Date: [__date__]

Dear [__name__];

Welcome to the September edition of our monthly newsletter. This month we take the opportunity to discuss EA and FEI medication control and failure of passive transfer in foals. We hope that you find this edition of our newsletter useful and informative. Please do not hesitate to contact our office if you have any further questions about these topics.

Practice news

Wow, what a busy month we have had with both Lara and Mike away at different times attending courses. It is great to have Mike back from America after attending the latest International Society of Locomotor Pathologists course on the Hock. Mike travelled to Peninsula Equine Medical Centre in Melow Park California to attend the course and we are pleased to report that Mike is now up to speed with some new and exciting ultrasound techniques for examining this complicated structure.

Lara has just returned from the Sydney International Equestrian Centre where she attended the FEI Veterinarians Seminar and helped out at the Sydney Three Day Event. The course was a great success and we have decided to use this edition of our newsletter demystify some of the medication control issues for our clients competing at EA and FEI levels.

Failure of Passive Transfer in the Neonatal Foal

Well it is that time of the year again! The breeding season is in full swing and in anticipation of the arrival of our next generation of superstars, we thought it would be a good time to review the care of the foal in it's first 24 hours of life. Foals are born without a fully competent immune system and it takes 1 to 2 months for the foal's immune system to be functioning adequately. Until this time, the foal relies upon immunoglobulins from its dam for basic immunity against infectious diseases. Unfortunately, immunoglobulins are too big to pass from the dam to the foal. Instead, the dam produces colostrum, which is a special form of milk that contains immunoglobulins. Colostrum is only produced once during each pregnancy and is replaced by normal milk within 24 hours of the commencement of lactation.

A normal foal should rise and suckle within 3 hours of birth. The foal's gastrointestinal tract has the greatest capacity to absorb immunoglobulins within the first 6 hours after birth. The capacity of the foal's gastrointestinal tract to absorb immunoglobulins steadily declines until immunoglobulins can no longer be absorbed by the time the foal is 24 hours old.

It is very important that foals receive 2 litres of colostrum in the first six hours of life. Any foals that do not nurse within 3 hours of birth should be given colostrum via a nasogastric tube. When foals do not recieve adequate colostrum, we term the condition 'failure of passive transfer'.

Causes of failure of passive transfer include:

1. Failure of the foal to ingest enough colostrum within the first 24 hours.
2. Premature lactation resulting in loss of colostrum.
3. Low concentrations of immunoglobulins in colostrum.
4. Sub-normal absorption of immunoglobulins by the foal's gastrointestinal tract.

If failure of passive transfer does occur, it is very important that it is recognised and managed appropriately because failure of passive transfer is strongly associated with increased susceptibility to disease and death in foals.

Diagnosis of failure of passive transfer is possible using a simple blood test that detects the concentration of IgG (a type of immunoglobulin) in blood plasma. We recommend that all foals undergo routine screening between 24 and 48 hours of birth.

If failure of passive transfer is proven to have occurred, the foal can be given an intravenous plasma transfusion to provide it with immunoglobulins. After the plasma transfusion, the blood test should be repeated to check that the plasma has provided the foal with enough immunoglobulins. If the foal's IgG level is still low, it may be necessary to administer more plasma.

Finally, it is good practice, to provide any foals that are premature, weak or born to mares that have lactated prematurely, with an alternative source of colostrum within 6 hours of birth. It is possible to establish a colostrum bank by collecting and freezing 250ml of colostrum from mares within six hours of foaling, provided they have not lactated prematurely and their own foals have already suckled. The immunoglobulins in frozen colostrum are stable for 1 year. It is important to note, that frozen colostrum should not be defrosted in the microwave (this will destroy the immunolgobulins). Colostrum should be defrosted slowly in a bucket of warm water.

Medication control

When competing in EA and FEI competitions, it is important to remember that most medications are prohibited at the time of competition. For each horse competing there is a person responsible. This person is usually the competitor who rides the horse in an event. The concept of a person responsible becomes important because of the 'strict liability' principle. This means that the person responsible is stricly liable when a prohibited substance is detected in a swab sample. It is for this reason, that the person responsible needs to understand which medications are prohibited. The person responsible also needs to understand which medications might result in a positive swab result for a prolonged period, even when that medication would no longer be having a therapeutic effect on the horse.

