Horse Notes
October 2008 Newsletter
No. 2 ISSN 1836-3539 (Print)
ISSN 1836-3547 (Online)
Inside this issue
- Equine Influenza – free at last!
- Hendra virus in Queensland
- Welcoming your new foal into the world
- Property biosecurity following equine abortion
- Founder or laminitis in horses
- Strangles
- Rearing the new foal: the first 12 months
- Horse dentistry: good oral hygiene is important to the wellbeing of a horse
Equine Influenza – free at last!
Dr Roger Paskin, Acting Deputy Chief Veterinary Officer, DPI Attwood
On 30 June 2008, Australia reached a major milestone in its animal health history – the final eradication of equine influenza (EI).
After testing tens of thousands of samples from horses in Queensland, New South Wales and other states and territories, it was possible at last to say with certainty that the virus which caused last year’s epidemic is extinct. Because of an international regulation (based on outdated testing regimes) that requires a 12-month waiting period since the last case, Australia will not be able to send its submission to the OIE (the Paris-based World Organisation for Animal Health) until December this year. During this ‘waiting phase’ we will still need to investigate cases resembling EI in order to continue to exclude the disease.
Australia is the only country in the world to have scientifically proven that it has eradicated equine influenza. The eradication of EI follows a string of successes with other diseases over the past decades – contagious bovine pleuropneumonia, bovine tuberculosis and bovine brucellosis.
Note from the Editor
Welcome to the second edition of Horse Notes. Many thanks to readers of the first edition who sent us their questionnaires and provided us with some very useful feedback on the publication.
To those readers who asked specific questions, we responded by mail as soon as possible.
I hope you enjoy the second edition of Horse Notes as much as the first.
Hendra virus in Queensland
Dr Roger Paskin, Acting Deputy Chief Veterinary Officer, DPI Attwood
Hendra virus is known as a pathogen of fruit bats; it is thought that up to 50% of Australian fruit bats may be infected with the virus. The bats prefer tropical and sub-tropical environments and are more concentrated in the northern and eastern parts of the country.
Transmission of Hendra virus from bats to other species is extremely uncommon. The only other species in Australia to which Hendra virus has been transmitted directly from bats is the horse. Since 1994, only 11 such incidents (involving 36 horses) have been recorded, mainly from Queensland. It would appear that horses become infected through contact with bat urine or placental fluids, which would require horses to be in very close proximity to bats.
Horses contract pneumonia and may also display nervous signs. It is possible for an infected horse to infect other horses with which it is in close contact.
Bats seem not to pass the virus to humans. The only way that a human can become infected is through close contact with infected fluids from horses. The case fatality rate in humans is high; about half of the people known to have been infected with Hendra virus have died.
It is a characteristic of this particular virus that animals that have apparently recovered may relapse some time later.
During the month of July, two outbreaks were recorded in Queensland: one a Brisbane veterinary clinic, where five horses were infected, and one on a property in northern Queensland, where two horses were infected. All of the horses either died or were euthanized. Two people – a veterinarian and a veterinary nurse working at the affected veterinary clinic – were infected and the veterinarian has, tragically, died. More than thirty other horses and all other staff at the same clinic remain unaffected, indicating that transmission between horses and to humans is rare. All property quarantines have now been lifted.
So far, no cases of Hendra virus have been found in Victoria, probably due to the lower bat population density in Victoria. Nevertheless, horse owners are advised to inform DPI of cases of pneumonia in horses that are seemingly refractory to treatment. Infected horses show a high fever, facial swelling, and a frothy nasal discharge. They may also be unsteady, exhibit muscle twitching, head tilting and blindness.
It is important to remember that humans contract Hendra virus from contact with infected horses, and not directly from bats.
Hendra virus is not expected to show up in Victoria anytime soon, but it is always better to be aware and alert.
Welcoming your new foal into the world
Annemaree Docking
Your mare is cleaning her newborn foal. The mare is happy, the foal looks great – exactly what you hoped for. What an achievement! The hard work of getting the mare in foal, feeding her carefully through the pregnancy and making thorough preparations for the foaling have paid off.
Foaling your mare at home is a big commitment and a decision not to be taken lightly. So, what is involved in successfully foaling your mare at home?
