Abomasal bloat
Abomasal bloat (tympany) is a common health problem affecting artificially-reared lambs and kids, especially hand-fed ones. Some farms have experienced death losses as high as 25 to 30 percent [3]. On other farms, it is a sporadic disease.
While the mechanism of abomasal bloat is not completely understood, it is believed to be caused by a build-up of bacteria in the stomach of lambs and kids. Bacteria such as clostridium perfringins type A and species of Sarcina [2,5,9] have been identified in the stomachs of affected animals [3]. Clostridium perfringins type E has been found in the stomachs of affected calves.
As the bacteria multiply, the sugars in the milk ferment with excess gas production. At the same time, the stomach becomes more acidic to the detriment of other bacteria. As the gas cannot escape, it bloats the abomasum. Death is rapid and unpleasant.
Risk factors
Abomasal bloat seems to occur most commonly in lambs that are 2 to 4 weeks of age. It may occur later in goat kids, as they are typically fed milk for a longer period of time. The incidence is highest when lambs/kids are fed warm milk infrequently, e.g. twice daily. Feeding goat kids in a pail or trough without a nipple may cause similar greedy feeding behavior.
Warm milk provides an ideal substrate (lactose) for fermentation. Abomasal bloat is rarely seen in lambs/kids that are self-fed cold milk. Rapid ingestion of milk can result in rapid fermentation of the milk. To keep lambs/kids from ingesting milk too rapidly, you should stop and resume feeding every 10 seconds. Be sure the hole in the teat isn't too large. When you tip the bottle upside down, the milk should trickle, not flow. Worn-out nipples should be replaced.
The use of cheap or poor quality milk replacers can also contribute to the incidence of abomasal bloat. Be sure the milk replacer relies on milk proteins and not plant-based protein sources. Pipestone Vet Clinic recommends that skim milk be the first ingredient listed [7]. The protein in skim milk (casein) is slowly released, vs. the protein in whey which is fermented more rapidly [7].
As many factors contribute to the risk of disease, abomasal bloat is most likley to occur when multiple factors occur together.
Treatment
Treatment of abomasal bloat is often unrewarding. It is estimated that 75 to 100 percent of cases die. Affected lambs/kids will have swollen bellies. They will be dull and lethargic. Abdominal pain (colic), accompanied by teeth grinding is common. The disease can progress rapidly, within 30 minutes of feeding. Sometimes, all you find is a dead lamb or kid.
Early intervention is the key to saving affected lambs/kids. Many treatments have been advocated. Oral penicillin may help to counteract the bacteria. In fact, when antibiotics (penicillin) are added to milk replacer, abomasal bloat usually does not occur. Abomasal bloat is not likely be a problem if lambs are reared on (antibiotic) treated cow's milk. Waste milk can be fed to lambs successfully, so long as the milk is fortified with fat or oil.
Sodium bicarbonate (baking soda) mixed in water is the common treatment for bloat, as it helps to neutralize acid.
Dosing with cooking oil or antacids may also help. Powdered ginger may help with mild cases of bloat. Mix two tablespoons of ginger in a small amount of warm water and administer with a syringe. Ginger has traditionally been used for the treatment of gastro-intestinal ailments. Pain meds may also be given to affected lambs/kids.
In extreme circumstances, a needle can be inserted into the abomasum to relieve the gas. This procedure should only be performed by a veterinarian or other trained person.
The scientific literature reports a successful chemical
treatment for abomasal bloat in 1 to 2 week old kids. Affectedkids were given a single intramuscular injection of Hyloscine (0.3 mg/kg), Metaclopramide (0.5 mg/kg) and vitamin E/selenium (0.1 mg/kg) [8].
Prevention
Milk replacers should be mixed according to the manufacturer's instructions. Lumps can contribute to abomasal bloat [5]. Diluted milk replacer may cause lambs/kids to gorge, especially if they are on an automatic feeding system.
Milk replacer is usually mixed in warm water, then cooled to body temperature before feeding. Cooling milk to at least 40°F (4°C) has been shown to help contain the growth of
References and further reading
[1] Abomasal bloat - Veterinary Clinic Morrinsville
[2] Bloat in young calves and other pre-ruminant livestock - Merrick's
[3] Bloat in lambs - NZAgBiz Limited
[4] Effects of warm vs. cold milk replacers - Canadian J. Anim. Sci
[5] Information sheet: abomasal bloat - Probiotec Limited
[6] [PDF] Managing abomasal bloat - Meat & Wool New Zealand
[7] Milk replacer - Ask-a-Vet Sheep (Pipestone Vet Clinic)
[8] A new treatment for goat tympany in goat kids - CabDirect
[9] Sarcina Ventricula as a potential cause of abomasal bloat
Sarcina bacteria [2,5]. On the other hand, if Sarcina bacteria is not present, lambs fed chilled or cold milk replacer could be at greater risk for abomasal bloat [5].
The risk of abomasal bloat will be reduced if lambs/kids are self-fed milk using a bucket feeder, nipple bar, or automatic feeding system. Self-feeding simulates dam-raising, as lambs/kids are able to ingest smaller amounts of milk at frequent intervals. In cold weather, a heat lamp can be used to keep milk from freezing. In warm weather, frozen bags of milk can be fed.
Regardless the method of milk feeding, good sanitation is a must. If lambs/kids are being bottle-fed, bottles and nipples should be cleaned after each feeding. If buckets and nipple bars are used, the equipment should be frequently dismantled, cleaned, and disinfected. Make sure leftover milk is stored in hygienic cold conditions.
Sour milk is another proven way to prevent abomasal bloat [6]. Sour milk is made by adding acidophilus yogurt to milk replacer and allowing it to convert for several days.You can also add probiotic powder to the milk.
The addition of formalin (0.10%) to milk replacer has also been shown to reduce the incidence of bloat, allowing warm milk to be safely fed to lambs ad libitum [4]. However, too much formalin could affect intake and could even poison lambs.
Since clostridial bacteria have been implicated in abomasal bloat, it is essential that lambs/kids be vaccinated for clostridial perfringins type C & D. Pipestone Vet Clinic recommends vaccinating every 10 days or so.
Feeding lambs milk replacer for too long can increase the incidence of abomasal bloat. The ideal weaning age is 30 days. There is usually no benefit to later weaning. The early introduction of high quality concentrates will promote rumen function and lessen the risk of abomasal bloat. It will also facilitiate earlier weaning.
This article was written in 2014 by Susan Schoenian.