|
Hereditary and Congenital Disorders: |
| These can affect locomotion, prevent the pig from nursing, or predispose to problems such as neonatal polyarthritis. Congenital tremors cause pigs to shake when awake and remain still when sleeping. Either heredity or viral infections may cause the problem. Congenital tremors usually last for 1 wk and make it difficult for pigs to nurse. Affected pigs must be assisted with nursing until the tremors subside. Mycotoxins in the sow’s feed can cause arthrogryposis, which involves
deformity of limb bones, but the primary effect may be on the neuromuscular system. Pigs affected by hereditary hyperostosis have thickened thoracic limbs and a domed forehead and generally do not survive. |
|  |
|
Joint-ill and Localized Infections: |
| Neonatal septic arthritis (joint-ill) causes death of up to 1.5% in pigs. Joint-ill is caused by various organisms, both facultative and specific pathogens. Microorganisms gain entry to the circulatory system via the tonsils, oropharynx, or a damaged integument, or as a result of an ascending omphalophlebitis. Suckling pigs typically “paddle” with their legs, abrading the skin of the carpuses or coronary bands. A localized infection soon becomes established. Poor hygiene when
pigs undergo tail-docking, ear-notching, or castration, and careless clipping of needle teeth also can result in localized infections. Separate instruments should be used for teeth and tails, and the instruments should be put in a disinfectant solution between pigs. Castration equipment must be kept clean and sharp. If teeth are not clipped or if there are sharp remnants of clipped teeth, pigs that suckle aggressively can lacerate the faces of other pigs, which results in
pyoderma. Regardless of cause of a local infection, if a bacteremia ensues, polyarthritis is likely to develop. Pigs with exudative epidermitis (
Exudative Epidermitis: Introduction) are also prone to polyarthritis. |
| |
|
Polyarthritis: |
| Affected pigs are lethargic and may fail to suckle. Joints are warm, painful, and swollen, and lameness is severe. With time, the soft, fluctuating swellings become firm. The umbilicus should be examined to see if it is hard and swollen. Ultimately, untreated, affected pigs become runts. At necropsy, cream or green pus is found in and around swollen joints (particularly the elbows, carpuses, stifles, and hocks), in the umbilical stalk, and sometimes over the meninges. Organisms
isolated from baby pigs have included streptococci (including
Streptococcus
suis
), staphylococci,
Actinobacillus
suis
,
Arcanobacterium (Actinomyces)
pyogenes
, and occasionally
Erysipelothrix
rhusiopathiae
or
Haemophilus
spp
. |
| Treatment must be based on a bacterial culture and an antimicrobial sensitivity profile. Antimicrobial therapy must be initiated early in the course of the disease if it is to be effective, and treating all pigs in the group at risk may be prudent. Penicillin and lincomycin have been the drugs of choice, but increased numbers of penicillin-resistant
S
suis
isolates have recently been identified. |
| Prevention is based on selecting flooring that minimally abrades and contaminates the feet and skin. The lesions are associated with worn floor surfaces and with floors that have solid floor surfaces adjoining perforated surfaces. Plastic-covered woven wire provides a smooth, self-cleaning flooring; plain woven wire is similar. An “all-in/all-out” flow of pigs is important, and scrupulous hygiene in farrowing crates helps to reduce the frequency of neonatal polyarthritis. Rough
flooring can cause bruising in the soft tissue below the hoof wall or sole; if spaces are large, the digits can be entrapped, and the pig can become lame because of bruising or damage and infection at the coronary band. Pigs on expanded metal floors have incurred heel and wall injuries and have lost accessory digits. Second and third digits were damaged as the pigs thrust with their feet during suckling and caught their toes against sharp metal edges. Sharp spicules on woven wire
lacerate the feet of pigs and predispose to infectious laminitis. Crossfostering within 24 hr of birth to reduce large litter sizes reduces competition at the udder. Large litters are prone to lesions on the faces and the forelimbs. Piglets nursing sows with hypogalactia spend more time nursing, leading to more forelimb lesions. Piglet processing techniques should be reviewed to ensure appropriate use; lack of equipment maintenance often leads to polyarthritis. Hemorrhages in the
wall and sole of feet of newborn pigs from sows fed high concentrations of selenium have been reported, but there was no indication of the longterm effect of these lesions. Infectious conditions can be controlled by improving floors and the environment, and antimicrobial therapy must be initiated before abrasions become infected. Litters of gilts are more prone to neonatal polyarthritis; colostral protection against this syndrome and other infectious diseases of baby pigs may
increase as the sows age. |
| |
|
Splayleg or Spraddleleg: |
| This lameness is precipitated by weakness and immaturity of skeletal muscles at birth. Unless affected pigs are carefully managed and pelvic limbs are temporarily hobbled, skin and foot abrasions develop rapidly, predisposing to arthritis, polyarthritis, or pododermatitis and osteomyelitis of the digits. These pigs may require assistance to suckle colostrum and milk for the first few days of life. |
| |
|
Neurologic Disorders: |
| Meningoencephalocoele and cerebellar hypoplasia interfere with locomotion in affected pigs, as can infections with
Listeria
monocytogenes
and
S
suis
. Thus,
S
suis
can cause locomotion problems as a result of meningitis and neurologic signs, or a suppurative arthritis can be the primary complaint. |
| |
