Guinea pig tongues are approx 5 to 8mm wide and 20mm long, with the front half freely moving and the back half dome shaped and attached to the floor of the mouth. The tongue is covered in taste buds, affording guinea pigs a reasonably well developed sense of taste. The tongue is usually moist, being coated with the saliva of the mouth.
The tongue is used for grooming and also for eating and drinking, where the front half of the tongue is lifted upwards to push water or food boluses towards the back of the mouth to aide with swallowing. If dental disease is present the tongue can become entrapped by the overgrown molar teeth. This prevents the tongue from moving and makes swallowing much more challenging. The tongue can also be traumatised by sharp spurs on the molars.
If the tongue is diseased or injured then syringe feeding may be necessary. Syringe feeding can also be utilised when there is any other cause of inappetance present. Guinea pigs need to eat fairly constantly, no more than 8 hours should go by without a guinea pig eating. Therefore Syringe feeding can be a life saver whilst other disease processes are being treated.
There are commercially available 'critical care' products which can be used for syringe feeding. These are often made up with water. Ideally the mixture should be fairly thick eg porridge or thick cake batter. As a guide 10ml of food should be given per kg of bodyweight every 3hrs. This can vary dependent on how much your guinea pig is eating independently (ask your vet for advice). 1 to 2ml can be syringed into the mouth at a time before allowing time to chew and swallow. Because guinea pigs are obligate nose breathers (they breathe only through their nose) the risk of aspiration during syringe feeding is less than in some species.
Whilst breathing the soft palate and laryngeal cartilages (the epiglottis and arytenoid cartilage) function to close off the oral cavity and the oesophagus to allow the flow of air to go from the nasal cavity down the trachea (windpipe). During swallowing the soft palate raises to close off the nasal cavity, whilst the laryngeal cartilages close off the trachea, allowing passage of food from the oral cavity into the oesophagus.