With the summer temperatures of June 2020 you would say that it is still too warm even for flies, but that is not true.

I was recently on a suckler cow farm where I noticed that some calves were very slow and separated from the group.


The animals had a dirty tail and a dirty hindquarters. Wet spots were clearly visible.

My first impression was Myiasis, a thought confirmed by the ammonia smell and the presence of dead tissue with maggots in various stages underneath.

The calves were immediately washed with a maggot killing and wound disinfectant agent. Then they were treated with a long-acting antibiotic and a painkiller.


The farmer told me that a cow had calved the night before my visit. Her calf was hiding against the edge of the forest. The calf lay in the tall grass and was already covered with flies, (including the green meat fly “Lucilia sericata”).

You could already see tiny maggots on the calf. Treating with a maggot-killing and fly-repellent agent came to the rescue for this (several hours old) calf.

A maggot infection is caused by flies (including the green meat fly), which are attracted to body odors.

More specifically ammonia odor. A wet coat, often caused by body moisture, is the perfect place for these flies to lay eggs. A fly lays hundreds of eggs, which, under favorable conditions, hatch within hours and result in an invasion of larvae and maggots.

The larvae and maggots rot tissue and skin by producing enzymes. The rotting skin becomes soft, making it even easier for the maggots to pierce and digest. This makes it easier for them to absorb the nutrients from their host.

It is a downward spiral, in which more and more flies are attracted by the rotting odor of the skin.

Ultimately, the affected animal dies from the toxins (in the enzymes produced by the maggots), from exhaustion and from damaged tissues.


Fortunately, it all ended well here. The farmer is shocked by these 3 cases in his herd. He is now following up his group of animals extra closely and is doing preventive fly control.

A maggot infection is unfortunately not limited to cattle.

You can also see damage in sheep, goats, dogs, rabbits, guinea pigs, in the hooves of horses, etcetera. You have been warned!