The PARVOVIRUS is a viral disease of dogs , highly contagious and often fatal. It is also called Gastro hemorrhagic enteritis .
It is due to the Canine Parvovirus (CPV ), very resistant virus in the environment , as well as many disinfectants . Contagion is mainly in environments contaminated by the feces of sick dogs .
Affected animals are mostly puppies, unvaccinated adult dogs and community dogs (kennels ) .
a) SYMPTOMS :
They are dazzling : the animal is suffering from bloody diarrhea with foul odor. Vomiting are also possible.
The dog has to fever, is shot and becomes dehydrated very quickly.
The virus also attacks the white blood cells leading to lower the body 's defenses.
b) DIAGNOSIS :
It is based on the symptoms and evolution , namely:
- A serological screening test for possible blood test.
- A test MADE DIRECTLY ON THE STOOL which allows to highlight the virus .
c) TREATMENT AND EVOLUTION :
It requires a hospital with intensive care : infusion , antibiotics, anti emetic ...
The disease is often rapidly fatal in puppies in 2 to 5 days.
d) LEGISLATION :
Canine PARVOVIRUS is a fatal flaw in the dog. It is a disease subject has legal obligations on the part of the seller, to protect the customer.
If a puppy is sold sick or carrying the virus , it must be made and will be reimbursed by the seller .
Among the canine coronavirus , the best known is the enteric coronavirus that can infect dogs of all ages. Transmission is by the fecal -oral route. However, young puppies 6 to 12 weeks are the most susceptible to infection ; vomiting and diarrhea is observed 1 to 3 days after infection . The diarrhea may be bloody, but this is not always the case. Mortality from enteric canine coronavirus is rare. Recently, two genotypes have been identified in faeces of patients pups : the CCOV CCOV I and II. The CCOV I did not grow in cell culture unlike CCOV II.
In 2005, a highly pathogenic variant CCOV II was identified in Italy , clinical signs observed in three dwarves Pinschers 45 days from a pet store were fever , anorexia , apathy , diarrhea bleeding and seizures. The death occurred in 48 hours. The experimental infection of dogs showed that hemorrhagic diarrhea arose between 2 and 7 days after infection, vomiting were later ( 4-5 days after infection). Leukopenia was also observed in these dogs . The lesions on autopsy show haemorrhagic enteritis, spleen increased volume with bleeding under the capsule , the liver and the lungs were congested and hemorrhage were visible on the surface. Decaro and colleagues have shown that age of the dog, the outcome was not the same . Older (6 months ) recovered slowly, while the youngest, aged 2.5 months , presented more severe clinical signs and two of three experimentally infected puppies had to be euthanized .
This canine coronavirus is not different from CCOV II viruses in fecal dog materials. However, the prevalence of infection is responsible for the disease severity . Also, the virus was called canine coronavirus pantropic ( Eng: panatropic canine coronavirus - CCOV ) .
Since March 2008, six episodes of bloody diarrhea followed by convulsions and death within 48 hours of the puppies were highlighted in northern France and Belgium. In many cases, the affected puppies have been in contact with animals from countries in Eastern Europe, one to two weeks before the onset of clinical signs. The autopsy of the bodies showed lymphadénomégalie , pulmonary congestion and degenerative liver disease. Analysis by RT -PCR has made it possible to demonstrate the presence of infection CCOV II. The fact that the CCOV II is present in all organs removed ( intestine, spleen , lung, kidney , liver and brain) allows to call him a pantropic .
Further studies are needed to better understand this virus and the disease it causes widespread . However, the following factors will lead to suspect infection with canine coronavirus pantropic and differentiate it from canine parvovirus with which it is often confused likely : the rapid evolution of the disease , the presence of seizures and context of vaccination against canine parvovirus . Laboratory diagnosis is made by RT-PCR on faeces and deep organs , spleen , lung, kidney , liver and brain.
Vaccines against canine coronavirus are available in both Europe and the United States . This vaccine contains the same antigens as canine coronavirus pantropic . It was found that the puppies were naturally infected with enteric CCOV were not protected against experimental infection pantropic virus. The symptoms , however, were less pronounced.
