Parvovirus in dogs (parvovirus) was identified in Europe in the 70s of the last century. The first case of an outbreak of infection in Russia was registered in 1980. Now the disease is less common, thanks to the invention of effective vaccines against parvovirus.
Puppies are most susceptible to the disease in the first six months of life. The virus primarily infects the epithelium of the small intestine, causing gastroenteritis. Because of this feature, the disease is called parvovirus enteritis.
What is parvovirus in dogs
Parvovirus is a dangerous infectious disease of viral etiology, caused by an infectious agent from the parvovirus family (Parvoviridae).
The epithelium of the small intestine, bone marrow and heart muscle are especially sensitive to the pathogen.
In nature, there are two types of canine parvovirus (Canine parvovirus, abbreviated as CPV): types 1 and 2. The first is not pathogenic for canids.
The danger is posed by Canine Parvovirus type 2, a small DNA-containing virus without an envelope. At low temperatures, the pathogen remains infectious for several years. Dies when treated with formaldehyde or 30% soda ash solution.
Parvovirus type 2 causes myocarditis or gastroenteritis in dogs. The second form of pathology is the most common.
Etiology of occurrence
Canine parvovirus is widespread in the environment. However, not every pet that comes into contact with the pathogen becomes infected. Whether a dog is infected or not is determined by factors such as living conditions, feeding, the presence of endo- or ectoparasites, internal pathologies, and exposure to stress.
A high incidence rate among puppies is observed due to an incompletely formed immune system. It has also been noted that parvovirus tends to infect young dividing cells. Therefore, young animals are more susceptible to the disease.
The mode of transmission of CPV 2 is fecal-oral. There is also a version about the possibility of intrauterine infection.
Infection with parvovirus enteritis most often occurs through contact with food, water, environmental objects or things that a sick dog has used (toys, bedding, etc.). An animal becomes infected when it licks or sniffs contaminated objects.
Parvovirus enteritis in dogs - disease prevention
Proper living conditions and the prevention of diseases play an important role in the health of dogs. First of all, you need to keep the place where the dogs live clean. It is necessary to clean the enclosures and change the bedding in a timely manner. Avoid allowing large numbers of puppies to live in a small space. Feeding should be complete and correct. Feeding adult dogs should be different from feeding puppies.
Vitamins and vitamin supplements help strengthen the immune system. It is necessary to reduce the risk of diseases in puppies from unvaccinated females. To do this, they need to be given mono- and polyvalent vaccines/serums against parvovirus enteritis in a timely manner. Immunoglobulins are also used.
Do not forget about regular prevention of fleas, ticks and worms. If there is any suspicion of a disease, the sick dog should be isolated from the rest. And so on until complete recovery or until it is confirmed that the dog is healthy. New dogs should not be immediately placed in a common enclosure.
Annual vaccinations are required to prevent the disease. You can choose a vaccine yourself or consult a doctor. The choice of vaccines is now large: Doramun, Vanguard, Nobivak, Primodog and others.
Is parvovirus dangerous?
CPV 2, which causes canine parvovirus enteritis, is not infectious to humans. However, the causative agent of parvovirus, Canine parvovirus, is antigenically related to Virus panleukopenia feline, which causes distemper in cats. As a result, it is believed that canine parvovirus can be transmitted to felines, causing clinical signs of panleukopenia. This hypothesis turned out to be wrong. Classic canine parvovirus poses a threat only to the canine family.
It has been scientifically proven that upon contact with a sick animal, the virus is not transmitted to humans and cats.
Diagnosis of the disease
Parvovirus enteritis in dogs, the causative agent of which belongs to the known types of this infection, is diagnosed in a complex manner. The basis for diagnosis is epidemiological data, clinical manifestations of the disease, observed pathological changes, test results and laboratory studies. The most effective methods of laboratory diagnostics are enzyme-linked immunosorbent assay (ELISA), blood serum tests, hemagglutination reaction and hemogglutination inhibition reaction (RHA and HRI), and electron microscopy method. To establish an accurate diagnosis, differential diagnosis is used.
The clinical similarity of canine parvovirus enteritis to other causes of viral enteric infections requires a combination of compatible clinical and pathological abnormalities in parallel with detection of viral antigen or viral DNA in feces using polymerase chain reaction.
Pathogenesis
The incubation period from the moment of infection to the appearance of the first symptoms of parvovirus infection ranges from 3 to 10 days. How quickly the disease manifests itself depends on the immune status and age of the individual.
An infected dog releases the virus into the environment 3 days after infection and is potentially dangerous to other animals.
The virus primarily affects the lymph nodes of the throat or tonsils. CPV 2 then enters the bloodstream, from where it enters the bone marrow and the epithelium of the small intestine.
In puppies, parvovirus often settles on the heart muscle, causing arrhythmia and myocarditis.
When the bone marrow is damaged by parvovirus infection, the death of leukocytes responsible for the immune status of the dog’s body is observed.
