Musculoskeletal diseases Flashcards
Musculoskeletal diseases in piglets
Congenital defects: Splay leg
Abrasions, trauma and foot lesions
Arthritis: Streptococcus suis I, Staph. spp., T pyogenes.
Musculoskeletal diseases in weaners and growers
Arthritis: G. parasuis, E. rhusiopathiae. Strep. suis, Mycoplasma hyorhinis.
Musculoskeletal diseases in finishers
Arthritis: Mycoplasma hyosynoviae
Bursitis and shoulder abrasions
Trauma: fractures and muscle injury
Porcine Stress Syndrome
Musculoskeletal diseases in adults
Degenerative Diseases: Osteochondrosis, epiphysiolysis.
Foot lesions: Erosive lesions and hoof rot, laminitis, overgrowth.
Miscellaneous and nutritional: white muscle disease, Kyphosis / ricketts, biotin deficiency
Less significant: osteomalacia, osteodystrophia fibrosa, rickets, proliferative osteitis.
Incidence of splay leg in piglets
An important abnormality that may severely compromise the survival of neonatal piglets.
Quite common. Seen especially in Landrace, Large White and Welsh breeds; also hybrids.
Aetiology of spley leg in piglets
A polygenic hereditary abnormality but also caused or exacerbated by a choline deficiency or fusarium (mycotoxin) toxicity.
Pathology of splay leg in piglets
Myofibrillar hypoplasia and associated with reduced diameter of motor neurons.
Epidemiology of splay leg in piglets
Affects up to 4% UK neonatal piglets.
Morbidity in litter can be 25% and mortality of affected piglets 50%.
Death usually caused by crushing injuries, as piglets can’t take evasive action, and also through hypoglycaemia or hypothermia.
Both sexes affected but males more so than females.
Affected animals often have a low birth weight.
Clinical signs of splay leg in piglets
Affected piglets recognised within a few hours of birth.
Can’t stand on their hind legs, which are splayed out laterally.
The forelegs may be normal or also splayed.
Piglets can suck milk if they can get to the teats.
Treatment of splay leg in piglets
Piglets are helped by loosely tying their hind legs together with a figure of eight tape just above the hocks- as soon as possible after birth.
Will help up to 50% piglets walk quite normally.
Help needed for a few days only by which time piglets walking normally.
Low impact/less common congential disorders in piglets
Crooked/kinky tail
Polydactyly
Legless piglets
Arthrogryphosis
Kyphosis and scoliosis
Pietrain creeper syndrome
Dwarfism
Congenital porphyria
Abrasions, trauma, and foot lesions in young piglets
Foot lesions very common- 100% show sole bruising by 24 days, with large numbers showing sole erosions, carpal abrasions, and healed wounds.
Can allow entry of pathogens- local or systemic infection
Treatment of Abrasions, trauma, and foot lesions in young piglets
Temporary improvements to environment (bedding).
Antibiotics to control infection (penicillin, amoxicillin)
Prevention of Abrasions, trauma, and foot lesions in young piglets
Improved hygiene and floor maintenance.
Existing housing: use of floor mats, renew concrete or cover with rubberised pain, provision of bedding.
Refurbish housing with updated plastic flooring.
Incidence of Infectious arthritis (joint ill) in young piglets
Common.
Piglets affected in the first 10 days of life.
Aetiology of Infectious arthritis (joint ill) in young piglets
T. pyogenes, Streptococcus spp including Strep suis type 1, Staphylococcus spp.,
In many clinical cases the actual cause is unknown and is not determined.
Ascending tenosynovitis.
Epidemiology of Infectious arthritis (joint ill) in young piglets
Infection gains access through tonsil or other vulnerable access points (umbilicus, tail-dock lesion) soon after birth.
Infection spreads haematologically through the body.
Infection can also gain access through dirty syringes and needles, poor teeth clipping technique, and through abrasions, trauma and foot lesions.
Clinical signs of Infectious arthritis (joint ill) in young piglets
Reluctant to take weight on all four legs.
Hot to the touch and are pyrexic.
One or more joints distended, warm and painful.
Hock, carpus and stifle most commonly affected.
CNS signs rarely occur but occasionally signs of meningitis in which case Strep suis Type 1 may be the specific cause.
Diagnosis of Infectious arthritis (joint ill) in young piglets
Age, clinical signs.
Joint fluid is increased in volume and may be turbid and hypercellular.
Recently euthanized piglets should be submitted to APHA for collection and culture of joint fluid.
Differential diagnoses of Infectious arthritis (joint ill) in young piglets
When possible the cause should be ascertained to determine whether a specific infection such as Strep suis Type 1 is present.
Treatment of Infectious arthritis (joint ill) in young piglets
The whole litter, affected and unaffected, should be treated.
A full 3 - 5 day course of antibiotics should be given.
