A bilateral watery or frothy , foamy , blood-tinged or brown nasal and / or oral discharge can occur with Hendra virus infection .
Sometimes a discharge can change and this needs to be watched carefully , For example a normal serous nasal discharge after travel can quickly progress a mucoid or purulent discharge , and from there to severe and lifethreatening pneumonia and / or pleurisy ( travel sickness ). The earliest sign of progression with secondary bacterial / viral / fungal invasion and complications is a fever within 20 hours post travel . Monitoring body temperature twice daily is important after travel as early , aggressive treatment is required .
The presence of other signs , along with a nasal discharge can help in the diagnosis .
Coughing is more common with lower airway disease , except if the cause is a foreign body stuck near the pharynx or larynx or swallowing problems . An increased respiration rate or difficulty breathing usually indicates pulmonary , lung or lower respiratory tract involvement , whereas severe respiratory obstruction and reduced airflow through the nose often occurs in horses with sinusitis and nasal masses ( tumour , maxillary cyst or ethmoidal haematoma ). Horses with obstructive lesions in the pharynx ( abscess , tumour ) or guttural pouch problems can show signs of respiratory obstruction and a snoring respiratory noise even at rest . Swelling in the throat can be a sign of a tumour or abscess , or of guttural pouch disease . ( Table 1 )
Respiratory tract disorders and diseases can present with a whole range of signs either singly or in combination , including : nasal discharge , flaring of the nostrils , increased effort or rate of breathing , facial swellings , halitosis , abnormal respiratory noises , coughing and reduced exercise capacity – any one of these symptoms can signal disease or abnormality in the upper and / or lower respiratory system . Determining the cause requires a full veterinary clinical examination and often additional investigations .
In foals , a discharge from both nostrils is common with infections acquired before , during or soon after birth ; meconium aspiration ; herpes virus infection , and in older foals with rattles or pneumonia . In foals that have a nasal discharge containing milk soon after birth , congenital defects of the palate , throat ( nasopharynx ), cysts or oesophagus problems may be the cause . Recently on some studs in Australia and overseas , Chlamydia a zoonotic pathogen spilling over from birds , has caused pneumonia in vets , horses and farmers ; a serous nasal discharge in adult horses ; premature birth and abortions in mares , and acute respiratory distress with serous to mucopurulent nasal discharge in new-born foals . Biosecurity and personal protective equipment is needed when dealing with Chlamydia-associated respiratory disease .
Several gastro-intestinal parasites can also be a problem in foals and young horses . Roundworms ( ascarids ) are a real and present danger to horses from two months to four years old – partly due to increasing resistance to common wormers . The larvae of roundworms migrate through the lung tissue and occupy the airways - causing a nasal discharge ( which may contain worms ). Once lung tissue is damaged by the roundworms , viral or bacterial infections can occur . Threadworms ( strongyloides ) can also cause respiratory signs and a nasal discharge when they enter through the skin and migrate to the lungs . And although donkeys are the primary host they are rarely affected by lungworms – but horses paddocked with donkeys can become infested with a lungworm ( dictyocaulus ).
This parasite spends its adult life in the lungs , lays eggs that are coughed up and swallowed , then passed in the manure . With all of these parasites ,
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AQHA SEPTEMBER / OCTOBER ISSUE 2022