1. Viral Diseases 4-H Veterinary Science Extension Veterinary Medicine Texas AgriLife Extension Service College of Veterinary Medicine and Biomedical Sciences Texas A&M System http://aevm.tamu.edu

2. Objectives Describe pox diseases List and describe common viral respiratory diseases Describe viral abortion diseases Describe meningitis and encephalitis Describe hepatitis Describe anemia

3. Background Remember Five infectious diseases Bacterial Viral Fungal Parasitic Rickettsial

4. Infectious disease An illness due to a specific infectious agent or its toxic products that arises through transmission of that agent or its products from an infected person, animal or reservoir to a susceptible host, either directly or indirectly

5. Viruses An ultra-microscopic micro-organism, parasitic within living cells and of which many can cause disease. They consist of a strand of nucleic acid (DNA or RNA) that contains genetic instructions concerning viral reproduction that is enveloped by a protein coat Not alive nor dead, has DNA or RNA, makes copies of itself, must be inside a living cell

6. Antibiotics have no affect Treatment is to easy symptoms Vaccines available Entrance of virus into cell is “viral infection” Virus uses cell structures to replicate new viruses

7. Animal viruses look like Capsid  Outer shell Core  Surrounds genetic material Envelope  Kind of life skin around outside of virus  Lipid bilayer (membrane) Genetic material Function Make more viruses

8. Harmful Replication leads to cell death Takes over cell function How exit cell Budding  Few at a time Lysis  Cell membrane ruptures

9. All living things can be affected Animals People Plants Infectivity Single species  Humans – smallpox 1-2 Species  Influenza Particular kind of plant  Tobacco mosaic virus Particular species of bacteria  Lambda bacteriophage – E.coli

10. Different kinds of viruses Double-stranded DNA Single-stranded DNA Double-stranded RNA Single-stranded RNA Retroviruses  Unique kind of single-stranded RNA virus Can mutate Kill virus Make new-strain

11. Infectivity The characteristic of a disease agent that embodies capability of entering, surviving in, and multiplying in a susceptible host Basically How efficiently it invades specific animal’s tissues

12. Specificity Its ability to infect certain animal species and tissues

13. Symptoms Depend on tissue affected Skin Blood Liver Uterus Fetus Brain Lungs Stomach Intestines Bloodstream (viremia)  Phase of the disease

14. Exposure – symptoms Recent exposure Normal incubation period Long ago exposure Replicate/multiply immediately  May become dormant  Recrudesces  After stressful event After incubation period may exhibit symptoms

15. General Conditions Hepatitis Infectious canine hepatitis (ICH) Causes  Liver inflammation  Viremia  Affects liver, kidneys, spleen and lungs Not zoonotic Symptoms  Decreased appetite  Appear depressed  Fever  Opacity of one or both corneas of their eyes (so-called ‘Blue Eye’) one to two weeks later  Respiratory signs  Eye and nose discharge  Cough Prevention  Vaccine (puppy)

16. Anemia Systemic viral disease Transmitted Vectors Vehicles Symptoms Fever Anemia Weight loss Abortion Examples Equine Infectious Anemia (EIA) Bluetongue – cattle Leukosis – cattle Malignant catarrhal fever - cattle

17. Skin Warts Definition Fibrous tumors of the skin and occasionally the mucous membranes Species affected Animals  Cattle, dogs, rabbits Humans Transmission Direct contact Arthropods Symptoms Cauliflower-type growths  Head  Neck  Shoulder  Mouth  Vulva  Penis Vaccine available

18. Pox Definition Acute skin condition caused by replication of poxviruses in the skin Transmission Direct transmission (through skin) Arthropods (vectors) Types of lesions Bumps Blisters Pustules Crusts Named after affected animals

19. Fowl Pox Swine Pox Cow Pox

20. Respiratory System Pneumonitis; Pneumonia Contagious infection of the lungs and causes severe damage to the lung Causes Hemorrhages Edema Emphysema Bacteria can complicate Symptoms Cough Fever Heavy breathing Lethargy Decreased appetite

21. Viral respiratory diseases Infectious Bovine Rhinotracheitis (IBR) Bovine Parainfluenza-3 (PI³) Equine Rhinopneumonitis Equine Influenza Swine Influenza Canine Infectious Tracheobronchitis (Kennel Cough) Canine Distemper Feline Viral Rhinotracheitis (FVR) Feline Calicivirus (FCV) Fowl Infectious Bronchitis Fowl Infectious Laryngotracheitis (LT) Fowl Influenza

22. Reproductive System Abortion Viruses terminate pregnancy by attacking Fetus Embryo Placenta Uterus Examples Swine parvovirus Infectious bovine rhinotracheitis (IBR) Bovine viral diarrhea (BVD) Swine pseudorabies Equine rhinopneumonitis

23. Nervous System Meningitis Definition Inflammation of the brain covering (meninges) Encephalitis Definition Inflammation of the brain tissue Causes damage to brain tissues

24. Digestive System Gastroenteritis Affects Stomach Intestines Highly contagious Symptoms Vomiting Diarrhea More severe in young Dehydration and electrolyte imbalance

25. Types Rotavirus Coronavirus Parvovirus Feline panleukopenia Bovine viral diarrhea (BVD) Swine transmissible gastroenteritis (TGE)

26. Summarize Viral conditionAffectsSystem EncephalitisBrainNervous HepatitisLiverGeneral AnemiaBloodGeneral AbortionFetusReproductive MeningitisMeningesNervous GastroenteritisStomach, intestine Gastrointestinal PneumonitisLungsRespiratory WartsSkin

27. Meningoencephalitis Symptoms Depression Blindness Partial or complete paralysis Wobbling Seizures Coma Delirium

28. Vaccination is important No treatment Types Rabies Equine encephalomyelitis  VEE, WEE, EEE Canine distemper Parvovirus Swine pseudorabies