MASTITIS

Causative Agent(s)

Contagious pathogens involved in ruminant mastitis are spread from infected quarters to other quarters and cows especially during milking. They include Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis, and Mycoplasma bovis.

Environmental pathogens usually present in the cow’s environment and reach the teat from that source especially in between milking; they include Streptococcus uberis, Streptococcus dysagalactiae, Streptococcus equinus; coliforms such as E. coli, klebsiella spp., Citrobacter spp., Enterobacter spp., and Pseudomonas spp. etc.

Uncommon pathogens are infections caused by organisms usually sporadic and affect only one cow or a few cows. They cause severe mastitis. They include Arcanobacterium pyogenes, Nocardia spp., Pasteurella spp., Mycobacterium spp., Bacillus cerues; anaerobes and fungi such as Trichosporon spp., Cryptococcus neoformans, algae such as Prototheca trispora.

Minor pathogens often found colonizing teat streak canal and rarely cause clinical mastitis. They include coagulase negative Staphylococcus spp. e.g., Staphylococcus epidermidis, Staphylococcus hyicus, Staphylococcus chromogenes, etc.

Clinical Presentation and Epidemiology

Abnormalities of milk includes discolouration, clots, flakes, pus, watery consistency

Physical abnormalities of udder: acute cases may present with diffuse swelling, warmth, pain, redness, and gangrene. Chronic cases may present with local fibrosis, granulomatous lesions, and atrophy of gland.

Systemic response: this is associated with severe mastitis, and includes anorexia, toxaemia, dehydration, fever, tachycardia, ruminal stasis, recumbency and death.

Diagnostic Considerations

California mastitis test (CMT)

Somatic cell count (SCC) using automated counter

Confirmation of diagnosis is by bacterial culture of pathogens, and Somatic cell count (SCC) Other more recent diagnostic tools are ultrasonography and mammary gland glandoscopy. Management and Treatment

Antibiotics may be systemic (injected into the body) or may be forced upwards into the teat through the teat canal (intra-mammary infusion). Examples of antibiotics are ceftriaxone, ampicillin, a combination of penicillin and dihydrostreptomycin and a combination of ampicillin and cloxacillin,

Anti-inflammatory agent such as Ketoprofen and dexamethasone should be given. Antihistamine agent should also be given. This will help in tissue healing

Carefully massage the mammary organ with lukewarm water 2-3 times a day for 2 days.

Ampicillin 2-5 mg/kg IM x 7/7
Combination of penicillin 17,000-25,000 IU (10-15 mg)/kg IM or SC, q12-24 h and dihydrostreptomycin10 mg/kg IM, q12h x 7/7
Combination of amoxicillin + clavulanic acid 7 mg/kg SC or IM daily x 5/7
Anti-inflammatory agent such as ketoprofen 3 mg/kg, SC, SID, 3/7 and dexamethasone 0.07-0.2 mg/kg PO, IM, SQ SID