SIX STEPS TO ANTIBIOTIC SELECTION FOR NURSERY AND FINISHING DISEASE
John Roberts
North Carolina State University
College of Veterinary Medicine
Treating disease in nursery and finishing pigs can be trying. Producers and service men are often left to choose proper antibiotic treatment with little information. Applicable or not, most treatment is usually based only on someone’s past experience. Following is a six-step guide to aid treatment decisions. The guide is simple. The first step determines what part of the pigs is diseased. The next decision separates sudden death from routine treatment. Then, antibiotic choices are automatically eliminated that have extreme withdrawal times, can not reach the site of infection, or are not likely to work. Fourth, remaining antibiotics are rated by likelihood to work. Fifth, withdrawal time and prescription status is affirmed. Last, antibiotic costs are considered.
1. Where in the Affected Pigs is Disease Located?
There are four locations to differentiate. The locations are the skin, a joint, a respiratory location, or an enteric location.
· Skin - Skin disease usually looks like dark patches on the neck or back. The disease is called “greasy pig disease”. The pigs do not scratch as they do with mange.
· Joints – Swollen and enlarged joints are easy to notice visually, especially as lame pigs are separated.
· Respiratory Location – A respiratory disease is found primarily in the upper body cavity where the lungs are located. It is best to distinguish respiratory disease from digestive disease by opening several dead pigs. Respiratory disease will show signs in the upper cavity and maybe in the lower cavity. An upper cavity respiratory indicator is pneumonia in the lungs. Pneumonia is characterized by portions of lung that are hard, hold no air, and do not float when an affected piece of lung is placed in water. Another upper cavity indicator is fibrin. Fibrin has the form of strands of fine material on and between lungs, heart, and cavity walls. The material looks like spider webs. Sometimes a gelatinous substance will be found with fibrin if the disease is severe. Fibrin and gelatin will sometimes be found in the lower cavity also.
· Digestive Location – A digestive disease is found primarily in the lower body cavity where the intestines are located. Enteric disease shows no signs in the upper cavity and may not show anything in the lower cavity. When enteric signs are present in lower cavity, the indicator is usually a thickened intestinal wall.
2. Is the Treatment Situation Routine or are
Sudden Deaths Occurring?
·
Routine
Treatment - Routine situations usually involve finding and treating a few
individual pigs. Routine is normal daily nursery and finishing treatment.
Routine disease infrequently requires water medication. Skin disease and joint
enlargements should always be routine treatment of individual pigs by
injection. Should either show as a prevalent problem in pigs, ask for help.
·
Sudden Death -
Enteric and respiratory disease have variations of routine and sudden diseases.
Sudden death is characterized by finding healthy
pigs suddenly dead, often showing red or blue tinted discoloration on the
lower abdomen or ears.
3. Elimination of Inapplicable Antibiotics
The charts in the next step include antibiotic choices for different locations and conditions. These charts originally considered 12 legally available injectable antibiotics and 17 water-soluble antibiotics. Several antibiotic choices are excluded from the charts for the following reasons.
· Extreme Withdrawal Times - Gentocin (Garacin) Injectable is not included as the compound stays in kidneys. Withdrawal time in nursery and finishing pigs can reach as long as 180 days.
· Injectable Sulfa Products – Injectable sulfas are irritating and often do not act as sensitivity tests predict. These products have fallen from most swine treatment inventories over the years.
· Poor Oral Absorption – Gentocin (Garacin), Neomycin (NeoMix, Biosol), Apramycin (Apralan), and Spectinomycin (Spectam, LS50) are absorbed from oral intake at rates that are less than 25%. Most are less than 12% in normal conditions. If the target is the digestive tract, then absorption from the tract is not an issue. However, water-soluble and feed grade antibiotics that are not absorbed from the intestine will never be blood borne or available to treat respiratory locations. Lincocin is reported in the charts when sensitivity is adequate. Lincocin is less than 50% absorbed orally.
· Oral Penicillins – Water-soluble and feed grade penicillins are not includes as less than 15% of these products move pass stomach acid intact. Acid degraded penicillin is not available for absorption. The synthetic penicillins (ampicillin, amoxicillin) are unaffected by stomach acid and are included as a choice.
· Antibiotic Resistance – The charts do not include antibiotics that were ineffective against particular organisms on over two thirds of laboratory testing. The included antibiotics were effective 33.3% to 100%. The rating system of antibiotic effectiveness scales from 0 to 10, corresponding to 33.3% to 100%. The rating of predicted antibiotic effectiveness was based on combined fiscal ’99 test results from three major US diagnostic laboratories.
4. Choose Antibiotics Based of Effectiveness
The following charts guide antibiotic selection based on laboratory effectiveness of products that remained after step 3.
I.
