Bovine Infectious Diseases Flashcards
1
Q
- Growth medium: Hayflick’s agar (microaerophilic environmental)
- Common cause of otitis media-externa (usually caused result of consuming contaminated milk); head tilt, unilateral ear droop, ptosis, apiphora.
- Lameness, fever, respiratory signs (cough, tachypnea, and nasal discharge), death, swollen joints, and tenosynovitis.
- Post mortem: lungs with multiple abscesses full of pus and caseated material
- Treatment: Tulathromycin. ________ lack a cell wall drugs that act on cell wall (penicillin, cephalosporins) never good choice. Other good choices are tetracyclines or tilmicosin(resistance)
A
Mycoplasma bovis
2
Q
- Rickettsial organism transmitted by ticks.
- Obligate intracellular bacterium
- Decreased milk production
- Fever
- Blood smear: organism at the margin of the red blood cells
- Low mortality rate in calves; adult cattle 20-50% mortality.
- Treatment: Oxytetracycline. Single injection of long acting tetracycline (20mg/kg)
- PCV below 12% blood transfusion needed.
- Cattle weak, depressed, staring into space. Pale, icteric, and febrile, no hemoglobinuria.
- No hemoglobinuria due to extravascular hemolysis
- Large destruction of red blood cells, fever, weight loss, respiratory distress, abortion and death
- Sometimes lifetime carriers.
A
Anaplasmosis
Anaplasma marginale
3
Q
- G (-) obligate anaerobe, normal rumen micrflora.
- Hepatic abscesses, gastroenteritis in ruminants
- Foot rot
- Metritis
- Bacteremic spread -> liver -> release of toxins leading to damage and potential abscess formation
- Lesions: yellow and spherical with irregular outlines
- Calf diphtheria (necrotic laryngitis / laryngeal necrobacillosis): caused by Histphilus somni and _____
- Can result in death or a premanently misshapen larynx
- Inspiratory dyspnea, loud respiratory noises, open mouth breathing, extended head and neck, moist painful cough, febrile, anorectic and depressed
- 3-18 months of age. Acute signs. Die within the week if no treated. Respiratory distress 1 day duration.
- Moist painful cough and loud inspiratory stridor
- Head nd neck extended.
- Swelling around larynx.
- Episcleral injection.
A
Fusobacterium necrophorum
4
Q
- Blackleg (Clostridium sordelli (called malignant edema) can also be a cause)
- Vaccines containing up to 8 different Clostridia are often used.
- Start vaccination at younger age in high risk farms to maintain high colostral levels of antibody, give booster 4-8 weeks. Annual revaccination
- Calves under one year are most susceptible
- Post-mortem black leg
- Vaccinate all calves 4-6 months age with killed vaccine containing Clostridium septics and several other common clostridial organisms
A
Clostridium chauvoei
5
Q
- Black leg can also be seen (often called malignant edema)
A
Clostridium Septicum / Sordellii
6
Q
- Woody or wooden tongue
- Introduced by breaks in the mucosa allowing the normal rumen inhabitant causing painful granulomas
- Treated with IV sodium iodide.
- Other systemic antibiotics (tetracyclines) can be used
- Inability to pretend, excessive salivation, visibly enlarged tongue rot rides.
- Enlarged submandibular area.
- Tongue hard, painful and nodular.
- Treatment: Sodium iodide IV as a 10-20% solution, repeat after 7 day interval (70mg/kg IV)
A
Actinobacillus lignieresii
7
Q
- Gram (+), obligate pathogen of the mammary gland
- Usually causes subclinical mastitis, sometimes high somatic cell counts and clinical signs
- Diagnosis: CAMP reaction (plate S. aureus and _____ act together to lose red blood cells (clearing on culture plate)
A
Streptococcus agalactiae
8
Q
- To eliminate: treat and vaccine.
