Animal diseases

As a reindeer owner, you need to be aware of the risks with keeping many animals in a limited space. If you follow the guidelines regarding feed, water, hygiene, routines and design of the enclosure, you will significantly reduce the risk of your reindeer falling ill. It is important to minimise all forms of stress, such as a high number of animals, crowding around the feeding cribs and unnecessary handling.

At the same time is it important to start the supplementary feeding one step ahead, before the reindeer have lost too much of their condition. A starving reindeer who suddenly is being fed large amounts of feed will have troubles adjusting to the abrupt change. If this happens when temperatures are particularly low, the risk of illness and death is high.

You should learn how to recognise signs of disease to be able to undertake measures at an early stage and keep a good dialogue with your veterinarian. In case of disease, you have to isolate the sick animals from the rest of the herd in a separate pen and seek veterinary advice. In preparation, please document the status of the animal with pictures and check the symptoms. Below, you can find more about common diseases of reindeer.

What is slosh stomach?

Slosh stomach, or rumen acidosis, is a condition that occurs when the reindeer consumes a large amount of easily digestible carbohydrates (for example pellets) without a prior transition period. In animals with rumen acidosis (slosh stomach), the rumen pH is lowered (acidic), there is a reduction in important microorganisms and an increase of the number of lactobacilli in the rumen. Rumen acidosis causes fluid from other tissues in the body to be relocated to the rumen which can lead to diarrhoea, dehydration and eventually death due to circulatory collapse in the reindeer.

What are the symptoms?

The general condition of the reindeer quickly worsens when rumen acidosis occurs. The reindeer can develop a large swollen stomach, diarrhoea, loss of appetite and dehydration. When the reindeer moves, the stomach can make a “sloshing” noise. Sometimes the reindeer might regurgitate/vomit loose ruminal content just before it dies.

How is slosh stomach avoided?

Slosh stomach is best avoided by allowing the reindeer to slowly adapt to new feed types and avoid abrupt changes to the diet. When introducing pellets – limit the volume but ensure that all reindeer are eating the pellets. This allows for the rumen to adapt. Even reindeer already on a pellet diet without any complications can develop slosh stomach when changing the type of pellets, or if the content in a different batach of pellets is very different to the previous one.

The risk of slosh stomach is significantly lower if the reindeer are on pasture or are being fed sufficient roughage of good quality as a complement to the pellets. This will stimulate both rumination and production of saliva. Reindeer saliva is alkaline and will buffer the ruminal content to prevent the ruminal environment from becoming too acidic.

What can I do if I have a reindeer with slosh stomach?

If the reindeer is already in a bad state due to the rumen acidosis, the prognosis tends to be poor. In most cases, intensive care will be needed to save the reindeer. If you suspect slosh stomach, immediately contact your veterinarian! Here are a few measures that you can try to treat the reindeer with:

  • The most important measure if you have a suspected case of slosh stomach is to immediately stop giving the reindeer pellets and only allow access to lichen and a good quality silage.
  • Give sodium carbonate or baking powder to buffer the ruminal content. You might have to empty the rumen from fluid before you give new fluid with sodium carbonate.
  • In USA, goats who easily can develop rumen acidosis, are sometimes offered free access to sodium carbonate as a preventive measure. This would probably work also for reindeer.


Diarrhoea is a frequently occurring problem in reindeer, especially when pellets are first introduced to the diet and as a result of abrupt changes of diet. A normal “readjustment diarrhoea” can cause high levels of disease and death if the animals are in poor condition in combination with severe cold. Diarrhoea can also be caused by infections, but those cases tend to be more severe.

