Functional anatomy of cattle
- Well demarcated lung lobes, distinct lobulation
- Small alveolar surface area
- Extensive lymphatic drainage-pleural effusion rare
Clinical Signs URT dz cattle
- Inspiratory dyspnea: stridor/stertor
- Open-mouthed breathing, tongue protrusion
- Head extension
- +/- nasal d/c (watch out for lickers)
- +/- lymphadenopathy
- +/- cough
Upper respiratory tract dzs to know
- Allergic rhinitis
- Pharyngeal trauma
- Calf diphtheria
- Oral necrobacillosis
- Necrotic laryngitis - Sinusitis
- Tracheal edema syndrome
Allergic rhinitis
AKA: summer snuffles, chronic granular rhinitis
- Type 1 hypersensitivity w/ pruritis
- Commonly not treated, can do topical corticosteroids
Mycotic nasal granulomas
- Rhinosporidium most common etiologic cause
- These usually ulcerative, so can have epistaxis
- Sodium iodide treatment
Pharyngeal trauma
AKA phlegmon
- Grass awns, iatrogenic
- Won’t want to swallow
- Diagnosis with the hand in mouth, can lance abscesses at the same time
Common etiologic agents in oral trauma infections
- Truperella pyogenes - smells necrotic
- Actinobacillus spp.
- Pasteurella spp.
- Bordetella spp.
- Fusobacterium necrophorum - anaerobic situations
Calf diphtheria
Two kinds -necrotic laryngitis -oral necrobacillosis Pathophys involves mucosal injury Diagnosis easy - young calf, not adult
Sinusitis
Dehorning, tooth root abcess, other
DX: percussion, trefination/aspiration
Tracheal edema syndrome
Two forms
-Acute dyspnea form
-Chronic cough form
Pathogenesis unknown, tx ush not effective
Viral respiratory disease
- BHV1*-Infectious bovine rhinotracheitis virus
- BRSV*-Bovine respiratory syncytial virus
- BVDV-bovine viral diarrhea virus
- PIV-3-Parainfluenza virus type 3
- BCoV*-Coronavirus
- BHV-4; MCF (OHV2, AHV1)*-adenovirus; rhinovirus; reovirus; enterovirus
Viral respiratory diseases dairy cattle
enzootic pneumonia calves up to 6mo
Viral respiratory disease beef cattle
More common after arrival at feedlots > 6mo
Immunosuppression of viral resp dz
- Nasopharyngeal lymphoid tissues
- Ciliated tracheobronchial epithelial cells
- T-lymphocytes
Viral resp paths and synergism with Mannheimia haemolytica
- BHV1
- BRSV
- PI3
- BVDV
Bovine Herpesviruses
- BoHV-1
- 1.1 - infectious bovine rhinotracheitis (IBR)
- 1.2- Infectious pustular vulvovaginitis and balanoposthitis - BoHV-2: Bovine herpes mammillitis
- BoHV-3: Bovine cytomegalovirus
- BoHV-4: Mild resp dz; Mammary pustular dermatitis
- BoHV-5: Neurological dz in calves
IBR
Florid conjunctivitis without ulceration
Hyperemia of muzzle=rednose
Viremia - risk abortion
BRSV
- Fuses epithelia cell into syncytia-lots of cytoplasm and multi-nucleated
- Risk for enzootic pneumonia
Parainfluenza virus type 3
- Ubiquitous, but mild
- Least likely to cause disease
BVDV
- Contact with a PI calf
- Oral/tracheal ulcers can resemble mild IBR
Bovine Coronavirus
- Emerging resp viral strain
- Predisposes to shipping fever
- NO VACCINE
Lower respiratory tract dieseases
Bronchopneumonia -enzootic calf pneumonia -shipping fever complex -sporadic occurrence in dairy cows Metastatic Pneumonia -Vena caval thrombosis Interstitial Pneumonia -Acute resp distress syndrome -Hypersensitivity pneumonitis -Chronic interstitial pneumonia -Parasitic pneumonia
Bovine Bronchopneumonia (Respiratory dz complex)
Bad environment \+ Viral infections \+ Stress => Impaired pulmonary defense mechanisms => Colonization by bacterial pathogens => Bacterial bronchopneumonia
Enzootic Calf Pneumonia
-Intensively raised
-2 weeks to 5 mo
-Failure passive transfer
-Environmental factors
-Nutritional deficiencies
Pasteurella multocida most imp
Resp distress and otitis media
