ASK THE EXPERTS
This article was originally printed
in the February / March issue of Deer Tracking
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and may not be reproduced in any form without
permission.
Question: We've heard that feeding too much peas or corn to deer is harmful because of high levels of carbohydrates. Why is this?
Answer: The sudden ingestion of large amounts of carbohydrate-rich feed, such as grain and peas, is the most common cause of a disease called "grain overload" or "acidosis" that is the result of excessive production of lactic acid in the rumen. It can also be seen with excessive ingestion of apples, bread, brewers grain and sugar beets. This overload of carbohydrate is followed within 2 - 6 hours by a marked change in the bacterial population of the rumen. Certain normal rumen bacteria increase dramatically in numbers and produce large amounts of lactic acid. This drops the pH of the rumen to below 5 so that a very acid environment exists. At this point many of the essential microbes of the rumen (the good bugs) are killed. The ensuing acidosis can result in acute death or, more commonly, chronic gastrointestinal disorders with diarrhea, bloating and even rumen ulcers. The condition is most commonly seen when deer are suddenly given access to high levels of grain.
Another complication of high carbohydrate diets is founder. This condition can occur concurrently with grain overload as above, or can be more subtle. Sludging of blood flow in the hoof leads to partial to complete separation of the hoof wall from the underlying lamina of the digit and leads to lameness and hoof changes. The mechanism is fairly complicated but can be avoided with the feeding recommendations above.
Randall S. Murray, DVM
(Randall
is a vet in Texas who also raises
whitetail & elk at M4
Ranch)
Question: Is there a best time during gestation to handle/move bred does ?
Answer: In a perfect world, one would never have to handle a pregnant doe. However, from time to time it becomes necessary to handle these does (e.g.. vaccinations for necrobacillosis that must be done during pregnancy ). At times like this it becomes important to keep the risks to a minimum.
Gestation can be divided into trimesters. In the first trimester the fawn is developing into a complete animal and insults during this time could result in congenital abnormalities or loss of pregnancy. In the second trimester the fawn is completely developed and only needs to increase in size. It is developed enough to no longer be susceptible to defects yet small enough to be protected within the body of the doe. In the third trimester the fawn is large enough to be vulnerable to trauma through the doe's body wall - especially if there are twins or triplets.
Therefore, I recommend only handling does during the second trimester when the fawns are the most protected within the does. However, I am always astounded by how resilient these animals can be if handled properly. Deer are at much more risk of getting capture myopathy during handling than they are from losing a pregnancy. Any handling procedures that prevent capture myopathy are probably adequate to prevent pregnancy loss.
Ken Vanderwekken, DVM
Lacombe
Veterinary Centre
Lacombe, AB
Question: Can you briefly touch on deworming deer. What is the difference between Safeguard and Ivomec in treating deer for parasites? Also, I have heard that Cydectin is approved for use in deer. Is this true? (and is Cydectin a pour on or injectable?) Is there any such thing as an oral dewormer (as in horses, often they are orally syringed injectable ivomec)? Also, the benefits of pour on vs injectable? And finally have any studies been done on the effects of deworming pregnant does? What types of parasites are we attempting to treat/prevent with these dewormers?
Answer: What is the active ingredient in Safeguard? In New Zealand we have found that Ivomec Oral, Pour-on and injectable at the cattle/ Deer dose rate are all very effective in red deer and elk for treating lungworm, but our experiences suggest that doubling the dose rate achieves better efficacy against abomasal parasites, especially during the dormant phase in winter. It is routinely used under NZ conditions at 4 - 5 weeks intervals in autumn to control lungworm. They can be used during pregnancy.
Cydectin/Vetdectin/moxidectin is licensed in NZ as a pour-on, but is also used as an oral drench. The injectable is not recommended in deer because they have low fat reserves. It is highly efficacious against lungworm and abomasal worms at the normal cattle/ sheep/ deer dose rate.
They are used at 5 - 6 week intervals.
