AQUACULTURE IN THE UNITED

STATES: APPROACH TO INFECTIOUS

DISEASES AND USE OF ANTIBIOTICS

John A. Plumb

Department Of Fisheries And Allied Aquacultures,

Auburn University, AL 36849

e‑mail \<jplumb@acesag.auburn.edu\>

INTRODUCTION ‑ AQUACULTURE IN THE U.S. HAS GROWN TREMENDOUSLY DURING THE
PAST 40 YEARS. MUCH OF THIS GROWTH HAS BEEN THE RESULT OF EXPANSION OF
CHANNEL CATFISH CULTURE ACROSS THE SOUTHERN STATES. HOWEVER, INCREASE IN
TROUT, SALMON, TILAPIA AND STRIPED BASS CULTURE HAS ALSO CONTRIBUTED TO
THIS PHENOMENAL GROWTH. IN SPITE OF THE GROWTH OF AQUACULTURE THE
INDUSTRY IS SMALL COMPARED TO BEEF, POULTRY AND SWINE BUT IN THE SOUTH,
CATFISH CULTURE IS THE PRIMARY INDUSTRY IN MANY OF THE POOREST,
IMPOVERISHED COUNTIES.

ALONG WITH THE GROWTH OF AQUACULTURE, WELL KNOWN INFECTIOUS DISEASES
HAVE BECOME MORE PROBLEMATIC AND INTENSIFICATION HAS ALLOWED NEW
DISEASES TO EMERGE. AS A RESULT, INFECTIOUS DISEASES REMAIN ONE OF THE
TOP THREE LIMITING FACTORS OF AQUACULTURE.

**[SOURCE OF SEAFOOD IN THE U. S.]{.underline}**

\>AQUACULTURE ‑ 20%

\>WILD CATCH ‑ 3 0 %

\>IMPORTS ‑ 50%

**[AQUACULTURE GROUPS]{.underline}**

\>FOOD FISH

‑CATFISH

‑SALMONIDS

‑OTHER (TILAPIA, STRIPED BASS, ETC.)

\>BAIT FISH

\>ORNAMENTAL FISH

\>CRUSTACEANS (CRAWFISH AND SHRIMP)

\>OYSTERS

**[AOUACULTURE PRODUCTION IN U.S.]{.underline}**

**[WT. MIL. LBS. PROCESSED 1999)]{.underline}**

CATFISH 525

TROUT 56.7

SALMON 39.7

CRAWFISH 49.3

OYSTERS 62

OTHER 50

BAIT FISH -

**[LOSSES IN AQUACULTURE]{.underline}**

\>DISEASES 45.4%

\>PREDATION 37.4%

\>LOW DISO. OXY. 12.1%

\>OTHER 5.1%

**[MOST SIGNIFICANT DISEASES: CHANNEL CATFISH]{.underline}** \>ENTERIC
SEPTICEMIA

\>COLUMNARIS

\>PROLIFERATIVE GILL DISEASE

\>WINTER KILL (SAPROLEGNIA)

*\>ICHTHYOPHTHIRIUS*

\>CHANNEL CATFISH VIRUS

**[MOST SIGNIFICANT DISEASES: SALMONIDS]{.underline}** \>FURUNCULOSIS

\>COLD‑WATER DISEASE

\>BACTERIAL KIDNEY DISEASE

\>ENTERIC REDMOUTH

\>COLD WATER VIBRIOSIS

\>INFECTIOUS HEMATOPOIETIC NECROSIS VIRUS

**[AQUACULTURE APPROACH TO DISEASE]{.underline}**

**[HEALTH MANAGEMENT:]{.underline}**

**PREMISE‑** MOST CLINICAL DISEASES OF

FISH RESULT FROM MANAGEMENT OR

ENVIRONMENTAL STRESS; PATHOGENS ARE

SELDOM PRIMARY AETIOLOGIES ALONE

i

i ‑

AGE

ACQUIRED SPECIES STRAIN FISH DENSITY

IMMUNITY

HOST HANDLING

NATURAL

RESISTANCE

FACILITIES

SPECIES ORGANIC LOAD

ENVIRONMENT TEMPERATURE

NITRITE

TYPE

pH

STRAIN

SCHEDULE NUTRITION C0~2~ 0~2~

QUANTITY QUALITY

John A. Plumb, 1996

The integral effect of \"Host\". \"Husbandry\", \"Environment\",
\"Nutrition\", \"Pathogen\" and \"Physiological Status\" to \"Fish
Health Status\". Each factor not only affects the fish health status,
each subpart may affect the stability of an other factor.

**[DISEASE PREVENTION (PROACTIVE)]{.underline}**

\>PROPER HANDLING

\>POND/RACEWAY HYGIENE

\>WATER QUALITY MANAGEMENT

•WATER FLOW

•AERATION

•ALGAE/PLANT CONTROL

•ALKALINITY/HARDNESS

\>MODERATION IN STOCKING DENSITY

\>FEED MANAGEMENT/NUTRITION

\>DISEASE RESISTANT STOCKS

\>SPECIFIC DISEASE FREE STOCKS

\>PROPHYLACTIC TREATMENT

\>VACCINATION

**[CHEMOTHERAPY (REACTACTIVE)]{.underline}**

(NOT USED INDISCRIMINATELY)

