Welfare
ABOVE: X-rays are invaluable to determine whether a swelling over the jaw is caused by a tooth problem, or by another cause, such as a fracture, an infection of the bone, or a swelling of the soft tissue.
Tooth anatomy The crown is the part of each tooth above the gum line, and is covered by enamel. Tooth enamel is one of the hardest compounds in nature, but it cannot repair itself once damaged. The enamel of incisors is uneven in alpacas, with a thick layer towards the lips, but only a thin layer towards the tongue. This contributes to the chisel-like shape of alpaca incisors. The part below the gum line is called the tooth root, and is covered in cement instead
of enamel. The cement helps to keep the tooth in its bony socket. The next layer in is dentin, and this is present in both the crown and the root. Dentin
can repair itself in response to wear. It needs the right stimulation and good blood supply, though, and this secondary dentin is of lower quality than the original one. At the centre of each tooth is the pulp. Blood vessels and nerves enter via the root
canal and continue into the pulp. Pulp is very sensitive and will become infl amed and often infected if exposed (eg, through teeth trimming). As it contains nerves, any exposure is very painful.
You can’t beat a good bite In an alpaca with a correct bite, the incisors are not visible when the mouth is closed and they touch the dental pad in the upper jaw close to its front. An overbite (incisors stick out) can lead to reduced feed intake and occasionally broken
teeth. An underbite is rarer, but can lead to damage of the mouth lining as the incisors miss the fi rm dental pad. Always check the cheek teeth in an alpaca with an incorrect bite: often the jaws are misaligned, as well, leading to uneven wear and sharp points in the cheek teeth.
When should I consider dental disease? Often there are no signs that an animal is suffering from dental disease. However, the following observations should trigger a thorough examination of the teeth. Remember that for a good look at the cheek teeth, your alpaca is likely to need sedation. • Weight loss. • Poor digestion. For example, the fl ank not looking very full or too much undigested fi bre in the dung.
• Taking longer to feed. • Dropping feed or a cud. • Drooling saliva. • Unpleasant smell from the mouth (halitosis). • Discolouration of a tooth. • Jaw swelling. • Discharging tract along the upper or lower jaw. • Excessive tear fl ow. Regularly feel along the jaw and tooth line, for example, each time you body condition
score your animals. If you fi nd a swelling, act promptly as an infection of the bone or tooth can lead to rapid destruction of the jaw. A jaw swelling can be caused by several conditions other than a tooth infection, for example, infection of the bone (including lumpy jaw), a fracture (eg, after a kick), a tumour, an abscess (including caseous lymphadenitis
Figure 2: The cheek teeth have sharp ridges and act as blades, rather than grinding stones. Rasping cheek teeth is only occasionally necessary, but when it has to be performed it is important to not smoothen the tooth completely.
Figure 3: Fighting teeth appear at around three years of age in the natural gap between the front and the cheek teeth. There are two in the upper jaw and one in the lower jaw. In females and castrated males they do not always erupt.
Alpaca Summer 2012 39
Figure 1: Alpacas have three pairs of incisors (front teeth) which are shaped like a chisel and continue to grow well into adulthood. Instead of incisors, there is a dental pad in the upper jaw. This animal has a good bite, with the incisors meeting the dental pad close to its front, and no teeth protruding when the mouth is closed.
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