There are several viral diseases that veterinarians deal everyday within a small animal practice . This page will present many of these diseases, describe them and explain the prevention and treatment of each disease process.
Canine Parvovirus Infection (Parvo)
Parvo, as it is commonly called, is a systemic illness with primarily gastrointestinal and immnue system effects. Common characteristic seen with pets that have contacted the disease include, inappetence (not eating), vomiting, diarrhea, and weight loss.
What pets are at the most risk?
Most cases of Parvo are seen in dogs between 6 weeks and 6 months of age, with the most severe cases seen in the younger patients. There seems to be breed predilections for Rottweilers, Dobermans, Pit Bulls, Labrador retrievers, German shepards, English springer spaniels and Alaskan sled dogs, but any breed can be affected. Any canine pet (of any age or breed) showing the signs of lethargy, inappetence, vomiting or diarrhea should be viewed as suspicious for the parvovirus.
How is Parvo Diagnosed?
Parvo can be diagnosed with many different techniques. The most common would be with the combonation of a CBC, fecal examination and in-house canine parvo tests. The CBC is generally needed to determine how affected the white blood cells have been due to the fact that the virus will infectt the blood marrow and decrease the immune systems ability to fight off infection (either the primary viral infection and/or secondary bacterial infections). A fecal examination should also be preformed to look for changes to the stool itself and for parasites that could also be causing the characteristic symptoms. The last thing usually preformed is an in-house canine parvo test, which actually detects the excreted virus itself. Idexx labratory makes a very good test that is utilized in most cases and only take about 10 minutes for results.
How can my pet become infected and what happens when they are?
The Parvovirus is spead by a fecal-oral route, meaning that the excrete virus (in the stool of a pet with a active infection) must make contact with the oral membranes of another dog. The virus will then be taken up by the lymph tissues of the mouth and upper neck (tonsils and other lymphnodes) and then enters the blood stream moving then to the bone marrow and crypt cells of the small intestines. The infection of the bone marrow deceases the bodies normal defenses by decreasing white blood cell product. The infection in the crypt cells of the small intestines directly affects the microvilli causing the microvilli to slough off leaving the patient inable to absorb nutrients at the normal rate. This also depletes the intestine’s normal defenses and creates an opportuny for secondary bacterial infections.
The infection with canine parvovirus creates many disease process that will have to be address to be successful with treatment. Treatment protocols for the disease generally includes:
1) Dehydration – Due to decreased water intake, vomiting and/or diarrhea the pet will quickly become dehydrated, this is compounded by the depletion of the microvilli of the small intestine where fluids are absorbed into the body. Fluid therapy will generally be needed to replaced the lost fluids. In some cases an electrolyte inhanced oral fluid can and will be administered, but generally replacement fluids are administered through an IV line.
2) Low Blood Sugar – With the body working as hard as possible to fight off the systemic infection and the inability to replace nutrients needed with the diet, the blood sugar can get dangerously low. This can be corrected by adding glucose to the fluids being given through an IV line.
3) Secondary bacterial infections – With the immune system impaired and ulceration of the normal lining of the small intestine, these secondary bacterial infection can mean the difference between life and death. Most commonly, antibiotic are added to the IV fluids and can be directed straight into the blood stream instead of hoping that they are absorbed through the digestive tract.
4) Pain management – Parvo is generally regarded as a very painful disease and no treatment is complete without regards to the comfort and reducing of pain to these special patients. Pain medication can be administered via injection.
5) Vomiting – There are several medications that can be given to aid in decreasing the nausea that this disease process brings about. These drugs are often added to a IV fluids or given in a subcutaneous (skin) injection.
6) Other parasitic infections – If intestinal parasites were found on the fecal examination these must also be eliminated to speed up the recovery process and decrease the loss of other nutrients.
This diagram shows the microvilli which erupt from the crypt cells (not shown). The lose of the microvilli in a parvo infection creates most of the symptoms during the disease process.
What do I do about the enviroment a parvo positive pet has been in?
There is only one known over the counter disinfectant that will kill the parvovirus and that is bleach. This can be diluted down to 1:32 to effectively kill the virus but I usually recommend a slightly higher concentration (one part bleach in 8 parts water) so that the enviroment in question can be disinfected to the best of the owners ability. Please do not bleach anything that will be ruined! Cleaning the outside concrete, dog houses, some pet bedding and some indoor flooring will be all that can be bleached with no harm.
How can I protect my pet?
Canine Parvovirus is a very serious condition and is something that can be easily prevented. Getting your new puppy seen by your veterinarian early and starting a vaccination regiment at around 6 weeks of age and then continuing every 2-3 weeks until 16 weeks of age will dramatically decrease the chances your pet will contract this virus. Also receiving scheduled boosters either yearly or every 3 years (depending upon the age of the pet and the types of vaccinations your veterinarian gives) will decrease the likelyhood your pet contracts or spreads the disease. Recently, there has been lots of press on the negative side of vaccinations but with the advancement in the quality of today’s canine vaccinations and combined with the use of a high quality brand, the benefits FAR out way the risks!