Penicillin / streptomycin or ampicillin.
Single shot long acting preparations such as tulathormycin (Draxxin) and ampicillin may be appropriate.
Clavulanic acid with amoxyicillin is also effective.
Small doses of steroids or NSAIDs speed recovery in severely affected animals.
Incidence of Chronic septic arthritis in weaners and growers
Common and likely to increase.
There are both economic and welfare issues to be addressed
Aetiology of Chronic septic arthritis in weaners and growers
A range of organisms especially T. pyogenes although this may not have been the primary organism.
Glaesserella parasuis, E. rhusiopathiae, Streptococci, Staphylococci, Actinobacillus suis and possibly the mycoplasmas may have contributed to the primary pathology.
Epidemiology of Chronic septic arthritis in weaners and growers
Many cases were victims of an outbreak of arthritis as younger piglets - especially joint ill at a few days of age
Clinical signs of Chronic septic arthritis in weaners and growers
Lameness and deformity.
One or more joints are affected and there is often severe loss of muscle mass caused by atrophy of disuse.
The affected joints are swollen and sometimes abscessated.
They may have opened with thick pus exuding.
In many cases the joint movement range is greatly reduced and there may be total ankylosis.
Affected animals are often in very poor condition and are unable to compete for food and water.
Diagnosis of Chronic septic arthritis in weaners and growers
History, clinical signs and orthopaedic evaluation.
Most affected commercial pigs are not economic to treat, further diagnosis is not justified.
For pet pigs an X - ray is essential if treatment is contemplated and economic to check that irreversible pathology is not already present.
Treatment of Chronic septic arthritis in weaners and growers
This is seldom economical, or justifiable on welfare grounds, and euthanasia may be the best option.
However chronic joint infection of high value / pet pigs can be treated with some success.
Antibiotic therapy, NSAIDs, joint drainage and lavage may be appropriate in some situations where there is suitable nursing care available.
Control of Chronic septic arthritis in weaners and growers
Environmental and managemental improvements, alongside effective individual pig care.
Early detection and treatment of properly diagnosed disease, with completion of courses of treatment, are effective in dealing with most joint infections in pigs.
Glasser’s disease
World wide occurrence.
Caused by Glaesserella parasuis.
This organism can cause polyarthritis.
Affects pigs from weaning - 4 months of age (sometimes older).
Occasionally, pre-weaned pigs affected.
Serotypes 4,5 believed most prevalent but some studies indicate serotype 10 is more relevant in UK.
Clinical signs of Glasser’s disease
Sudden onset of lameness and fever; may also see CNS signs and respiratory signs.
Joints swollen and affected pigs walk with short strides.
May also see polyserositis with pleurisy, peritonitis, pericarditis on necropsy of found-dead pigs.
Diagnosis of Glasser’s disease
Isolation of organism from joints or other non-respiratory locations (non-virulent strains of GPS reside in the URT and can descend to lungs as by-stander organisms).
Use chocolate agar or Staph streak (NAD dependent).
Serotyping of the isolate is useful for determining if commercial vaccines are suitable for use.
Treatment of Glasser’s disease
Parenteral penicillin / streptomycin, oxytetracycline or trimethoprim sulpha for 3 days.
Metaphylaxis for in contacts can be done using oxytetracycline or amoxycillin in drinking water.
Alternatively, inject all pigs with tulathromycin (Draxxin) a prolonged action product, if there are doubts over water/fed intake.
Prevention of Glasser’s disease
Vaccination (Intervet and Zoetis) but these vaccines are directed only against serotypes 4 and 5.
Protection against other serotypes can be achieved through autogenous vaccination.
Streptococcus suis type 1
A common infection of pigs in the10 - 14 day age group.
Carried by sow and enters piglets body via tonsillar crypts leading to septicaemia with involvement of joints and other organs.
Abrasive environmental conditions and insufficient colostral derived immunity are factors.
Chronic joint infection can carry over to post-weaning phase.
Clinical signs of Streptococcus suis type 1
May see occasional sudden death and /or several members of litter lame with swollen joints, fever, and reluctant to move.
May see CNS signs and occasionally endocarditis.
Diagnosis of Streptococcus suis type 1
Isolation of organism.
Joint fluid is sero-sanguinous.
Treatment of Streptococcus suis type 1
Immediate treatment with parenteral penicillin, ampicillin or trimethoprim sulpha for 3 - 5 days.
Tulathromycin (Draxxin) or other prolonged action antibiotic injectable options.
NSAIDs (ketoprofen) may help cases.
Incidence of Swine Erysipelas
Quite common.
Chronic arthritis caused by erysipelas is probably less common than that caused by other organisms such as T. pyogenes.
In many cases the cause of arthritis is not determined but the clinical signs of erysipelas are quite specific.
