The Physical Illness and its Treatment
Treatment for parvovirus infection centers on what is called "supportive care." This means that our job is to keep the patient hydrated, comfortable and as strong as possible so that he or she has time and ability to generate an effective immune response. We cannot kill the virus inside the patient's body; only the patient's own immune system can do that.
BE PREPARED FOR A 5-7 DAY HOSPITAL STAY AND A SUBSTANTIAL EXPENSE.
There are certain basic treatment principles which can be viewed as “must haves” in addressing the parvo puppy. Beyond these basics are some “added pluses” which may or may not contribute to the chance for survival. In order to achieve the usual survival rate of approximately 75-80%, the basics must be delivered. Many practices will add additional treatments to their basic regimen in order to improve survival or shorten the disease interval depending on expense and preferences of the doctor. We will cover some of the treatments that may be employed.
ANTIBIOTICS: The second way parvo kills is through bacterial invasion of the circulatory system (“sepsis.”) The intestine is normally full of bacteria and when the parvovirus ulcerates the intestine there is little to prevent the bacteria from marching easily into the bloodstream with little opposition. With the GI tract damaged, antibiotics cannot be given orally. They are given either as shots or are added into the IV fluid bag. There are a number of antibiotics which may be selected. The important thing is that they are given directly intravenously so as to avoid issues with attempting to absorb medication from the diseased intestinal tract or from poorly perfused peripheral tissues. Intravenous antibiotics are taken directly to the "battlefield" of the infection in the intestine where bacteria are attempting to invade. Since the patient's white blood cell count is typically drastically reduced during the height of the parvo infection, we are relying on antibiotics to keep the bacteria out.
CONTROL OF NAUSEA: Patient comfort is a very important part of treatment for any disease but is especially important for parvo treatment as these puppies feel extremely nauseated. Again, the GI tract is too damaged for oral medication so medications are given as injections. There are several popular medications for nausea control:
The vomiting typical of parvo infection is not only uncomfortable but can ulcerate the esophagus. The disease itself ulcerates the stomach and small intestine. Medications called “gastroprotectants” help heal ulcers and help minimize their formation. These medications might include the injectable antacids (H2 receptor blockers or proton pump inhibitors) as well as sucralfate, which forms webbing over ulcers to facilitate healing.
HEAT SUPPORT: One might expect fever with such a serious infection (and sometimes there indeed is a fever) but usually the opposite is the problem. Little dehydrated puppies tend to get cold and with cold comes poor blood circulation. It is important to keep the puppy warm enough to maintain a normal body temperature without too much work on the puppy's part as he or she will need body resources to overcome the infection and not divert extra to body heat. Fluid warmers for the IV fluids are sometimes used and special heated blankets are common.
NUTRITIONAL SUPPORT: Originally, patients treated for parvo were kept off food in an effort to minimize the nausea since they are not able to perform much food digestion anyway. More recently it has been found that intestinal cells survive and recovery better if they receive some nutrients. Not much is necessary, just enough to lightly coat the intestinal cells. For this reason, a very tiny amount of food is now recommended early in the course of treatment and throughout until recovery. The patient will not have an appetite at first and the goal is not so much to nourish the puppy as to nourish the cells of the intestinal tract.
The following tests are helpful in adjusting parvovirus treatment:
Fecal flotation or deworming to rule out worms/internal parasites
White blood cell counts/complete blood counts
Electrolytes and Glucose levels
Urine specific gravity/Lactate levels
Total blood protein
EXTRA TREATMENT WHICH MAY HELP:
“Neupogen” is the brand name of a genetically engineered hormone called “granulocyte colony stimulating factor.” This hormone is responsible for stimulating the bone marrow to produce white blood cells and its administration easily overcomes the bone marrow suppression caused by the parvovirus. In other words, neupogen helps the white cell count recover. A recent study did not find increased survival with the addition of this product to the parvo regimen; however, in sicker puppies it may make a significant difference. It is very expensive and can add substantially to the treatment cost.
Transplanting fecal material from a healthy dog into the colon of an infected dog has been shown to reduce the number of days that parvo puppies experience diarrhea. Reducing the diarrhea fluid losses potentially can mean the difference between life and death so this treatment is becoming more popular. Many hospitals actually keep frozen fecal samples properly mixed in saline for this exact purpose. This treatment is emerging for many intestinal diseases and is likely to become more common in the future.
An intravenous treatment that prevents the attachment of the virus to patient cells has been released in 2023. A single injection of monoclonal antibodies against canine parvovirus is given to the puppy as early in treatment as possible so as to minimize the virus' ability to produce infection. This treatment appears to reduce symptoms experienced as well as hospitalization time.
HOME TREATMENT FOR PARVO
Proper treatment for parvo infection involves intensive support and monitoring of numerous parameters which may require special additional treatment. Survival statistics with hospitalization are high and there no comparable treatment that can be performed at home. That said, sometimes financial concerns preclude hospitalization and home care may be a puppy's only chance. The owner will need to administer injections, manage feedings, clean up a great deal of vomiting and diarrhea. Colorado State University has published an out-patient parvovirus treatment protocol that has demonstrated good success but in this protocol, the patient returned daily for hydration assessments and blood sugar and electrolyte testing which would contribute to expense and effort. If home treatment turns out to be the only option, ask your veterinarian about the most practical options for your own situation.
Page last updated: 8/23/2023