1. Infectious diseases of horse

4. Druhově specifické zvláštnosti při používání antibiotik:  Peniciliny podané per os mohou narušit bakteriální fermentaci v caeku a kolonu u dospělých zvířat vedoucí k vážným poruchám trávení.  Tetracykliny mohou vyvolat těžké enterokolitidy u koní vystavených stresu.  S výjimkou perorálního podání erythromyciniumestolatu spolu s rifampicinem hříbatům při rhodokokové pneumonii (Rhodococcus equi) je třeba se vyvarovat použití makrolidů a linkosamidů.  Také je třeba se vyvarovat podávání fluorochinolonů - obecně u rychle rostoucích zvířat - zejména hříbatům.

6. Bacterial infection in respiratory system  The upper RS  airsaculitis, acute sinusitis –Streptococcus equi – subsp.zooepidemicus  strangles –Streptococcus equi subsp.equi (vaccine)  The lower RS  bronchopneumonia - acute –S.equi subsp.zooepidemicus  bronchopneumonia - chronic  S.equi subsp.zooepidemicus  Staphylococcus intermedius  E.coli,  Klebsiella spp.  Enterobacter spp.  Salmonella spp.  Rhodococcus equi  Actinobacillus equuli  Pasteurella spp.  Fusobacterium necroforum  Bacteroides spp.

7. Respiratory system - Viruses Equine Rhinopneumonia (EHV-1 and 4) Equine viral arteritis Equine Influenza Equine Rhinovirus Equine Adenovirus

8. Equine Rhinopneumonia  Etiologic agents- EHV-4, EHV-1  Virus Replication on mucosal surface of respiratory system, establishment of latency  Rhinofaryngitis, tracheobronchitis, fever  Disease of young horses(up to 2 years), older animals – mild clinical signs

9. Equine Rhinopneumonia  Incubation period 2-10 days  Frequent secondary bacterial infection  EHV-1 biphasic fever  EHV-1 – fulminant pneumonia in transplacental infection (late pregnancy) RPK

10. Equine Adenoviruses  Viruses with low virulence  Ocurrence in the age of 3 – 6 months  Mostly subclinical  Horeses are periodically reinfected  Bacterial superinfections

11. Equine Adenoviruses  Adenoviral pneumonia –Immunosupression –Failure of passive transfer of antibodies  Polysystemic disease –SCID (severe combined immunodeficiency) in arabian horses

12. Equine Influenza  Acute febrile, highly contagious disease  Incubation period 1-3 days  Dyspnoe, cough, fever, rhinitis, conjunctivitis FLU

13. THE ALIMENTARY SYSTEM  acute enteritis –Salmonella spp –Actinobacillus equuli –Clostridium perfringens type A cpb2+  chronic enteritiS –L.intracellularis  acute peritonitis –enterobacteria –Bacteroides spp. –Bacteroides fragilis –Rhodococcus equi –Actinobacillus equuli

14. THE URINARY SYSTEM  pyelonephritiS  Escherichia coli   cystitis, uretritis  E.coli, P.mirabilis  Klebsiella spp., Enterobacter  Actinobacillus equuli  Streptococcus equi subsp.zooepidemicus  Pseudomonas aeruginosa

15. THE REPRODUCTIVE SYSTEM  endometritiS –E.coli, K.pneumoniae –Pseudomonas spp. –S.equi subsp.zooepidemicus  orchitis, epidimitis, vesiculitis –S.equi subsp.zooepidemicus  abortions –Salmonella spp., S.Abortus equi

16. Urogenital system- Viruses EHV-1EHV-3 Equine viral arteritis Equine infectious anemia

17. Equine virus abortion  Virus is ubiqituous in the horse population, animals became infected in the first year of age  Latency in the ganglion trigeminale  abortogennic strains (various level of endotheliotropism) EHV-1

18. Pathogenesis  Epithelial cells  Leukocytes  Endothelial cells  In respiratory tract,  immune system  Pregnant uterus EHV-1

19. Pathogenesis  Primary replication - epithelial cells of respiratory tract  Infection of endothelial cells of vessels in nasal region, viremia associated with monocytes and lymphocytes.  Secondary replication in endothelial cells of the uterus, CNS, testes, endocrinne organs, infection of ganglion trigeminale EHV-1

20. Viremia (Lymphocytes) Infection of the uterus... Latency (lymphocytes, gangl. trigem.) Establishment of latency Reactivation EHV-1

