Viral Diseases of Domestic Animals

Viral Diseases of Dogs

A. Rabies (Hondsdolheid)

  • Overview: A fatal viral disease caused by Rabies lyssavirus, affecting warm-blooded vertebrates, posing a serious zoonosis risk for humans.

  • Preventive Measures: Vaccination of at-risk animals and humans is essential.

A1. Sources of Infection

  • Transmission: Primarily through bites from infected animals; vector species include dogs (especially unvaccinated), mongooses, jackals, and foxes.

  • Rare Transmission: Infected ruminants can transmit the virus, but it is uncommon.

A2. Route of Entry / Pathogenesis

  • Pathway: Introduced through bites leading to nervous system infection.

  • Virus concentrated in saliva

  • Incubation lasts weeks to months

  • Spreads to the brain and spinal cord

A3. Clinical Signs
A3.1. In Dogs

Excitability, aggression, inability to swallow, excessive salivation, aimless wandering

  • Fixed stare, characteristic howling/barking, paralysis leading to death

  • Forms: Furious (aggressive behavior) or dumb (neurological symptoms).

A3.2. In Cattle

  • Unsuccessful drinking attempts (hydrophobia), salivation, aggression, locomotion disturbances, and severe gastrointestinal symptoms.

A3.3. In Wildlife

  • E.g., mongooses, jackals exhibit curiosity/dangerous behavior; aggressive attacks on other animals.

A4. Diagnosis

  • Handle with care; veterinary intervention is crucial for suspected cases.

  • Observation, euthanasia, and laboratory testing of brain tissue are standard procedures.

A5. Community Preventative Measures

  • Vaccination policies for dogs/cats (every 3 years).

B. Canine Distemper

  • Overview: Highly contagious viral disease affecting dogs, characterized by fever, pneumonia, and neurological symptoms.

  • Pathogen: Canine morbillivirus.

B1. Sources of Infection

  • Excreted through aerosols and body fluids by infected animals.

  • Common in unvaccinated populations, particularly in high-density settings (animal shelters, kennels).

B2. Transmission

  • Mainly through respiratory droplets.

  • At-Risk: Puppies and unvaccinated dogs in close contact.

B3. Clinical Signs

  • Acute: Mucopurulent discharge, coughing, vomiting, diarrhea, skin lesions, thickened paw pads.

  • Chronic: Neurological symptoms such as seizures or involuntary muscle twitching.

B4. Diagnosis

  • Combination of clinical signs, history, and laboratory tests.

B5. Treatment

  • No specific antiviral; supportive care includes antibiotics for secondary infections and management of dehydration.

C. Kennel Cough

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  • Overview: Respiratory syndrome caused by multi-factorial pathogens including Mammalian orthorubulavirus 5 and Canine mastadenovirus A.

C1. Transmission & Sources of Infection

  • Primarily spread in kennels through coughing and close contact, worsened by stress and poor environmental conditions.

C2. Clinical Signs

  • Gagging and severe coughing, usually following kennel exposure.

C3. Treatment & Prevention

  • Supportive treatment; antibiotics for systemic signs. Vaccination available and recommended before kennel entry.

D. Canine Parvovirus (CPV)

  • Overview: Highly contagious gastroenteritis in dogs.

D1. Clinical Signs

  • Severe dehydration, vomiting, and diarrhea; rapid weight loss.

D2. Diagnosis

  • Based on clinical signs and laboratory tests (ELISA, PCR).

D3. Vaccination and Management

  • Vaccines at 8 weeks; revaccination every 3 years.

E. Infectious Canine Hepatitis (ICH)

Image result for infectious canine hepatitis

  • Overview: Contagious viral disease with serious effects on younger dogs.

E1. Clinical Signs

  • Jaundice, abdominal pain, bloody diarrhea, and vomiting.

E2. Diagnostics

  • Fluid therapy, blood transfusions, vaccination.

F. Canine Herpesvirus

  • Overview: Fast-acting disease in puppies leading to high mortality rates; requires careful environmental management post-whelping.

Viral Diseases of Cats

A. Feline Respiratory Disease (FRD)

  • Overview: Multifactored disease caused mainly by FeHV-1 and FCV, often with secondary infections.

A1. Transmission

  • Close contact with infected carriers during stress phases.

A2. Clinical Signs & Management

  • Fever, sneezing, eye discharge; treat with anti-microbials and maintain hydration.

A3. Vaccination Schedule

  • Vaccinations recommended starting at 8 weeks and revaccination annually.

B. Feline Panleukopenia (FPL)

  • Overview: Highly contagious, fatal to young cats, destroys actively dividing cells.

B1. Treatment & Prevention

  • Supportive care; vaccination at an early age critical for prevention.

C. Feline Leukemia Virus (FeLV)

  • Overview: Oncovirus leading to a variety of health issues, vertically transmitted.

C1. Control Measures

  • Test before vaccination; manage only negative cats with vaccinations.

D. Feline Immunodeficiency Virus (FIV)

  • Overview: Lentivirus leading to chronic immune suppression.

D1. Signs & Management

  • Acute signs lead to long-term chronic effects requiring supportive treatment.

E. Feline Infectious Peritonitis (FIP)

  • Overview: Fatal disease linked to coronavirus mutations.

E1. Management & Control

  • High prevention is critical; avoid exposure in multi-cat environments.

Viral Diseases of Horses

A. African Horse Sickness (AHS)

  • Overview: Transmitted by midges, characterized by serotypes; affects horses.

A1. Management

  • Vaccination before peak seasons; control of insect populations critical.

B. Equine Encephalosis Virus Infection

  • Overview: Mild cases may develop severe neurological signs; control via quarantines.

C. Equine Influenza

  • Overview: Highly contagious respiratory disease that affects all equids.

C1. Prevention & Control

  • Routine vaccinations, isolation of sick animals, and infection control measures are necessary.

D. Equine Rhinopneumonitis/Abortion

  • Overview: Caused by EHV-1 and EHV-4; vaccination of pregnant mares and biosecurity measures critical.

Viral Diseases of Sheep and Goats

A. Bluetongue (BT)

  • Arthropod-borne illness affecting sheep; monitor vector populations.

A1. Clinical Signs

  • Hyperemia of mucosa, excessive salivation; steady management prevents high mortality.

B. Orf (Contagious Pustular Dermatitis)

  • Overview: Affecting young animals primarily; management through supportive care.

C. Rift Valley Fever (RVF)

  • Mosquito-borne virus; vaccination provides lifelong immunity.

Viral Diseases of Cattle

A. Bovine Viral Diarrhoea/Mucosal Disease (BVD/MD)

  • Overview: Subclinical or severe with potentially fatal outcomes; effective management critical.

A1. Control Strategies

  • Quarantine, vaccination, and testing are essential for herd immunity.

B. Lumpy Skin Disease (LSD)

  • Caused by Capripox virus; control measures include vaccination.

C. Foot and Mouth Disease (FMD)

  • Highly contagious; vaccination and management protocols must be strictly followed to prevent outbreaks.