ANSWERS

1. Give 6 reasons why you would recommend a client to vaccinate their dog.
   • Vaccination is the most successful way of controlling infectious diseases.
   • All unvaccinated dogs are at risk of canine distemper, parvovirus, leptospirosis, infectious canine hepatitis and kennel cough.
   • Viral diseases have no specific treatment, and therefore therapy is often lengthy, expensive and cannot be guaranteed to be successful.
   • Unvaccinated dogs can act as a source of infection to other dogs, and it is up to us to encourage responsible pet ownership.
   • An unvaccinated dog will be refused entry into boarding kennels/dog shows/training classes.
   • Dogs partaking of the PETS Scheme should be routinely vaccinated in addition to immunisation against rabies.
2. Give 6 reasons why you would recommend a client to vaccinate their cat.
   • Vaccination is the most successful way of controlling infectious diseases.
   • All unvaccinated cats are at risk of feline infectious enteritis (FIE), cat 'flu and leukaemia virus (FeLV). The viruses that cause these diseases are widespread in the UK cat population.
   • Viral diseases have no specific treatment, and therefore therapy is often lengthy, expensive and cannot be guaranteed to be successful.
   • Feline leukaemia virus is incurable.
   • Unvaccinated cats can act as a source of infection to other cats, and it is up to us to encourage responsible pet ownership.
   • An unvaccinated cat will be refused entry into boarding catteries and cat shows.
   • Cats partaking of the PETS Scheme should be routinely vaccinated in addition to immunisation against rabies.
3. State the general factors that must be known in order to plan the best disease control strategy by the use of vaccination.
   • The epidemiology (the study of distribution of diseases) of the disease.
   • The natural immune responses of the host.
   • The virulence of the disease.
   • The species at risk.
   • Environmental factors such as population density and hygiene.
4. State the 2 most important causes of cat 'flu.
   • Feline viral rhinotracheitis (FVR).
   • Feline calicivirus (FCV).
5. Explain in "layman's" terms how vaccines work.
   Vaccines stimulate the body's own defence system to produce protective antibodies in the blood. These protective antibodies protect against specific diseases. This protection is called immunity. Vaccination is the administration of an altered antigen that evokes an immune response in the absence of clinical disease.
6. What is an antigen?
   Any substance which in suitable conditions can stimulate the production of antibodies.
7. What is an antibody?
   A specific form of blood protein produced in the lymphoid tissue that is able to counteract the effects of bacterial antigens or toxins.
8. What is passive immunisation?
   The transfer of antibodies that provide immediate, but temporary, resistance against a disease because the antibodies are catabolised and cleared from the circulation with time. Neonates, young puppies and kittens are protected by antibodies transferred to them by the dam (both transplacentally and via cholostrum). Passive immunity is also provided by hyperimmune serum which is produced by raising antibodies to a disease in a donor animal.
9. What is active immunisation?
   The generation of an immune response by means of vaccination.
10. List 3 ways in which viruses used to make live vaccines are made safe.
    • Gentle heat treatment.
    • Treatment with sublethal chemicals.
    • Attenuated by passage through another host cell until pathogenicity lost.
11. Why are live vaccines usually lyophilised?
    To improve their stability and life span.
12. Give an example of a modified live vaccine.
    UK distemper virus vaccine.
13. Give 2 examples of vaccines that may be modified live or killed.
    • Canine adenovirus (CAV-1 & CAV-2) vaccine.
    • Canine parvovirus vaccine.
14. State 2 advantages of the use of killed vaccines.
    • Safer (the organisms used in live vaccines have the potential to revert to virulence and may cause disease in immunosupressed or sick animals).
    • More stable than live vaccines.
15. Give 4 examples of killed vaccines.
    • Rabies vaccine.
    • Leptospira icterohaemorrhagiae vaccine.
    • L canicola vaccine.
    • Bordetella bronchiseptica vaccine.
16. State 2 disadvantages of the use of killed vaccines.
    • They are removed more quickly by the immune system and therefore have to be given more frequently.
    • Many of the surface antigens are destroyed and changed meaning that they do not provide such an effective response as a live vaccine.
17. For what purpose is an adjuvant employed?
    To enhance the immune response to a vaccine (particularly killed vaccines). This substance slows the release of antigen and therefore prolongs the period of time that the antigen is present, and which creates an inflammatory response that attracts the cells of the immune system.
