Viral diseases dogs and cats (Canine and Feline)

This list covers major viral diseases affecting dogs and cats, detailing their causative agents, family, genera, transmission, replication, pathogenesis, clinical signs, and control strategies.

1. Viral Diseases of Dogs

1.1 Canine Distemper (CD)

• Causative Agent: Canine Distemper Virus (CDV)
• Family: Paramyxoviridae
• Genus: Morbillivirus
• Transmission: Aerosolized droplets from infected animals; contact with respiratory secretions.
• Replication Cycle
  • CDV attaches to SLAM (Signaling Lymphocyte Activation Molecule) receptors on immune cells.
  • Enters via fusion, replicates in the cytoplasm, assembles, and exits via budding.
• Pathogenesis
  • Multisystemic: Targets respiratory, gastrointestinal, and nervous systems.
  • Leads to lymphopenia, immunosuppression, and demyelination of neurons.
• Clinical Signs
  • Respiratory: Coughing, nasal/ocular discharge.
  • GI: Vomiting, diarrhea.
  • Neurological: Seizures, ataxia, paralysis.
  • Hyperkeratosis of footpads (“hard pad disease”).
• Control
  • Vaccination: Modified live vaccines.
  • Isolation and supportive care.

1.2 Canine Parvovirus (CPV)

• Causative Agent: Canine Parvovirus (CPV-2)
• Family: Parvoviridae
• Genus: Protoparvovirus
• Transmission: Fecal-oral route; highly stable in the environment.
• Replication Cycle
  • Virus infects rapidly dividing cells in crypts of intestinal villi.
  • Replicates in the nucleus, released through cell lysis.
• Pathogenesis
  • Targets intestinal crypts, lymphoid tissues, and bone marrow.
  • Causes villous atrophy, lymphopenia, and secondary infections.
• Clinical Signs
  • Severe bloody diarrhea, vomiting, dehydration, fever, lethargy.
  • High mortality in untreated cases.
• Control
  • Vaccination: Core vaccine for puppies.
  • Strict hygiene and isolation.

1.3 Canine Adenovirus (CAV)

• Causative Agent
  • CAV-1: Infectious Canine Hepatitis (ICH).
  • CAV-2: Respiratory disease.
• Family: Adenoviridae
• Genus: Mastadenovirus
• Transmission: Fecal-oral (CAV-1); aerosol (CAV-2).
• Replication Cycle
  • Attaches to cellular receptors, replicates in the nucleus, exits via lysis.
• Pathogenesis
  • CAV-1: Hepatocellular necrosis, endothelial damage, corneal edema (“blue eye”).
  • CAV-2: Upper respiratory tract infection.
• Clinical Signs
  • CAV-1: Vomiting, jaundice, abdominal pain, bleeding disorders.
  • CAV-2: Coughing, nasal discharge, fever.
• Control
  • Vaccination: Cross-protective (CAV-2 vaccine prevents both types).

1.4 Rabies

• Causative Agent: Rabies virus
• Family: Rhabdoviridae
• Genus: Lyssavirus
• Transmission: Bite wounds; saliva of infected animals.
• Replication Cycle
  • Entry via bite, replicates locally, then spreads to the CNS via peripheral nerves.
• Pathogenesis
  • Encephalitis, neuronal dysfunction, and death.
• Clinical Signs
  • Prodromal phase: Behavioral changes.
  • Furious form: Aggression, hyperexcitability, paralysis.
  • Paralytic form: Progressive paralysis, death.
• Control
  • Vaccination: Core vaccine for dogs.
  • Post-exposure prophylaxis (PEP) for humans.

2. Viral Diseases of Cats

2.1 Feline Panleukopenia (FPV)

• Causative Agent: Feline Parvovirus
• Family: Parvoviridae
• Genus: Protoparvovirus
• Transmission: Fecal-oral route; highly contagious.
• Replication Cycle
  • Infects rapidly dividing cells (intestinal crypts, bone marrow).
• Pathogenesis
  • Causes immunosuppression, enteritis, and cerebellar hypoplasia in kittens.
• Clinical Signs
  • Vomiting, diarrhea, fever, lethargy, dehydration.
• Control
  • Vaccination: Core vaccine for cats.

2.2 Feline Leukemia Virus (FeLV)

• Causative Agent: Feline Leukemia Virus
• Family: Retroviridae
• Genus: Gammaretrovirus
• Transmission: Saliva, nasal secretions, grooming, vertical (mother to kittens).
• Replication Cycle
  • Retrovirus integrates into host DNA and establishes persistent infection.
• Pathogenesis
  • Immunosuppression, anemia, lymphoma.
• Clinical Signs
  • Recurrent infections, weight loss, pale gums, tumors.
• Control
  • Vaccination and test-and-isolate strategies.

2.3 Feline Immunodeficiency Virus (FIV)

• Causative Agent: Feline Immunodeficiency Virus
• Family: Retroviridae
• Genus: Lentivirus
• Transmission: Bite wounds, vertical transmission.
• Replication Cycle
  • Targets T-cells, integrates into the genome, causing immunodeficiency.
• Pathogenesis
  • Progressive immunosuppression.
• Clinical Signs
  • Chronic infections, oral ulcers, weight loss.
• Control
  • Test-and-isolate strategies; limited vaccine availability.

2.4 Feline Infectious Peritonitis (FIP)

• Causative Agent: Mutated Feline Coronavirus (FCoV)
• Family: Coronaviridae
• Genus: Alphacoronavirus
• Transmission: Fecal-oral; primarily from asymptomatic carriers.
• Replication Cycle
  • Mutates in the host, leading to macrophage tropism.
• Pathogenesis
  • Immune-mediated vasculitis and organ failure.
• Clinical Signs
  • Effusive (wet): Ascites, pleural effusion.
  • Non-effusive (dry): Granulomas, neurological signs.
• Control
  • No effective vaccine; focus on reducing exposure in multi-cat settings.

Summary Control Strategies

1. Vaccination: Core vaccines for common viruses.
2. Biosecurity: Isolation, hygiene, and minimizing animal stress.
3. Surveillance: Early diagnosis and prompt intervention.
4. Supportive Care: Fluid therapy, antibiotics for secondary infections, and nutritional support.