Deaths have been reported among milk fed calves as a result of accidental exposure to bloat control materials (antifoaming agents, AFA's). Most of these are non ionic surfactants which work best at bloat control when given in very low continuous doses. Giving high doses intermittently can be dangerous. In a number of cases calves have been fed milk from old plastic bloat detergent containers, which apparently even after rinsing out have still retained sufficient of the toxic material to cause illness and death. In other cases antibloat preparations have been used to prevent colic in calves and cattle with fatal results.
Other, less toxic, substances such as liquid paraffin and silicones are also used to treat bloat. Ionophores such as monensin are used to prevent bloat.
There are many detergents sold for bloat control over the counter.
Most of these products either poloxamers or nonoxinols, but NZ manufacturers use a variety of very confusing obsolete nomenclature. All are polyoxyethylated nonionic surfactants. The oxyethylene and hydroxyl groups are hydrophilic, the oxypropylene groups are lipophilic.
Poloxamers (Pluronics) have the general formula HO (C2H4O)a (C3H6O)b (C2H4O)a H. The commonest ones are poloxalene, where a averages 12 and b averages 34; and poloxamer 182, where a averages 7 and b averages 30.
Nonoxinols are nonylphenyl esters of macrogols with the general formula C15H23 (O CH2 CH2)n OH where n is usually 9 - 30.
Commercial products are often mixtures.
Examples of losses reported in New Zealand associated with detergent poisoning.
| Toxic Material | Animal Type | Animals Affected | Animal Deaths< |
|---|---|---|---|
| Blogon Oil (Teric) | 5-7 week calves | 32 | 28 |
| Blogon Oil (Teric) | 6 week bull calves | 30 | 20 |
| Blogon Oil (Teric) | 6 week calves | 9 | 3 |
| Bloatenz No. 1 (Pluronic) | 7-8 week calves | 7 | 2 |
| Bloatenz No. 1 (Pluronic) | Mature Cows | 7 | Nil (Treated Calcium Borogluconate) |
| Bloatenz No. 1(Pluronic) | 3-6 week calves | 18 | 5 |
These detergents are extremely toxic to fish, so care must be taken with disposal of chemicals and containers.
Presumably damage to the gut lining allowing leakage of ions and water into the gut.
Clinical signs usually appear rapidly (3 - 24 hours from dosing). Animals are depressed, become ataxic and develop fine head tremors. Abdominal pain and severe straining are reported. Animals become recumbent and develop severe tympanitis and respiratory distress. Bellowing and tongue protrusion are reported. In the terminal stages there is struggling with opisthotonos and nystagmus. Mature cattle are reported to adopt a typical milk fever posture with a sub normal temperature.
Animals which have been dosed with Bloatenz have been reported to show pulmonary congestion and swelling of the pulmonary lymph nodes and varying degrees of enteritis.
Calves which have died as a result of being fed milk from old bloat oil containers have shown few post mortem signs other than those associated with agonal struggles prior to death. In some cases tympany of the gut was reported. The abomasum usually contains quantities of undigested milk and in some, very fluid intestinal contents have been seen.
Treatment is largely symptomatic. In adult cattle a good response has been reported following treatment with normal (milk fever) doses of calcium borogluconate. Calves apparently have not responded to such treatment.
Reid, C.S.W. and O'Reilly, R.J.R. (1983). Recent Advances in Bloat Control. Proc. Dairy Cattle Medicine Soc. of N.Z.V.A., Massey University, New Zealand. 228 238.
Teague, W.R. (1986). Pluronic Poisoning in a herd of dairy calves. N Z vet J. 34: 104 105.
Surveillance (1979) 6(5): 12 Pluronic poisoning (dairy calves).
Surveillance (1980) 7(5): 8 Pluronic poisoning (dairy calves).
Surveillance (1981) 8(2): 11 Pluronic poisoning (calves).