An Overview of Diseases Vaccinated for in the DA2PLPC Series: Part 2

In the last article I wrote about the first disease in the DA2PLPC series, Distemper. I explained how the disease makes them sick, how it is treated and how it affects their health. In this article I am going to explain about the next two diseases in the DA2PLPC series, which are Canine Hepatitis and Canine Parinfluenza virus.

Infectious Canine Hepatitis is a highly contagious viral disease affecting the liver and other organs and is caused by Canine Adenovirus type 1 (CAV-1). This disease is closely related to Canine Adenovirus type 2 (CAV-2), which causes Infectious Canine Tracheobronchitis, which we will discuss in a later article. CAV 1 is spread only among domestic and wild dogs such as wolves, coyotes, bears, skunks and foxes and is not related to human hepatitis.

A dog or puppy can become infected with this disease by direct contact with an infected animal, feces or contaminated objects such as food dishes or leaches; or by inhalation and parasites such as fleas, ticks or mosquitoes. Four to seven days after the initial exposure to the virus it begins to multiply and is shed in the feces, saliva, and urine making this the most contagious period of the disease. For the first eight days it will travel from the tonsils to the lymphnodes and on to the blood stream. From there it infects the liver, kidneys, eyes and other organs, causing extensive cell damage. It is because of this that the virus can be found in all tissues of infected animals and shed in all body secretions. An infected canine may even shed the virus for 6-9 months after recovery through secretions.

Signs and symptoms of this disease vary from a slight fever to death. A puppy or dog that has a healthy immune system can fight the disease by producing antibodies, but it can stay in the kidneys and be shed in the urine for up to nine months posing a threat to other dogs. There are three forms of systemic disease of this virus. The peracute form usually affects puppies and causes death within a short period of three to four hours with little or no signs of illness. The Acute form usually has a duration of four to nine days and may involve many clinical symptoms; these include fever, apathy, anorexia, thirst, conjunctivitis, serious discharge from eyes and nose, abdominal pain, vomiting, tachycardia, leukopenia, bleeding of the gums, prolonged clotting time, enlarged tonsils, and swelling of the head, neck and trunk. Central nervous signs are not common but may be seen in a severely affected animal. It is sometimes very difficult to control hemorrhaging depending on the severity of the disease because of the prolonged clotting time. Since the liver is an important organ that performs many vital jobs, any disturbance in its function is a serious matter that should be treated early.

Treatment for this disease consists of many systemic procedures. Blood transfusions may be necessary in severely ill dogs with prolonged clotting time. A 5% dextrose solution in isotonic saline should be given IV along with a broad-spectrum antibiotic. If the puppy or dog develops corneal edema, then an atropine ophthalmic ointment may be given and they should be protected against bright lights. These signs could be the beginnings of “blue eye” which is temporary clouding of the cornea of one or both eyes caused by antibodies that attach to the virus present in the eye. This problem is common in about one-quarter of dogs, usually puppies under six months old, which have an acute Infectious Canine Hepatitis. This problem may last for six months after recovery and may even lead to permanent eye damage. After the recovery begins, the liver will be able to heal itself but this disease leaves the dog more susceptible to kidney infections because of the amount of time the virus remains in the kidneys.

As with all other viruses, prevention is the key to keeping your puppy or dog safe from disease.

The third disease in the DA2PLPC series is Canine Parinfluenza Virus. This disease is almost obsolete, but it is still good to vaccinate against. It is transmitted through aerosol spread such as coughing or sneezing, personnel, cages, food and water bowls. Though this disease causes mild problems it can be harbored in the airways of dogs or puppies that may not show any signs. In puppies and imunocompromised animals this disease can cause a secondary bacterial invasion of the lower respiratory tract and life threatening pneumonia.

The main clinical sign of the mild form of this disease is a dry hacking cough that can be high pitched because of laryngitis and swollen vocal folds. The cough may be more frequent during exercise, excitement, or changes in temperature and humidity of inspired air. A cough can be elicited by tracheal palpation or by pulling on the collar. A mild naso-occular discharge is sometimes seen. The clinical course of this disease is usually 7-14 days and typically the dog or puppy continues to eat and remains active and alert.

The severe form of this disease is a lot less common and is usually the result of mixed infections in unvaccinated puppies in animal shelters or pet shops. A productive cough due to Tracheobronchitis plus bronchopneumonia may be present. Other signs are conjunctivitis, anorexia, depression and fever. The severe form of this disease is sometimes hard to distinguish from canine distemper, which can sometimes be fatal.

Radiographs, airway cytologies, cultures and virology can be used to help diagnose Parinfluenza, but reveals many nonspecific findings. Since these tests are not definite this disease is usually diagnosed on circumstantial evidence of clinical signs and exposure history.

Treatment of this disease varies. The mild form requires no specific therapy. The severe form however, can be fatal because of lower respiratory involvement prompting aggressive treatment for bronchopneumonia. All antitussives need to be avoided. If the cough persists for more than 14 days other tests need to be performed to rule out other diseases. If possible this disease is treated on an outpatient basis to prevent transmission to other boarding and hospitalized animals. Other treatment includes supportive care such as adequate fluid intake, either oral or IV, and airway humidification and rest.

As with all diseases, prevention is vaccination. In the next two articles I will be explaining about the next three diseases in the DA2PLPC series. I hope you have enjoyed this article and will be looking forward to the next two articles on this topic.

Kami R Guy CVT