Mastitis occurs worldwide in gilt and sows. The effects are hot hard swollen udder, or chronic lumps, illness may be sow, piglet mortality.
Related: Agalactia, MMA
- Causes of Mastitis >
- Effects of Mastitis >
- Diagnosis of Mastitis >
- Treatment & Control of Mastitis >
Causes of Mastitis
Mastitis in sows is caused by ascending infection of the teats by bacteria. The organism most commonly involved is Escherichia coli or related organisms (coliform). Bacteria such as Arcanobacterium pyogenes, streptococci and staphylococci may cause infections of single glands. And severe acute mastitis caused by Klebsiella spp. may occur in outbreaks of fatal disease following trauma to the teats caused by rough sawdust bedding.
A wide variety of E. coli serotypes may be isolated from mastitis, often Differing from gland to gland. The E. coli fimbriae possess all types concerned (adhesive fibers), can Adhere to epithelial surfaces and 95% are serum resistant (not easily destroyed by the body).
Traumatic injury that resulted from unclipped piglet teeth, sawdust bedding, or poor quality flooring predisposes to infection. One or both glands Supplying a single teats may be infected. Infection enters through the canal teats teats following contamination the bacteria multiply in the gland. Infection may be transient, or Colonization, multiplication and acute mastitis with systemic signs and agalactia may result from the effect of E. coli endotoxin on prolactin production.
Introduction of endotoxin into the mammary gland will cause mastitis and agalactia and endotoxin can be detected in the blood.
Effects of Mastitis
Acutely affected sows are usually depressed, inappetent and fevered (temperatures of 40.5-42 ° C, 105-107 ° F are not uncommon). The udder is usually swollen and oedematous, often with massive congestion. Any secretion that may be obtained after oxytocin injection contains pus. Pain in the udder may lead to restless ness in piglets when the sow attempt to suck. The litter rapidly loses condition.
Acute mastitis usually occurs within 1-3 days of Parturition. The body temperature falls below normal, the animal can no longer rise and frequently develops respiratory distress leading to death.
Coliform mastitis appears to regress within 3-4 days although in severe cases lactation may cease entirely. Sub-acute infection or infection in one or more glands occurs much more commonly and may be recognized by the increased hardness of the gland and, in its early stages, by a square area of the skin or rescued ning over the affected gland. The litter loses condition. Secretion may appear grossly normal in sub-acute or sub-clinical infection but cytology demonstrates raised cell counts (> 106/ml). Mastitis in a single gland is often noted only when an affected gland fails to return to normal after weaning. There is often teats injury, especially in the thoracic and anterior abdominal pairs of teats.
Diagnosis of Mastitis
Acute mastitis is easily recognisable as affected sows are off their feed and have obvious swelling of the udder, sometimes with rescued tion and edema. The litter is usually in poor condition. Animals are often recumbent, but must be made to rise in order to confirm that mastitis is present. The udder should be palpated (felt) on both sides by running the hand under both lines of glands. Individual affected glands feel firm and hot. Laboratory examination of expressed secretion confirms that presence of mastitis by means of cell counts and the organism (s) responsible can be identified Collection requires oxytocin injection as milk let down is under voluntary control. Sub-clinical mastitis may only be detected after cell counts on expressed milk which may reach 2.0 x 108/ml with 75% white blood cells. Normal milk contains 1 x 106 cells / ml. Chronic mastitis is easily Palpable upon inspection during lactation and easily seen in dry sows. Physical damage to the teats or its end may be found. At post-mortem examination, the carcass muscle and the liver may be pale and the subcutaneous tissue over the affected breast was oedematous. The cut surface of affected glands were diffusely or focally reddened.
Treatment & Control of Mastitis
Acutely ill sows may be saved by injection with neomycin, tetracyclines, ampicillin, amoxicillin, streptomycin, fluoroquinolones, ceftiofur or trimethoprim: sulphonamide for 2-4 days. Oxytocin should also be given. The litter should be fostered or reared artificially.
After recovery it may be necessary to cull the sow. In severely affected cases the Prognosis is poor but rehydration with hyper tonic saline given intravenously by flutter valve may cause a dramatic improvement in moribund animals.
Other supportive treatment may include anti-inflammatory drugs such as flunixin meglumine where registered. In sub-acute cases, rehydration is not necessary. Antimicrobial single injection may improve condition where glands are affected, but results are poor where abscessation has occurred or teats ends are damaged.
Control depends upon hygiene, use or other soft bedding than sawdust, clipping piglets' teeth, early treatment and, possibly, the use of commercial E. coli vaccine if the condition is due to E. coli. Prophylactic treatment with trimethoprim: sulphonamide at 15 mg / kg given in the feed from day 1 to day 112 post-partum or posted may prevent the condition as may feed medication with other agents.
Animals which have had severe or repeated bouts of mastitis should be culled. Affected sows should be retained only if they have sufficient functioning teats.
