Diseases

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Non-specific colitis associated with Brachyspira pilosicoli

Nonspecific colitis is caused by Brachyspira (Serpulina) pilosicoli. These are oxygen-tolerant gram-negative anaerobic spirochetes, which live in the large intestine of pigs in the absence of Brachyspira (Serpulina) hyodysenteriae, which is responsible for swine dysentery. Infection by these bacteria has several levels of clinical pathology ranging from an asymptomatic carrier to severe bloody diarrhea.1

Clinical Signs +

Piglets are often infected through horizontal transmission in endemic farms, and clinical pathology is often observed around 10 to 14 days after the transfer of post-weaning piglets.

On many farms, this period is associated with the removal of the antibiotic from the diet, which can play a role in the manifestation of the disease. However it also seems that diet composition can play a role in the expression of the disease. Diarrhea can also occur following other forms of stress such as transportation, mixing pigs or changes to diet.

The diarrhea typical of nonspecific colitis has a shiny appearance and a similar consistency to wet cement. Over 30% of pigs in a batch can have diarrhea and growth retardation that may last 4 to 6 weeks; however, mortality is rare. Affected batches may need more time to reach market weight, and this decrease in weight must be included in economic losses due to non-specific colitis.

Transmission +

The main source of infection by Brachyspira spp. in pigs is the ingestion of fecal matter from a clinically affected animal; however asymptomatic animals can spread the organism into the environment. Transmissions from pigs that have been asymptomatic for more than 60 days have been described in literature.

Continuous livestock systems and low biosecurity can contribute to transmission. Brachyspira spp. are relatively resistant in the environment, particularly in wet feces, and transmission can occur through contaminated boots and vehicles. B. hyodysenteriae survives well in manure pits, and we reproduced the disease by exposing pigs to contaminated effluents. Other breeding animals can also transmit the pathogen, including dogs, mice, rats and birds. We also recovered viable pathogenic spirochetes in the faeces and paws/feet of wild rodents and birds, which shows that these agents can be a potential source of contamination between farms.

Diagnosis +

Several diseases form part of the differential diagnosis: salmonellosis, ileitis, dysentery, post-weaning colibacillosis, enteritis with circovirus. A definitive diagnosis is based on the presence of B. pilosicoli associated with lesions in the colon.

Treatment +

Usually, non-specific colitis with B. pilosicoli resolves spontaneously. In the most severe cases, infected pigs must be treated as quickly as possible. An effective therapeutic profile generally includes treatment in the drinking water of infected animals, followed by treatment in food for the rest of the herd to prevent disease transmission. If the animals are unable to eat or drink, an injectable antibiotic should be used. Antibiotics are effective if they are administered in the early phase.

Consult with your veterinary doctor before administering antibiotics and vaccines to animals.

Your veterinary doctor is the best source of recommendations that are truly suited to your farm.2 

REFERENCES:

1 Merck Veterinary Manual, Third Edition

2 Maladies d’élevage des porcs [Pig Farming Diseases], 2nd Edition, Guy-Pierre Martineau

Prevention +

Prevention and control of pathologies associated with Brachyspira should focus on the detection of carrier animals and improved biosecurity. Decontamination of boots and foreign vehicles is recommended at the farm, and it is guaranteed that efforts to control rodents, birds and other wildlife around the farm will reduce the potential exposure of nearby farms.