Rickets is a fairly common condition affecting alpacas in Northern Europe, mainly young ones in their first year, but can also affect older alpacas. You may at first notice lameness and hunched back, followed by severe weight loss. The primary cause appears to be lack of Vitamin D, associated with low blood phosphorus.
Alpacas can get some Vit. D as Vit. D2 from plants, but they also rely on producing Vit. D3 by the action of U-V light on the skin; this is no problem on the high altiplano where there is about 12 hours of daylight year-round. However, because winters in Northern Europe have much shorter daylight hours, we need to supplement our alpacas with Vit. D, and in the UK we administer Vits A,D&E either by injection or oral paste as a preventative. We normally start in late October/early November. Injections can be given to crias every 8 weeks, and injectable A,D&E can be imported by your vet under licence. However, since we have experienced abscesses and lameness after the injection we now drench with A,D&E paste every 6 weeks until March. Because we have noticed a few cases of rickets in adults as well, we routinely give all our adults a single dose in early winter, and any thin or poorly alpacas get dosed regularly along with the crias.
The paste comes in tubes with an applicator, so that you can give 1,2 or 3 clicks of paste. 1 click will dose a youngster up to 50 kilos body weight, 2 clicks is more than adequate for adults. Available from www.alpacacare.co.uk
If you haven’t got your crias started on their A,D&E in November or even December, don’t worry – it’s better late than never to start in January or even February. It’s also a good idea on your daily rounds to check the individuals in your herd for signs of the disease whether or not you have already dosed them.
There is some Vit. D in proprietary alpaca supplementary feeds; also in hay. However, the level of Vit D2 in Spring grass is relatively lower than in mature grass, and so the time when your young weaned alpaca starts to favour the tasty new Spring grass over hay may just be the time when its vitamin D level falls below optimum, resulting in rickets.
Crias with rickets will generally be noticeably smaller than their same-age peers. They may hang behind the rest of the group. They may look as if it’s painful for them to walk, as they may have painful swollen joints. Angular limb deformities may follow. This condition will not right itself on its own. If you suspect your alpaca is suffering from a Rickets, then your vet. can do a blood test to confirm this. However, he must spin off the plasma very soon after taking the blood in order to obtain a correct result from the test. Then, as well as Vitamin A,D&E paste, you will need to give a daily dose (about ¼ teaspoon) of prescription phosphorus plus supplementary feeding to promote weight gain, which could be milk feeds (we have given extra milk to weanlings with rickets up to 8 months old) or hard feed such as calf nuts or alfalfa pellets.
N.B. Whether you decide to use paste or injection, it is very important to note that you should only give the dosage prescribed. The injectable A,D&E is currently available only from your vet., as it is a prescription medicine; he will need to obtain a licence to import it into the UK, as it is not currently licenced for use in the UK. If you give a higher or more frequent dose (or both), you are at risk of overdosing your alpaca, which may even result in death.