Make the decision early. Foaling your mare requires a considerable time commitment. Most (but not all) mares foal at night, generally between midnight and 5 am, so keeping an eye on your mare can be difficult. There are many establishments with professional fulltime foaling attendants. Mares are watched 24 hours a day. They have specialist facilities and veterinary assistance available if there is an emergency. It is an expensive exercise having your mare professionally foaled down and you cannot leave the decision to the last minute. Your mare should not be transported in the month prior to foaling and she needs time to settle in her new surroundings.
1. Preparation
You have made the decision to foal your mare at home. What do you need to do beforehand to make sure that everything is ready for the big night? Firstly, talk to your trusted equine vet. Make sure that they know that you have a foal on the way – get any advice they will offer. There have been many books written on the subject of breeding horses and foaling mares. Do your research and prepare yourself. There is a wealth of information out there, far more than what can be contained in this article.
Make sure you have sufficient facilities. You will need access to a well-grassed yard with some form of lighting, preferably close to the house so you are able to watch your mare closely. Avoid dusty or high traffic yards, as that will increase the chance of disease and infection in a newborn. It is also preferable to have a large stable to house the mare and foal if there are any complications, such as limb deviations, which may require the movement of the foal to be restricted. A yard will suffice, but it needs to be sheltered or you could end up with additional complications.
You need a foaling kit. The table shows what I keep on hand. You may wish to expand on it.
2. Useful ‘wish-list’ extras
Other items that are helpful are a foaling alarm, a pre-foaling colostrum test kit and a brix refractometer. Foaling alarms are not so dependable that you can completely rely on them, however, they will help you to get some sleep.
The pre-foaling colostrum test kit allows you to test the mare’s colostrum and determine calcium content (an indicator of how imminent foaling is). It can narrow down foaling time to a 24-hour period. The brix refractometer allows you to test the quality of colostrum, so you have confidence your foal will receive the antibodies he needs for a strong immune system.
| Item | Use |
|---|---|
| Watch | An essential item. If crucial stages of the foaling do not happen by certain times, you need to get veterinary assistance. |
| Notebook and pen | Write down the time everything happens – if anything goes wrong, your vet will need these details. |
| Mobile phone | To call for assistance. |
| Torch | You don’t want to turn on the floodlights every time you check your mare. |
| An extra pair of hands | Doing the job on your own is difficult and tiring. Make sure you have someone close by who is able to come quickly if you need them. |
| Dilute iodine | For treating the umbilical stump. |
| Tail bandage | Keeps tail hair out of the way. |
| Shoulder length disposable gloves | For checking foal position, handling afterbirth etc. |
| Caslick scissors | Just in case. |
| Baby bottle | A human version works fine, just make the hole in the teat a little larger so the foal doesn’t have to work so hard. |
| Jug | For collecting colostrum. |
| Gauze swabs | For straining colostrum. |
| Water-based lubricant | Handy to have. |
| Foaling chains | Generally if things get to the point that these are required, you will hopefully have veterinary assistance. However, they are handy to have as they may help you intervene early before complications occur. |
| Enema | In case of meconium retention. |
| Scissors | Handy – you can never find a pair when you need them. |
| Hay band | Or string of some sort to tie up the amnionic membranes. |
| Bucket | To put the afterbirth in once the mare has cleansed. |
| Alcohol handwash | Use before handling the foal to help prevent infection. |
3. A month before the due date
The yard is ready. The kit is gathered together. Remember your mare’s due date is an indication only. A mare can foal a month early or late without complications. Be ready for that. All your mare’s vaccinations should be up to date and, if your mare is caslicked, she should be open by now. Keep a close eye on her for signs that foaling is imminent.
4. What to look out for
As foaling approaches, the mare will ‘bag up’ meaning her udder will develop. A relatively reliable sign that the foal will soon be on its way is filling in the teats and wax forming. This is colostrum dripping and drying on the teats. Some mares will run milk. Losing a lot of colostrum is a concern. You may wish to collect and freeze some colostrum if your mare is running milk.
The muscles in the mare’s hindquarters will slacken prior to foaling, although this is more obvious in some mares than others. The mare may show signs of being uncomfortable, such as pacing, or may become very quiet. They are all different. At this stage, it is vital to keep a very close eye on her, so you are there to assist early in the foaling if anything does go wrong.
5. The moment has come…
Follow the photographs to give you an idea of what to expect. Don’t get in the way. Remember that this is a natural occurrence and most of the time goes off without a hitch. Most likely, you will be able to watch quietly, without interfering and enjoy every minute. If you are at all worried, call the vet.