18. What is the name given to a vaccine made from a specific immunogenic protein antigen that is identified on the organism, and produced in large amounts by genetic manipulation of a carrier organism?
    A subunit vaccine.
19. Why are toxoid vaccines not commonly used in small animal practice.
    The only toxoid vaccine in common use is the tetanus toxoid, but this is not a prevalent disease in dogs and cats so is therefore not licensed for use in these species.
20. What is a heterologous vaccine?
    A vaccine made using an organism from the same genus as the disease organism to protect against the disease.
21. Give 2 examples of heterologous vaccines.
    • Measles virus vaccine - can used to protect puppies against distemper.
    • CAV-2 - can be used to protect puppies against CAV-1.
22. At what age should puppies have their first vaccination?
    This depends upon the type of vaccine and the practice protocol. Generally, routine vaccines are given at 9 and 12 weeks of age, although some practices may prefer to begin the course at 8 weeks. Always ensure that you are kept informed so that you can give your clients the correct information.
23. At what age should kittens have their first vaccination?
    This depends upon the type of vaccine and the practice protocol. Generally,
    routine vaccines are given at 9 and 12 weeks of age.
24. Why are yearly boosters necessary for adult dogs and cats?
    Initial vaccine protection does not last for life, and therefore an annual booster vaccination is necessary in order to maintain immunity. In addition, it is an opportunity for the veterinary surgeon to carry out a routine annual health examination, which can only be beneficial to both client and animal.
25. An additional vaccination is available for dogs that helps to protect against Bordetella bronchiseptica (one of the viruses that cause kennel cough). How frequently should this vaccine be administered?
    Every 6 months.
26. Most vaccines are administered by subcutaneous or intramuscular injection. How does the Intrac vaccine for Bordetella bronchiseptica differ?
    This vaccine is administered intranasally.
27. State 3 disadvantages of the Bordetella bronchiseptica vaccine.
    • Vaccination is required every 6 months.
    • Protection cannot be guaranteed.
    • Intra-nasal administration is generally not well tolerated by dogs (and the owners can find the subsequent struggle, coughing and spluttering distressing).
28. How frequently should Rabisin rabies boosters be administered?
    Dogs require a booster every 2 years, whilst cats require a booster annually.
29. Name the 2 diseases affecting rabbits that may be vaccinated against.
    • Myxomatosis.
    • Viral haemorrhagic disease.
30. How can veterinary personnel ensure that annual boosters are not overlooked?
    • By providing information at the time of the initial vaccination to ensure that the client is aware that annual boosters are necessary.
    • Provision of a record of immunisation for the client to take home. This should clearly state when the next vaccination is due.
    • Remind clients when vaccination is due by sending a postcard or letter.
    • Follow up clients that do not respond to vaccine reminders with a telephone call -establishing whether the client still owns a particular pet will ensure that practice records are kept up to date (clients will usually inform you if a pet has died, but often will omit to tell you if a pet has been rehomed).
31. A client comes into the surgery to make enquiries about vaccination. She is concerned about their safety, having read about the possible dangers associated with the inoculation of children. How would you put her mind at rest?
    • Advise of the benefits of vaccination (see Q1 and Q2) - these far outweigh any risks.
    • Inform her that all vaccines licensed for veterinary use have been subjected to the safety, quality and efficacy proofs required by the Veterinary Medicines Directorate before a veterinary product license is issued.
    • Do not belittle her concerns. There have been recent debates on reactions to vaccine injection, with reports that annual vaccinations can actually harm patients, and even cause neoplasia. However, the experience of most veterinary surgeons is exactly the opposite to such reports. We vaccinate countless numbers of cats and dogs, but our surgeries are not full of patients with problems associated with vaccination. The diseases caused by the infective agents against we vaccinate are now dramatically reduced thanks to vaccination.
32. State some circumstances in which vaccination may be contraindicated.
    • In pregnancy (some vaccines may not be safe eg. live vaccines for FURD).
    • If an animal is on a course of steroids.
    • If an animal is not in good general health.
    • In cases where the immune system of the patient is compromised.
    • If the patient is too young.
33. State 3 reasons why a puppy or kitten may fail to respond to vaccination.
    • Levels of MDA (maternally derived antibodies) are too high.
    • The immune system is compromised in some way.
    • The disease to be vaccinated against has already been contracted.