Synonyms

Ostertagiasis due to hypersensitivity

Name of the disease in English

Allergic osteoarthritis

The disease in brief

 Allergic osteostagiosis is caused by an exaggerated immune response to reinfestation by Ostertagia ostertagi inducing edematous gastritis responsible for profuse diarrhea which can sometimes be fatal.

 This disease occurs when animals aged 2 are returned to grass.^th or 3^th grazing season. It does not affect an entire flock but only a few individuals poorly regulating the immune response to reinfestation. It is an uncommon form of ostertagious disease.

The reinfestation immune response eliminates existing worms by activation of mast cells armed with IgE present in the mucosa and stimulated by the antigens presented by the new infesting larvae. This mast cell activation induces a modification in the physiology of the abomasum (hypersecretion of mucus, contractions of smooth fibers, etc.) allowing the elimination of adult worms. Poor regulation of this response induces type I hypersensitivity.

Clinic & diagnosis

 The disease can be suspected when profuse diarrhea suddenly occurs when cattle aged 2 are returned to grass.^th or 3^th grazing season. Evolution affects one or a few individuals.

Weight loss may be significant within a few days and the animal may show marked dehydration.

Typical sign of the disease

No description

Pictures

See below

Diagnostic formulas

No description

Differential diagnosis

-Dietary diarrhea due to nitrogen excess or sudden DG42 transition

-Salomonellosis-DG43

-Winter hemorrhagic enteritis DG41

-Acute ruminant BVD -DG44.4

-Diarrhea of toxic origin DG42.2

Confirm a suspicion?

 There are no reliable means of confirming a clinical suspicion other than demonstrating lesions at autopsy.

Prognosis and treatment 

The prognosis is guarded because the syndrome appears suddenly and the gastric lesions can be significant (edematous infiltration of the abomasum which can multiply its weight by 3).

Antiparasitic treatment has no effect and priority should be given to treating the hypersensitivity reaction.

Prevention

Prevention of allergic ostertagiosis is not possible because it will affect individuals with a particular sensitivity that does not allow them to correctly regulate the normal reinfestation response. Unlike a classic allergic reaction, it does not last over time and only affects animals of 2^th and 3^th grazing season.

References

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