Animal safety

Animal safety and welfare are major concerns world-wide. In Quebec, MAPAQ intervenes when animal health or welfare are threatened. Inspections are conducted in accordance with the regulations in force.

Some livestock diseases can compromise animal health. An outbreak of these diseases can cause major economic costs for livestock producers and can even have impacts on human health.

In addition, different programs, particularly intended for businesses in the agricultural sector, have been established to improve animal health and welfare. To learn more about animal health, visit the MAPAQ website.

The leading animal health issues in cattle production are biosecurity, antibiotic resistance and veterinary drugs.

Biosecurity

All meat sold in Canada by retailers, restaurants and institutions has been inspected in advance. There are two inspection levels: those of the federal and provincial governments. The role of these inspection services is to supervise cattle production to ensure compliance with the health and safety directives.

Biosecurity in cattle farming means…

  • Understanding how to secure your farm against the introduction of new diseases, such as Salmonella Dublin.
  • Controlling the spread of diseases within the herd.
  • Preventing contamination of other herds.

All these measures form the Biosecurity Plan for the farm.

Prevention of introduction of diseases

Biosecurity poster

There are many external biosecurity measures that can contribute to protecting your herd, such as:

  • Control of visitors and workers
  • Control of purchases
  • Control of transportation companies
  • Reintroduction of animals

In the case of Salmonella Dublin, control consists of preventing bacteria from entering through contaminated manure.

Examples of good practices:

  • Prohibit unauthorized entry to buildings
  • Compliance with visitor hygiene rules
  • Ask the transporter to wait at the door
  • Never buy a calf at an auction
  • Never buy a calf from an unknown herd
  • Ask the seller relevant questions before buying
  • Ask for tests before buying
  • Perform tests if no information is available
  • Do not go to auctions in your barn clothing
  • Beware of machinery used collectively
  • Beware of labour used collectively

Control of propagation

There are many internal biosecurity measures that can contribute to protecting your herd. This involves adopting selected measures as a start and then implementing biomanagement.

Examples of good practices:

  • Isolate a sick animal whenever possible
  • Clean pails, bottles, watering troughs, feed mangers
  • Beware of manure carried on boots
  • Separate equipment for feeding and cleaning
  • Keep birthing areas clean
  • Do not put sick cows in the birthing areas
  • Tend to sick calves last
  • Additional washing/disinfection in the calf areas
  • Isolate a new animal for 14 days
  • Effective monitoring of the vaccination program
  • Adequate mineral intake at the end of gestation

Biocontainment

This involves containing bacteria on your premises until the situation is resolved. Keeping sick animals out of the transportation and marketing process is very important for the production sector. The deployment of biosecurity measures will soon be one of the important criteria for   livestock buyers.

It is impossible for anyone to be “perfect” in biosafety, but we can all do a little more by adopting a good biosecurity plan. Document the measures in force on your farm and require your visitors and workers to comply with them.

Salmonella Dublin in cow-calf operations

In terms of clinical diagnostic paths, Salmonella Dublin mainly affects calves that are less than 3 months old and they typically exhibit the following symptoms:

  • Super-acute form: calves 1-3 days old die rapidly
  • Diarrhea and/or pneumonia and/or mortality, sometimes combined with nervousness, lameness and necrosis of the extremities
  • Variable morbidity and mortality

In adults, typical symptoms are:

  • Diarrhea accompanied by fever
  • Miscarriages in the final third of gestation
  • Stillbirth

Treatments

  • Use of antibiotics, but this may increase the risk of carriers
    • Necessary for animals with severe symptoms/blood in feces
  • Consult your veterinarian to determine whether antibiotic therapy is justified
  • Supporting treatments
    • Relieve fever (e.g. banamine)
    • Hydrate (solutes, calflyte)
  • Measures to take during treatment
    • Isolate the sick animal, if possible, to prevent propagation
    • Clean the environment as much as possible to reduce the intensity of the infection

Detection in a cow-calf operation

  • Screening analysis
    • Serology of 10 animals that are 4 to 12 months old: detection of antibodies
    • Composite samples: 2 composites of 5
    • OR
    • Serology of 15 animals that are 4 months to 5 years old: detection of antibodies
    • Composite samples: 3 composites of 5
  • Interpretation of the results
    • Negative result of screening: operation considered at LOWER risk of having been exposed
  • Other considerations
    • Several negative screenings in a row reduce this risk
    • Adjustment of screening frequency based on level of risk
      • Introduction or reintroduction of an animal
      • Biosecurity level

Screening at a cattle farm

Recommended frequency of screening tests at a cattle farm for Salmonella Dublin

Farm context Suggested frequency
Closed operation and biosecurity well applied Annual

Open operation, biosecurity well applied and purchases verified

Every 6 months
Open operation, inappropriate biosecurity and/or purchases not verified Improve biosecurity and the purchasing protocol and schedule new screening tests

Screening of an individual animal

  • Screening tests
    • 2 serologies at 30-day interval: detection of antibodies
    • Isolate the animals for 14 days before the tests begin
  • Interpretation of the results
    • Negative screening results: animal considered at LOWER risk of having been exposed
  • Other considerations
    • Prioritize farm-level screening over individual screening
    • Antibody rates highly variable

Screening of asymptomatic carriers

  • Screening tests
    • 3 serologies over a 120-day period: detection of antibodies
  • Interpretation of the results
    • Negative screening results: animal considered at LOWER risk of being an asymptomatic carrier
  • Other considerations
    • Antibody rate variable over time
    • For tracking of animals that have exhibited clinical signs
    • Asymptomatic carriers
      • 18% of the exposed animals that have exhibited clinical signs
      • 1.5% of the exposed animals that have not exhibited any clinical sign

Disease transmission method

How is an animal infected?

  • By ingesting or licking food, water, the airborne environment, an object or clothing contaminated by the feces of an infected animal (including a carrier).
  • Other possible sources
    • Milk and colostrum
    • Urine
    • Saliva
    • Vaginal secretions
  • The animals are contagious/excreters
    • While they are sick in the acute phase.
    • When the disease becomes chronic, after about 30 months.
    • If the animal becomes a carrier, periodic or continuous for years, in the feces and sometimes even in the milk.
  • Sources of contamination of a farm site
    • Introduction of an animal from an infected herd
    • Mechanical vectors: contaminated visitors or equipment

The level of infection depends on the dose!

  • Infecting dose = 108 bacteria ingested
  • 1 gram of feces from an animal in the acute phase or an active carrier

In conclusion, prevention and control of Salmonella Dublin depend on biosecurity and not on treatment or eradication.

Antibiotic resistance

Antibiotic resistance is the ability of bacteria to resist antibiotics and certain other antimicrobials. This resistance may have different causes, but resistance acquired after misuse or intensive use of antibiotics is of more particular concern to the international community.

This is the reason why the World Health Organization (WHO), in May 2015, published its Global Action Plan on Antimicrobial Resistance, whose objective is to ensure continuity of successful treatment and prevention of infectious diseases with effective and safe medicines that are quality-assured.

Controlling the increase in antibiotic resistance is the responsibility of everyone who uses antimicrobials. Whether they are used for human medicine, for pets or for livestock production, everyone must review the way they use these critically important medications.

The Programme québécois d’antibiosurveillance vétérinaire (Quebec Veterinary Self-Monitoring Program) provides annual data for cattle. To familiarize yourself with the results of this study, visit the MAPAQ website.