Goats have no top teeth and instead have a hard dental pad that their bottom incisors bite against.
You can estimate the age of goats by the age at which the milk teeth are replaced by permanent incisors. They get new ones in pairs working from the middle outwards.
But be warned about average ages of eruption – there is enormous variation between animals. Here are some values:
- Kid - starts with 8 temporary incisor milk teeth
- Hogget - the centre pair of permanent teeth start to erupt at 12 months of age.
- 2-tooth - first central pair of permanent teeth present at 13-15 months old.
- 4-tooth - second pair present at 18-21 months old.
- 6-tooth - third pair present at 22-24 months old.
- Full mouth - complete set of 8 permanent teeth present at 27-32 months old.
Looking in a goat’s mouth
Goats don’t like dental examinations, so you’ll have to firmly restrain each animal. Here are some tips:
- Sit the goat upright in the shearing position and use both hands to open its mouth.
- Cup your left hand around its jaw and use your left thumb to lift its top lip and then use your thumb on the other hand to pull the bottom lip down.
- You’ll be able to see if the teeth are meeting the gum correctly and are not “undershot” or “overshot”.
- When undershot the teeth meet the gum back from the edge (called parrot mouth), and when overshot the teeth stick out beyond the gum edge and can be very sharp as they have not been worn down with biting off grass.
- If you want another view, slide your left thumb into the space behind the incisors where there is a gap before the molars start and this will open the mouth so you can see the top of the teeth.
- If you are not able to tip the goat up, then hold it up against a fence or in the corner of a pen and pull its lips down as described above. You don’t get such a good view.
Be prepared for surprises
You can often get a shock when you see the state of a goat’s teeth. Teeth do an enormous amount of tearing and pulling of fibrous herbage and are subject to great mechanical stresses.
Here are some things regularly seen:
- Overshot and undershot jaws as mentioned above. The overshot teeth may be only partly overshot where the back half contacts the gum and the front half has a lance-like edge that can lacerate your fingers. Goats with undershot parrot-mouths have great difficulty in eating short pasture.
- Gum cavities that still have both the old tooth present and the new one pushing it out, and the gum looking very inflamed.
- Missing permanent teeth – especially the central pair which are critical for grazing.
- Very long wobbly teeth that are loose in the gum. This may be “periodontal disease” which has many causes and there’s not much you can do about it.
- Most permanent teeth missing and only an odd single very long loose tooth left. It’s better to pull this out to even up the sheep’s bite.
- No permanent teeth at all – the goat is described as being “broken mouthed” or called a “gummy”. They have all worn off by the gum. In pumice country this can be a special problem with the very abrasive nature of the soil.
- If all the teeth are worn right down to the gum but are still there, it’s very difficult to age the goat as you cannot tell which stumps are temporary and which are permanent teeth.
- Long permanent teeth where grass has been getting in between them and wearing away great holes.
Goats with no teeth can still manage to eat if there is plenty of pasture available, as the front teeth only bite off the grass and the back incisors do the grinding.
When fed root crops like turnips, they really need good teeth to break the skin of the bulb and eat it down to ground level once the leafy top has been eaten. Also good teeth are important if goats are to browse hard woody shrubs.
Sheep breeders have shown that the solution to teeth problems is through an effective selection and culling programme.