- Infectious Diseases of Livestock
- Part 3
- Mycoplasmal polyserositis and arthritis of pigs
- GENERAL INTRODUCTION: SPIROCHAETES
- Swine dysentery
- Borrelia theileri infection
- Borrelia suilla infection
- Lyme disease in livestock
- Leptospirosis
- GENERAL INTRODUCTION: AEROBIC ⁄ MICRO-AEROPHILIC, MOTILE, HELICAL ⁄ VIBROID GRAM-NEGATIVE BACTERIA
- Genital campylobacteriosis in cattle
- Proliferative enteropathies of pigs
- Campylobacter jejuni infection
- GENERAL INTRODUCTION: GRAM-NEGATIVE AEROBIC OR CAPNOPHILIC RODS AND COCCI
- Moraxella spp. infections
- Bordetella bronchiseptica infections
- Pseudomonas spp. infections
- Glanders
- Melioidosis
- Brucella spp. infections
- Bovine brucellosis
- Brucella ovis infection
- Brucella melitensis infection
- Brucella suis infection
- Brucella infections in terrestrial wildlife
- GENERAL INTRODUCTION: FACULTATIVELY ANAEROBIC GRAM NEGATIVE RODS
- Klebsiella spp. infections
- Escherichia coli infections
- Salmonella spp. infections
- Bovine salmonellosis
- Ovine and caprine salmonellosis
- Porcine salmonellosis
- Equine salmonellosis
- Yersinia spp. infections
- Haemophilus and Histophilus spp. infections
- Haemophilus parasuis infection
- Histophilus somni disease complex in cattle
- Actinobacillus spp. infections
- infections
- Actinobacillus equuli infections
- Gram-negative pleomorphic infections: Actinobacillus seminis, Histophilus ovis and Histophilus somni
- Porcine pleuropneumonia
- Actinobacillus suis infections
- Pasteurella and Mannheimia spp. infections
- Pneumonic mannheimiosis and pasteurellosis of cattle
- Haemorrhagic septicaemia
- Pasteurellosis in sheep and goats
- Porcine pasteurellosis
- Progressive atrophic rhinitis
- GENERAL INTRODUCTION: ANAEROBIC GRAM-NEGATIVE, IRREGULAR RODS
- Fusobacterium necrophorum, Dichelobacter (Bacteroides) nodosus and Bacteroides spp. infections
- GENERAL INTRODUCTION: GRAM-POSITIVE COCCI
- Staphylococcus spp. infections
- Staphylococcus aureus infections
- Exudative epidermitis
- Other Staphylococcus spp. infections
- Streptococcus spp. infections
- Strangles
- Streptococcus suis infections
- Streptococcus porcinus infections
- Other Streptococcus spp. infections
- GENERAL INTRODUCTION: ENDOSPORE-FORMING GRAM-POSITIVE RODS AND COCCI
- Anthrax
- Clostridium perfringens group infections
- Clostridium perfringens type A infections
- Clostridium perfringens type B infections
- Clostridium perfringens type C infections
- Clostridium perfringens type D infections
- Malignant oedema⁄gas gangrene group of Clostridium spp.
- Clostridium chauvoei infections
- Clostridium novyi infections
- Clostridium septicum infections
- Other clostridial infections
- Tetanus
- Botulism
- GENERAL INTRODUCTION: REGULAR, NON-SPORING, GRAM-POSITIVE RODS
- Listeriosis
- Erysipelothrix rhusiopathiae infections
- GENERAL INTRODUCTION: IRREGULAR, NON-SPORING, GRAM-POSITIVE RODS
- Corynebacterium pseudotuberculosis infections
- Corynebacterium renale group infections
- Bolo disease
- Actinomyces bovis infections
- Trueperella pyogenes infections
- Actinobaculum suis infections
- Actinomyces hyovaginalis infections
- GENERAL INTRODUCTION: MYCOBACTERIA
- Tuberculosis
- Paratuberculosis
- GENERAL INTRODUCTION: ACTINOMYCETES
- Nocardiosis
- Rhodococcus equi infections
- Dermatophilosis
- GENERAL INTRODUCTION: MOLLICUTES
- Contagious bovine pleuropneumonia
- Contagious caprine pleuropneumonia
- Mycoplasmal pneumonia of pigs
- Mycoplasmal polyserositis and arthritis of pigs
- Mycoplasmal arthritis of pigs
- Bovine genital mycoplasmosis
- Neurotoxin-producing group of Clostridium spp.
- Contagious equine metritis
- Tyzzer's disease
- MYCOTIC AND ALGAL DISEASES: Mycoses
- MYCOTIC AND ALGAL DISEASES: Pneumocystosis
- MYCOTIC AND ALGAL DISEASES: Protothecosis and other algal diseases
- DISEASE COMPLEXES / UNKNOWN AETIOLOGY: Epivag
- DISEASE COMPLEXES / UNKNOWN AETIOLOGY: Ulcerative balanoposthitis and vulvovaginitis of sheep
- DISEASE COMPLEXES / UNKNOWN AETIOLOGY: Ill thrift
- Eperythrozoonosis
- Bovine haemobartonellosis
Mycoplasmal polyserositis and arthritis of pigs
This content is distributed under the following licence: Attribution-NonCommercial CC BY-NC View Creative Commons Licence details here
NJ Maclachlan and M-L Penrith (Editors). P Wallgren, Mycoplasmal polyserositis and arthritis of pigs, 2018.

