The Mara Mobile Veterinary Unit

Field Report - February 2009

 Return to the David Sheldrick Wildlife Trust Website

Summary

The veterinary activities were quite successful during the month of February; one male adult Masai Giraffe was rescued by removal of a snare from the right hind leg in Crater Lake sanctuary in Naivasha. A dominant male white rhino in Ol-Choro Oiroua conservancy in Mara which kept fighting other rhinos and inflicting severe injuries was successfully captured and horn trimmed to solve the problem. As part of on-going investigations on epidemiology of mange infestations in wildlife, two Thompson’s gazelles were sighted with severe infestation, they were captured by darting and skin scrapping samples collected then treated for mange and released. A case of a wild dog (Lycaon pictus) suspected of canine distemper or rabies infection near Cottars camp in Mara was examined and later on euthanized for postmortem examinations and samples collected to help in diagnosis. It had signs of hind leg paralysis, convulsions, marked alopecia and skin encrustations suggestive of rabies or canine distemper infection. Further information about these cases can be found in the report.

Rescue of a snared giraffe in Crater lake Sanctuary – Naivasha

This was a case of and adult male giraffe that was entangled by a wire on its left hind leg, it was reported to the veterinary team by the KWS district warden in Naivasha. The veterinary team responded fast to rescue the giraffe, the snare was still loosely attached on the leg and had not inflicted any injury yet, but it was very much irritating to the animal and restricting its free movement in the wild.

The giraffe was darted using 13mgs of etorphine hydrochloride combined with 30mgs of Xylazine hydrochloride, the first dart failed to discharge the drug but the second dart worked well and the animal was well anaesthetized within 6 minutes. The wire was cut off using a wire cutter; it had not inflicted any injury to the animal.

The snare around the giraffes leg

Removing the snare  The immobilized giraffe

The giraffe gets back to its feet

The giraffe after the snare is removed

Revival from anesthesia

The animal was then revived from anesthesia 36mgs of Diprenorphine hydrochloride combined with 5mgs of Atipamezole hydrochloride administered through the jugular vein. It was then released back to the wild feeling relieved.

Horn trimming of a white rhino (Ceratotherium simum) in Mara to avoid injuring others

Overview

There were several reports of frequent fights and injuries to other sub-adult male and female white rhinos in Ol-choro Oiroua conservancy in Mara. The dominant male (named Madaraka) which had a very long and sharp horn was frequently fighting other rhinos and there was need to trim the horn such that it will be unable to inflict any severe injuries to others.  The veterinary team in Mara organized and did the horn trimming effectively.

Chemical capture

The rhino was darted on the left shoulder using 4.5mgs of etorphine hydrochloride combined with 80mgs of Xylazine hydrochloride. The drugs took effect after 5 minutes and good anesthesia was achieved. Nalorphine hydrobromide (10mgs) was administered through the superficial ear-veins to help improve the respiratory rate.

Vital physiological parameters

The following physiological parameters were recorded during the time of anesthesia;

Respiration rate:     8 cycles per minute

Body temperature:  38.5 degrees Celsius

Heart rate: 80 beats per minute

Capillary refill time:  2 seconds.

These parameters confirmed that the animal was in stable anesthesia and the horn trimming exercise went on.

Horn trimming and treatments

The larger horn was immediately trimmed properly using a hacksaw to make it smooth and blunt. It was then treated with long-acting oxytetracycline administered intramuscularly and eyes covered with Opticlox eye ointment to avoid infection and desiccation.

The immobilized rhino before its horn is trimmed

The horn after it is trimmed

Anesthesia Reversal

After horn trimming, the rhino was revived from anesthesia using 24mgs of Diprenorphine hydrochloride combined with 10 mgs of Atipamezole hydrochloride administered through the superficial ear vein. Another 12mgs of Diprenorphine was administered intramuscularly to enhance a quick recovery from anesthesia. Naltrexone (50mgs) administered intramuscularly for complete reversal of narcosis. It took about 2 minutes to recover from anesthesia and it was successfully released back to the wild. This has greatly reduced incidences of rhino injuries due to fight in the conservancy. The small piece of horn removed from that rhino was kept in safe custody in KWS armory.

Samples collection and treatment of Thompson’s gazelles with mange infestations in Masai Mara.

This is part of the on-going investigations on cases of mange infestations in cheetahs, Thompson’s gazelles, wildebeests and other wildlife in Mara. The disease is a threat to the survival of cheetahs and lions in the wild and Thompson’s gazelles act as the source of the parasites to cheetahs. The parasites are transmitted to cheetahs through contact with gazelles particularly when cheetahs hunt or feed on these gazelles.

During the month of February, two Thompson’s gazelles which were heavily infested with the parasites were sighted near Talek gate, they were then captured by darting, skin scrapping samples collected in 70% ethanol. The gazelles were then treated using Ivermectin administered subcutaneously and tincture of iodine applied on the skin lesions.

Clinical signs of mange in Thompson’s gazelles

Most of the lesions were found on the scrotum skin, medial side of thighs, inguinal region, and the entire hind legs. The infected body parts were completely alopecic (loss of hairs), scabs formation, itching and pruritis, skin desiccation, fissures and slight heamorrhages on infected skin. The gazelles had poor body condition caused by restlessness due to itching and scratching of the skin and lack of feeding. There are high chances of recovery from the parasites after treatment with ivermectin and antibiotics. If not treated, the disease can lead to death of cheetahs or any other wildlife by making them weak and vulnerable to predation or susceptible to secondary infection by bacteria or any other disease.