21. Equine Viral Arteritis  Virus is ubiqitous  American isolates are more virulent  Incubation period 3 – 14 days  Subclinical course  Clinical signs: fever, leukopenia, oedema of scrotum and abdomen, conjunctivitis, nasal and ocular discharge, abortion  Clinical signs: fever, leukopenia, oedema of scrotum and abdomen, conjunctivitis, nasal and ocular discharge, abortion (10 – 60%) E V A

22. Pathogenesis Initial infection of bronchial macrophages Following 48 h. regional lymph-nodes, 3. day viremia Secondary replication in the walls of medium and small vessels Longlasting immunity follows natural infection(up to 3 years). Protection mediate by colostral antibodies last for 2 – 6 months, but interferes with vaccination. E V A

23. Pathogenesis  Respiratory route – primary and most frequent way of infection, virus is shed for 7 – 14 dní  Infected semen - virus id transmitted from persistently infected stallion to the mare.  In stallions virus can persist in accessory glands for the life. Perzistence is testosteron dependent! E V A

24. EHV-1 × EVA  EHV-1 –Virus reactivation preceedes abortion for months –Pulmonary eodema, transudate in the thoracic cavity, petechias in myocardum of the foetus  EVA –Abortion follows the disease of mare –Foetus is partially autolysed –Without specific changes

25. Equine exanthema coitale  Occurs in mares and stallions (vesicular and pustular changes, ulcerations)  Virus replicationon the mucosa of genital tract  Infection is „self-limiting“ because of the termosensitivity of the virus  Ulceration are often contaminated by bacterias EHV-3

26. THE CENTRAL NERVOUS SYSTEM  meningo-encefalitis(secondary infection) –S.equi subsp.zooepidemicus –enterobacteria  Tetanus (Clostridium tetani)

27. CNS infection - Viruses EHV-1 Myeloencefalopathy Rabies Bornas disease

28. EHV-1 Myeloencephalopathy  Virus strains displaying endotheliotropism  Ischemic changes due to infection of vascular endothelium (vasculitis, thrombosis, petechias in the CNS)  Dysuria, cystitis (dysfunction of motor. neurons)  Infection of mare in 2/3 pregnancy  Higher incidence during winter and spring  Paresis, ataxia of pelvic limbs

29. THE EYE  bacterial conjunctivitis –S.equi subsp.zooepidemicus –Pseudomonas aeruginosa –Staphylococcus intermedius –Moraxella equi –Listeria monocytogenes –Acinetobacter spp. –Corynebacterium spp. –Bacillus spp.

30. SEPTICEMIA  E.coli  Salmonella spp.  Actinobacillus equuli  S.equi subsp.zooepidemicus  Staphylococcus intermedius  CNS.

31. Equine infectious anemia  Disease of odd-toed animals  Acute febrile disease with frequent exacerbations (2-3 týdny)  Virus is replicating in monocytes and macrophages  Virus transmission  blood sucking insect  needles (vaccination) E I A

32. Pathogenesis  Antigenic variations – cause of frequent exacerbations  Immunocomplexes of free virus with antibodies - glomerulonephritis,  Virus is sensitizing erythrocytes and thrombocytes to the action of complement– anemia, petechias, icterus, hearth failure, oedemas  Splenomegalia E I A

33. THE SKIN  folikulitis a furunculosis  Staphylococcus intermedius  lymphangitis  S.equi subsp. equi  Mycotic infection –Microsporum canis –Trichophyton equinum(vaccines)

34. Equine Papillomaviruses Virus type LesionsLocalisation EqPV-1Papillomas Hairy skin EqPV-2PapillomasGenitals BPV-1Sarcoids BPV-2Sarcoids

35. Equine Papillomaviruses  Typical cytopathology on the skin  Histological changes in the stratum granulosum (inclusions)  Virus id shed by contact and desquamation  Decontamination of the environment is impossible

36. MUSCULOSKELETAL SYSTEM  Septic artritis –E.coli –Salmonella spp. –Actinobacillus equuli –Pseudomonas aeruginosa –S.equi sp.zooepidemicus –Rhodococcus equi –Staphylococcus intermedius

37. WOUNDS  Traumatic  Clostridium perfringens type A  S.equi sp.zooepidemicus  Pseudomonas aeruginosa  Surgical wounds  enterobacteria  Actinobacillus equuli  Pseudomonas aeruginosa  S.equi subsp.zooepidemicus  Staphylococcus aureus  S.intermedius

38. Nosocomial infection in veterinary hospital  multirezistant strains –Actinobacillus equuli –Staphylococcus inetrmedius –S. aureus (MRSA) S. equi supsp. zooepidemicus