STUD NOTES

THE VET & AVOIDING TWIN MISDIAGNOSIS

MISDIAGNOSIS OF TWINS
Misdiagnosis of twins can and does occur for a number of reasons and here's how to avoid it.

Firstly, it must also be remembered that good vets can get great results performing the twin elimination procedure - but they are only human and will not get a 100% strike rate.

Misdiagnosis and a twin elimination failure (usually resulting in losing both pregnancies) does not automatically mean we point the finger at the vet on the end of the scan. The responsibility of dealing with the possibility of a twin or multiple pregnancy lies equally with the breeder or stud master. The points below cover both the diagnostics and procedure:

• Asynchronous ovulation: When two or more follicles ovulate 3, 4 or even 5 days apart. The change in size from 10 days - only a little larger than a pin head, to 13 days, then 13-16 is significant. Roughly a pregnancy from 10 days to 16 days will double in size on a daily basis. If the mare is initially checked at the desired 13 -14 days, and a second follicle ovulates 3 days later, this second pregnancy of 10 -11 days can be easily missed. This supports the idea of rechecking for later ovulations if it appears there are follicles that may progress to this outcome.
• Shadowing Twins: (one behind the other) may look like a single pregnancy (see picture below)
• Uterine cysts: A very cystic mare can make it difficult to check for a single pregnancy, let alone multiples. Also, we see many cysts that can look very similar to a pregnancy - except they do not grow or move location (see below). Mapping and measuring becomes extremely important in this instance, literally drawing the picture, or with advanced ultrasounds, taking a photo or video.
• Good Record Keeping (noting the following):
  » Date of service, am or pm
  » Noting leading up to service location and size of follicles
  » Day and time (am or pm) of the administration of ovulation drugs (ovuplant, chorulon or other similar drugs)
  » Noting the day, number and location of ovulations, and if further ovulations may occur
• Poor environment for ultrasound: for example too much light reflection or scan located too far from vet's vision whilst his/her arm is in the mare.

This is in fact a couple of uterine cysts. On the left we have an obvious cyst. The one on the right, without noting prior to service could easily be identified as a 16 day pregnancy. I demonstrate how many cysts can be quite a nuisance in diagnosing twins.	This is in fact twins at 13 days, one behind the other. At the time we could get an “impression” that there was a second pregnancy present. We knew we had a multiple ovulation, so re checked the next day.	Sure enough this was twins, and they had moved apart enough to enable a successful twin squeeze. This could have easily been a misdiagnosis without good records. Also note the size difference between the twins. There is a day difference in age, and it is quite clear there has been double the growth in that 24 hour period between the 2 shots.

VETERINARIAN PERFORMANCE OF MULTIPLE CONCEPTIONS
And once the actual procedure of the twin elimination is required, this is where the owner/stud master can be of the greatest help:

• Make sure that you do whatever you can to present the mare on the day the vet requests for the initial diagnostic scan, along with the full history you recorded during the service heat. This is very important.
• Provide the vet with a good powered facility, with appropriate light, sturdy and practical crush (out of poor weather)
• Do not put extra costs, associated with additional scans, ahead of good veterinary practice for a positive outcome - accommodate the vets request to re visit the mare for whatever reason.
• Stay focused on your job of holding the mare still and quiet in the crush.
• Never remind vets how important this pregnancy is to you, or place any other undue pressure on their performance such as small talk, extra spectators etc.
• Say thank you - even if you are good and keep the atmosphere pressure free, the vet still knows what you are thinking ... and does still feel the pressure! Equally, the vet will feel the pain if for whatever reason, the pregnancy is lost.

We have had 4 confirmed embryos in a mare, in which - over a period of a couple of days - 3 were successfully eliminated and we had a lovely foal the following year. We have also, on several occasions, confirmed 3 pregnancies, also successfully dealt with.

In summary, correctly supervised, multiple ovulations are regarded as good news, and with proper management, the process of dealing with a resulting multiple pregnancies need not be an issue.