Death of two tigers: Immature science in immature hands?
A leading daily newspaper published report about the death of two Bengal tigers (panthera tigris tigris) in Sundarban mangrove during research by anesthesia and radio-collaring (The Prothom Alo, January 31, 2008). According to the report the first tigress was captured around end April 2005 and died six months later having the collar on. The second tigress captured in March 2006 was second time tranquillized in December 2006 to remove the collar. The BBC film crew captured this second tranquillizing sequence of near dead tigress and added it to the film “Ganges” and are now showing worldwide the last scenes of that pathetic tigress. The tigress was assumed dead immediately afterwards.
The research project was initiated about four years back by Bangladesh Forest Department. James. L. D. Smith, Professor, Department of Fisheries, Wildlife and Conservation Biology of The University of Minnesota appointed as a consultant and Adam Barlow, a Ph.D. candidate in the Conservation Biology Programme is engaged in the field research. The project effectively started its field activities in February 2005. They claimed that the idea for creating such a project was first developed during a field survey in 2001 conducted by Md. Osman Gani, Ishtiaq U. Ahmad, James L. D. Smith and K. Ullas Karanth.
Initially the project was called “Tiger Study Project in the Sunderbans” but later the project was addressed as “Sundarban Tiger Project” or STP. Initially the main goals of the project were: A. To find out the home range of tiger. B. Tiger density and prey abundance in relation to forest cover. C. Tiger-human interaction. D. Change of behaviour in response to tidal, diurnal and seasonal fluctuations. E. Behaviour change with cubs and last kill etc. The initial objective of the project was purely scientific but after the death of the first tiger and related public reaction, the project changed its face and added some monster goals like A. Conservation capacity building. B. Creating public awareness etc. The initial goal, Research became a part of the programme. But even after inflating the project paradigm in such a vast forest like the Sundarbans, the project working manpower remained the same -- the PhD student Adam Barlow, one forest guard, one speedboat driver and three helpers1 who had no prior experience and no considerable education. The Save the Tiger Fund and the United States Fish and Wildlife Service funded the initial phase of research as the project website claimed.
On one of my many trips to the Sundarbans sometime in 2005 I met Adam Barlow. I came to know about his project and was delighted to know that something good was going to happen for the tigers in Bangladesh. I also found out that he was going to radio-collar eight to nine tigers, six female and two or three male. On my question of the method of radio collaring, I got to know that he was going to bait cows and trap them using snare and then tranquillize by using Telazol, a general purpose anesthetic used for animal anesthesia. As wildlife photographers naturalists we always gather information on the species and try to remain informed. It struck in my mind that somewhere I read that tranquillizing wild tiger can be fatal to the animal and that's why it has been stopped in many countries and not permitted any more. But I couldn't recall where I got that information from. I expressed my concern to Adam and told him to check this matter with experts.
After I came from the forest I sent a mail querrying the effect of Telazol anesthesia on wild tiger to one of my American friends who is working Roche, a leading pharmaceutical company in the USA. He forwarded the querry to one of his veterinary colleagues and she wrote:
"Telazol (tiletamine/zolazepam) is used in a number of wild cat species, but specifically should not be used in tigers. Experience has shown that tigers originally exhibit normal anesthesia during the procedure, but have neurologic signs 2-4 days later which include seizures, ataxia, and paresis. Two theories behind this involve recycling of the tiletamine component to an active metabolite or enterohepatic recycling via bile. The white variant of tiger has been documented to seem especially susceptible to this effect. Some practitioners have found that this adverse effect of Telazol is found only in Siberian tiger populations; however, the number of mixed tigers precludes reliable identification of subspecies outside the carefully documented lineage of zoo tigers”.
