OVC Student Veterinarian Externship Project: “B” is for Biosecurity

Each summer DVM students from the Ontario Veterinary College delve into practical experience at veterinary clinics across Ontario and additional locales. These blog posts are an opportunity to tag along with five of them this summer. This week student veterinarian Chelsea talks about biosecurity. Check out all the student blogs at www.ovc.uoguelph.ca/externship

Biosecurity, it’s more than just a buzz word when it comes to agriculture. Carrying out biosecurity practices is very important in large animal medicine, when dealing with animals all day and from multiple farms.

In animal agriculture, biosecurity can be defined as practices implemented to prevent or contain transmission of disease between farms or between individual animals on one farm.

There are three different factors that contribute to disease:

The host:
How susceptible is the animal? Does that animal have any natural immunity or immunity from vaccines? How old is the animal? (younger or older may be at higher risk)

The environment:

Is the environment favourable for the growth and survival of bacteria, viruses or parasites?

The agent or disease:

How ‘potent’ is the agent to the animal? How fast can it multiply?

As veterinarians we have to constantly consider these three factors and use our knowledge of diseases to prevent transmission to other animals.

Some simple methods of biosecurity that are used on farm to avoid transmission of disease from animals within a farm are as follows:

• wash boots between different pens (i.e. when moving from the milking cows to the heifer cows)
• go to naïve animals or ones with less immunity first (i.e. check out calves first and then go to older cows
• wear gloves when working with the animals and wash your hands after (be sure to change gloves between animals)

Some methods of biosecurity that are used to avoid transmission of disease from one farm to another include:

• changing coveralls between farms
• cleaning and disinfecting boots between farms

As a veterinarian it is also important to remember that you are dealing with all kinds of diseases. Some diseases are ZOONOTIC (see personal experience below) which means that they can be transmitted from the animal to you. Not only is it important to prevent the spread of disease between the animals you are working with but it is also important to prevent disease transmission to yourself.

For example, this past week I got infected with ringworm. There are two nice patches on the inside of my right arm. Ringworm isn’t a worm as the name suggests but is actually caused by a fungus and is referred to as  “Dermatophytosis”. In cows, ringworm typically targets younger animals that have not yet been exposed to the agent. As a fungus, it grows in dark, moist places and can live for long periods in the environment. Due to a very wet spring, ringworm seems to have been a greater problem on some farms this year. This means I’ve been working with a large number of infected animals and that’s how I contracted it. Fortunately, ringworm is not typically a serious problem if it is identified and treated appropriately. And after my visit to the human ‘vet’, for the next little while I’m going to be putting anti-fungal cream on my arm twice a day. Here is a picture of what ringworm looks like in dairy cows and what it looks like on me!!

For more information about biosecurity check out this great factsheet from OMAFRA.