6. Timeframes
These timeframes for key stages of the delivery are an approximate guide, but they give you an idea of what to expect. If things are taking longer, it is an indication that things are not happening as they should and you should call for veterinary assistance. All times are taken from the mare breaking water.
- delivery – 30 minutes
- foal standing – 1 hour
- mare cleansed – 3 hours
- foal nursing – 3 hours
 |
| Photo Two: A presentation to be happy with – two front hooves and a nose. The mare is settled and concentrating on the job at hand. Photo Three: A happy maiden mare with her first colt. Note |
 |
| Photo Five: The mare has cleansed. Check the afterbirth and ensure the entire placenta has been expelled. The foal is up and heading in the right direction – towards the mare’s udder. |
Congratulations on a job well done!
Property biosecurity following equine abortion
Dr Karin Morgan, District Veterinary Officer, DPI Seymour
Equine abortion can occur at any stage of pregnancy. For many owners anxiously awaiting a spritely foal, an abortion can be very stressful to deal with. Abortions can occur for a multitude of reasons including contagious, infectious agents, such as Equine Herpes Virus type 1 (EHV-1), a noncontagious infectious cause, such as a bacterial placentitis, or due to non-infectious causes such as a systemic illness, twinning, foetal abnormalities, uterine pathology or other unknown causes. As there can be potentially serious ramifications with abortions, it is important that the cause is investigated and veterinary advice is sought.
All abortions should be treated as a contagious cause until proven otherwise, as in the case of EHV-1. This virus is highly infectious and can be spread via direct contact between horses or with aborted foal and membranes or via transmission by handlers and the sharing of equipment such as halters, lead ropes, and feeders.
If an abortion occurs, the following steps should be taken to prevent potential spread.
1. Prevent contact with foetal tissues, membranes and contaminated pasture by other horses.
Often these are the source of spread to other susceptible animals, especially with EHV-1 where the foetus and membranes are highly infectious.
- Wearing gloves, place aborted foetus and membranes into leak proof container or double bag in garbage bags. Keep cool (not frozen) for examination by veterinarian before sending to laboratory for diagnosis.
- Disinfect and fence off contaminated area, for example fence off with temporary electric fence and sprinkle the soil and grass with lime.
2. Keep the mare isolated from all other horses and isolate contact mares until diagnosis is made.
This is to prevent further spread of the causative agent, as any uterine discharge the mare may have is likely to be as infectious as the foetus and membranes.
Contact horses will have a high possibility of already being exposed, so will need to be monitored closely. If practical, contact mares should be moved to another paddock and remain isolated, provided they are not putting at risk another susceptible group. Alternatively, they can remain in the same paddock, provided the section where the abortion occurred is fenced off and feeders and water troughs are disinfected or replaced.
Avoid any unnecessary entry into the isolated mare’s paddock. If entry is required then a footbath and hand washing station should be placed immediately outside.
3. All contact equipment should be kept with mare/s in isolation.
Any equipment that has come into contact with the mare, such as headstalls, leads, thermometer, feeders, and waters should be kept with the mare.
4. Any personnel who have had contact with the mare or aborted tissues should follow a strict disinfection protocol.
Any person, who has had contact with an aborted mare, may transmit the causative agent and unsuspectingly infect other animals. It is important that anyone who has had contact should:
- Disinfect hands and boots using either an iodine derivative, chlorhexidine, or a phenol disinfectant for example iovone scrub, hibiscrub, or stericide.
- Shower and change clothes. Clothes should be washed immediately and dried in sunlight to effectively remove any infectious agent. If clothes can not be immediately washed they should be double bagged until such time that they can.
- Until a diagnosis is made, only minimal people should have contact with the mare and then they should not have contact with other horses, especially pregnant mares and young stock. If this is not a possibility, then the person should attend to healthy horses before attending to the aborted mare and then shower, disinfect and change clothes before handling other horses.
Other points to consider whilst waiting a diagnosis are:
- Restricting the movement of horses on and off the property in order to localise the infection and eliminate spread.
- As prevention is better than cure, it is a good management strategy to run mares in small, isolated, closed groups, preferably of the same gestation stage.
- It is also advisable to group maiden mares away from other mares. This allows for easier management if a disease incident was to occur and prevent a wider spread.
- Finally, keeping mares separate from yearlings and younger horses is advisable to avoid exposure to EHV-1 virus that may be circulating in runny-nosed youngsters!
For more information contact Karin Morgan, District Veterinary Officer, DPI Seymour or your local DPI District Veterinary Officer.
