Canine Parvoviral Enteritis (CPV)

Canine Parvoviral Enteritis (CPV) is a highly contagious viral disease of young dogs characterized by acute haemorrhagic gastroenteritis.

Etiology

• Canine Parvoviral Enteritis (CPV) is caused by  canine parvovirus -2  (CPV-2) belongs to family Parvoviridae.
• It is  a single stranded DNA virus.
• The virus is stable in the environment. They are resistant to lipid solvents and wide pH range (pH 3.0 to 9.0). The virus is inactivated by formalin, beta-propiolactone, sodium hypochlorite and oxidizing agents.

Epidemiology

• Distribution: Worldwide.
• Rottweiler, Doberman, Bull terrier, Spaniels and German shepherd have been described to increased risk of disease.
• Young unvaccinated or incompletely vaccinated dogs at 6 wks to 6 month age group are most susceptible.
• The severity of infection increases, when dog have concurrent infection with intestinal parasitism, enteric pathogens (eg. Clostridium spp, campylobacter sp, Giarrdia spp and Coronavirus infection).

Source of infection

• Infected animal shed virus  in faeces for upto 10 days after recovery.

Transmission

• Direct contact with an infected animals.
• Indirectly through contaminated fomites.

Pathogenesis

Clinical manifestation

Incubation period is 3-7 days for Canine Parvoviral Enteritis (CPV). Clinical signs manifested in two types:

• (a) Parvoviral enteritis
• (b) Parvoviral myocarditis

(a) Canine parvoviral enteritis

• Lethargy, anorexia, fever.
• Vomition is often severe.
• Rapid onset of dehydration.
• Haemorrhagic small bowel diarrhoea.
• Elevated rectal temperature (40^oC-41 ^oC ).
• Abdominal pain.
• Severely affected animal may present collapsed , prolonged capillary refill time, poor pulse quality.
• Tachycardia.
• Hypothermia.
• Neurological signs may occur as a result of haemorrhage in CNS or disseminated intravascular coagulation or hypoglycemia.
• Immunity after natural infection is persist for 20 months.

(b) Canine Parvovirus myocarditis

• The myocarditis can develop from infection in utero or in pups younger  than 6 weeks of age.
• All pups in a litter are usually affected.
• Pups with parvoviral myocarditis is often die, they showed symptoms of dyspnoea, crying and retching before death.
• Cardiac dysfunction can be preceded by enteric form.
• Sudden onset of congestive heart failure occur in apparently normal pups at 6 weeks to 6 months of age.
• Death is due to cardiogenic shock.

Necropsy Finding

• Discoloured intestinal walls.
• Haemorrhagic intestinal contents.
• Congestion of abdominal and thoracic lymph node.

Sample collection

• Faeces and paired sera sample.

Diagnosis

• Based on clinical signs and lesion.
• Clinical pathology:Leukopenia, lymphopenia and neutropenia.
• Serum biochemistry: Prerenal azotemia, hypoalbuminemia, hypokalemia, hyponatremia, hypochloremia and hypoglycemia.
• Detection of antigen in faeces by ELISA and PCR, HA&HI test.
• Antibodies in serum by HI test.

Treatment

• Restoration of body fluids and electrolytes by administration of isotonic balanced electrolyte solution.
• Oral electrolyte solution is indicated in the absence of vomition.
• Use antimicrobial agents to prevent secondary infections (mostly for gram negative bacteria)-Gentamicin- 6-8 mg/kg b.wt given after fully hydration, alternatively third generation penicillin or  cephalosporin can be used.
• Antiemetic drugs- metoclopromide @0.2-0.4 mg/ kg b.wt and ondansetron  @ 0.1- 0.15 mg/ kg.b.wt.
• Motility modifiers- Loperamide HCL.
• Gastric protectants- Ranitidine 2-4 mg/kg b.wt.
• Whole blood or plasma transfusion @10-20 ml/ kg b.wt.
• Plasma volume expanders @10-20 ml/ kg b.wt.
• Colloids @ 20 ml/kg b.wt should be used 1/3^rd of total fluid requirement to maintain plasma oncotic pressure.
• Transfusion of specific hyperimmune serum.

Prevention and control

• Live attenuated vaccine administered to pups at 6 -8  weeks of age, two booster at 3-4 weeks interval after primary dose then annual revaccination every year.
• Strict hygienic measures should be adopted in kennel.
• Cleaning and disinfection of kennel with 1:30  bleach solution.
• Segregation of infected animal from the normal healthy animals.

Canine Parvovirus-1 Infection

• Canine Parvovirus-1 Infection is a minute virus of canine. The Physical and chemical properties virus is similar to CPV-2.
• The disease is restricted to pups less than 3 weeks of age.

Clinical manifestation

• Infrequently mild diarrhoea, enteritis, pneumonitis, myocarditis and lymphadenitis in pups between 5- 21days of age.
• Affected pups usually have diarrhoea, vomiting and crying constantly.
• Some puppies have respiratory signs without enteric signs.
• Transplacental infection causes bitch failure to conceive or abortion.

Necropsy Finding

• Thymic edema and atrophy and enlarged lymph node.

Treatment and prevention

• Mortality  may be reduced by  ensuring environmental temperature of new born pups kept warm, adequate nutrition and hydration.
• Currently no vaccine is available.