Mostly affects pigs >12 - 16 weeks (possibly after decline of colostral antibody).
Aetiology of swine erysipelas
Potential zoonosis
Erysipelothrix rhusiopathiae
Epidemiology of Swine Erysipelas
Chronic erysipelas may follow the acute form of the disease but often there is no history of this.
The changes in the joint are of a non-suppurative proliferative arthritis.
Damage to the articular cartilages can result in their loss and the joints become dry and ankylosed.
Clinical signs of peracute Swine Erysipelas
Sudden death
Congestion and discolouration of the skin
Clinical signs of acute Swine Erysipelas
Diamond shaped skin lesions: classic rhomboid urtical lesions (septicaemia)
Pyrexia, leading to fertility problems (abortion in sow/poor semen quality boar)
Clinical signs of chronic Swine Erysipelas
Lameness, paralysis
Cyanosis, skin necrosis
DIagnosis of Swine Erysipelas
Clinical signs and progression of the untreated disease.
At post-mortem the joint capsule is thickened and the synovial membrane is proliferative with areas of granulation tissue.
In advanced cases there is loss of articular cartilages.
A definitive diagnosis is based on culture of the organism from the joints.
Differential diagnoses of Swine Erysipelas
Other causes of lameness eliminated by careful clinical evaluation and culture of joint contents and synovial membranes.
Specific diseases include Glasser’s disease (G. parasuis), Streptococcus suis Type 2, Mycoplasma infections, leg weakness and diseases of the foot.
Treatment of Swine Erysipelas
Can be unrewarding.
In cases where there are chronic pathological changes in the joints euthanasia may be advisable as the chance of recovery and normal growth are poor.
In early cases parenteral injections of penicillin for at least five days are advised.
NSAIDs including ketoprofen or oral aspirin may be used.
Prevention of Swine Erysipelas
Vaccination of sows
Higher challenge may require vaccination of growing pigs
Streptococcus suis types 2 and 14
A zoonotic organism.
A common and important disease in the UK usually affecting weaned or finishing pigs - usually affects older animals than Strep. suis Type 1.
Infection often follows stresses such as mixing and moving.
Zoonotic infections reported for serotypes 1,2,14.
Clinical signs of Streptococcus suid types 2 and 14
Occasional sudden death and then several pigs in group show signs. Piglets - 2-6 weeks (peak at 6 weeks).
Pyrexia 40-41 degrees, lameness, swollen joints.
May see acute polyarthritis. May also see meningitis and CNS signs.
Diagnosis of Streptococcus suid types 2 and 14
History and clinical signs.
Isolation of organism from pathological sites with serotyping – can be done on a smear by FAT.
Culture from tonsils may be confused by co-existent non-virulent strains.
Some labs have developed PCR tests to discriminate virulent strains but these are not 100% specific.
Treatment of Streptococcus suid types 2 and 14
Aggressive course of antibiotics such as penicillin, ampicillin or trimethoprim sulpha for 3 - 5 days.
Long acting preparations of tulathromycin (Draxxin) or other antibiotics can be useful by single injection.
NSAIDs may help painful cases but a welfare endpoint must be agreed on a case by case basis, particularly if meningitis also present.
Control of Streptococcus suid types 2 and 14
strategic medication of the group with in-feed or in water antibiotic (amoxicillin, potentiated sulphonamide)
Incidence of Mycoplasma hyorhinitis
Exact incidence unknown but quite common.
Mostly affects pigs aged
3 - 10 weeks often just before or just after weaning.
Increasing awareness of its role.
Aetiology of of Mycoplasma hyorhinitis
Mycoplasma hyorhinis.
Epidemiology of of Mycoplasma hyorhinitis
May originate from an older pneumonia case.
The organism is found in the nasal tracts of 60% pigs.
Colonisation from dam or from groups mates at weaning.
Organism gains access to susceptible piglets and septicaemia develops.
Settles in the joints causing a polyarthritis, some strains may also cause pneumonia.
Clinical signs of of Mycoplasma hyorhinitis
Affected pigs are dull, lame and anorexic.
Slight fever, and appetite is depressed.
Growth rate is markedly depressed.
Joints are swollen and warm to the touch - the hock, stifle, shoulder and elbow are most frequently affected.
Diagnosis of of Mycoplasma hyorhinitis
Clinical signs.
Joint fluid is sero-sanguinous or serofibrinous - there is an increase in numbers of plasma cells and lymphocytes.
PM reveals joint changes including villous hypertrophy of the synovial membranes.
M. hyorhinis also causes polyserositis (pleurisy, pericarditis, peritonitis) and low grade pneumonia.
Differential diagnoses for Mycoplasma hyorhinitis
Other causes of lameness including H. parasuis, Strep. suis., E. rhusiopathiae.
Diagnosis is by PCR on fresh or frozen material (from non-respiratory location).