Cattle 4 Flashcards
Coxo-femoral luxation (hip dislocation) prognosis better if
§ Cow able to stand before reduction
§ Cow <3 years, <400Kg
§ Duration dislocation less than 12 hours - less likely for bleeding and inflammation
Sacro-iliac luxation clinical presentation in mild and severe cases
○ Partial or complete separation joint surfaces sacrum, ilium
○ Mild cases - slight ataxia, knucking fetlock
○ Severe form - back appears dropped, sacral tuberosities very pronounced
Paralysis what do most result in and the 4 main ones
- Downer cow when become recumbent can affect any of the nerves - sciatic, tibial, peroneal nerve
○ Especially with calving paralysis - sciatic nerve thought to be involved more
1. Radial paralysis
2. obturator paralysis
3. peroneal paralysis
4. tibial paralysis
Radial and obturator paralysis generally when occur and result
Radial paralysis
○ After recumbency - milk fever, cast for surgery
Affects ability to extend carpal, digital joints
Obturator paralysis
○ Damage where trunk of nerve passes close to medial aspect of the shaft of the ilium
Result - limb abduction affected leg pushes out to the side
Peroneal and tibial paralysis when occur and results
Peroneal paralysis
○ Nerve susceptible to damage where it runs down (subcutaneous) over the lateral femoral condyle, head of fibula
○ Knuckling of fetlock, over-extension of hock
○ In severe cases dorsal aspect fetlock joint contacts ground
Tibial paralysis
○ Hocked over-flexed
○ Fetlock slightly flexed, but bearing surface of hooves remains in contact with the ground
Prevention of digital disease what are the 2 main factors and factors within
1. Environment ○ Farm track maintenance ○ Gate ways, troughs ○ Selection of concrete for yards 2. Management ○ Don't hurry, force cows along track ○ Try to avoid turning on concrete ○ Design of laneways § Minimal abrasive qualities § Avoid sharp stones § Adequate drainage § Eliminate congestion points § Objective □ Cows walking quietly at their own speed are able to carefully place their feet so as to avoid obstacles and rough or sharp objects □ If try to hurry back of the cows will restrict area around the back, overall speed of the herd will hardly change as this is set by the dominant cow group in the herd ○ Minimise time on concrete
What are the 3 main functions of the respiratory system
- Gas exchange
- Hypoxia / Hypercarbia lead to dyspnoea, lung sounds - Thermoregulation
- Cows don’t sweat much –they increase resp rate - Acid/Base balance
- Particularly in young calves
What is special about bovine respiratory system and disease
SYSTEM
- decreased capacity - greater clinical effect of minor disease
DISEASE
- Mostly infectious or toxic
- Clinical signs often relate to toxaemia rather than respiratory dysfunction
- Respiratory dysfunction may be due to non-respiratory disease (eg anemia)
Assessing respiratory rate and nature what is normal and abnormal
- Dairy cattle 20 to 30 breaths per minute “at rest”
○ Costo -abdominal (move ribs as much as diaphragm) - “Normal” = Inspiration –expiration –pause - normal generally not occurring when doing clinical exam - stressed
○ Prolonged inspiration -> upper respiratory tract disease
○ Prolonged expiration -> lower respiratory tract disease
○ Tachypnoea –rapid shallow respiration
○ Hyperpnoea –increase in depth of respiration
○ Dyspnoea –laboured respiration. (also neck extenstionetc…)
Dyspnoea what are 3 respiratory causes at rest and 4 non-respiratory causes
RESPIRATORY ○ Filled alveoli (eg pneumonia) ○ Compressed alveoli ( pleural effusion) ○ Obstructed air passages (eg lungworm) NON- RESPIRATORY 1. Cardiac disease, peripheral circulatory failure, DIC 2. Blood disease - Anaemia, methemagolbinemia… 3. Nervous system disease - Encephalitis, muscle paralysis (tetanus, hypocalcaemia…) 4.General systemic states ○ Hyperthermia, pain, acidosis
List 4 abnormal lung sounds and possible causes
- Crackles
○ Inspiratory and expiratory sounds
○ Clicking, popping, bubbling -like separating Velcro
○ Alveolar pathology -Air bubbling through airway secretions - Wheezes
○ Airway pathology -vibrations - sounds like waves crashing
○ Inspiratory –extra thoracic obstruction - most common
○ Expiratory –from intra-thoracic airways - Friction Rubs
○ Sandpaper like sound
○ Inflamed parietal and visceral pleura rub together - Stridors
○ Inspiratory wheezes
○ Tracheal in origin - Expiratory grunting
○ Trachea or thorax
○ Pain associated with acute pleurisy, peritonitis, extensive consolidation
What are the 3 main pneumonias causes, clinical signs and lung sounds
1) Bronchopneumonia
- Pathogens gain access through pulmonary tree
- Depression, fever, toxaemia - generally due to septicaemia
- Cranioventral lung sounds and lesions
2) Interstitial pneumonias
- Non-infectious damage to alveolar septa by inhaled allergens or toxins
- “atypical” because affected animals tend not to be as depressed and toxic
- Abnormal lung sounds diffusely distributed
3) Metastatic or Embolic Pneumonia
- Septic embolism from other foci (eg liver or caudal vena cava)
- Often signs of toxaemia.