- Vaccine will not eliminate existing carriers
- Long acting tetracycline
- Mid- to late-gestation abortions
A
Leptospira interrogans
Serovar Hardjo (type Hardjo-Bovis) is carried by cattle.
Cattle maintenance host of Hardjo
9
Q
- Most common CNS infection in adult ruminants
- Associated with feeding silage
- Microabscesses in the brain resulting in unilateral cranial nerve signs: facial nerve paralysis, vestibular signs (circling), head tilt, and dysphagia.
- CN V-XII may be involved.
- Head pressing.
- Abortions
- Treatment: Tetracyclines or high levels of penicillin
- CSF: monocytosis
A
Listeria monocytogenes
10
Q
- Respiratory disease and septicemia
- TEME (Thromboembolic meningencephalitis) or otitis media / interna young feedlot animals: head tilt, nystagmus, circling and stumbling. Ipsilateral facial paralysis.
- Affects the cerebellum and brain stem
- Systemic diseases such as pneumonia, laryngeal disorders, joint infections, metritis, orcHitis and conjunctivitis
- History of pneumonia that resolves with antibiotic.
- Swelling carpi, tarsi and stifles. Distension of associated tendon sheaths.
- Stiff gait.
- Postmortem: Fibrinous pleuritis and papillary muscle necrosis.
A
Histophilus somni
11
Q
- Worst pathogen in Bovine Pulmonary Disease
- Severe fever, dyspnea, cough and respiratory distress
- Necropsy: Fibrinopurulent bronchopneumonia
- Most common primary cause of shipping fever (multifactorial etology (bacterial and viral) - Histophilus somni, Pasteurella multocida, and Mycoplasma)
- Most cattle carry it as commensal.
- Stress proliferate and infect lungs
A
Mannheimia hemolytica
Formerly called Pasteurella hemolytica
12
Q
- Abortions (last half of pregnancy), retained placenta, metritis, lack of signs in younger animals.
- Relatively normal appearance of the examined fetuses.
- Late abortion (6-7 months), weak or stillborn calves.
- Placenta retention and/or metritis
- Younger - pre-pubescent heifers no affected
- Necropsy fetus: lung consolidation
- Diagnosis: Serologic testing
A
Brucella
13
Q
- Abortion - first half of gestation.
- Placentitis + pneumonia fetus
- Commonly associated with pos-coital pyometra + Early embryonic death
A
Tritrichomonas fetus
14
Q
- Manifests as sores and abscesses in cattle, common on the lateral thorax, neck, flank or head
- An injury can result in inoculation of the organism.
- Cows are relatively unaffected systemically and the lesions will resolve on their own 2-4 weeks
- Flush the wound and let it heal
A
Corynebacterium pseudotuberculosis
15
Q
- Recent uterine infection.
- Cattle less common that horses, sheep and goats (they are less sensitive to the toxin)
- Toxins moves retrograde up the peripheral neuron into the spinal cord, where it prevents release of inhibitory neurotransmitters (GABA) - causing spastic paralysis
A
Tetanus
16
Q
- Tends to cause Septicemia in dairy calves 4-8 weeks of age
- Transmitted from carriers to neonate at birth via milk
- Cull carriers. Vaccine calves modified live vaccine
- Lesions: serosal and subcutaneous petechial hemorrhages and heavy wet red lungs
A
Salmonella dublin
17
Q
- Deltaproteobcterium.
- Transmitted by ground-dwelling soft tick Ornithodoros coriaceus.
- Abortion 3-4 month after exposure.
- Prevention: Raise heifers in the foothills and put pregnant heifers in the hills only when 6 months or more pregnant (provide premonition immunity)
- Control tick by irrigated pastures
-No vaccine available
A
Epizootic Bovine Abortion
18
Q
- Forage poisoning.
- Occurs in groups of animal fed improperly stored or contaminated animal carcass
- Down, unable to get up, weak, staggering.
- Normal TPR, profoundly weak, tongue stays out, masseter muscle strength, pupillary light response poor.
A
Botulism