Skin Location:
|
Drug |
Cetiofur |
Tylosin |
Lincocin |
Ampicillin |
Penicillin |
Erythromycin |
Florfenicol |
|
Product |
Naxcel Exonel |
Tylan |
Linco |
Polyflex |
Pfi-Pen G Aqua-Pen |
Gallamycin |
Nuflor |
|
Rating |
9.3 |
1.9 |
1.6 |
1.0 |
.7 |
.7 |
NA |
II.
Joints:
|
Drug |
Cetiofur |
Florfenicol |
Ampicillin |
Spectinomycin |
Penicillin |
Oxytetracycline |
|
Product |
Naxcel Exonel |
Nuflor |
Polyflex |
Spectam LS50 |
Pfi-Pen G Aqua-Pen |
LA 200 Biomycin C |
|
Rating |
10.0 |
9.9 |
9.7 |
6.7 |
5.5 |
1.5 |
III.
Respiratory
Location:
A. Routine Treatment
|
Drug |
Florfenicol |
Ampicillin |
Oxytetracycline |
Cetiofur |
Penicillin |
Spectinomycin |
|
Product |
Nuflor |
Polyflex |
LA 200 Biomycin C |
Naxcel Exonel |
Pfi-Pen G Aqua-Pen |
Spectam LS50 |
|
Rating |
8.2 |
7.6 |
7.1 |
6.5 |
2.5 |
.6 |
|
Drug |
Chlorotetracycline |
Trimethoprim and Sulfa |
Amoxicillin |
Tetracycline |
Oxytetracycline |
Tiamulin |
Sulfathiazole |
|
Product |
CTC
Soluble Chlor-Tet |
SMZ-TMP (Pediatric) |
Amoxicillin (Pediatric) |
TetraBac |
Terramycin |
Denagard |
* |
|
Rating |
9.2 |
8.8 |
7.6 |
7.3 |
7.0 |
1.0 |
.4 |
B. Sudden Death – Respiratory sudden death is charted in two categories based on presence or absence of an additional finding in opened pigs and noting downer pigs in an affected group. The additional finding in opened pigs is infarction. Infarcts are big (11/2 inch to 3 inches across) deep black, well circumscribed, hard areas in the middle to upper portions of the lung. Infarcts form when the blood vessels that feed an area of the lung are plugged. A spherical tissue area around the plugged artery fills with fluid and blackened blood. Infarcts are a sign of App (Actinobacillus pleuropneumonia). Infarcts are not seen with the other primary causes of respiratory sudden death, Hps (Hemophilus parasuis) and Ss (Strep suis). Hps and Ss may produce a few downer pigs, but not always. Downer pigs may paddle their legs.
|
Drug |
Cetiofur |
Ampicillin |
Florfenicol |
Spectinomycin |
Penicillin |
Oxytetracycline |
|
Product |
Naxcel Exonel |
Polyflex |
Nuflor |
Spectam LS50 |
Pfi-Pen G Aqua-Pen |
LA 200 Biomycin C |
|
Rating |
10 |
9.7 |
7.3 |
7.1 |
5.3 |
2.1 |
Average of Strep suis and Hemophilus parasuis
|
Drug |
Amoxicillin |
Trimethaprim
Sulfa |
Tiamulin |
Sulfathiazole |
Sulfadimethoxine |
|
Product |
Amoxicillin (Pediatric) |
SMZ-TMP (Pediatric) |
Denagard |
* |
Agribon * |
|
Rating |
9.7 |
8.8 |
8.4 |
5.9 |
5.5 |
|
Drug |
Cephalothin |
Sulfachloro Pyridazine |
Chlorotetracycline |
Oxytetracycline |
Tetracycline |
|
Product |
Cephalexin (Pediatric) |
Vetasulid |
CTC
Soluble Chlor-Tet |
Terramycin |
TetraBac |
|
Rating |
5.5 |
3.6 |
3.2 |
2.1 |
.9 |
|
Drug |
Cetiofur |
Florfenicol |
Ampicillin |
Spectinomycin |
|
Product |
Naxcel Exonel |
Nuflor |
Polyflex |
Spectam LS50 |
|
Rating |
9.9 |
9.5 |
6.0 |
5.4 |
|
Drug |
Cephalothin |
Trimethaprim
Sulfa |
Sulfachloro pyridazine |
Tiamulin |
|
Product |
Cephalexin (Pediatric) |
SMZ-TMP (Pediatric) |
Vetasulid |
Denagard |
|
Rating |
9.8 |
9.8 |
7.6 |
7.0 |
|
Drug |
Amoxicillin |
Sulfathiazole |
Sulfadimethoxine |
Chlorotetracycline |
|
Product |
Amoxicillin (Pediatric) |
* |
Agribon * |
CTC
Soluble Chlor-Tet |
|
Rating |