Chapter 22

1. Chapter 22 Large Animal Medical Nursing

2. Learning Objectives List the common diseases and disorders of horses and describe the causes, symptoms, treatment, and control List the physiological parameters used to monitor hospitalized equine patients Describe unique requirements for care of hospitalized recumbent and infectious equine patients Describe concerns related to placement and care of intravenous catheters in horses

3. Learning Objectives List common medications used on equine patients and describe their indications Describe routine laboratory studies performed on equine patients List the common diseases and disorders of food animals and describe the causes, symptoms, treatment, and control

4. Learning Objectives List the common diseases and disorders of small ruminants and describe the causes, symptoms, treatment, and control List the common diseases and disorders of swine and describe the causes, symptoms, treatment, and control List the common diseases and disorders of camelids and describe the causes, symptoms, treatment, and control

5. Equine Medicine

6. Strangles Highly contagious disease caused by Streptococcus equi Clinical signs Difficult to treat successfully Maintain under strict isolation protocol Immunization can be helpful Recently developed modified live intranasal vaccine

7. Guttural Pouch Empyema Sequela to strangles or lymph node abscesses Bacterial infection = guttural pouch empyema Clinical signs Treated with antibiotics and lavage Chondroids may form Resolution requires removal of chondroids Surgical drainage

8. Guttural Pouch Mycosis Fungal infection of the guttural pouch Aspergillus spp. Fungal plaque forms

9. Guttural Pouch Tympani Air accumulation in guttural pouches Occurs in foals and weanlings Characterized by fluctuant, non-painful swelling in throat-latch region

10. Influenza Highly contagious viral disease Incubation period Transmission Damages clearance mechanisms in lungs, predisposing them to bacterial pneumonia Rested for minimum of 3 weeks after recovery Immunization is recommended

11. Herpes Contagious virus Clinical signs indistinguishable from influenza Incubation period 2-10 days Transmitted

12. Herpes Abortion Neurological disease uncommon Standard quarantine protocols Vaccines Inactivated univalent vaccines administered to brood mares during 3rd, 5th, 7th, and 9th months of pregnancy to prevent abortion Not 100% protection against abortion

13. Viral Arthritis Contagious disease Clinical signs Stallions Mares Vaccine approved for stallions and non-pregnant mares Under USDA supervision Pregnant mares are not vaccinated

14. Heaves Recurrent airway obstruction (RAO) Allergic airway disease due to airway inflammation, bronchoconstriction, and excessive mucous production Clinical signs Never “cured” of heaves Controlled with management practices Medical therapy as necessary

15. Equine Infectious Anemia (EIA) Persistent viral disease Clinical signs Transmitted from infected horses by biting flies Permanently infected Become carriers for rest of life Horses not traveling or sold should be tested yearly

16. Equine Infectious Anemia (EIA) EIA regulations Coggin’s test Negative Coggin’s test Veterinarian must draw blood and provide detailed description of horse on specified forms Health certificates

17. Gastric and Colonic Ulceration Young are particularly prone Predisposing factors Clinical signs Treatment Phenylbutazone (NSAID) toxicosis Colonic ulcers secondary to phenylbutazone toxicity Clinical signs

18. Colitis Condition develops rapidly Etiologic agents Salmonella spp. Clostridium spp. Ehrlichia risticii Clinical signs Treatment Complications

19. Choke Indicates obstruction of esophagus Usually obstructed by grain or hay Predisposing conditions Clinical signs Attempt to eat despite inability to swallow Diagnosis Complications

20. Potomac Horse Fever Ehrlichia risticii Clinical signs Transmission Suspected arthropod vector Geographically, in states east of Mississippi Two inactivated bacterins available Diagnostic aids

21. Rabies Zoonotic infection and universally fatal Usually acquire infection by bite wound from wild animal Clinical signs Vaccination

22. Rabies Post-exposure rabies vaccine given to humans Rabies diagnosis Important to handle suspects and tissues cautiously Individuals having contact with rabid horse must be informed of test results

23. Viral Equine Encephalitis Eastern, Western, Venezuelan, and West Nile Rapidly progressive, highly fatal neurologic disease Transmission—mosquitoes Clinical signs of encephalitis Clinical signs of West Nile Treatment Prognosis Diagnosis

24. Viral Equine Encephalitis Vaccines for Eastern and Western highly efficacious Clinical disease is rare after vaccination Vaccine for Venezuelan encephalomyelitis not routinely given

25. Equine Leukoencephalomalacia Moldy corn toxicity Ingestion of fungal toxin produced by Fusarium moniliforme Clinical signs Treatment Prognosis

26. Skull Fractures Two types depending on nature of injury Diagnosis is confirmed by radiographs Treatment

27. Spinal Cord Disorders Five most common disorders are: Cervical vertebral malformation (Wobbler) Equine protozoal myelitis Equine herpesvirus myeloencephalopathy (rhinopneumonitis) Equine degenerative myeloencephalopathy Vertebral fracture Diagnostic aids

