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First Defense Bolus (Canada)

This treatment applies to the following species:
Company: ImmuCell



For veterinary use only

OMRI LISTED For Organic Use


FIRST DEFENSE® is a capsule containing antibodies which aid in the reduction of morbidity and mortality from neonatal calf scours caused by K99+ E. coli and bovine coronavirus. Maximal protection is achieved when administered in the first 12 hours after birth and used in conjunction with good colostrum feeding and calf nutrition programs. Neutralizing antibodies against bovine coronavirus as well as antibodies specific for E. coli K99+ pilus antigens present in FIRST DEFENSE® are prepared from hyperimmune bovine colostrum. A FIRST DEFENSE® capsule containing dried colostral antibodies dissolves readily upon reaching the calf’s stomach to provide passive protection against intestinal infection. Specific antibodies in FIRST DEFENSE® serve to block enterotoxigenic E. coli adherence and interfere with virus infection of intestinal epithelial cells, thereby reducing scours-related morbidity and mortality.


While diarrhea in newborn calves can result from a variety of nutritional and management-related factors, the most common form of scours in calves during the first weeks of life is colibacillosis caused by enterotoxigenic K99+ E. coli (ETEC). ETEC infections alone cause 30-50% of scour-related deaths in newborn calves(1,2). Adherence of ETEC to intestinal epithelial cells via K99 pili permits colonization and enhances enterotoxin induced hypersecretion of electrolytes and water. The resulting profuse yellowish diarrhea can lead to severe dehydration and death(3,4).

An additional 15-38% of neonatal scours mortality is associated with infections caused by coronavirus either alone, or in combination with K99+ E. coli, rotavirus or Cryptosporidium(2). While coronavirus diarrhea is most common between 7-14 days of age, coronavirus has been isolated in high frequency in calves during the neonatal period and is endemic in many dairy herds(2,5).


FIRST DEFENSE® is used as an aid in the reduction of morbidity and mortality from scours caused by K99+ E. coli and bovine coronavirus.


FIRST DEFENSE® has been tested in a total of 473 beef and dairy calves under both laboratory and field conditions. No allergic or other adverse reactions were observed.

Clinical studies showed that 90% (18 of 20) of calves treated with FIRST DEFENSE® in the first 12 hours after birth survived without additional treatment following a severe challenge of K99+ E. coli. In contrast, only 40% (4 of 10) of control calves survived the study interval (five days) under the same challenge conditions. Morbidity, as measured by fecal scores and dehydration scores, was also significantly reduced in FIRST DEFENSE®-treated calves when compared to control calves in this K99+ E. coli challenge trial.

In a similar challenge study with virulent, calf-passaged coronavirus, animals receiving FIRST DEFENSE® had a significant reduction in mortality (0/18 deaths) when compared to untreated controls (4/10 deaths). FIRST DEFENSE®-treated also showed a significant reduction in scouring and dehydration compared to control animals in this study.


FIRST DEFENSE® capsules are supplied in individual, moisture resistant blister packs which can be stored at, or below room temperature -23°C (72°F). Product is not harmed by freezing. If frozen, allow blister package capsule to warm to room temperature before removal from blister and administration. Capsules should remain in their blister packs until administered. Anaphylactic reactions may occur. If an anaphylactic reaction occurs after feeding FIRST DEFENSE®, administer epinephrine, or equivalent. Improper administration of the capsule may cause choking. See the Directions for more information.


A capsule dose of FIRST DEFENSE® should be given to each calf within the first 12 hours after birth. If the calf is to be tube fed, it is recommended to do so prior to dosing. To administer, remove a FIRST DEFENSE® capsule from its blister pack by tearing off the foil backing and follow the instructions recommended below:

1. Place the large end of the capsule in a dosing gun (16 mm/5/8” opening) until firmly seated. Avoid guns with undersized openings which may fracture the capsule shell or oversized openings which could allow the capsule to slip.

2. Restrain the calf. Gently pry open its mouth and place the dosing gun containing the capsule into the back of the throat. Administer the capsule as close to the esophageal opening as possible. Use caution to avoid delivery to the trachea.

3. To assist passage of the capsule down the esophagus and to stimulate a swallowing reflex, stroke the surface of the tongue or the outside of the throat. Whenever possible, bottle feed or allow the calf to suckle immediately after administering the capsule. Watch for signs of breathing difficulty after administering the capsule.

A capsule may block the airway if not properly administered, or if not swallowed by the calf. If the calf shows signs of choking or suffocating, immediately manipulate its body to dislodge the capsule.

4. Dosing gun should be cleaned and dried immediately following administration of capsule to each calf.


1. Haggard, D.L. Bovine enteric colibacillosis. Vet. Clin. N. Amer. Food Animal Prac. 1:495-508, 1985.

2. House, J.A. Economic impact of rotavirus and other neonatal disease agents of animals. JAVMA 173(5):573-576, 1978.

3. Moon, H.W., Whip, S.C. and Skartvedt, S.M. Etologic diagnosis of diarrhea disease of calves: Frequency and methods for detecting interotoxin and K99 antigen production by Escherichia coli. Am. J. Vet. Res. 37:1025-1029, 1976.

4. Moon, H.W. Mechanisms in the pathogenesis of diarrhea: a review. JAVMA 172:443-448, 1978.

5. Crouch, C.F. et al. Prevalence of rotavirus and coronavirus antigens in the feces of normal cows. Canad. J. Comp. Med. 48:340-342, 1984.

Manufactured by: IMMUCELL CORPORATION, 56 Evergreen Drive, Portland, ME 04103


Made in USA

U.S. Veterinary License No. 327

PCN 36B5.00

Rev: 10 (1/2015)

5 single dose capsules

1508 REV: 6

30 single dose capsules

1509 REV: 6

CPN: 1270000.8

Telephone:   207-878-2770
Order Desk:   800-466-8235
Fax:   207-878-2117
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