**[EXAMPLE: TREATMENT OF ENTERIC]{.underline}**

**[SEPTICEMIA OF CATFISH (ESC) ON]{.underline}**

**[571 CATFISH FARMS]{.underline}**

TREATMENT % OPERATIONS

TAKE OFF FEED 72.6

FEED ROMET‑30\* 41.4

NO TREATMENT 14.6

OTHER ACTIONS 4.2

\* PRIMARILY JUVENILES

**[CATFISH FEED WITH ANTIBIOTICS]{.underline}**

**[YEAR PERCENTAGE]{.underline}**

1994 1.5

1995 1.7

1996 l.4

1997 1.3

1998 0.9

1999 0.9

2000 O.6

**[METHODS OF CHEMOTHERAPY]{.underline}**

\>DIP ‑ SECONDS

\>FLUSH ‑ MINUTES

\>PROLONGED ‑ MINUTES/HOURS

\>INDEFINITE ‑ DAYS

\>FEED ADDITIVE ‑ DAYS

\>INJECTION ‑ SINGLE

**[FDA REGISTERED DRUGS]{.underline}**

**1. [FORMALIN]{.underline}**

\>BATH TREATMENT

\>EXTERNAL PARASITES

\>FUNGICIDE ON EGGS

\>ALL FISH

**2. [TERRAMYCIN (OXYTETRACYCLINE)]{.underline}**

\>FEED ADDITIVE

\>SYSTEMIC BACTERIAL INFECTIONS

\>CATFISH & SALMONIDS

\>TAG FISH BY IMMERSION OR FEED

**3. [ROMET‑30]{.underline}**

\>FEED ADDITIVE

\>SYSTEMIC BACTERIAL INFECTIONS

\>CATFISH

**[EPA REGISTERED CHEMICALS FOR]{.underline}**

**[PLANT CONTROL/WATER QUALITY]{.underline}**

1\. **[COPPER SULFATE]{.underline}**

\>ALGAE CONTROL

\>INAD IN PLACE FOR CONTROL OF

*ICHTHYOPHTHIRIUS* ON CATFISH

AND OTHER EXTERNAL PARASITIC

INFECTIONS ON ALL FISH

2\. **[POTASSIUM PERMANGANATE]{.underline}**

\>ORGANIC OXIDIZING AGENT

\>INAD FOR EXTERNAL BACTERIA,

PARASITES, FUNGI ON ALL FISH

**[OTHER DRUGS UNDER CONSIDERATION WITH INADS (LICENSING
QUEST.)]{.underline}**

**1.** **[ORAL ANTIBIOTICS]{.underline}**

**[\>ENROFLOXACIN:]{.underline}** FURUNCULOSIS IN SALMONIDS

> **[\>FLORFENICOL:]{.underline}** FURUNCULOSIS IN SALMONIDS (RECENTLY
> APPROVED IN CANADA)

**[\>AMOXICILLIN:]{.underline}** ANTIMICROBIAL RESISTANCE NEEDS
ADDRESSING

**2.** **[INJECTABLE]{.underline}**

> **[\>ERYTHROMYCIN:]{.underline}** SALMON PRIOR TO SPAWNING; INHIBIT
> TRANSMISSION OF BACTERIAL KIDNEY DISEASE

**[OTHER DRUGS CONT.]{.underline}**

**3. [BATH/IMMERSION TREATMENT]{.underline}**

> **\>FUMAGILLIN:** MICROSPORIDIA IN MUSCLE, EYE, INTERNAL ORGANS
>
> **[\>CHLORAMINE‑T:]{.underline}** EXTERNAL BACTERIA (FLAVOBACTERIA) ON
> GILLS/SKIN (USED EXTENSIVELY IN EUROPE)
>
> **[\>HYDROGEN PEROXIDE:]{.underline}** LOW REGULATORY PRIORITY FOR
> FUNGUS CONTROL ON EGGS/FISH

**[ANTIBIOTICS IN U.S. AQUACULTURE]{.underline}**

\>MORE RESTRICTIVE THAN IN OTHER PARTS

OF THE WORLD

\>FOR CLINICAL DISEASE TREATMENT; NOT PROPHYLACTICALLY

\>CATFISH: 0.6% FEEDS CONTAIN ANTIBIO.

\>SALMONIDS: 37,000 LB OF 20% ACTIVE

OXYTETRACYCLINE/YR

\>TILAPIA/STRIPED BASS: LIMITED

\>MARKING FISH WITH OXYTETRACYCLINE BY

IMMERSION OR IN FEED IS LIMITED

**[ANTIBIOTICS IN U.S. CONT.]{.underline}**

\>ABUSE OF ANTIBIOTICS IN AQUACULTURE IS NOT COMMON

\>USE OF ANTIBIOTICS HAS DECLINED IN

AQUACULTURE BECAUSE:

1\. FDA REGULATION LIMITS THEIR USE

2\. CONCERNS FOR PATHOGEN RESISTANCE

3\. LACK OF DEPENDABLE EFFICACY

4\. DISEASE PREVENTION THROUGH HEALTH MANAGEMENT IS

BETTER APPROACH TO INFECTIOUS DISEASES

5\. IMPLEMENTATION OF VACCINES ‑ WILL BECOME MORE

IMPORTANT

**[CONCLUSIONS]{.underline}**

1\. U.S. AQUACULTURE PROVIDES 10% TO SEA FOOD

MARKET

2\. MAJOR PORTION COMES FROM WILD CATCH, IMPORTS

3.  HEALTH MANAGEMENT HAS BECOME MORE IMPORTANT IN

COMBATING INFECTIOUS DISEASES IN U.S. AQUACULTURE

4\. USE OF ANTIBIOTICS IN AQUACULTURE DECLINING