Hypodermosis
The hypodermosis , synonym: The same case , Dassel fly attack , Dassel disease or Dassel bump disease (engl. Cattle grubs , heel flies or warbles ) is an animal disease . It is caused by the skin bass flies and is mainly a disease of ruminants that are not exclusively kept indoors.
Pathogen
Hypodermosis is a specific form of fly maggot infestation ( myiasis ) in which the larvae (fly maggots) parasitize for months , especially in the area of the back, in the subcutaneous tissue ( hypodermal ) or in the skin ( dermal ) .
The botflies have a strong host specificity. In cattle , the large ( Hypoderma bovis ) and the small botfly ( Hypoderma lineatum ) occur, Hypoderma diana is specific for the roe deer , Hypoderma actaeon for the red deer , Hypoderma tarandi for the reindeer . Dermatobia hominis affects humans, but is only found in South America.
Clinical picture
The botflies lay their eggs on the hair in the abdomen and limbs in early summer. The larvae hatch within a few weeks, pierce the skin and migrate towards the diaphragm . After about 4 to 5 months (in December) they reach their "resting place". In Hypoderma bovis, this is the vertebral canal, which can trigger temporary symptoms of paralysis (“paralysis”). For Hypoderma lineatum , the resting place is the mucous membrane of the esophagus , occasionally also the mediastinum , pleura or lungs , which can manifest itself in digestive disorders or lung infections or pneumonia .
In late winter or spring, larvae 2 and 3 migrate into the skin of the back and cause a skin swelling about 3 cm in size, which is called the same owl and contains one larva each. The larvae create a breathing opening so that the same bumps have a centrally located hole. In spring, the larvae leave the skin, fall off the animal and pupate on the ground. After two to three months, the adult bot flies hatch, live only a few days and in turn lay eggs on the host animals.
The economic importance consists primarily of leather damage (“gunshot skins”) and reduced performance of the infected animals. Deaths can also occur.
In his Economic Encyclopedia from the Enlightenment period, JG Krünitz describes the problems and horror that emanate from these pests:
“The Brämse is an unsightly creature, but a terrible creature for almost every species of animal. The brams that stalk our cattle often cause great damage to the skins. They float after the animal until they have found the opportunity to drop an eye on it. The eye has something sticky about it, clings to the animal's hair, and finally slides down onto the skin. Here it is hatched by the natural warmth of the animal; the worm eats its way into the skin, and between it lives on the juices of the animal until it becomes a brownish pupa (grub), from which in the following spring a brace again arises. The skin of the animal is so perforated, and full of scars, on its whole back by this worm, where it attaches itself, that it becomes completely useless. "
proof
A serological test ( ELISA ) can also be used for detection .
Epidemiology and control
The control aims at the elimination of the larvae from the animal population and thus at the interruption of the reproduction cycle and the prevention of reinfection by silent parasite carriers. The treatment should take place in autumn after the pasture has been removed, before the larvae reach their hibernation site. Are used avermectins such as ivermectin .
It is a disease that was largely eradicated in Germany by state control measures between 1933 and 1967, but is increasing again due to imports of live cattle. In Switzerland, hypodermosis is one of the animal epidemics of group 3 (epidemics to be combated), it has been practically eradicated since 2002 and only occurs very rarely. In Austria it is notifiable.
literature
- Chantal Boulard: Durably controlling bovine hypodermosis . Vet. Res. 33 (2002) 455-464. doi : 10.1051 / vetres: 2002032
Individual evidence
- ↑ a b Bottom disease. Federal Food Safety and Veterinary Office FSVO (blv.admin.ch) -
- ↑ a b Federal Act of December 16, 1948 on combating the same-ulcer disease in cattle. StF: Federal Law Gazette No. 21/1949 ( online , ris.bka.gv.at).
- ↑ Entry Leder , Oekonomische Encyklopädie by JG Krünitz, online uni-trier.de
