Question

The type of mastitis spread by head flies is _________

• A. Environmental mastitis
• B. Contagious mastitis
• C. Summer mastitis
• D. Winter mastitis

Hint:

Associate "Summer Mastitis" with:
- Pathogen: Trueperella pyogenes.
- Vector: Headfly (Hydrotaea irritans).
- Targets: Dry cows and heifers on summer pastures.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Mastitis in dairy cattle can be classified based on its clinical severity, epidemiological source (contagious vs. environmental), or seasonal occurrence.
Certain forms of mastitis are spread by biological vectors, such as insects, which transmit pathogens between animals.

Step 2: Detailed Explanation:
Summer mastitis is an acute, severe, and suppurative form of mastitis that primarily affects dry cows, pregnant heifers, and occasionally non-lactating heifers during the summer months.
It is most common in wet, humid summer conditions when pasture insect populations peak.
-Etiology:
The primary pathogen responsible for summer mastitis is Trueperella pyogenes (formerly known as Arcanobacterium pyogenes or Actinomyces pyogenes).
It often occurs as a mixed infection with anaerobic bacteria such as Peptoniphilus indolicus, Fusobacterium necrophorum, and Streptococcus dysgalactiae.
-Transmission Vector:
The disease is primarily transmitted by the sheep headfly, Hydrotaea irritans.
These flies are attracted to the secretions of the teat and udder.
As they feed on the teat ends of dry cows or heifers, they mechanically transmit Trueperella pyogenes and its co-pathogens from infected animals or environmental sources into the teat canal.
Because the animals are dry and not being milked daily, the infection can establish and cause severe, irreversible tissue damage before it is detected.

Step 3: Final Answer:
The type of mastitis spread by head flies is summer mastitis.