Benzimidazole (white) drenches are also used in NZ but they must be used at 3 week intervals against lungworm and appear to be less effective against abomasal parasites, especially in elk. Some are not recommended during the first trimester of pregnancy.
Dr Colin Mackintosh
AgResearch
Invermay
Mosgiel New Zealand
Safeguard and Panacur are just a couple of names for the anthelmintic (anti-parasitic) drug fenbendazole. It is available for oral administration (granules, crumbles & paste) and in some cases is prescription only. It is moderately effective in treating intestinal worms and lungworm. Not particularly effective on adult liver flukes. Withdrawal times established in New Zealand range from 4-14 days. Suggested time is 14 days in the US. (NOTE: AMDUCA (Animal Medicinal Drug Use Clarification Act)) does not allow extra-label drug use (ELDU) of feed mixed anthelmintics, but does allow pour-ons, oral, injectible and water mixed medications. None are approved for use in cervids aside from ELDU application. (Canada has approved the use of Ivomec Eprinex for cervid stock.) Most effective recommended dewormer for cervids is Cydectin (moxidectin) which is a pour-on. Label directions should be carefully read for this application to assure maximum effectiveness. (NOTE: not to be given to fawns with little body fat or emaciated adults.) Meat withdrawal times are not established in US or Canada. NZ rates 21 withholding, and Australia approves 7 days. Suggested withdrawal interval (WDI) in US is 21 days. Levasol (levamisole) is not effective in deer species, according to Dr. Ken Waldrup of the Small Ruminant Practitioner's Association and the Texas Animal Health Association. Valbazen (albendazole) dewormer should not be used in pregnant does, as it is known to cause birth defects. Ivomec (ivermectin) is available in sub-cutaneous injectible form as well as pour-on. Veterinarians tell me that it is just as effective to give the injectible form orally. Promectin (generally used for horses) is basically the same thing. Ivomec Plus includes a liver-fluke additive. Ivomec F is NOT effective against liver flukes. Ivermectin's withdrawal time is 28 days in New Zealand for the pour-on. No time established for sub-cutaneous. Suggested withdrawal here in US is 56 days.NOTE!!!! It is recommended that in whitetail deer the dosages be doubled when treating for intestinal worms. Ivomec and Cydectin deliver anthelmintics for control of gastrointestinal roundworms, lungworm, liverflukes in some forms, cattle grubs, sucking lice and mange mites. October and April are months to routinely deworm deer. A repeat dose should be given in approximately 30 days. Even if only one animal is diagnosed, the entire herd should be treated with a preventive dose and afflicted animals receive the treatment dose. Fecal testing does not always tell the true story. Since first-round treatments may knock down the egg-laying process, second fecal samples tested may show "negative" infestation. Best to be safe rather than sorry and give the 2nd round of dewormer to be sure. Deworming should not be done on a continuing basis. Constant exposure to the anthelmintics creates parasites that are more and more likely to be resistant to the drugs. Use only under the advice of your Veterinarian, even if the medications are available over-the-counter. Pour-on dewormers are usually most easily applied to tame deer. All others will have to be run through a chute or immobilized for the process of pour-ons or sub-cutaneous injection. Deerfarmers must weigh heavily the risks of confinement or CI against the benefits of deworming. It is important to use preventative measures such as anthelmintic therapies coupled with pasture rotation to prevent repopulation after parasitic invasion. Quarantine of newly acquired animals for at least 30 days is also beneficial in determining if they are carrying unwanted parasites and preventing an outbreak in a clean herd. An ounce of prevention is worth a pound of cure!!!
Thelma Morgan
(Thelma has extensive training and hosts seminars in AI as well as CI -Chemical Immobilization, with Safecapture International. She is active with NADeFa as a current member of the NADeFA Legislative Committee. She is presently collaborating in on farm research collection with Charlie Alsheimer, field editor of Deer and Deer Hunting magazine. She is also a moderator on deerfarmer.com's forums. Thelma and her husband Tom own Morgan's Birchwood Whitetail Deer Farm, Union City, Pennsylvania.)
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