Founder or laminitis in horses
Dr Jeff Cave, District Veterinary Officer, DPI Wodonga
Spring conditions often bring their own set of animal health problems. In horses, laminitis or founder is a condition to be aware of coming into spring. The word laminitis means inflammation of the hoof wall. The effects of toxins in the blood on the hoof wall cause laminitis.
Overweight ponies grazing lush spring pastures are typically affected. Laminitis can also follow engorgement of grain or infections of the womb after foaling. As a result, a horse with laminitis will experience pain in the hooves, particularly in the front legs, will be reluctant to move, and will assume a ‘saw horse stance’. Prompt veterinary treatment is required when a horse has laminitis.
The veterinarian will treat the underlying cause and give anti inflamatories to help treat any pain the horse is experiencing. In some cases, a horse will develop hoof deformities as a result of laminitis. Such horses often require corrective trimming and shoeing of their hooves.
As always, prevention is far better than cure and measures should be put in place to prevent laminitis particularly in those ponies that are prone to the condition. Some ponies founder easily and their feed intake needs to be significantly modified during spring. Small ponies need to be carefully monitored at this time.
For more information contact your local veterinarian or DPI Veterinary or Animal Health Officer.
Strangles
Dr Karin Morgan, District Veterinary Officer, DPI Seymour
Strangles is a highly infectious disease of the upper respiratory tract that effects horses, ponies and donkeys and is caused by the bacteria Streptococcus equii. Outbreaks may occur following mixing groups of horses or new introductions to a property. Strangles is generally more common in younger horses; however horses of any age can become infected.
Clinical signs (within three to eight days of becoming infected) may include:
- rapid on-set of high temperature (>39.5 degrees Celsius)
- loss of appetite
- discharge of yellow pus from nostrils
- enlarged glands of head and neck that often form abscesses
- coughing
- difficulty swallowing.
Sometimes a discharge of mucus from the nostrils is all that is seen, and a carrier state without any obvious clinical signs can occur. Symptoms can last for days to months with affected horses remaining infectious for a minimum of four weeks after they have recovered and appear healthy.
Veterinary treatment should be sought in an attempt to control any infection and treat symptoms. Infected horses should be kept isolated for six to eight weeks in order to prevent spread to other horses. Good biosecurity should be observed when handling infected horses to prevent transmission. Transmission occurs via the oral and nasal routes and can occur from direct contact with infected horses or by indirect contact with equipment such as headstalls, leads, feed buckets, stable utensils etc.
Infection can be controlled through the isolation of infected horses until they are free of infection. All infected horses and those in close contact should be placed in isolation, following strict hygiene standards. These include having separate equipment kept in the isolation area, having separate handlers for infected horses or if this is not possible handling infected horses last, then washing hands, face and any exposed skin and changing and washing clothes before handling other horses. Horses should be kept in isolation until they have been proven to be free of disease via consecutive negative swabs.
In order to prevent introduction of disease, all new horses should be closely monitored for at least two weeks post arrival and ideally quarantined. Any horse that develops a nasal discharge should be isolated and swabbed for strangles.
Close monitoring of horses should also occur after attending events such as shows and camps, going to stud, or returning from agistment.
Vaccination for strangles does not always prevent disease in individual horses, but it can assist control programs by reducing the severity and duration of the clinical disease and thus reducing the spread during an outbreak.
For optimal protection, it is important that horses are given the full course of vaccinations (three injections two weeks apart) and have regular boosters.
Strangles is now a notifiable disease in Victoria under the Livestock Disease Control Act 1994 and must be reported within seven days even if it is only suspected. Notification can be made by telephoning the local DPI office and asking for the Animal Health Officer.
Information on the control of Strangles in horses is available on www.dpi.vic.gov.au/notes
For more information contact Karin Morgan, District Veterinary Officer, DPI Seymour.
Rearing the new foal: the first 12 months
Amy Wilkinson, Animal Health Officer, DPI Swan Hill
The arrival of a new born foal is an exciting time for commercial and recreational horse breeders. As with any new born farm animal, regular observation is the key. Understanding the vital signs and behaviours is paramount to the health and well being of the foal.
The table provides a guide to what a foal should do in its first few hours of life.
If you find that the foal is failing to achieve these actions it is important to consult your veterinarian as there may be abnormalities with the foal that need to be addressed immediately.