I also found many other references soon about the adverse effect and reports on cause of death of tiger relating to application of Telazol. I came in contact with Simba Wiltz, who is a Handler of big cats in Thunderhawk Big Cat Rescue, Florida. Simba got his Doctor of Pharmacy from University of North Carolina at Chapel Hill in 2004. He personally wrote me:
“It has been shown that Telazol recycles in the system of cheetahs and it is suspected that it may do the same for tigers--in fact, Tiletamine/Zolazepam should NOT be used in tigers for that very reason. You should consult the on-staff veterinarian regarding other agents available, and make sure that someone experienced veterinarian is available to perform the procedure who knows emergency responses. Still, standard of care at least in US facilities does not include Telazol for chemical control of tigers. He also noted Ketamine is notorious for causing seizures in big cats which can be lethal, proper protocol should be maintained”
An article published in Australian Veterinary magazine, named Tiger anesthesia, by L Vogelnest, Veterinary and Quarantine Centre, Taronga Zoo, Mosman, New South Wales:
The use of Zoletil (same as Telazol, Tiletamine/Zolazepam) is contraindicated in tigers: recoveries are prolonged (hours to days), various neurological signs have been encountered, and there have been reports of deaths during and after its use in tigers. - Aust Vet J Vol 77, No 6, June 1999.
Husbandry manual for small felids describes:
Another commonly used drug for felid anesthesia is Telazol® (Animal Health Group, A.H. Robins Co.), (also marketed as Zoletil®, READING Laboratories), a 1:1 combination of Tiletamine HCl and Zolazepam HCl. An advantage of Telazol is its availability as a dry powder that can be concentrated from 100 to 500 mg/ml permitting small drug delivery volumes. …. The disadvantages are occasional minor CNS signs, usually in the form of mild tremors. A re-sedation 3 to 4 days following Telazol anesthesia has been reported in some species of large fields (tiger, lion, cheetah). The cheetahs experiencing this problem originally had prolonged anesthetic episodes that required several Telazol supplements. Similar observations have been reported in some tigers. These animals usually show mild sedation with stumbling and may require supportive treatment for 12 to 24 hours before returning to normal. The use of Telazol in tigers has been replaced with Ketamine and Xylazine due to this re-sedation. If supplementation of the Telazol is required, it is advisable to supplement with Ketamine (instead of Telazol) at a dose of 2-4 mg/kg intramuscularly or 0.5-2 mg/kg intravenously.
Nielsen L. also suggested in his book “Chemical immobilization of wild exotic animals” that Telazol should not be used for tigers and can cause death8.
Instead of Telazol, some experts are suggesting Ketamine and Xylazine. But as a newer anesthetic there are not much field data available. Also the protocol is more complicated for Ketamine than Telazol. Telazol is more popular to the field researchers because it has a simpler protocol and it is found in power form which is easy to carry and preserve.
Cat metabolism and pathology is complex and not very well known yet to science. Most of the research regarding chemical immobilization is done by the veterinary and anesthesia specialists. In most cases the animal tested remains in captivity or in the zoo. For wild animal the research is very difficult and often not permitted in most countries. Which is specially true for endangered and rare species. Many of these drugs are used for emergency situations for wild animal where there is a life threat for the animal or for human. Many local people reported and in the BBC film “Ganges” it was commented that both the tigers showed abnormal behaviour and there were reports of attacking people. In Eastern Sundarban, places like Katka and Chaprakhali, where many tourists walk on the meadow and the beach, or fishermen work day and night, there were never reports of aggressive behaviour of tigers. Even the first tiger jumped over Dr. Tapan Kumar Dey, DFO and his team when they were trying to photograph it collaring. They jumped on the nearby pond to save themselves in Kochikhali.
Tranquillizers work on the central nervous system of the animal. There are reports that Telazol may cause long term psychological effects on tiger. The tranquillized tiger may feel dizzy, sedated some time and can feel irritated or anxious some other time. Possibility of hallucination also claimed.
“Some tigers, especially Siberian tigers have shown greatly prolonged recovery and recycling of Telazol that has caused CNS signs several days after immobilization. These signs may come and go for days or weeks post-immobilization.” - Christopher J. Katz D.V.M, Anesthesia of Exotic Cats
In 1992 during the research on Amur (or Siberian) tigers (Panthera tigris altaica), researchers caught some tigers using Aldrich foot snares, the snared foot was swollen in all cases. They anesthetized tigers with a mixture of ketamine hydrochloride and xylazine hydrochloride instead of telazol.
