Chris Gregory BVSc MRCVS, Molecare Veterinary Services
Pneumonia is one of the most common veterinary diagnoses made, and one of the key areas where antibiotics are still regularly used for both targeted and blanket treatments. However, as dependence on antibiotic use is coming under increased scrutiny across all industries, emphasis will shift to alternative prevention measures in order to maintain healthy productive stock. No prizes for stating the obvious, the question is: how?
There are three overlapping lines of attack when tackling pneumonia at the herd level. Addressing any one of these points in isolation is unlikely to work; rather all three must be used in a delicate balance to reinforce the others:
- Control the environment (e.g. ventilation, humidity, stocking rate, mixing of age groups
- Control the animals own immune defences (e.g. colostrum protocol, vaccination, nutrition)
- Treatment with medicines if required (e.g. antibiotics, anti-inflammatories, (wormers))
The scope of this article is to focus on effective vaccination, just part of point two above. Pneumonia vaccination has become relatively common practice across the cattle industry; whether in response to increased stocking densities and cattle movements, or a full on preventative push towards reduction of antibiotic use.
Vaccines induce an animal to manufacture their own protection against a specific virus or bacteria, aiming to prevent or supress infection when exposed to the real thing. Hence, a vaccine needs to be specifically matched to the anticipated bugs on farm.
From experience, most decisions to start a vaccination programme stem from grumbling herd pneumonia problems. It’s not uncommon to hear histories of poor-doers after a long course of antibiotics, or chasing coughs around a pen with endless jabs.
Before you build a vaccination plan there are a few question to ask:
What bugs are we dealing with?
There are several known pneumonia bugs, and several vaccines targeted against one or multiples of them! You may already have a known herd health status for some diseases (e.g. BVD, IBR).
Some of the key pneumonia bugs will live quite happily in or on the animal under normal conditions, only causing disease if given the opportunity i.e. immune system challenged by stress, respiratory or irritants. In this respect, controlling the environment is of high importance.
Ask your vet to do a surveillance screen to give an indication of what the herd has been exposed to (e.g. blood sampling, tracheal washes, farm history and previous diagnoses).
Bought-in animals can be sampled in isolation, but must have some background history (e.g. previous vaccinations or origin herd health status).
Bear in mind that the spectrum of bugs can vary even within a farm. A vaccination plan will need monitoring and periodic review to make sure it is working effectively.
What is the dosing protocol and timing?
The only point to emphasise here is to stick to the data sheet on dosing protocols. Most will initially require two doses separated by a few weeks. This is important for two reasons. Firstly, to ensure the vaccine ‘takes’ effectively; secondly, if anything does go wrong the vaccine company will be much more helpful.
It is essential that the primary course is finished a good couple of weeks before exposure to the real thing, or exposure to a ‘stress’ event that might knock the animals immune system (e.g. prior to housing, movement, weaning or disbudding). It is also essential that all at-risk animals are vaccinated to the same protocol at the same time. Any ‘holes’ in the vaccine wall can allow disease to accumulate, and may leave individual animals with no defence.
Actual timing of the vaccine revolves around knowledge of where and when the pneumonia exposure or stress event might occur, not as a reaction to clinical disease.
What can I expect of the Vaccine?
The perceived benefits of vaccination are often difficult to quantify. Best case scenario, the response to vaccination is…nothing, i.e. no clinical disease. Often the success of the vaccination plan will be judged on comparison to previous seasons.
Importantly, vaccination is not a bullet proof barrier. As already alluded to, vaccinal immunity can be overwhelmed if the challenge is great enough, or if the protocol is not executed properly.
The take home message; a solid vaccination plan relies on good planning and flawless execution of an agreed protocol.
For more information phone Molecare Vets on 01392 872934.