Also known under the name harvester or red mullet, chiggers are a parasite whose particularly irritating bite is felt in all mammals: for us humans but also for our four-legged companions. How to relieve your dog or cat who is scratching after a bite of chiggers? When should it be presented to your veterinarian?

The chigger is a mite scientifically named Thrombicula automnalis. It is a temporary parasite because only the larva infests mammals for food while the adult form is free in the environment.

The parasite is active during the summer months (approximately July to September). It is found throughout France but is concentrated in certain centers favorable to its development.

Chiggers have an orange-red body and measure 0,25 mm to 1 mm when gorged. It is therefore initially microscopic but can be seen with the naked eye.

The larva infests an animal host (dog, cat, other mammal or bird) for food. It will prick the skin and inject saliva containing enzymes that will predigest the tissues and skin cells and then feed on the resulting fluid. Once its meal is finished (after a few hours to about 2 days), the parasite is released and returns to the environment to continue its cycle. 

Be careful, although several individuals can suffer an infestation at the same time, there is no contagion between them (between humans and animals or between two animals). It is always an infestation caused by the same outbreak in the environment.

The larva will seek to attach itself to areas where the skin is thin: the interdigital spaces (between the fingers), the auricular pavilions, the eyelids, under the tail, the face for example.  

The bite will cause a lesion of the skin but also a local allergic reaction due to the injected saliva. 

The following signs may appear: 

• a significant itching, sudden onset and localized is often the call sign;
• one can observe a small area of ​​redness and an elevation on the skin locally;
• repeated and intensive scratching of animals can then cause other lesions (excoriations, wounds, edema for example). These lesions can be numerous and grouped together in the event of a significant infestation.. 

It is rare to see the parasite on the animal because the itching is due to the allergic reaction and often manifests after the parasite has left. 

The chigger bite is usually mild and the clinical signs may subside on their own. 

In the event of a severe itching, however, it may be necessary to provide a solution to relieve your pet. The first thing to do is to rinse with clean water and disinfect the injured area with a suitable antiseptic (chlorhexidine or betadine). 

If the pruritus persists and your pet’s discomfort remains significant, then it is advisable to present it for consultation with your veterinarian. After examination, he can implement local and / or oral care to reduce the allergic reaction and the itching sensation (an ointment containing corticosteroids for example).

If after the bite you have the impression that your animal has a swollen face or has significant breathing efforts, urgently contact your veterinarian because he could be having a generalized allergic reaction.

Unlike anti-tick and flea treatments, the effectiveness of usual antiparasitic treatments is limited to fight chigger bites. Some products in the form of shampoo or spray include suitable treatments (pyrethroids for dogs, Fipronil for dogs and cats). But it is necessary to repeat their application several times a week because their action does not last over time.

The best solution to avoid bites is therefore not to let animals roam the homes where these parasites are spread: 

• tall grass ;
• fallow land;
• forest edges;
• proximity to wetlands.

If it is a private property infested by chiggers, treatment of the external environment is difficult to implement. Performing thorough brush clearing and keeping the grass low can be effective.