Viable Solution for Canine Parvovirus Disease
Dr. Masood Rabbani (PhD)
Assistant Professor, Department of Microbiology,
University of Veterinary & Animal Sciences, Lahore
The disease caused by canine parvovirus (CPV-2) has been known only since 1978. This is a highly contagious infectious viral disease of sudden onset, which can attack dogs of any age.
If a puppy seems sick, several diseases should immediately be suspected. The most common infectious canine disease is parvovirus disease due to a highly contagious virus, transmitted from dog to dog, spread by infected feces.
This disease is very serious and often fatal and can leave recovered dogs with lasting after effects. Mortality associated with canine parvovirus infection is reported to be 16-35 per cent on global basis.It is spread primarily via contact with the feces of an infected dog. The virus can also be carried on the shoes and clothing of people. The incubation period of the disease is three to twelve days.
Signs of parvovirus are severe gastrointestinal distress, usually vomiting and bloody diarrhea, accompanied by fever and obvious illness and listlessness. Symptoms are generally sudden but may be preceded by a loss of appetite.
Diagnosis is based on an appropriate history, and the clinical signs and confirmed by a positive faecal haemagglutination (HA) test or ELISA test. Leukopenia or lymphopenia is seen in most infected dogs during the course of illness. The detection of parvovirus particles in the faeces can also be detected using immunoelectron microscopy. Very expensive commercial diagnostic kits are available for DNA probing of even very minute quantity of parvoviruses in serum and faecal suspensions. Differential diagnosis may be done from salmonellosis, compylobacteriosis, canine coronavirus infection and canine distemper.
There is no specific therapy to eliminate the virus. Most dogs recover with appropriate supportive care directed to restoration of fluid balance. Food and water should be withheld until vomiting has subsided.During the acute phase of infection massive amounts of infectious virus are excreted and since the virus is very resistant to chemical and physical influences, infectious virus may persist in biofilms for long periods in contaminated areas.
Disinfection of the contaminated area with household bleach (1:30) is the only potent inactivator of parvovirus. Pups should be kept isolated from adults. Prevention by proper vaccination is by far the best course to take. Three doses of vaccine are recommended at 6, 9, and 12 weeks of age.
High number of stray dogs roaming about in the streets probably reflects a poor husbandry of these pets in the municipalities. These dogs through their infected faeces contaminate public places. In this way healthy dogs pick up infection and become ill.
The parvovirus disease is prevalent in Pakistan at a very high rate. One of the studies by the author, based on clinical suspection, indicated a 21.33 per cent incidence of canine parvovirus. These clinically suspected case could not be confirmed/diagnosed by any lab test. To ascertain and confirm the presence of parvovirus particles in faeces of suspected dogs present study is undertaken first time in Pakistan.
The clinically suspected cases approached to clinics were with the history of anorexia, vomiting, and diarrhoea with or without streaks of blood, accompanied by fever. Some of the dogs were excreting plain blood instead of faeces. Out of these suspected canine parvovirus cases 100 dogs were randomly selected for through examination. German Shepherd and their cross bred dogs were at increased risk of canine parvovirus disease as out of these 100 cases 84 per cent of the cases belonged to this breed. Rest of the cases belonged to the breeds: Rottweiler (9 per cent), Doberman (5 per cent) and Bull Terrier (2 per cent).
Out of 100 cases 85 (85 per cent) were male dogs and rest of 10 per cent were female. History of these suspected dogs showed that 93 per cent were not vaccinated against canine parvovirus and 7 per cent were vaccinated weeks after due date of vaccination. Based on the information collected from owners on a prescribed proforma, few (8 per cent) of the dogs suspected of parvovirus disease were bought from the same private kennel.
This reflected on one hand the absence of protective maternal antibodies against canine parvovirus in blood of pups from non-vaccinated bitches and on the other hand presence of active challenge of parvovirus in environment in general and at the kennel premises in particular. In the present study it was noticed that the 80 per cent of the pups were sold between the ages of 2-6 weeks thereby sparing ample chances to contract this disease.
The 10 per cent pups separated at very early age (day 1 to day 14) could not consume their mother's milk thereby remained deficient in getting passive immunity through colostrums. Most of the remaining 10 percent pups sold after this age (7 weeks and above) were also not vaccinated by some of the kennels to save the additional cost of vaccination (almost Rs. 600/- per pup for priming and booster) to the sale price of the pup.
Out of 100 faecal samples tested for haemagglutination (HA) test, 76% were positive for parvovirus antigens. The Escherichia coli was the main bacteria in the faeces.
No chemotherapeutic agent is available for the treatment of the canine parvovirus disease. Vet-varsity scientists 1st time discovered the solution for this disease. Dr. Masood Rabbani is the leader of this research group on canine diseases. Dr. Khushi Muhammad is patronizing this group.
Two of the postgraduate students of the Department of Microbiology namely: Dr. Umar Ahmad and Dr. Muzzaffar Ali, are actively working on detailed characterization of CPV to achieve further objectives. In this project, two clinically healthy dog have been vaccinated against CPV-2. This vaccination induces specific antibodies in blood. The blood from the vaccinated dogs is routinely collected to separate serum for therapeutic use in parvovirus-affected dogs. These antibodies in the serum are titrated and haemagglutination inhibition (HI) units of these antibodies are determined. It is observed that 1ml of 64 HI units of antibodies against CPV-2 is able to give 100 per cent protection of the affected dogs.
It is necessary to inject 1ml of 64 HI units of antibodies soon after the onset of clinical signs of the parvovirus disease. The same quantity of serum can even be injected to remaining contact dogs staying in the same premises/kennel.
No need of injecting this serum to dogs brought for treatment one week or so after the appearance of clinical symptoms. Because there may be production of dogs own antibodies against parvovirus disease. This crude extract of antibodies is no much costly. A dog owner / breeder can easily afford this treatment for his dogs / kennel.
It is concluded that after necessary processing the antibodies in hyperimmunized serum can effectively be used to cure the parvovirus infected dogs. It is further added that such hyperimmunized serum is available in the market for commercial use.
Source: Business Recorder