Mycoplasmal polyserositis and arthritis of pigs
Previous authors: P WALLGREN
Current authors:
P WALLGREN - Professor, State Veterinarian, Dipl ECPHM, Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, Uppsala, 75195, Sweden
Introduction
Mycoplasma hyorhinis was the first mycoplasma to be isolated from pigs.25 It occurs worldwide and is mainly associated with development of polyserositis and arthritis in pigs less than three months of age.17, 23 However, the agent is also able to induce pneumonia in gnotobiotic pigs,8, 10 and dual infections with porcine reproductive and respiratory syndrome virus (PRRSV) and M. hyorhinis can cause severe outbreaks of pneumonia.12
Aetiology
For information on the characteristics of the mollicutes the General Introduction: Mollicutes should be consulted.
Mycoplasma hyorhinis is readily isolated from specimens collected from diseased pigs in fluid media containing sterols, and forms typical mycoplasmal colonies on solid media that measure 0,5 to 1mm in diameter after one to five days.22 It requires sterols and ferments glucose but does not utilize arginine or hydrolyse urea.22
Epidemiology
Mycoplasma hyorhinis is commonly found in the upper respiratory tract of fattening pigs,9 but does not appear to have significant pathogenic effects in them16 unless they are also infected with other pathogens such as Pasteurella multocida,6 porcine reproductive and respiratory syndrome virus (PRRSV),15 influenza virus or Haemophilus parasuis.27 Mycoplasma hyorhinis is a frequent inhabitant of the upper respiratory tract of apparently healthy sows:24 older pigs serve as a reservoir for the organism. The shedding of M. hyorhinis by carriers may be enhanced by stress such as overcrowding.
Piglets younger than three to four weeks of age rarely develop the disease.23 This age- related reduced susceptibilityis probably as a result of maternally- derived immunity as antibodies to M. hyorhinis have been proved to protect from the development of the disease.10
As the disease is seldom seen among animals older than 10 to 12 weeks, it appears that piglets probably mount a protective acquired immunity to M. hyorhinis by that age. A partial, but not total, resistance may develop with ageing since lesions in M. hyorhinis infected and colostrum- deprived piglets were less severe in pigs aged 13-16 weeks than in piglets aged 10 weeks, which in turn were less severely affected than piglets 7 weeks old.18
Pathogenesis
Mycoplasma hyorhinis may be an inhabitant of the upper respiratory tract of apparently healthy pigs. It appears that stress induced by adverse environmental factors or other diseases may trigger septicaemia in pigs that are carriers of M. hyorhinis.23 Thus, when causing disease in piglets, M. hyorhinis primarily colonizes the upper and lower respiratory tract and may then disseminate to other parts of the body.10 Lesions are seen in the lungs, serosal surfaces and joints of affected piglets.
Clinical signs and pathology
Diseased piglets 3 to 12 weeks old initially manifest inappetance and a moderate fever, signs which are easily overlooked. Subsequently, an obvious discomfort is noticed which is characterized by a roughened hair coat, abdominal pain caused by serositis and/or stiffness as a result of arthritis. Long-term signs comprise lameness and swollen joints. The number of affected joints may vary from one to several:21 the tarsal, stifle, carpal and shoulder joints in particular being affected.26 If more than one joint is affected the pigs may shift their weight between different legs due to the pain.21 Sudden deaths during the acute course of the disease may occur, but the mortality rate is generally low. Chronic signs comprise lameness and swollen joints that may persist for up to six months, resulting in suffering and poor performance of the affected animals:23 consequently, the overall mortality due to M. hyorhinis infections may become substantial due to the culling of diseased pigs for humane reasons.
Mycoplasma hyorhinis has been isolated from the lungs of piglets one month of age with pneumonia,8 and has, under experimental conditions, induced pneumonic lesions involving the apices of the cranial and middle lung lobes of gnotobiotic piglets,8, 10, 18 as well as pleuritis, serositis and pericarditis.10 Following experimental infections, clinical signs included dyspnoea, anorexia and drowsiness in some animals, while in others no apparent clinical signs of respiratory disease were evident.12, 15 The clinical signs associated with Mycoplasma hyorhinis infections are exacerbated by mixed infections Severe dyspnoea with abdominal breathing has been reported in piglets aged one to two months suffering from a dual infection with M. hyorhinis and PRRSV.12 Varying pathogenicity between different strains of M. hyorhinis has been suggested,5, 13 as indicated by the different clinical signs seen among experimentally infected gnotobiotic pigs.8, 10, 15 Mycoplasma hyopneumoniae should probably not be considered as the sole aetiologic agent of porcine catarrhal pneumonia as M. hyorhinis is commonly isolated also from pneumonic lesions of M. hyopneumoniae infections.1, 2, 20 Consequently, it has been suggested that M. hyorhinis contributes to the porcine respiratory disease complex and aggravates the pneumonia caused by porcine reproductive and...
To see the full item, subscribe today:
- Individual subscription
- Individual subscription to all resources R1200.00 Subscribe now
All prices shown in South African Rand.