- Epistaxis or hemoptysyslater in disease
Bovine respiratory disease complex what makes it up and important thing for treatment
Triad of causes
○ Causal agents
○ Animal factors (immune competence)
○ Environmental factors
- Viruses –PI3, BRSV, BoHV-1, BVDV
- Bacteria –Mannheimia haemolytica, Pasteurella multiocoda, Arcanobacterium pyogenes, Fusobacterium necrophorum, Histophilus somni
○ Apart from H. Somni, most pathogens don’t cause severe disease on their own
- Often, treating or preventing one or two agents is enough to impact on clinical disease - important for control
List the 4 main respiratory diseases of calves and young stock
- Enzootic pneumonia
- Histophilus somni disease complex
- Calf Diphtheria
- Lungworm
In summary what is the cause of young calves with 1) lungs sound reared inside 2) dying of suppurative penumonia 3) pasture coughing 4) inspiratory stridor
1) enzootic pneumnia/BRD complex
2) H. somni
3) lungworm
4) calf diphtheria
Enzootic pneumonia causes and diagnosis
Causes
- Viruses -Parainfluenza 3; Paramyxovirus, Bovine respiratory Syncytial virus; BVDV; Mycoplasma (first year a major issue but after that become immune but still present on the farm), secondary bacteria
- Caused by calf housing –lack of ventilation - most common predisposing factor
○ Ammonia irritates airways - “Ammonia = pneumonia”
Diagnosis
- can just come back with a mixed culture so sometimes cytology and culture don’t give you proper information
- May use specific PCR
Enzootic pneumonia of calves clinical signs, post mortem change, treatment and prevention
Clinical signs
- Elevated temp (40 to 40.5 °C), Rhinitis, Pneumonia , Mild diarrhoea, Harsh hacking cough
- auscultation - harsh and loud ventral lung sounds
Post mortem change
- Areas of collapse with little bronchiolar reaction
- Dark red blotchy lungs
- In the later stages a dark red consolidation with little or no fluid in the lung is detected.
Treatment: - Antibiotics / supportive care
Prevention: COLOSTRUM and HOUSING
- Kneel down in the calf pen and see if you can smell ammonia - if you can then probably causing the issue
Histophilus somni Disease Complex bacteria characteristics, transmission and diagnosis
- Histophilus somniis incapable of prolonged survival outside the body - only one that can cause disease by itself
Transmission - Infection is by inhalation
Diagnosis - Clinically signs suggestive of Histophilosis
- Pure cultures of H. somnifrom the heart, joints, lungs, ears, conjunctivalsacs and other affected areas are strongly indicative of Histophilosis
○ H. somni will not survive for prolonged period in commonly used transport media HOWEVER - now just PCR so doesn’t need to be alive
Histophilus somni Disease Complex what are hte 3 main forms and clinical signs
- Respiratory form
○ cause laryngitis as well as tracheitis
○ capable of causing a suppurative bronchopneumonia or may be a part of the classical “shipping fever complex“
○ May be sudden death - Septicaemic form
○ localise in the brain, heart, skeletal muscle, joints, larynx, liver and kidneys
○ Clinical signs vary depending on the affected area - Nervous form
○ The nervous form of the disease is Thrombo-embolic meningo-encephalomyelitis (TEME)
○ Early stage - high fever (greater than 40 °C) and profound depression
○ Ophthalmic examination -scattered haemorrhages
○ Other signs -lameness, stumbling or knuckling of the hind limbs, stiffness, incoordination
Calf Diphtheria main clinical signs, cause and treatment options
- Calves with inspiratory stridor, frebrile and anorexic
- Fusobacterium necrophorum infection of larynx/pharynx - gram negative but behaves as gram positive -> TREAT WITH PENCILLIN
Treatment options - Long term antibiotics - penicillin
- Long acting corticosteroids? - dexafort (dexamethasone) - as inflammatory reaction the main issue
- If don’t respond to first load of treatment generally don’t do too well
Lungworm what presentation, clinical signs, treatment and diagnosis
- Coughing calves on pasture - main one that causes coughing
- Dictyocaulus viviparus
Clinical signs - Mild –coughing
- Severe –they sit down and quietly die
Treatment - macrocyclic lactones
Diagnosis L1 in faeces -> do faecal sink as larvae diagnosis
What are the 4 things to prevent calve respiratory disease
- Colostrum
- Good nutrition
- Good housing (ventilation)
- Good parasite control
List some respiratory diseases of growing/adult cattle in australia
- BRD (bovine respiratory disease cycle) Complex in feedlot cattle
- IBR
- Acute Undifferentiated Bovine Respiratory Disease
- Aspiration Pneumonia
- Pulmonary haemorrhage
- Pleuritis
- Mycotic Pneumonia
- Interstitial Pneumonias
- Anaphylaxis
- Nasal Granuloma
BRD (bovine respiratory disease cycle) Complex in feedlot cattle when generally present and the 2 main causes
- Mostly within 4 weeks of entry to feedlot - significant cause of death on feedlots
CAUSES
1) stress factors - weaning, transport, co-mingling, pen competition, weather, handling, nutrition changes
2) infectious agents - virual - IBR, BVD, bacerial - pasterurella, haemophilus somni