Coronaviruses can cause respiratory, digestive and nervous systems in various species . There is little longer , disease and the symptoms associated with coronavirus infections were mild. That is why we have conducted very little research on antiviral specifically directed against coronaviruses .
But especially since the emergence of SARS-CoV in human medicine and, to a lesser extent, since the emergence of infectious peritonitis in cats in veterinary medicine, diligent search was initiated for drugs that may be used in these infections.
Regarding infections pantropic canine coronavirus , it has not proposed until now , in addition to symptomatic treatment , of specific antiviral therapies .
The recombinant feline omega interferon is currently approved in Belgium in the treatment of feline leukemia and canine parvovirus . A recent controlled study failed to demonstrate efficacy in the treatment of feline infectious peritonitis, feline coronavirus infection. This result does not argue in favor of the efficacy of omega interferon in the treatment of canine pantropic coronavirosis . Controlled studies are needed to evaluate this treatment in dogs.
So vigilance is still required , even for pets , which are not immune to the emergence of new viral diseases.
What is the importance of this disease ?
Its importance lies in several points:
it is a contagious disease affecting mainly the young and causing malassimilation syndrome;
• it is a disease that can persist enzootic (that is to say that the parasite is still present in a specific location) ;
• growing canine farms are faced with this disease: in about one third of French farms , the parasite was isolated. The prevalence in France is about 7 % in adult dogs . 30 to 45% of the puppies under 6 months are carriers of the parasite (and up to 100% in a kennel or shelter)
• it is a zoonosis , that is to say that man can be contaminated : Human giardiasis is even a public health problem of increasingly important
What is the causative agent of the disease?
Giardiasis is caused by the pathogenic action of an intestinal parasite of the family of protozoa called Giardia duodenalis (or intestinalis ) .
This parasite exists in several forms : a typical mobile flagellated form ( trophozoite ) and a form of resistance ( the cyst ) .
The trophozoite has an adhesive disc allowing it to bind to the gastrointestinal mucosa .
To grow, the parasite has to go through the two forms mentioned above : it has a life cycle :
The dog is contaminated by ingesting cysts located in the external environment ( ingestion of contaminated water , licking the ground, licking bowls ...).
It would appear that the intake of ten cysts sufficient to infect a dog. Under the action of digestive juices , the cyst is lysed at the beginning of the small intestine and releases trophozoites . These are mobile, they move along the gastrointestinal mucosa , the lining , sometimes it insert deep and adhere with their adhesive disc .
It occurs later in the small intestine, an asexual multiplication trophozoites which re-form cysts.
These cysts will eventually be eliminated in the environment through feces , one to two weeks after infection.
Note: Humans can also ingest cysts : indeed, if he gets his hands on the mouth after petting an animal ( whose coat may be contaminated with cysts ) or after handling bowls for example, there is a risk of contamination.
What is the pathogenicity of the parasite?
The pathogenicity of the parasite is variable depending on the strain of Giardia and in responsiveness and sensitivity of the subject (there was indeed symptomatic individuals, and others simply carriers).
The parasite is in two main ways :
it irritates the digestive mucosa : in fact, trophozoites lining the digestive epithelium and destroys the microvilli on the surface. Therefore enzymatic and absorption capacities of the digestive tract are highly altered .
* It robs the animal by absorbing certain nutrients (glucose, triglycerides, vitamin B12, folate , for example)
• it inhibits the action of pancreatic lipase , resulting in lipid maldigestion .
• it would disrupt bile secretion promoting intestinal bacterial overgrowth .
What are the main symptoms?
Young animals seem most receptive (especially during the period from weaning at the age of 2 years). Therefore , young animals with symptomatic giardiasis and are the major source of cysts. The incubation is several weeks.
Adults, less responsive and less sensitive subjects are healthy carriers (asymptomatic giardiasis ) and play an important role in the survival of the parasite.
The clinical presentation of giardiasis is that of a malassimilation syndrome with :
• a normal appetite increased concomitant with progressive wasting of the animal. Note also the absence of hyperthermia ;
• an increase in frequency of stool , chronic diarrhea, persistent or intermittent , non-bleeding ( loose stools, putty aspect , glossy, fat : signs of steatorrhea that is to say, the presence of undigested fat globules in stool ) ;
• discomfort on palpation of the abdomen.