A lesion on the scrotum  The legs were badly affected

The lesions were found on the scrotum.

Examining one of the thompsons gazelles teeth  Taking a skin sample

The second Thompsons gazelle after treatment  The thompsons gazelle after treatment

The samples so far collected will be analysed for the presence of mites which are the causative agents of mange, then the generated data will be used to make informed decisions of how to control the disease in endangered wildlife species particularly in cheetahs.

A case of wild dog (Lycaon pictus) paralysis and loss of skin condition in Masai Mara

Case history

The wild dog was found by Masai herdsmen near Cottars Camp on the southern part of Mara, it was completely paralysed, loss of hairs, wrinkled skin with pinkish patches on the ventral parts, the skin was covered with flakes and scabs, and the dog was unable to move, it was then wrapped into a blanket and taken to store room in Cottars camp. The Camp manager later called the veterinarian to come and examine the dog, meanwhile it was provided with a slaughtered sheep and water overnight, it was only able to eat or drink a little.

Chemical restrain and examination

The dog was anaesthetized using 70mgs of Ketamine hydrochloride combined with 0.75mgs of Medetomidine, it was darted on the right thigh using Danject dart gun from inside the room where it was lying. The drug took effect after 5 minutes.

Clinical examination revealed that the dog was completely alopecic with a lot of scabs on the skin, slight haemorrhages and pus at certain parts, very poor body condition and weak. It was then transferred into an animal cage for transport to the veterinary clinic in Mara. Further observations from inside the cage revealed hind limb paralysis, seizures and convulsions, the dog was unable to stand or walk.

The dog had pinkish patches on the skin  The dog had poor body condition

Examining the dog

Tentative diagnosis

The skin lesions could be due to extensive mange infestation or Canine dystemper infection, paralysis, convulsions and seizures could be due to Canine dystemper, rabies or poisoning.

Prognosis

After a series of clinical examinations, it was clear that the dog could not survive from the nervous signs it was exhibiting and it had the risk of spreading the disease to other carnivores in Mara if it were to be released back to the wild, the painful skin condition and seizures were undesirable. The dog was later euthanized using Pentobarbitone (Euthatol) to relieve it from undue suffering and to be able to get samples that would lead to accurate diagnosis which will help in making a decision that can save other wild dogs in the wild.

The dog was euthanazed

Postmortem lesions

A postmortem is done on the wild dog

  • Enlarged spleen (splenomegally)
  • Enlarged lymph nodes
  • Congested brain capillaries
  • Pale mucous membranes (oral and conjuctiva membranes)

 Samples collected

Taking a blood sample before the post mortem

  • Tissue samples from liver, lungs, spleen, kidneys, lymph nodes, heart and brain were collected and immediately subdivided into two portions preserved in formalin and freezer respectively.
  • Blood collected in EDTA coated tubes and plain tubes (blood was obtained before euthanizing the dog).
  • Skin scrapings and tick samples kept in 70% ethanol.
  • Brain tissues were later preserved in viral transport medium, Trizol and RNAlater cryovials and frozen.

NB/ The samples will be submitted to various laboratories in Kenya and outside for diagnosis.

Discussions

Overview
Canine distemper which is the likely diagnosis for the wild dog can be described as a contagious, incurable, often fatal, multisystemic viral disease that affects the respiratory, gastrointestinal, and central nervous systems. It is caused by the canine distemper virus (CDV). The disease is highly infectious for many species of carnivores and causes high death rates in immunologically naïve populations (Appel MJ, 1987).  

Canine dystemper occurs among domestic dogs and many other carnivores, including raccoons, wild dogs, lions, skunks, and foxes. The disease is fairly common in wildlife. The development of a vaccine in the early 1960s led to a dramatic reduction in the number of infected domestic dogs. It tends to occur these days only as sporadic outbreaks.

The disease is a known cause of death in free-living African wild dogs (Alexander KA, et al., 1996) as well as other wild carnivores, both free-living and captive (Harvell CD, et al, 1999), Daszak P, et al., 2000).

Transmission of CDV virus to free living wild dogs is through direct contact with infected domestic dogs or wild carnivores. Domestic dog populations in some parts of Tanzania are endemically infected with CDV and were considered to be the source of infection for canine distemper in Serengeti lions in 1994 (Cleaveland.S et al., 2000). Conservation of endangered species, both free-living and captive, has been jeopardized by infectious disease outbreaks in the past (Daszak P, et al., 2000).

Clinical signs and control

Some of the clinical signs include fever, loss of appetite (anorexia), eye and nose discharge, depression. Many dogs experience gastrointestinal and respiratory symptoms, but most dogs that die from distemper, die from neurological complications such as ataxia (muscle incoordination), paralysis, paresis (partial or complete paralysis), convulsions and seizures.

Canine dystemper has no cure but can be controlled by vaccination and avoiding contact with infected individuals.

Conclusion

Most of the veterinary activities in Central Rift region were quite successful, the wild dog samples will be submitted to the laboratory for a more accurate diagnosis. Cases of wildlife injuries due to human-wildlife conflicts are still on the rise in Mara and Naivasha areas. Snaring of giraffes and common zebras in Naivasha is still a great threat to wildlife conservation in the area and the Central Rift veterinary unit makes several attempts to rescue as many animals as possible.

Reported by: Dr. Domnic Mijele