DIGESTIVE PARASITES
Worms
The classical sign that your animals have these is diarrhoea, but they can also become quite suddenly ill and poor without showing this.
Worms are usually borrowed from sheep, although they are thought susceptible to cattle worms too, and exposure to sheep-grazed pasture is a major risk. Worm burdens build up throughout the summer on ground that is continuously and heavily stocked. If left empty over a hard (i.e. several hard frosts) winter, pasture becomes “clean”, i.e. most of the worm larvae die. It’s reinfested by putting stock on it that are carrying worms which have gone dormant inside them, and which wake up and start producing eggs again in the Spring.
Your Vet can test for worms on dung samples, and if there’s evidence of infestation, will recommend treatment before your animals get ill. Youngstock are particularly at risk.
Whether, when and with what you should treat worms depends on your situation:
If an animal has been diagnosed sick with worms, obviously it should be treated. Treatment is usually with an avermectin, e.g. Dectomax, Ivomec, but some species aren’t killed by these drugs, and when identified, will need treating with (probably) one of the “white” (benzimidazole) drenches.
If dung samples prove positive for worm eggs treatment may be indicated. It’s more common to need to treat youngstock, and just before the onset of winter if dung samples have been positive for worms in the Summer.
Liver Fluke
This is a flat worm which affects the liver, either causing rapid catastrophic damage, or, more commonly in alpacas, long term chronic damage. The animals will lose weight, and look generally unthrifty. They may have diarrhoea and may demonstrate fluke eggs in the faeces. Generally local inquiry will reveal that the land supports the snail which is the essential intermediate host for this parasite. Usually this snail can only survive on boggy, wet ground which fails to dry out completely in summer. Problems are most often seen in September/ October/ November. Treatment is with e.g. Fasinex (triclabendazole) or albendazole, but be careful with pregnant animals, since albendazole has been associated with birth defects in other species.
Coccidia
This can cause diarrhoea in very young stock, usually as a result of concentrated use of an area or building for calving. It is treatable with e.g. Bimadine (if currently available) or Vecoxan. Diarrhoea is not always seen, sometimes an animal is just obviously ill. There are many species of coccidia, and not all are detected by standard methods on dung samples. One particular cause of problems in camelids, E. macuniensis, has such large oocysts (eggs) that they must be looked for with the method usually used for liver fluke.
More effective than Vecoxan is Baycox, given at 3ml/10 kg body weight, but it is also more toxic, so you must have a reasonably accurate idea of their weight.
Cryptosporidia
Also causes diarrhoea in very young stock in a similar way to Coccidia, but is more difficult to treat. Prevention is by avoiding contamination and over use of calving areas.
Johne’s
This is a disease which is caused by a bacterium related to TB, although not the same. Alpacas have been reported to get it, but some seem able to self-cure, without becoming chronic carriers.
Enterotoxaemia
This is caused by bacteria from the Clostridia family and can cause a variety of symptoms, but most commonly diarrhoea, dullness and/or sudden death. It tends to occur sporadically and we hope to protect against some of its variants by using Clostridial vaccines such as Lambivac or Heptavac.
Dr Julio Sumar reports Enterotoxaemia in Peru - caused by Clostridium perfringens A & E. These are not contained in Lambivac or Heptavac.
Control is achieved there by moving calving areas to clean ground.
Vitenium is a useful and (at that point) available injectable Selenium supplementation.
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