The evolution is usually slow over several weeks to months and can result in wasting the diseased animal without deterioration of general condition. The prognosis remains favorable.
Note: There is an acute form rarer during which the dog has a profuse and watery diarrhea associated with decreased general condition .
How to diagnose giardiasis in livestock ?
The collection of memorials ( dog from communities ) and the Clinque table ( chronic diarrhea unresponsive to conventional treatments ) are used to guide suspicion.
The differential diagnosis must be made with exocrine pancreatic insufficiency : For this, a c- TLI assay ( Canine Trypsin - Like Immunology ) must be made from a blood sample.
Several laboratory tests can be used to highlight the parasite
• Demonstration of mobile trophozoites a rapid examination of fresh stool. The intermittent shedding of cysts that there are many false negative results. This method is much less sensitive than the next.
• Demonstration of cysts by microscopic fecal examination by the flotation technique . To avoid false negatives should be réaliserau least 3 stool examinations before dismissing the hypothesis of giardiasis : indeed, one exam detects 73% of parasite carriers , two exams 93% and three nearly 100% . In breeding , it is advisable to carry out a collective parasite fecal examination by mixing the feces of several suspects dogs to increase the probability highlighted the parasite. This examination seemed to be the method of choice although a recent study has highlighted the poor accuracy of this technique and its ineffectiveness in the diagnosis of giardiasis .
• Identification of parasite antigens in stool . A commercial kit direct immunofluorescence exists but its use needs to have a fluorescence microscope to visualize the cyst . ELISA techniques may also beings used; of human detection kits exist to detect canine parasite antigens. Nevertheless, the bibliographic data show a low sensitivity and specificity of this method. Recently, a laboratory has marketed a quick kit specific for the parasite dog and cat : this kit is easy to use ( from a rectal swab ) and allows to have a result in minutes . The laboratory reported a sensitivity of 92 % and a specificity of 99 %.
Therefore , the microscopic coproscopy requires multiply analyzes and to have a look familiar to the detection of the parasite . The newly developed rapid kits seem attractive .
How to fight against giardiasis in livestock ?
• In treating sick animals ... or carriers ...
First of all it should be noted that no treatment is 100% effective and that the lack of response to treatment in place does not allow to completely rule out giardiasis . Several reasons exist to explain the difficulty of eliminating Giardia duodenalis : 1) the parasite seems to become resistant to certain molecules , 2) general or systemic immunodeficiency disease may make it more difficult removal , 3) reinfection is easy because the cysts are very resistant in the environment and it takes little to infect an animal.
Treatment with fenbendazole ( seems effective : a recent study reported 90 % success rate in dogs experimentally infected .
The febantel , pyrantel , praziquantel combination for 3 days can also be used .
Metronidazole may also be used. . It should be noted that neurotoxicity of this molecule exists in Dogs However, there is very little risk if the dose is not exceeded .
This molecule is also interesting because it will allow to correct intestinal overgrowth of anaerobic bacteria accompanying a giardiasis .
Oxfendazole has shown efficacy in appropriate doses for 3 days.
In breeding , it is appropriate to treat all dogs except pregnant dogs and monitor the effectiveness of therapy by a Fecal examination at the end of treatment.
• By identifying carrier animals ....
For this it is necessary to perform regular checks with systematic coproscopies . Do not forget the animals of other species ( cat, herbivores, pigs) which can also be carriers.
• Adopting measures of draconian hygiene ....
Indeed , the cysts are mostly found in wetlands and easily withstand the cold (2 months to 8 ° C , 1 month at 21 ° C and 4 days at 37 ° C). By cons , they are sensitive to drying , with the quaternary ammonium as a disinfectant . Bleach seems very active on Giardia cysts .
Therefore, the parasite vectors ( farmers , technicians , equipment, animals) should be treated. To do this:
• Water bowls should be placed in height ( to avoid being contaminated by stool) and supplied with clean water.
• Cages should be cleaned with detergent , rinsed in boiling water , then disinfected with quaternary ammonium compounds : many specialties exist for the hygiene of livestock buildings.
• breeding Staff ( breeder , animal , technicians) will clean the equipment used (boots, shovels, rakes , ...) with the same products as before.
For the period of treatment to be effective it must hygienic measures last for at least 3 days.