74. Mastitis in small ruminants Flashcards
Mastitis background?
Mastitis
- Major disease in all intensive sheep production
- Clinical manifestations of mastitis
- Acute and chronic
- Acute cases:
- Ewe (toxaemia) + lamb (milk support)
- Chronic cases:
- important cause of culling (in meat-producing sheep)
Visualisation and palpation
Two distinct glands, median suspensory ligament, one teat per each gland
Visualisation and palpation
- supra mammary lymph nodes → only detected by deep palpation
- often masked by oedema and swelling
- heat, pain and swelling, and
- normal gland is firm, without obvious swellings and pain
Examinations of secretions and ultrasound?
Examination of secretions
- somatic cell counts (scc) → bulk milk or individual
- bacteriological culture and antibiotic sensitivity
Ultrasound
- 5 MHz linear or sector probe → deep-seated abscesses
- Tumours are rare
Gangrenous mastitis Causes?
Gangrenous mastitis
• Gangrenous mastitis occurs – sporadically - during the first 8 weeks of lactation
Cause:
- Mannheimia haemolytica → in the oropharynx of young lambs
- Staphylococcus aureus → healthy teat skin
Predisposing factors gangrenous mastitis?
Predisposing factors
- Trauma and/or superficial infection of the teat(s)
- Poor nutrition → bad condition → over-vigorous suckling
- Contagious pustular dermatitis (CPD)
Signs of gangrenous mastitis?
Signs
- sudden in onset → „ ewes being healthy 12 hours previously”
- separated from the flock
- show no interest over their lambs
- poor appetite
- lame → painful and swollen udder
- skin is discoloured
- red → purple → black
- extends along the ventral abdominal wall
- gangrenous areas of skin on the udder and ventral abdomen are cold
Milk and toxaemia?
Milk
• less (10-20 ml), yellowish-reddish milky liquid
Toxaemia:
- mucous membranes
- >41 C°, P >120/min., R ↑
Diagnosis and treatment?
Diagnosis:
• based on clinical signs, bacteriology
Treatment
- Acute
- AB iv. and NSAID
- euthanasia
- Chronic
- marked weight loss, pleuritis, endocarditis, lung abscesses,
- endocarditis and renal infarcts
Management of gangrenous mastitis?
Management
- Feeding, good condition
- Prompt treatment of these teat skin lesions
Acute Mastitis?
Acute mastitis
• sporadically in grazing sheep
Cause
- Streptococcus spp., Staphylococcus spp. and Escherichia coli
- through the streak canal
Acute Mastitis signs?
Signs
- broadly similar, although less severe, than those for gangrenous mastitis
- separated from the flock
- depressed
- marked swelling and oedema → rarely extends cranially along the ventral abdomen
- milk varies from ‚normal’ milk containing large white clots to serum-like
Treatment and prevention Acute Mastitis?
Treatment
- Parenteral (oxytetracycline or penicillin) and intramammary
- NSAID
Prevention
- in grazing meat-producing sheep difficult
- milk-producing sheep easier
Economic losses Acute Mastitis?
Economics losses
- milking sheep
- meat-producing sheep
- reduced lamb growth rate due to reduced milk supply
- increased culling rate
Chronic Mastitis Causes?
Chronic mastitis
• major cause of culling in both meat-producing and milk-producing sheep
Cause
- Acute → abscess formation (Trueperella pyogenes)
- detected at weaning!
Chronic Mastitis signs?
Signs:
• Deep-seated abscesses: fibrous capsule, several
centimetres thick, with a green viscous pus
• Superficial abscesses: thin wall, few millimetres thick,
which may rupture and discharge pus