It is important to note that horses may be tested at any time during an event. For FEI competitions, the onset of FEI ruls begins three days before the competition starts. For EA competitions, the onset of EA rules begins one hour before the commencement of competition and ends half an hour after the awarding of prizes.

5% of horses will normally be selected for sampling at each competition. Any horse may be sampled, regardless of whether or not it wins a prize. Once a horse has been selected for swabbing, the person responsible will be given a notification form to sign. The person responsible must stay with the horse from the time of notification until the completion of the entire sampling process.

Both blood and urine are collected from the horse whenever possible and all samples are analysed in an approved reference laboratory.

There are three classes of prohibited substances on the equine prohibited list. These include doping substances, medication class A substances and medication class B substances. Doping agents include, but are not limited to:

• Agents, cocktails or mixtures of substances that may affect the performance of the horse.
• Masking agents.
• Substances with no generally accepted medical use in competition horses.
• Substances which are usually products prescribed for use in humans or other species.
• Agents used to hypersensitise or desensitise limbs or body parts.

Medication class A and B are prohibited substances that are used in the genuine veterinary treatment of a horse. Medication class A substances include substances that could influence performance. For example, phenylbutazone is a medication class A substance. Some of these substances can be detected for prolonged periods. Procaine penicillin can be detected intermittently for up to six weeks after administration! Medication class B substances include substances that have limited potential to enhance performance. For example, cough suppressants and caffine are medication class B substances.

It is also important to remember that 'herbal' products are not necessarily free from prohibited substances!

There are some medications that are allowed close to and during competition. These include:

• Antibiotics (at FEI level you must submit a medication form 3).
• Wormers
• Gastric ulcer drugs (Ulcerguard, Omoguard, Gastrozol).
• Regumate (in mares only and at FEI level you must submit a medication form 2).
• Rehydration fluids.
• Saline by inhalation.

Treatment of horses close to or at a competition

As equine veterinarians, we have learnt to expect the unexpected! A minor mishap or veterinary emergency is just about inevitable in the course of an FEI riders life and it is very important that these situations are dealt with in a way that will ensure the best outcome for the horse and avoid jeapordising it's competitive career wherever possible. Sometimes, the best outcome for horse and rider will be to scratch from competition, however, small mishaps, if managed appropriately should not preclude a combination from competing.

In these situations, communication with the FEI Veterinary Delegate at the competition is absolutely vital. If your horse needs to be treated close to competition or during transport to an event, any treatments should be reported to the FEI Veterinary Delegate immediately upon arrival. The person responsible must arrange for the vet who treated the horse to complete an FEI medication form 1. A medication form 1 is an authorisation for emergency treatment involving medication with a prohibited substance at or close to an event.

If your horse is already at the event, the treating veterinarian must obtain permission from the FEI Veterinary Delegate before administering treatment. The FE Veterinary Delegate may wish to make their own assessment of the case before they give permission for treatment. In an emergency, such as colic, permission to treat can be obtained retrospectively.

However, it is important to note that there are some medications, for which permission to treat will never be given, regardless of the circumstances. These medications include, but are not limited to; finadyne, phenylbutazone and procaine penicillin.

At the end of the day, there is no sure fire way to ensure your horse stays in the competition. Each situation will be assessed by the FEI Veterinary Delegate on a case by case basis. This is why we encourage all our FEI riders to communicate with the FEI Veterinary Delegate to ensure that the best outcome is acheived. We also take this opportunity to assure our clients that we will be available by telephone to discuss with them how to navigate through this type of difficult situation should it arise whilst they are competing interstate.

We hope you enjoyed the September issue of our newsletter. Please do not hesitate to contact our office if you have any questions in relation to the above topics. We wish all our clients the best of luck with their upcoming competitions and look forward to hearing of all their success stories.

Kind regards,

Tweedie and Associates Equine Veterinary Services.