VACCINATIONS
BOOSTERS, BOARDING,BREEDING

Trevor Turner, B. Vet. Med., MRCVS

VACCINE REACTIONS

About eight years ago, concurrently with concerns raised regarding the wisdom of inoculating children with multivalent vaccines, doubts were raised regarding the safety of dog and cat vaccines.

Being a regular attender of North American veterinary conferences I was astounded at some of the problems attributed to multivalent vaccinations. Dogs with haemolytic anaemia, cats with sarcoma-like (cancerous) growths at the site of injection, all attributed to vaccination! This was to me inconceivable particularly since in the UK we had very little evidence of such reactions.

In consequence I wrote about risks and benefits and placed myself, unequivocally, in the pro-vaccination camp.

I will still say that in over 40 years of intensive small animal practice I have never seen a serious vaccinal reaction. This has always been my reason for advising "boost and be safe", rather than let the animal's immune status drop and then live to regret it.

However at the recent World Small Animal Congress in Vancouver in August, eminenet, well-known American veterinarians presented convincing evidence regarding problems that are caused by some of the components of multivalent vaccination.

Killed vaccines, such as the Leptospira components, generally provide less durable, solid immunity and consequently require more frequent re-vaccination. At least two injections are needed to establish immunity initially and annual boosters in order to maintain immunity.

Unfortunately, it has been found that these Leptospira components can cause reactions in a significant number of dogs.

According to our American colleagues, Leptospira canicola and icterohaemorrhagie are the most reactive components of multivalent (combination) canine vaccines.

These particular types of serovars, as they are known, have also been found to be ineffective against the common type of Leptospirosis affecting dogs. There is a newer, Fort Dodge, Leptospira vaccine that contains other serovars (L. pomona and L. grippotyphosa) and these are the types that we are told are isolated today from the majority of canine patients with Leptospiral infection. Clearly this is the vaccine that would be recommended if there is a risk of leptospirosis in any particular area.

Compared with 40 years ago, the disease today is rare indeed - in my view a triumph for the vaccine despite the drawbacks.

In cats, according to the Americans, the problems are even worse! Vaccine associated sarcomas in cats have a reported incidence of btween 1:1000 and 1:10,000 vaccinations, depending on which report you read. Feline vaccine associated sarcomas, although now recognised in the UK, are still extremely rare and yet, if anything, our use of feline vaccines is as great, if not greater, than on the other side of the Atlantic.

Feline vaccines implicated have been primarily 'killed' vaccines, especially FeLV and Rabies vaccine, and it appears to be a component of the vaccine other than the killed virus itself that induces the formation of these particularly nasty tumours.

WHAT SHOULD KENNELS OWNERS DO?

With this emerging evidence, the question is, as kennel owners, how do we handle it?

I am still convinced that the risk of contracting one of these diseases, easily preventable with vaccination, is infinitely greater if the animal's immunity has fallen than the chance of a vaccine reaction. In this country, at the moment, I am sure that the chance of a susceptible cat contracting flu, or a dog parvovirus, is considerably greater than the chances of an adverse reaction. These can vary from slight malaise for 24 hours to serious, life threatening conditions such as haemolytic anaemia in dogs or vaccine induced sarcome in cats. Therefore, in my view, as kennel owners, we must maintain a rigorous vaccination policy.

WHEN TO BOOST

However the current concern has led to certain new facts coming to light. Recent work has shown that many canine and feline vaccines, administered correctly to the young animal, will protect for many years, thus reducing the need for annual boosting.

This is particularly true in the case of distemper and parvovirus disease. Therefore the veterinary profession in this country is moving towards 'bespoke' vaccination, tailoring both the diseases covered and the frequency of re-vaccination to each animal's individual circumstances.

PUPPIES AND KITTENS SHOULD ALWAYS BE FULLY VACCINATED

One thing, however, comes through loud and clear, that puppies and kittens should have a full course of primary vaccination.

The difficulty for kennel owners is obvious. If the vaccine programme is tailored to the particular animal you might find one dog being admittted with an annual parvovirus booster, another from a slightly different area or a patient at a different practice having the same booster only administered every 2-3 years.

What do you do?

My advice can only be to do a 'bespoke' valuation. If it is clear that the owner is concerned about vaccinal reactions and is following veterinary advice, explain that your policy is to be 'better safe than sorry' and usually you insist upon annual repeat vaccinations. Then explain you are prepared to accept the baorder provided the owner signs a disclaimer to the effect that it is realised that the animal does not fulfil the kennels' present requirements regarding vaccination but the owner is prepared to accept the risk having discussed the matter with her veterinary surgeon and the knennels.

At least in that way you cannot be held responsible should cat flu or canine parvovirus suddenly strike.

BREEDING ESTABLISHMENTS

And what about the breeding kennels? Are you, too, concerned about vaccinations?

Here the advice of your veterinary surgeon has to be sought and followed.

My advice is certainly to ensure that vaccination against those diseases that may represent risk, should be carried out for all dogs and cats regardless of their lifestyle. These are becoming known as the core vaccines.

In general for dogs these include parvovirus, adenovirus, (hepatitis) and canine distemper. Until relatively recently, leptospirosis was always included.

With cats core vaccines include panleucopaneia (feline enteritis) and the two flu viruses. Feline leukaemia and Chlamydia will depend very much upon the source and life style of the animal and perhaps therefore should be classed as non-core. Certainly in the case of kittens from rescue, feline leukaemia inoculation included with primary vaccination is wise; if the cat is not living in a situation where it is likely to be in contact with feline leukaemia, repeat vaccinations should be assessed individually.

Thus the vaccine scene is changing and clearly my tune has certainly changed.