What is the Vaccination DHLPP Anyway?
Please remember that vaccination protocols may vary somewhat amongst veterinarians, so always follow the recommendations of your family veterinarian.
Let's start with an 8-week-old puppy. The cornerstones of preventive health care are immunizations (vaccinations) and parasite control. Let's start with immunizations.
It is important to realize that a series of vaccinations are necessary in order to properly immunize a puppy. In general, vets administer a DHLPP-CVK vaccine (more about those letters below) at 8, 12 and 16 weeks of age. Rabies and Bordatella (kennel cough) are given at 16 weeks of age. Before 8 weeks of age, antibodies the pup received from its mother protect it against disease. The initial vaccination in the series serves to "sensitize" the pup's immune system to the vaccine. Subsequent "booster" vaccinations stimulate the immune system to produce antibodies which protect against the diseases in question. Now, what exactly are the diseases we are trying to prevent?
The DHLPP-CVK vaccine is a multivalent vaccine; it protects against multiple diseases. "D" is for canine distemper. Distemper is one of the oldest known canine diseases. It is a severe and frequently fatal viral infection that can affect many organ systems in the body, particularly the respiratory, gastrointestinal, and nervous systems. The incidence of canine distemper has been on the decline over the last 30 years, due to improvements in vaccines to prevent the disease. Interestingly, the last two cases of distemper in my practice have been ferrets. Ferrets are extremely susceptible to canine distemper virus infection, and the disease is almost always fatal in ferrets.
"H" is for infectious hepatitis. This is also a viral infection, caused by canine adenovirus type 1 (CAV-1). Signs of hepatitis include fever, loss of appetite, vomiting/diarrhea and jaundice. The disease can be fatal and is usually seen in dogs less than one year old. There is also a type 2 canine adenovirus (CAV-2) which is a respiratory virus. Modern vaccines contain CAV-2, as the immunity that develops to it also cross-protects against CAV-1 infection.
"L" is for leptospirosis. Leptospirosis is a bacterial infection caused by the various forms of Leptospira bacteria. It primarily attacks the kidneys, but may also affect the liver and cardiovascular systems. There are many different types of leptospira organisms, called serovars. Unfortunately, disease may be caused by serovars not included within the vaccine. The leptospirosis fraction of the vaccine is often incriminated as the cause of occasional "allergic" reactions to vaccination. In those patients, I generally use a vaccine without leptospirosis. In recent years, there has been a significant outbreak of leptospirosis in the Long Island, NY area.
"P" is for parainfluenza virus. This virus attacks the upper respiratory system and is a component of the "kennel cough" syndrome. More on kennel cough later.
The second "P" is for parvovirus. Canine parvovirus attacks the lining of the small intestine in unprotected dogs, producing a syndrome of loss of appetite, severe vomiting and bloody diarrhea. Rarely, it will infect the heart muscle of very young puppies. Of all the canine diseases we vaccinate against, parvoviral infection is the most clinically significant in terms of frequency and severity of illness. It is usually seen in dogs less than one year of age, and death frequently occurs from severe dehydration and secondary bacterial infection (septicemia). Treatment of "parvo" is frequently successful, but entails hospitalization for aggressive fluid and antibiotic therapy. The parvovirus is spread in the stool of affected dogs, and can persist in the environment for several weeks. Thorough disinfection of contaminated areas with dilute bleach (four ounces per gallon of water) is a must to help prevent infection of other animals. There are other parvoviruses that affect other species, they are the causative organisms of feline distemper and reproductive failure in pigs.
"CVK" stands for coronavirus. Coronaviral infections in dogs are similar to parvo in that they cause vomiting and diarrhea, but the clinical signs are generally less severe than those produced by parvoviral infection. Very severe disease occurs in dogs that are infected with both coronavirus and parvovirus. Coronaviral disease of other species include FIP (feline infectious peritonitis) in cats and transmissible gastroenteritis in pigs.