Changes

==Description==

==Description==

Cutaneous '''Habronemiasis''' is a hypersensitivity reaction to the larvae of the nematode species ''Habronema'' and ''Draschia''. The adult nematode lives in the stomach of the horse and produces eggs which are then passed in the faeces as larvae. The larvae are ingested by the house fly (''Musca domestica'') or stable fly (''Stomoxys calcitrans'') in their larval phase, and deposited on equine skin when they feed as adult flies.

Cutaneous '''Habronemiasis''' is a hypersensitivity reaction to the larvae of the nematode species ''Habronema'' and ''Draschia''. The adult nematode lives in the stomach of the horse and produces eggs which are then passed in the faeces as larvae. The larvae are ingested by the house fly (''Musca domestica'') or stable fly (''Stomoxys calcitrans'') in their larval phase, and deposited on equine skin when they feed as adult flies.

The condition is characterised by ulcerative, granulomatous skin lesions which do not heal.

The condition is characterised by '''ulcerative, granulomatous''' skin lesions which do not heal.

==Signalment==

==Signalment==

Lesions most commonly occur on the legs, ventrum, around the eyes, urethral process and prepuce and at the site of pre-existing wounds.

Lesions most commonly occur on the legs, ventrum, around the eyes, urethral process and prepuce and at the site of pre-existing wounds.

The lesions are single or multiple ulcerative nodules with a serosanguinous discharge. There may be excessive granulation tissue and small yellow granules of necrotic debris which surround the larvae.

The lesions are single or multiple ulcerative nodules with a serosanguinous discharge. There may be excessive granulation tissue and small yellow granules of necrotic debris which surround the larvae.

Pruritus may be mild to severe.

Pruritus may be mild to severe.

In cases of conjunctival habronemiasis there will be gitty plaques on the conjunctival and palpebral borders, it is painful in severe cases leading to epiphora and blephrospasm. Conjunctival habronemiasis is fairly common and must be differentiated from Squamous cell carcinoma of the third eyelid.  

 

In cases of conjunctival habronemiasis there will be gitty plaques on the conjunctival and palpebral borders, which is painful in severe cases leading to epiphora and blephrospasm. Conjunctival habronemiasis is fairly common and must be differentiated from Squamous cell carcinoma of the third eyelid.  

===Biopsy===

===Biopsy===

==Treatment==

==Treatment==

Systemic glucocorticoids decrease the inflammatory response of the the hypersensitivity reaction, oral prednisolone is effective at a dose of 1mg/kg SID or BID for 14days and then tapered.

Systemic '''glucocorticoids''' decrease the inflammatory response of the the hypersensitivity reaction, oral prednisolone is effective at a dose of 1mg/kg SID or BID for 14days and then tapered.

Organophosphate pastes and anti-inflammatory pastes can be applied to the wound until it has healed, or thye wound should be bandaged to prevent reinfestation.  

Organophosphate pastes and anti-inflammatory pastes can be applied to the wound until it has healed, or the wound should be bandaged to prevent reinfestation.  

Excessive granulation tissue should be removed surgically.

Excessive granulation tissue should be removed surgically.

Ivermectin or appropriate anthelmintics should be used to limit nematode infestation, fly control will also reduce exposure to the larvae.

Ivermectin or appropriate anthelmintics should be used to limit nematode infestation, fly control will also reduce exposure to the larvae.