Having settled on the mucous membrane of the small intestine, the infectious agent releases toxins, blocks the absorption of nutrients and the absorption of water. This in turn leads to exhaustion, dehydration, and general intoxication.
The epithelium of the intestinal tract becomes inflamed during parvovirus enteritis, and erosive lesions are sometimes observed.
Infection of dogs with parvovirus infection
Parvovirus is released in high concentrations into the external environment with the feces of infected animals 4-5 days after infection, that is, before the first symptoms of enteritis appear in dogs. Virus shedding continues throughout the entire period of illness and for approximately another 10 days after clinical recovery.
Parvovirus infection enters healthy dogs through direct oral or nasal contact with contaminated feces. In addition, indirect infection is possible through contact through household items, the owner’s clothing and other objects that could be soiled with the feces of a sick animal.
Parvovirus in healthy dogs initially develops in the lymphoid tissue of the oropharynx with subsequent transition to a system-wide form as a result of spread throughout the body through the bloodstream. The viral infection primarily infects and destroys rapidly dividing mucosal epithelial cells of the small intestine, lymphopoietic tissues (lymphocyte-producing tissues), and bone marrow. From this point on, symptoms begin to develop.
The destruction of intestinal crypts by the virus leads to epithelial necrosis of the mucous membrane (death), villous atrophy, and impaired absorption capacity of the intestine. As a result, these pathological processes lead to the destruction of the functionality of the intestinal protective barrier, which ends with the active penetration of bacteria located in the intestinal lumen into the blood and the development of a secondary infection.
This pattern of enteritis in puppies under 8 weeks of age, as well as in older dogs, can lead to the development of heart infections, inflammation of the heart muscle and myocardial necrosis. Subsequently, myocarditis may clinically manifest as acute cardiopulmonary failure with or without symptoms of parvovirus enteritis. It is worth noting that heart problems are not observed so often in puppies, since their blood contains antibodies against parvovirus obtained from their mother's milk (colostral immunity).
How does the disease manifest itself?
Parvovirus enteritis in dogs is classified into 3 types: intestinal (gastroenteral), cardiac (myocardinal) or mixed, occurring in fulminant or acute form.
In adult animals, the symptoms are erased, often there are no clinical signs at all.
With a lightning-fast course, the death of puppies at the age of 1.5-3 months occurs several hours after the onset of a depressed state. In the acute form, the incubation period is 5-6 days.
The first signs of parvovirus enteritis of the gastroenteric form:
- depressed state;
- refusal of food and water;
- development of anorexia;
- acute stomach;
- severe vomiting;
- diarrhea (often with blood);
- foul odor of feces;
- temperature rise to 41 degrees (not always).
The myocardial form is extremely rare. It usually appears in puppies under 1 month of age and leads to sudden death.
With the combined type of parvovirus enteritis, the cardiac, respiratory and digestive systems are affected simultaneously. The above symptoms, characteristic of the intestinal form, are accompanied by shortness of breath.
Consequences
Parvovirus in puppies younger than 3 months of age, when affecting the myocardium, often causes heart failure, which can be fatal several weeks or months after the illness.
Sometimes the infection has a negative effect on the reproductive system of dogs. Males that have recovered from the disease lose reproductive function for several months or become infertile for life.
Bitches whose virus has caused damage to ovarian tissue lose their ability to reproduce. Puppy dogs with parvovirus enteritis may exhibit abnormal embryonic development.
When the bone marrow is damaged, the production of leukocytes is disrupted, which leads to leukopenia.
Parvovirus enteritis, against the background of a decrease in the immune status of the body, often provokes secondary bacterial infections, which can cause alveolitis and pulmonary edema.
Basic preventive measures
Initially, it is worth saying that if a pet has had parvovirus, then it retains fairly stable secondary immunity. However, it does not persist throughout life. Thus, it is worth noting that the most effective way to avoid infection is timely immunization of the animal. Vaccinations must be carried out strictly in accordance with the recommendations of a veterinarian, since timely vaccination is the real guarantee of your dog’s health.
Also, it must be said that when a puppy is born, it receives a certain amount of antibodies from its mother. This transfer is carried out through natural feeding of the puppy. However, this immunity lasts no more than six weeks, after which it is worthwhile to vaccinate the dog as necessary.
The second option for developing immunity in a puppy is the introduction of special antibodies through a vaccine. However, it is also worth noting that persistent production of these antibodies by organisms is observed after the second vaccination, therefore, the chances of becoming infected with parvovirus in a dog are significantly reduced.
How to treat parvovirus enteritis
Treatment is most effective in the early stages of parvovirus enteritis.
In the first 2 days after infection, serums with immunoglobulins are used that contain antibodies against CPV 2 (Vitacan, Immunovet, Globcan-5, etc.). Using them later than 3 days from the onset of the disease is irrational and dangerous for the pet’s health. Treatment regimen for parvovirus enteritis in dogs:
- the use of antiviral serums at the very beginning of the disease;
- rehydration (replenishing fluid in the body);
- detoxification therapy;
- elimination of vomiting and diarrhea;
- stimulation of immunity;
- prevention of the development of secondary infections;
- restoration of the cardiovascular and digestive systems.