Colostrum (first milk) is the most important food the foal will consume. It is full of antibodies produced from the mother to aid in providing immunity to the foal against common diseases in the first few weeks of life. The absorption rate of these antibodies in the foal is at its highest for up to 12 hours from birth. After this time the colostrum is less effective in providing immunity.
| Time frame | Action |
|---|---|
| Within first 60 minutes | Stand |
| Within first 2 hours | Seek security from mother. |
| Within first 3 hours | Suckle mother and expel accumulated waste (meconium). |
| Within 8-12 hours | Consume adequate amount of colostrum to ensure immunity. This will depend on the type and size of the foal. Thoroughbred sized foals need to consume around three to five litres of colostrum. |
A mare’s milk will contain adequate amounts of energy, protein, vitamins and minerals for the foal in its first four weeks of life. Therefore the mare needs to have an adequate diet not only for her wellbeing but also for milk production to supply the foal with a good start to life. From four weeks of age onwards, assessment needs to be made on the availability of feed for the mare and foal and specific supplementary feed may need to be considered. It is important however not to overfeed foals as this can cause limb abnormalities due to rapid growth and development. The graph gives an indication of the rate at which a foal will grow over its first two years.
The dietary requirements of lactating mares and suckling/growing foals varies throughout the growth path. The rate of daily growth is shown below. It is important that daily nutritional requirements are met to ensure the mare maintains condition and can continue to lactate so that the foal grows at an even rate to prevent future bone and joint abnormalities. When foals are in their rapid growth phase, which is approximately up to six months of age, it is important to ensure that there are no dietary upsets to inhibit natural growth as this can also cause developmental problems.
Further information on feeding a horse in Australia has been published by the Rural Industries Research and Development Corporation (RIRDC).
Graph reproduced with permission, from Feeding Horses in Australia – A Guide for Horse Owners and Managers, by J Kohnke, F Kelleher, P Trevor-Jones. RIRDC Pub. No. 99/049.
Horse dentistry: good oral hygiene is important to the wellbeing of a horse
Dr Jeff Cave, District Veterinary Officer, DPI Wodonga
Domestication has upset the natural balance between tooth eruption and tooth wear.
With modern feeds, the tooth surface may be worn away quicker than the edges, leading to the edges becoming longer and sharper. Because of their angled shape, the outside edge becomes sharp on the upper teeth, and the inside edge becomes sharp on the lower teeth.
Sharp or broken teeth can produce soreness to the tongue and cheeks, as well as reducing the efficiency of the chewing and eating process.
There are a number of signs that can suggest teeth problems in a horse:
- the horse dropping food out of its mouth whilst eating, especially in a ball called ‘quidding’
- the horse appearing to yawn with its head held on an angle
- increased resistance to the bit or bad riding behaviour
- loss of condition
- the horse's breath might be unpleasant and it may look like it has a swollen cheek on one side or both.
To eliminate any possible problems, your horse should have regular checks by a horse dentist or a veterinary surgeon. The practitioner will use a speculum, or ‘gag’, to open the horse’s mouth. The practitioner will then rasp or ‘float’ the teeth, removing sharp edges and fixing any other problems that may be evident at the time of examination.
Removal of retained deciduous (temporary) teeth, caps, wolf teeth extraction, and floating sharp pointed teeth to enhance comfort are some of the more common dental procedures in horses. In most cases the removal of sharp enamel edges and points through floating will be all that is required during a routine check-up. Floating is pain-free and usually straight-forward.
Teeth should be examined at least annually, but in young horses and in some disciplines checks might be required two or three times a year.
For more information please contact your local veterinarian or horse dentist.
If you would like to receive this information/publication in an accessible format (such as large print or audio) please call the Customer Service Centre on 136 186; TTY: 1800122 969, or email customer.service@dpi.vic.gov.au.
Published by: Department of Primary Industries, Victoria, Australia, October 2008
© The State of Victoria, 2008
This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968.
Authorised by: Victorian Government, 1 Spring Street, Melbourne,
Victoria 3000 Australia
ISSN 1836-3539 (Print)
ISSN 1836-3547 (Online)
Disclaimer: The information provided in this publication is offered by the Department of Primary Industries solely to provide information. While all due care has been taken in compiling the information, the State of Victoria and its officers take no responsibility for any person relying on the information and disclaim all liability for any error or omissions in this publication.
For more information about DPI visit the website at www.dpi.vic.gov.au or call the Customer Service Centre on 136 186.
