Saturday, December 12, 2009
Bush Blood Bank
Unfortunately the lovely warm climate here is also lovely for many tick, flea and musquito species. These parasites transmit many tropical diseases including blood parasites from animal to animal. Therefore we try to keep the animals tick free to reduce the chances that they get ill. But ticks are clever (and hungry!) and they often still find their way to a nice meal. Unfortunately we found a very ill and anemic roan calf this morning; anemia means a lack of red blood cells. Blood parasites, under which Theileria spp., are very common in this species, especially at young age. We decided to dart the calf for emergency treatments. When you treat an animal to kill these parasites, it will still takes some time before the animal has produced enough new blood cells to survive. In this period the animal can dy because of the anemia. Red blood cells transport oxygen in the blood to organs, so without blood cells, no oxygen: quite lethal. Therefore we needed BLOOD. Quickly. But what to do in the bush when dealing with a very rare wild species?? Indeed! We made the plan to dart a big healthy roan bull to get some blood from him to be able to give the calf a blood transfusion. First we had to find a strong and large bull, who would be able to act as a donor. The size and health of the animal are the most important when selecting a donor. A female with young and pregnant cows you would never dart without a clear reason. Male animals are therefore preferable over females. Great: we found a very handsome healthy bull, I made up a dart with Etorphine and Stresnil and darted him. It was windy and the animal was quite wild, but luckily I shot him nicely in the bump! After 1 minute after the dart went off the bull got quiet, stood still and showed typical Etorphine signs, such as ataxia. Finally he went to lay down. The Ethorphine is a very potent drugs, 10.000 times more potent than morphine. Just around 0.7 to 0.8 ml is necessary to immobilize strong animals like an adult roan bull! When the bull looked deep asleep I approached the bull quietly. Often animals are still strong enough to damage you badly with their horns while half asleep. Therefore you first check how deep the anaesthesia is before approaching the head. He was deep asleep and we kept his head high by holding his horns, both for safety as well as preventing it to regurgitate rumen contents. Putting ruminants under general anaesthetics is always more complicated than animals with 1 stomach, because the increased abdominal pressure while laying down together with stress can force the rumen to empty. An animal what is under anaesthetics can not swallow and the rumen contents can therefore enter the air way. This is in most cases deadly, so it's very important to prevent this! We removed the dart and treated the dart wound with antibiotics. Then we filled up the blood collection bags, just like you get it done at the blood bank. Only instead of your arm, we used the Jugular vene in the neck to be able work as quick as possible. We for sure did not want to put the bull at any risk during this procedure. Therefore I checked his respiration and heart rate all the time, to be able to give him emergency drugs if necessary. His anaesthetics went according to the books (as if he read it), so no further drugs were necessary. When the bags were full I gave the antidote Naltrexone in the ear vene and the very kind blood donor walked away in just a minute as if nothing had happened. And yes I told him: "Thanks for the kind donation". Not sure if he got this, as he took off rapidly! Then we rushed to the roan calf with anemia. I darted her with another drug A3080, quite similar to Etorphine, but it works even faster! It is very important to be able to find the small and fragile calf quickly after it has fallen asleep: the shorther the running time and therefore distance, the easier you can find the calf when it sleeps. The mum was standing close by and we had to be very careful as she would absolutely defend her baby agressively if we did not scare her off. I first applied a normal IV catheter in her Jugular vene. When the IV fluids was running, I attached the blood bag to this system and let it run into the animal very slowly to watch for any allergic reactions. Some small animal experiences in posh London and Amsterdam showed its advantage in quite a different setting with quite a different patient. But the principle is the same. Because the calf was okay, I continued to give the transfusion. I also treated her for different blood parasites, worms and gave multi-vitamins. To be able to check later, I made some blood smear to see if there were any parasites in the red blood cells; this was later confirmed. Unfortunately with wild animals, you can't first do some diagnostics and then give the appropriate treatments for that diagnose. You always try to do everything at once to avoid unnecessary general anaesthetics. The calf got better soon and it is happily running around again. We luckily did not have to dart her again. The rest of the blood bags are now in the fridge to be ready for another emergency case, so if anybody needs roan antilope blood, please let me know! Maybe we should start a Bush Blood Bank?