  • Avoid diarrhoea by gradually introducing pellets and make sure that the animals have access to silage, moss and clean water.
  • Mild diarrhoea can be handled by reducing the volume of pellets and carefully monitor the reindeer. If possible, offer the reindeer lichen and ensure there is free access to water or clean snow.
  • Liquid and massive diarrhoea should be handled by isolating the affected animal from the rest of the herd. Give lichen, withhold the pellets and consider giving rehydration and energy balance after consulting with a veterinarian.
  • Liquid, excessive or bloody diarrhoea in combination with a worsened general condition – isolate the reindeer from the rest of the herd and contact a veterinarian. Avoid giving pellets, give lichen, rehydration, energy balance and active charcoal (can be found as paste). Keep the reindeer warm, clean and dry. Consider putting a blanket on the sick animal if it is very cold.
  • If many reindeer are affected and have diarrhoea, always consult a veterinarian. Before you phone the veterinarian, count how many animals are affected and assess their condition – note down whether they seem alert, if they have appetite/are eating, if they are keeping away from the rest of the animals and so forth.


Animals can die from emaciation for many different reasons. It is important to rule out disease by contacting a veterinarian and perform autopsies.

What to do if I suspect starvation?

  • Isolate apparently thin reindeer and keep these monitored in a sick pen. Offer lichen as a complement to pellets and silage. Offer minerals and vitamins. Vitamin B is of specific importance to animals suffering from starvation.
  • When there are many reindeer with low body condition, avoid overcrowding the enclosure. You need to be able to see the individual reindeer and ensure that all animals are eating. Do not limit the number of feeding cribs and make certain that the silage is of good hygienic quality, not frozen, hard or too fibrous. Reindeer can sometimes die from starvation despite having their stomachs filled with silage. This occurs when the fibre content of the silage is too high since the reindeer cannot digest fibres that are too rough.

If you plan on giving supplementary feeding to reindeer already in poor condition:

  • Give the reindeer a chance to slowly adapt the ruminal flora to pellets. Feed the animals small amounts on multiple occasions on a daily basis.
  • Give a good quality silage before feeding pellets to get the reindeer to start ruminating.
  • Make certain that the reindeer all have access to clean water.
  • Offer lichen/moss in large quantities.
  • Feed minerals and vitamins.
  • Protect the reindeer from the extreme cold by having a well-planned enclosure that offers shelter in the form of hills and trees.
  • Keep a separate enclosure with multiple feeding cribs for the weakest reindeer. This way you can avoid overcrowding and associated stress as well as allow for close monitoring.
  • Sick animals need to be isolated from the rest of the herd and a veterinarian should be contacted.
  • Dead/euthanised reindeer should be subjected to autopsies. If the autopsy reveals a complete lack of fat tissue on the heart of the reindeer, this means that the reindeer has exhausted all its fat deposits and died from starvation.


What are impactions?

An impaction is a type of congestion or constipation of different segments of the gastrointestinal tract of the reindeer. If the reindeer is being fed silage that is too rough and fibrous, this can cause impactions, particularly in the omasum and abomasum. When this problem occurs, digestive matter is blocked from further passage through the gastrointestinal canal.

Constipation/congestion can also be caused by lack of water/dehydration. Keep in mind that reindeer that are fed pellets have higher water needs than reindeer on pasture.

Sometimes plastic and string from hay/silage bales can cause obstructions or other problems in the stomachs and gut of the reindeer.

Wet belly

Wet belly is a phenomenon not described in any other species. The reindeer becomes wet in the armpits, groin, on the abdomen and sometimes on the legs. The cause of the condition is unknown, but it has been suggested that mould toxins might be involved in the development of the disease. Mould toxins can form in silage if stored too hot and humid or if the plastic cover around the bales is broken, allowing air to come inside.

What are the symptoms of wet belly?

Affected reindeer normally do not lose their appetite but remain eating. They do not have a fever and will stay wet, even if kept on a dry surface. Characteristically, the reindeer can be scrunching to keep warm.

How can I treat wet belly?

The treatment consists of an immediate change of diet and providing shelter to protect the animals against cold. If the reindeer show no signs of improvement within a few days, contact a veterinarian. The survival rates vary. Autopsies performed on animals with wet belly have showed that the cause of death has been circulatory collapse.


