veterinary neonatology

1. ANTIMICROBIAL
THERAPY OF
NEONATES
gulmedicine1077@yahoo.com

2. Presentation Outline
 What is antibiotic ?
 Different classification of antibiotics.
 Selection of Antimicrobial Agent
 Common bacterial diseases of neonates.
 Antimicrobial therapy against bacteria.
 Questioning

3. Definition -Antibiotic
 An antibiotic is a substance produced by
various species of living microorganisms (e.g.
bacteria and fungi) and use against Bacteria.
e.g penicillin
 It also include semi-synthetic and synthetic
antibiotics.
e.g Cephalosporin and Quinolones

4. Classifying Antimicrobial
Agents
1) Mode of action
 BACTERICIDAL (kills the bacteria)
e.g Penicillin
 BACTERIOSTATIC (stops the bacterial
multiplication)
e.g Tetracycline

5. 2) Spectrum of activity
 BROAD SPECTRUM: effective a variety of
gram-negative & gram-positive bacteria e.g
Cholromphinicol.
 NARROW SPECTRUM: effective only against
gram-negative or gram-positve e.g
erythromycin

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3) Mechanism of action / site of action;
 Inhibitors of cell metabolism; (Sulfonamides,
Trimethoprim)
 Cell wall inhibitors; (β-Lactam, Vancomycin)
 Protein synthesis inhibitors; (Tetrecyclines,
Aminiglycosides, Macrolides, Clindamycin,
Chloramphenicol).

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 Nucleic acid inhibitors; (Floroquinolones and
Rifampin).
 Cell membrane inhibitors; (Isoniazid and
Amphotericin B).

8. Classification of Antimicrobials
by Site of Action

9. Selection of Antimicrobial
Agent
 Empiric therapy - prior to identification of
organism – critically ill patients
 The empiric method of antibiotic selection
makes use of this philosophy by using our
observations of the patient (history, physical
examination and laboratory test results)
along with our past clinical experiences.
 Choose Antibiotic on the bases of Sensitivity
culture.
 But in emergency, use any good antibiotic
available at clinic.

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 Organism’s susceptibility to the antibiotic
 Care should be taken while selecting antibiotic.
 e.g Penicillin and cephalosporin not effective
against Mycoplasma ( lack cellwall )
 but Tylosin is drug of choice for Mycoplasma.
 Effect of site of infection on therapy –blood
brain barrier. e.g Phinicol group is effective
against both Gram +ve and Gram -ve bacteria
but it can pass BBB and is hemolytic.

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 Patient factors - immune system,
renal/hepatic function
 e.g The tetracyclines can inhibit WBC
chemotaxis and phagocytosis.
 Hinders normal host defense system.
 Streptomycin greatly excreted via renal route.
 Renal patient may show complications.
 Safety of the agent
 Cost of therapy

12. Common bacterial diseases of
neonates
 Neonatal diarrhea
 Joint Ill
 Pneumonia

13. Neonatal diarrhea
 Etiology:
E coli,
Salmonella,
Cryptosporidium parvum,
Giardia duodenalis,
Coccidia spp,
Rota and Corona Viruses

14. Neonatal diarrhea
 Mild diarrhea without systemic disease is
not an indication for antimicrobial therapy.
 Use of parenteral antibiotics should be
considered whenever calves are
systemically ill or recumbent.
 Field studies revealed that at least 30% of
diarrheic calves with systemic disease are
bacteremic—a clear indication for
parenteral antimicrobial therapy.

15. Selection of Anti-Bacterial
 Because the large majority of cases of
bacteremia and septicemia in neonatal
calves are associated with E coli, the
chosen antibiotic should be effective
against gram-negative bacteria.
 Gram Negative are mostly resistant to
beta-lactam antibiotics so we should
chose Other Antibacterial.

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 Drug of choice for colibacillosis is Enrofloxacin
@7.5-12 mg/kg
 Third generation flouro-Quinolon.
 Broad spectrum, bactericidal.
 MOA is to inhibit bacterial gyrase prevent
super coiling and synthesis.
 It is also effective against the Salmonelosis
( bacillary white diarrhea), shigellosis.

17. Market drug
 Inj: Quinosel ( selmore product )
 Enrofloxacin 200mg
 1ml per 40kg IM

18. Coccidiosis
 The drug of choice for Coccidiosis is
Sulfonamides.

Sulfadiazine @50 mg/kg, PO, bid

Sulfamethazine @220 mg/kg/day, PO or IV

Combination Drug

Trimethoprim/sulfadiazine @15–60 mg/kg/day,
PO, IV, or IM

19. Market drug
 Inj: Sulphasod (selmore)
 Included drug is Sulphadimidine sodium
333mg.
@30ml/50kg body weight
followed by 15ml/50kg
body weight for 2-5 days IM.

20. Giardiasis
 Metronidazole (extra-label at 25 mg/kg, bid for
5 days) is ~65% effective in
eliminating Giardia spp.
 It is available in infusion form
as well as in syrup form.

21. Joint ill ( navel ill )
 Causes:
 Staphylococcus spps
 streptococci
 Corynebacterium spp
 E.coli

22. Selection of Antibacterial
 The drug of choice for these bacteria is
Penicillin Group and Streptomycin.
 dose
penicillin G @10000-20000 IU/kg IM
Benzathine penicillin @10000-40000 IU
IM
Amoxicillin @5-10 mg/kg IM
Streptomycin @15-25 mg/kg IM

23. Streptomycin
 Aminoglycoside
 produced by the soil actinomycete,
Streptomyces griseus.
 inhibit the initiation and elongation processes
during protein synthesis.
 Mostly active against Gram negative Bacteria
e.g E.coli and Salmonella

24. Market Drug
 Inj: Penbiotic
 Procaine Penicillin ....15 lacs i.u.
Benzyl Penicillin ....... 5 lacs i.u.
Streptomycin Sulphate ..... 5 gm
 Add 10 ml distilled water in the vial. The
resultant solution is 15 ml.
 1 ml / 16 kg IM

25. Pneumonia
 Inflammation of the lungs.
 Clinical signs
Nasal discharge,
dry cough,
body temperature of >41°C,
respiratory distress,

26. Causes
 Pasteurella spps
 Mycoplasma spps
 Hemophilus somnus
 Salmonella dublin

27. Effective anti-bacterial is
Macrolides
 Interfere with protein synthesis, reversibly bind
to the 50S subunit of the ribosome.
 Useful to treat respiratory infections.
 Active against Mycobacterium, Mycoplasma,
Pasteurella and Haemophilus.
 Interactions: Should not be used
with chloramphenicol or the lincosamides,
because they may compete for the same 50S
ribosomal binding site,

28.  Drugs include in this class is:

Erythromycin @8–15 mg/kg, IM, once to twice
daily.

Tylosin @10–20 mg/kg, IM, once to twice daily.

Tilmicosin @10 mg/kg, SC, once.

Of these most commonly use in Vet-practices
is Tylosin.

29. Market drug
 TYLOFAR ( Izfaar pharma )
 Included drug: Tylosin Tartrate 200mg
 At dose of 1 ml / 20kg bodyweight.