Pharmacokinetics is the process by which we know how a drug is absorbed, distributed, metabolized, and eliminated by the body. Any drug before application on any animal pharmacokinetic observation should be done. Little pharmacokinetic information is available for Telazol (Tiletamine HCl / Zolazepam HCl).
The Sundarbans is a unique place and also the only great ecosystem in the world where Bengal tigers live in saline water system. Life of a wild tiger is extremely challenging and very much depends on the physical and psychological integrity of the animal. For zoo or captive tigers physical wellbeing is enough for their survival. But for a wild animal her physical and psychological performance together only can ensure her survival. There has not been any pharmacological research to find how the above chemicals will affect specially the Sundarban tiger that drinks salt water and eat the intestine of the kill full of mangrove vegetation. Before this research is done and proven safe, there should be no other application of those drugs on healthy tigers in the wild.
Dr. Ullas Karanth started tiger research in Nagorhole reserve forest in India using chemical immobilization and radio collaring. After the death of several tigers the Chief Wildlife Warden of India (same as our CCF) cancelled his permission for that fatal research. From then onward tranquillizing healthy wild tiger is not permitted in India anymore. Exception is only in case of relocation if any tiger is proven to be a man-eater. Dr. Karanth and many of his foreign partners seem very eager to tranquillize wild tigers may be wants to finish their incomplete research which failed in India. The tiger radio collaring project in Bangladesh was motivated by the group of experts who are very keen to do research where getting the permission for it is easier. In an interview with the famous Indian technology magazine “Dataquest” Karanth said in June 2007:
"The biggest issue in use of technology, say radio telemetry or chemical immobilization, is the problems of getting research permissions.”
The present radio-collaring methodology of wild tigers incorporates many issues which can be harmful or lethal to the individual tiger, or to the whole or part of the population. It can even increase human-tiger conflict if it is not practiced with a lot of care, maturity and responsibility. Researchers are using live cow as bait, which can infect wild species with new disease. Amur tiger researchers say they trapped 19 tigers and all of them had swollen legs where the snare was caught. Traps and snares can injure tiger and that could be enough for the end of their life. Applying anesthesia without proper understanding of the pharmacokinetics of the specific population can cause fatality or abnormal behaviour of the tigers and eventually can increase human-tiger conflict.
We all are aware that getting adverse effect information about wild animal research with any drug or procedure is very difficult. Expert community in wildlife research is small and everybody knows each other. Only a few organizations are funding and nobody wants to say anything negative about friends and colleagues. Almost everywhere the wild animals are government's property and protected by the state law. If any wrong things happen somewhere, the news does not go very far, officials need to save themselves too. This creates misconception for others about choosing the proper method if it does not fall in his own discipline of knowledge. Often experts remain silent about a wrong idea fearing that criticism can make them isolated in the community.
Chemical immobilization techniques and their protocols for wild animals are still immature science. Many species of Asia and those which are special like saline water tigers cannot be experimented without proper knowledge of the drug and its interaction. For any chemical immobilisation a licenced veterinary doctor with specific knowledge on the species and the pharmacology should be present at the field and should be officially responsible for the status of the animal.
There are some experts who are very much interested in gizmo science. They think the use of GPS and radio telemetry or any other high-tech gadget will solve every problem. Thick canopy like the Sundarbans may also impair GPS function and can put a lot of void in data. If the tiger shows prolonged CNS signs and abnormal behaviour with the effect of the drug, the acquired data by the collar will be vitiated. Any planning or strategy if implemented based on those erroneous data can cause harm to the whole population. The same research can be done with camera trapping (like Trail Master). Camera trapping is allowed everywhere and used worldwide without any harmful effect on the species for similar research.
Sirajul Hossain is a wildlife photographer and naturalist Full version of this article may be available from: shossain.wordpress.com