Reindeer suffering from disease might lie down on their side (lateral recumbency). Lying on their side can cause bloat since animals lying down will not be able to eructate (burp) and the gas produced in the rumen becomes trapped. Sick animals need to be put on their chests (sternal recumbency) and supported physically to prevent them from falling back on their sides. The head should be positioned higher than the abdomen to enable the reindeer to pass the gas. If possible, try and make the reindeer stand up, gently massage the rumen and feed the animal a mixture of milk, yeast, oil and a small volume of washing up liquid. The purpose is to make the reindeer eructate.

Eye infections

Severe and contagious eye infections are easily spread between animals when a large number of reindeer are kept within an enclosure. There is an annual variation; some years the problems might be worse than other years.

What is causing the eye infections?

  • Multiple factors are thought to contribute to the condition, for instance; a dusty environment, dust from the feed and overcrowding around the feeding cribs which can cause stress and/or a weak immune system.
  • Some studies have shown a strong association between a high prevalence of herpes virus in reindeer and outbreaks of severe eye infections. Herpes infections will lie resting in the reindeer for the rest of their lives once infected. In times of stress, for example during transport, starvation or overcrowding, the virus is reactivated. The virus can cause small lesions on the cornea (outer layer of the eye) and these lesions can easily get infected by bacteria. Infected females can transmit the virus to their calves.
  • Bacteria from the Chlamydia family can also cause outbreaks of eye infections.

What to do if I discover cases of eye infections?

If you discover cases of eye infections in your herd, immediately isolate the affected animals and move them to a separate pen. This will prevent the infection from spreading to other animals as well as facilitating monitoring and potential treatment. Since eye infections can be caused by many different factors, the importance of finding out the underlying cause to an outbreak cannot be overstated. This can easily be done by taking swab samples from the animals with disease and sending the samples for laboratory analysis. Contact your veterinarian to discuss how to proceed.

Contagious echtyma/orf

Orf is caused by a virus (Parapox virus). When infected by the virus, the reindeer develops warts or/and blisters inside and around the mouth. These lesions may appear wartlike but have nothing to do with actual warts. Orf was diagnosed in one reindeer in Sweden in 2015 and during a larger outbreak in 2016 with many sick and dead reindeer. A number of cases were discovered in February and March in 2018. Prior to these outbreaks, the disease had not been reported in Sweden since the 70’s. However, in Finland, several major outbreaks have been recorded.

The time of incubation is about 10 days. If the reindeer survives it will be self-cured within 2-4 weeks. Reindeer who have had the disease are likely to develop immunity, nevertheless this is probably not lifelong.

What are the symptoms of orf?

Warts/blisters emerge on the nose, lips or inside the mouth. Severe states of the disease, with blisters covering large areas of the nose and mouth can be very painful and limit the reindeer’s ability to eat. Subsequently, these animals can become severely emaciated. The warts/blisters can become infected by bacteria which further aggravates the condition. It is not uncommon for necrobacillosis to develop in the orf lesions.

How do I treat orf?

No treatment exists against the orf virus. What can be treated are the secondary bacterial infections in the warts/blisters, but at the time of discovery they have often expanded to the degree that it is too late to initiate treatment. Hence, the main focus is to prevent the disease from spreading.

If the affected animals are kept in an enclosure and fed from feeding cribs, the risk of disease transmission of both orf virus and secondary bacterial infections between the animals is very high. Releasing the reindeer out on pasture will reduce the risk but make adequate monitoring more difficult and there is also a potential risk of spread to reindeer outside the herd. If the animals cannot be released onto pasture, the infected animals need to be isolated in a sick pen. Individual cases should be treated separately. Seek veterinary advice if you suspect your herd might be infected.


The virus can infect humans and cause painful skin lesions. Always handle animals with the above described symptoms with care and remember to use gloves!


What are parasites?

The definition of a parasite is an organism that lives off a host animal without contributing to the host.

What parasites do reindeer have?

