Diseases of the neonatal lamb 2 Flashcards
Joint ill is usually seen in lambs of what age?
2-3 wks old
How does joint ill in lambs present?
Sudden onset lameness
Single or multiple joints affected
Swelling on the joint
Name the bacterial cause of joint ill in lambs
Streptococcus dysgalactiae
What are the possible sources of infection for joint ill?
Teats
Milk
Dirty wool
Dirty pens
Cutaneous - umbilicus, docking, castration, tagging
How is joint ill treated?
Penicillin in early cases – long course
Euthanasia in later cases
How is joint ill prevented?
Colostrum, hygiene, navel dipping, farm specific risk factors
Erysipelothrix rhusiopathie is one cause of…?
Infectious arthritis (joint ill) in lambs
What are the clinical signs of infectious arthritis in lambs?
Polyarthritis (fibrinous)
Pyrexia
Lameness
Infectious arthritis affects lambs at what age?
6wks to 6mo
What is the source of infection of infectious arthritis (Erysipelothrix rhusiopathie)?
- Faeces, urine, saliva, nasal secretions
- Bedding, soil, water, food, equipment
- skin wounds: castration and docking sites
How is infectious arthritis treated?
Penicillin daily for 5 days… +
NSAIDs
Naval ill is also known as?
Omphalophlebitis
Describe what naval ill is
Ascending infection leading to abscessation of the navel
What are the possible sequelae of naval ill?
Peritonitis
Liver abscessation
Systemic infection
Polyarthritis
Endocarditis
How is the liver affected in naval ill?
Hepatic necrobacillosis with Fusobacterium necrophorum
How does Hepatic necrobacillosis with Fusobacterium necrophorum appear on PM?
2-10mm diameter white spots on liver
How is naval ill prevented?
- Total immersion of the navel in strong veterinary iodine within 15 minutes, Repeated 2-4 hours later
- Good hygiene practices
- Colostrum
How is naval ill treated?
Penicillin
Amoxicillin
Name 3 trace element and vitamin deficiencies that affect lambs
Iodine deficiency
Copper deficiency and sway back
White muscle disease
How does iodine deficiency present in lambs?
- Goitre in newborn lambs
- Late abortions
- Minimal fleece in live lambs
How can iodine deficiency be confirmed on PM?
- Histopathology of the thyroid gland
- Thyroid gland weight >0.4 g/kg live weight
How can iodine deficiency in lambs be prevented?
Ewe supplementation
- oral dosing 8 and 4wks before lambing
How does copper deficiency present in lambs?
- Swayback
- Fine head tremor
- Osteoporosis
- Tendon abnormalities
- Depigmentation of coloured wool
How can copper deficiency be diagnosed?
- Clinical signs
- Histopathology or brain and spinal cord
- Liver copper conc
How is swayback/copper deficiency treated?
Euthanasia
How can copper deficiency/swayback be prevented?
Supplementation of the ewe throughout pregnancy
- Injections of chelated copper
- Mineralised drenches – short term
- Mineral supplements – variable intakes
- Copper capsules and boluses – slow release copper
What must be considered when preventing swayback?
Risk of copper toxicity
White muscle disease is also known as?
- nutritional muscular dystrophy
- stiff lamb disease
White muscle disease is caused by a deficiency of?
Vitamin E/Selenium
What are the clinical signs/pathogenesis of white muscle disease?
- Weak lambs with difficulty sucking
- Degeneration of skeletal and cardiac muscle
How is white muscle disease treated?
Potassium selenate and Vitamin E
Name 3 congenital malformations of lambs that occur randomly due to genetic mutaion
- Atresia ani
- Schistosoma reflexa
- Brachygnathia
Describe atresia ani
Failure of the anus and sometimes the part or all of the terminal colon and or rectum to form properly
Name a congenital malformation of lambs that can be inherited
Entropion
What can occur as a result of entropion?
Severe keratoconjunctivitis and corneal ulceration, leading to perforation and blindness
When investigating lamb morbidity/mortality what should be asked/identified/examined on a farm visit?
- Examination of ewes and lambs
- Identification of risk factors for disease
- Weigh day old lambs
- Test colostrum transfer
- Pre-treatment faceal samples
How is colostrum transfer tested?
Lamb plasma protein
What are the adequate and inadequate values of colostrum transfer?
Less than 45g/L = inadequate
More than 60g/L = adequate
In-between = borderline
When performing lamb post-mortems what should be done before opening the carcass?
- Weight
- Hardening of the feet
- External staining e.g. meconium
- Naval or joint swelling
- Fleece: border disease
- Deformities
Excessive weight of a lamb suggests?
Dystocia
Once the carcass is open on a lamb PM, what should be assessed in the abdomen and thorax?
- Brown fat round the kidneys
- Milk/colostrum in abomasum
- Lung aeration indicates partum or post-partum death (does lung float/sink in water).
- Hepatic rupture, thoracic, abdominal or meningeal haemorrhage (open up cranium and spinal canal) indicate dystocia.
- Thyroid gland size
Once the carcass is open on a lamb PM what are some signs of dystocia?
- Swollen head /tongue
- Meconium staining
- Oedema head shoulders
- Fracture limbs ribs
- Free blood in carcase
- Haemorrhages
Once the carcass is open on a lamb PM what are some signs of hypothermia/starvation?
- No brown fat
- Minimal body fat
- No milk in abomasum
Describe the importance of selecting breeding flock to reduce lamb mortality
Ewe selection at Pre- tupping check
- Fit healthy, no mastitis, not lame, not broken mouth, not old
- Good mothers
- Low dystocia
Ram Selection
- Low dystocia
- Vigorous lambs
How can the environment be managed to reduce lamb mortality?
- Housing
- Stocking Density
- Group size and constitution
- Good ventilation
- Dry Clean bedding hygiene
- Clean and disinfect lambing pens between sheep
- Separate off ill ewes, ill lambs
- Provide shelter in fields
Describe lamb care management to reduce lamb mortality
- Lamb hygiene: wear gloves
- Dip navels twice in iodine
- Don’t castrate first 24 hours
- Ensure adequate colostrum
- Ewes and lambs clostridia/pasteurella vaccinated
- Disinfect all feeding equipment/ stomach tubes/tagging equipment / lamb warmer boxes between lambs