28. Cervical Vertebral Malformation Developmental orthopedic disease Characterized by compression of cervical spinal cord Clinical signs Diagnosis Surgical stabilization improves neurologic status

29. Equine Protozoal Myelitis (EPM) Horses dead-end, aberrant hosts of Sarcocystis neurona protozoan Clinical signs are directly referable to location of organism in CNS Neurological signs Diagnosis Treatment

30. Herpes Produces neurologic disease, respiratory disease, and abortion Neurological form Diagnosis Treatment Outbreaks in United States are reportable to state veterinarian

31. Equine Degenerative Myelopathy Symmetric spinal ataxia with limbs equally affected Clinical signs Diagnosis No definitive antemortem diagnostic test Treatment Prognosis is poor

32. Cervical Vertebral Fracture Most common sites Caudal thoracic vertebrae Thoracolumbar vertebral junction Results in tetraparesis Diagnosis Surgical correction may be attempted for cervical vertebrae

33. Tetanus Highly fatal neurological disease Clinical signs Causative organism present in environment Portals of entry Vaccine Tetanus toxoid Unvaccinated horses Tetanus antitoxin

34. Botulism Rapidly progressive, fatal neurological disease characterized by: Profound weakness Muscle fasciculations Dysphagia Neurotoxin Vaccination

35. Ringworm Dermatophytosis Fungal infection of superficial skin Trichophyton and Microsporum spp. Transmission Younger animals more likely to be affected Clinical signs Diagnosis Treatment

36. Dermatophilosis(Rain Scald, Rain Rot) Bacterial infection Dermatophilus congolense Produces crusty lesions Diagnosis Treatment

37. CulicoidesHypersensitivity Syndrome secondary to bite of Culicoides flies Classic body regions affected Pruritus Diagnosis Treatment Culicoides breeds in stagnant waters and feeds primarily at dusk, night, and dawn

38. Sarcoid Benign, locally invasive tumor of skin Most common tumor Raised, hairless lesions with corrugated surface, or Flattened form known as verrucoussarcoids Cause is unknown Viral agent is suspected Treatment: Surgical resection, cryotherapy (freezing), laser therapy, immunotherapy (intralesionalmycobacterial cell wall extract), radiotherapy (iridium 191), and chemotherapy

39. Melanomas Relatively common skin tumors Occur in perineal region Usually benign Surgical removal not recommended Treatment

40. Equine Recurrent Uveitis(Moon Blindness) Most common cause of blindness Immune-mediated condition, many factors implicated, cause often unknown Experience episodes of intraocular inflammation Episodes become more frequent and severe One or both eyes may be affected Treatment: Requires diligent observation and chronic treatment

41. Corneal Ulceration Commonly results from ocular trauma Fluorescein stains corneal abrasions Ulcer can be colonized by fungus Pseudomonas or Aspergillus spp. Treatment

42. Exertional Rhabdomyolysis Myositis, tying up, axoturia, Monday morning sickness Acute inflammatory disease of muscle Affected muscles in hind limbs and back Etiology Clinical signs Diagnosis Treatment

43. Monitoring Patients Level of patient monitoring depends on severity and nature of disease Critically ill patients monitored constantly IV fluid administration and intensive care Monitoring patients Forms Monitoring Treatment

44. Contagious Diseases Isolation facilities Personnel protection Exercise areas Waste disposal Personnel attending to animals with contagious diseases do not attend to foals or immunocompromised patients

45. Recumbent Horses Neurological and musculoskeletal diseases are most common problems Result in pressure sores (decubital ulcers) over pelvis, elbows, and head Deeply bedded on straw, placed on padded mat or mattress to prevent development of pressure sores Sling used only in horses that can support their own weight but are unable to stand on their own

46. Recumbent Horses Decreased intestinal motility and failure to void urine Adults rarely managed for more than 1-2 weeks without developing life-threatening complications

47. Feeding Hospitalized patients offered feed similar to what’s fed at home In some instances, feeding is specialized to accommodate patient’s disease Colic Gastrointestinal tract disease Heaves Anorexic

48. Therapeutics IV catheter placed for repeated administration of medications or fluid infusion Usually placed in jugular vein Placed aseptically and sutured to prevent dislodgment Central venous catheterization used in critically ill patients Intravenous catheters Infection at catheter site

49. Antimicrobials Penicillin Efficacy Procaine penicillin Potassium penicillin Aminoglycoside antimicrobials Efficacy Gentamicin, amikacin sulfate Administered Nephrotoxic

50. Antimicrobials Trimethoprim-sulfa Efficacy Administration Ceftiofur sodium Efficacy Administration Metronidazole Efficacy Administration Chloramphenicol used sparingly