Round worms (nematodes)

  • The stomach worm penetrates the hydrochloric acid producing glands of the abomasum and can cause problems with the digestion. Heavy infections can cause diarrhoea.
  • Lung worms live in the respiratory tract of the reindeer and can severely damage the lungs, cause difficulties breathing, emaciation and even death.
  • The meningeal worm inflames the brain or the spinal cord which can lead to disturbances in the coordination of the hind legs (ataxia) and paresis. The eggs are transmitted through saliva and faeces.
  • Setaria lives in the abdominal cavity and can cause severe inflammatory reactions that can lead to parts of the carcass being discarded at slaughter.


  • The reindeer sinus worm/tongue worm (Linguatula arctica (Pentastomida)) grows to a size of 12-14 cm. It lives in the sinuses of the reindeer and causes inflammation.


  • Reindeer warbles (caused by the reindeer warble fly Hypoderma tarandi) and the reindeer nasal bots (caused by the nasal bot fly Cephenemyia trompe) are two of the most common and visible reindeer parasites. Botflies resembling bumblebees lay their eggs (July-September) on the hoofs and lower limbs of the reindeer. The larvae hatch and migrate up to the back of the reindeer where they live under the skin. This will cause an inflammatory response in the reindeer and affect hides and meat negatively.

Lice and ticks

  • The common tick (Ixodes ricinus) is an arachnid who feeds off the blood of mammals and can carry a variety of diseases. Traditional reindeer grazing grounds in the Nordic countries used to be free from ticks due to the colder temperatures and hard winters, but these days the common tick is becoming increasingly more common also in these areas.
  • Reindeer can carry both blood sucking and chewing lice, but these can be difficult to find.

In addition to the parasites mentioned here, other parasites can infect the reindeer. You can read more about parasites in reindeer here.

How do I get rid of the parasites in my reindeer?

A number of harmful parasites can easily be treated using modern pharmaceuticals. Remember to take care and be sensible when using the antiparasitic drugs to minimise the development of resistant parasites. Treatment against parasites is important to ensure good animal welfare and for economic reasons.

Deworming with ivermectins

Ivermectins have a good effect against both parasitic insects and round worms. They are given via subcutaneous injections. Ivermectins are prescription drugs which means that you will need a prescription from a veterinarian.

  • The drug is injected under the skin of the reindeer. Use of this drug must be recorded by the reindeer owner. Marking (using for example spray paint) and keeping records of the animals that have been treated are of food hygienic importance. Animals treated with ivermectins have a 28 days withdrawal time from slaughter.
  • Overdosing can cause poisoning and an extended withdrawal time. Underdosing can from a long-term perspective be more hazardous since this will drive resistance in the parasites and the parasites will become more difficult to treat.
  • Animals that have been treated with antiparasitic drugs must be marked if practically feasible. The reason for this is to avoid sending treated animals to slaughter within the withdrawal time and to avoid repeated treatment. The type of marking used must be included in the records.

You can read more about antiparasitic treatment here.

Chronic wasting disease (CWD)

Chronic wasting disease (CWD) is a prion disease. It has been recognised in a number of different types of deer (cervids) in North America since the 1960’s. The disease is associated with severe injuries to the brain. No treatment or vaccine against the disease exists. The disease is contagious.

What are the symptoms of CWD?

The onset of the disease, before the animal exhibits any symptoms, can be one to several years. However, the disease can still be transmitted within this period, through saliva, urine and faeces. The symptoms can be a change in behaviour, staggering, emaciation, excessive urination and drooling. Once the animal starts showing symptoms it usually dies within a few months.

How can we protect ourselves?

So far, Sweden has not had any cases of CWD in reindeer, but the disease was diagnosed in Norway in 2016. The European Union has decided to increase the surveillance of CWD in wild deer and fenced reindeer and this will be done in 2018-2020.

SVA recommends all samebys (Sami reindeer-herding and economic district) to send in samples from dead animals to analyse for CWD. Read more about it here.