Synergistic effect of Fusobacterium necrophorum
T/F: Health certificates can be signed if footrot/scald is present as long as it’s being treated?
FALSE, it’s still an infectious disease
How is footrot treated?
- Isolate lame sheep
- Minimal or no foot trim
- 1 long-acting injection of tetracycline / gamitromycin
- Spray lesion with tetracycline spray
(FARAD meat withdrawal 90 days)
How is foot scald treated?
Individual ewes: treat as for footrot
Individual lambs: spray with oxytetracycline, re-treat if still lame after 5 days
Flock outbreaks: footbath, 10% zinc sulfate
When should sheep be culled for footrot/scald?
If lame more than twice a year or not responding to treatment
How can footrot/scald be controlled?
Regular footbaths (10% zinc sulfate) *No vaccination available in US
What generalities are true for all clostridial diseases?
Highly fatal, sudden onset
Often affect thriftiest animals
Therapy ineffective once ill
Vaccination is cost-effective and works well
How is C. tetani treated and prevented?
Dark, quiet location Tube feed Acepromazine to sedate and minimize seizures Debride wound and give penicillin Give antitoxin if early in dz course
Long-acting penicillin at tail docking
Remove tail/testicles in 3-5 days post-banding
Vaccinate ewes prior to lambing
What clinical signs are associated with botulism?
Lack of muscle tone, progressive weakness > recumbence
What is the main risk factor for botulism?
Spreading poultry litter on land that produces pasture, hay, baleage, or silage in same year
Is botulism zoonotic?
No
What is the causative agent of braxy? What does it look like clinically?
C. septicum
Gangrenous abomasitis in young lambs and calves
What are the causative agents of clostridal myonecrosis? What are the various disease names?
C. chauvoei, septicum, sordellii, or mixed infections
Blackleg, Malignant edema, Gas gangrene
What are the clinical signs of clostridial myonecrosis?
Lameness, fever, depression
Crepitus and swelling (bubble wrap muscles)
Rapid deterioration with up to 100% mortality
DDx for sudden death in ruminants?
Clostridium Bloat Lightning strike Grass tetany Atypical interstitial pneumonia
How can clostridial myonecrosis be diagnosed?
PCR sample of affected muscle
How can clostridial myonecrosis be treated? What’s the prognosis?
IV K penicillin
Poor
What is the causative agent of bacillary hemoglobinuria? What is its common name? What species does it infect?
C. haemolyticum / novyi type D
“Red water”
Cattle
What is the pathogenesis of bacillary hemoglobinuria?
Fluke liver infection > liver damage creating anaerobic environment > beta, eta, and theta clostridial toxins > localized hepatic necrosis and IV hemolysis
What clinical signs are associated with bacillary hemoglobinuria?
Red urine, bleeding from other orifices
Sudden death
What necropsy findings are consistent with bacillary hemoglobinuria?
Ischemic hepatic infarct with zone of hyperemia next to viable liver tissue
Widespread serosal and mucosal hemorrhages
Red-tinged fluid in abdomen and thorax
What is the causative agent of black disease? What species does it infect?
C. novyi type B
Sheep
What clinical signs are consistent with black disease? What is a major risk factor?
Infectious necrotic hepatitis
Similar to bacillary hemoglobinuria but NO red urine or bleeding from orifices
Liver fluke (F. magna) major risk factor
What is the causative agent of enterotoxemia?
What are two common names for the dz?
Clostridium perfringes type D
Pulpy kidney dz, overeating dz