143. Actinobacillosis of horses.

Question 1

Ethiology?

Answer 1

ETIOLOGY

• Caused by A. equuli subsp. Equuli / subsp. Haemolyticus : no pathological difference btw subsp.
• Gram negative rods, filaments, low resistance
• Habitat: mucous membrane of the alimentary tract, facultative pathogens

Question 2

Name the 2 diseases in Actinobacillus of horses?

Answer 2

1. Septicaemia of newborn foals (Sleepy foal disease)
2. Pyosepticaemia of adult horses

Question 3

SEPTICEMIA OF NEWBORN FOALS (SLEEPY FOAL DISEASE)

EPIDEMIOLOGY?

Answer 3

SEPTICEMIA OF NEWBORN FOALS (SLEEPY FOAL DISEASE)

EPIDEMIOLOGY

• Poor hygienic conditions, nutritional deficiencies in the case of mares
• Deprivation/shortage of colostrum, agammaglobulinemia (esp. in Arab horses)
• Clinical signs seen in the first days of life

Question 4

PATHOGENESIS, CLINICAL SIGNS AND PATHOLOGY of septicaemia of newborn foals?

Answer 4

PATHOGENESIS, CLINICAL SIGNS AND PATHOLOGY

Infection:

• P.O, umbilical, intrauterine
• septicemia
• reach the parenchymal organs

Clinical signs

• Fever, depression, cannot stand up, diarrhea, arthritis, tenosynovitis (lameness, sleepy foal disease), nasal
• discharge, labored breath, painful renal region
• Pathology:
• hemorrhages,
• abscesses in the kidney,
• lungs and liver

Question 5

Diagnosis and differential diagnosis of Septicaemia of newborn foals?

Answer 5

DIAGNOSIS

• Epidemiology, clinical signs and post mortem lesions (can reach diagnosis based on these)
• Detection of the agent: isolation of the bacterium
• Differential diagnosis: diseases with CNS signs & fever

Question 6

Therapy and prevention of septicaemia of newborn foals?

Answer 6

THERAPY AND PREVENTION

• Antibiotics: penicillin, cephalosporin, tetracycline, florfenicol, fluoroquinolones
• When you see lameness => arthritis is present, and treatment with antibiotics is very difficult (must reach the joint).
• Must euthanize
• Prevent predisposing factors
• Optimal nutrition of pregnant mares (produce good quality colostrum),
• good hygiene,
• navel disinfection,
• early suckling

Question 7

PYOSEPTICEMIA OF ADULT HORSES

OCCURRENCE AND EPIDEMIOLOGY ?

Answer 7

PYOSEPTICEMIA OF ADULT HORSES

OCCURRENCE AND EPIDEMIOLOGY

• Sporadic, typically occurred in draught horses (heavy working horses)
• Accumulation of predisposing factors at the same time
• Exhausting work,
• mycotoxins,
• cold or soaked by heavy rain,
• other infective agents (EHV, leptospirosis)

Question 8

PATHOGENESIS, CLINICAL SIGNS AND PATHOLOGY of pyosepticameia of adult horses?

Answer 8

PATHOGENESIS, CLINICAL SIGNS AND PATHOLOGY

• Predisposing factors:
• bacterium gets into the blood
• septicemia
• lysis of bacteria
• release of endotoxins
• which will damage the wall of blood vessels
• endotoxin effect (reason for clinical signs)
• Clinical signs
• Fever (40-41°C), depression, weakness, ataxia, sweating, increased breathing rate & heart rate,
• nasal discharge (can contain blood), hemorrhages on the mucous membranes, edema (head), abortion (due to high fever)
• Pathology
• Hemorrhages on the mucous membranes, enlargement and dystrophy of the parenchymal organs,
• abscesses in the kidney

Question 9

Pyosepticaemia of adult horses diagnosis, therapy and prevention?

Answer 9

DIAGNOSIS

• Epidemiology, clinical signs and pathology
• Detection of the agent ʹ isolation of the bacterium from parenchymal organs

THERAPY AND PREVENTION

• Antibiotics: penicillin, cephalosporins, streptomycin, tetracycline
• Rest and elimination of predisposing factors,
• no use of vaccines due to the sporadic feature of the disease