Therapy for parvovirus is aimed primarily at maintaining the dog’s vitality during the acute course until the body itself is able to cope with the viral infection.
The animal can be treated at home after a veterinarian has drawn up a treatment regimen.
Droppers and injections
Rehydration solutions are aimed at replenishing fluids and restoring the alkaline balance of blood in the dog’s body.
Ringer's solution or Trisol are indicated intravenously or subcutaneously. A rehydration mixture is also used, which is prepared from 200 ml of saline solution, 20 ml of glucose (40%) and 4 ml of ascorbic acid solution (5%). The dosage ranges from 30 to 100 ml per day per 1 kg of animal body weight, depending on the severity of the disease.
Solutions of Hydrolysine or Sirepar, which are administered intramuscularly or by infusion (dropper), help remove toxic decay products of parvovirus. Used in the first 3-5 days of parvovirus infection.
Antiemetic and hemostatic drugs
In case of severe vomiting, dogs are prescribed Cerucal or intramuscular/subcutaneous administration of the drug Sereniya.
If there is blood in the vomit or feces, give Vikasol, Etamzilat and other similar drugs with a hemostatic effect.
Heart medications
To maintain the functioning of the cardiovascular system, Cordiamin, Riboxin, Sulfocamphocaine are indicated for 2-4 weeks.
Painkillers and antispasmodics
In case of severe pain, the dog is prescribed Bellastesin, No-Shpa or Drotaverine.
Antibiotics and sulfa drugs
Cephalosporin antibiotics are prescribed - Cefazolin, Ceftriaxone, etc. Duration of use is from 5 to 7 days.
In some cases, antibacterial drugs can be replaced with antimicrobial agents: Biseptol, Sulgin, etc.
Immunomodulators and vitamins
During the period of illness, the dog is prescribed B vitamins, vitamin complexes (Hemobalance, Ketozal), immunomodulators with antiviral activity - Glycopene, Roncoleukin. Drugs in this category promote faster recovery.
Main characteristics of parvovirus
As for the first cases of animal infection with parvovirus infection, they almost all ended in death, but today, for the most part, puppies aged from six weeks to six months suffer from this disease.
As for adult dogs, in most cases they develop stable immunity to infection. This usually occurs as a result of vaccination or after suffering from a form of this disease.
After the puppy is born, the mother also transfers part of her immunity to him, but as a rule, such an immune response is not long-term. After six weeks, the immune system begins to weaken and the puppy can easily become infected with a disease such as parvovirus.
As for other factors that can cause parvovirus in dogs, they are mostly the following:
- persistent stressful situations of the animal;
- animal uncleanliness;
- poor living conditions;
- helminthic infestations;
- a variety of primary viruses and bacteria that significantly reduce immunity;
- genetic predisposition;
- certain breeds of dogs that are most susceptible to the effects of this virus.
As for the main method of transmission of this infection, it is mostly transmitted from a sick animal to a healthy one, both by airborne droplets and by feces.
Parvovirus is a disease whose treatment is quite complex and the virus is also very stable and can maintain its vital activity for several years.
Infection of an animal in most cases occurs through contact of the dog with a contaminated surface. Thus, it is very difficult to destroy viruses, since they can be located almost everywhere, and disinfection must be carried out exclusively with bleach, since other disinfectants do not eliminate this virus.
The main symptoms of parvoviruses include that their incubation period generally lasts about seven days, although in some cases this period can be longer or shorter. It is also worth noting that not all animals, after contact with a viral infection, can immediately become infected with its active form.
The main symptoms in young puppies may be as follows:
- sudden death;
- diarrhea due to intestinal tissue dying;
- septic shock (blood poisoning);
- complete dysfunction of all organs;
- death.
Rehabilitation period
After the end of the acute course of parvovirus enteritis, the animal must be provided with a gentle diet. Additionally, a course of probiotics and hepatoprotectors is given to restore normal functioning of the intestines and liver.
Diet therapy
You should start feeding your dog on the second or third day after vomiting and diarrhea stop. Until this moment, the animal is kept on a starvation diet.
The feeding regimen should be gentle on the gastrointestinal tract. It is important to include only easily digestible foods in your diet. Baby food made from vegetables and meat is suitable for these purposes.
Initially, the dog is given small portions of food (1-2 tsp puree) up to 4 times a day. If the pet feels well, the next day increase the amount of food consumed by 2-3 times.
The animal is given water also after vomiting and diarrhea have stopped. Drink every 30-60 minutes. The volume of water per dose is 5-10 ml, more is possible for large dogs.
After 5-7 days, the pet is transferred to dietary food indicated for gastroenteritis (Advance Gastro Enteric, Royal Canin Gastro Intestinal, etc.).
Probiotics
Within a month after the illness, the animal is given a drug with bifidobacteria: Bifidumbacterin, Vetom or Fortiflora for dogs, etc.
