Wildlife Diseases

Question 1

What causes anthrax?

Answer 1

Anthrax is caused by a bacterium; Bacillus anthracis; that causes sudden death to septicemia and shock. This bacterium forms spores on contact with oxygen and spreads through ingestion; inhalation and; more rarely; through insects that transfer the spores from the open wound of an infected animal

Question 2

What are the symptoms of anthrax?

Answer 2

Anthrax symptoms include the inability of blood to clot and therefore constant bleeding of wounds and possibly even from various orifices. The blood not clotting means that wounds don’t heal and instead become infected. This combined with the buildup of toxins produced by the bacteria mean that the animal will go into septic shock. Symptoms include trouble breathing; inability to stand; not eating and within a week of infection; death

Question 3

How is TB spread?

Answer 3

Transmission between ruminants is primarily through airborne moisture droplets released by an animal coughing and inhaled by another. However; the bacteria can also be present in the urine; faeces and milk of a host animal. That means that any suckling calf or lamb may be infected and possibly even through the sniffing of the urine by conspecifics

Question 4

What is the furious phase of rabies?

Answer 4

The furious phase refers to the state an animal progresses into whereby it exhibits irritability; restlessness and heightened responses to visual or auditory stimuli

Question 5

What are the signs of an animal infected with TB?

Answer 5

Signs of TB in wild animals are emaciation; lethargy and roughness of the animal’s coat. The animals will be coughing and sometimes enlarged lymph nodes in the jaw and neck can be noted

Question 6

What are the 6 most common wildife diseases?

Answer 6

Rabies, anthrax, foot & mouth, rinderpest, tuberculosis and contagious bovine pleuropneumonia (CBP).

Question 7

How may lions get TB?

Answer 7

Lions get TB by ingesting certain portions of an animal that has the disease; such as the lungs; infected lymph nodes around the face and neck and possibly even the intestines

Question 8

What is rinderpest?

Answer 8

Rinderpest was caused by a paramyxovirus (genus Morbillivirus) closely related to those that cause measles in humans and viral distemper in dogs. The virus was transmitted by close direct or indirect contact. After an incubation period of three to nine days, fever and loss of appetite occurred in an infected animal.

Question 9

What is a zoonotic?

Answer 9

A zoonotic is a disease that is transferable from verterbrate animals to humans e.g. Anthrax; Covid; ringworm and rabies

Question 10

How much of a significant factor is rabies to human health?

Answer 10

Rabies is zoonotic disease with deadly potential and is therefore a significant factor for human health

Question 11

What are the symptoms of rabies?

Answer 11

Symptoms include drastic behavioural changes – a shy dog becoming friendly or a friendly dog becoming shy; nocturnal animals active in the day; wild animals appearing tame. Some animals exhibit photophobia. There may be increased libido and frequent urination. Within 2 or 3 days the disease progresses to either furious aggression or dumb paralysis. Following this animals lose the ability to swallow (excessive salivation, classic symptom); develop pica and death within a week

Question 12

What causes TB?

Answer 12

Tuberculosis is caused by bacteria of the genus Mycobacterium

Question 13

What are the symptoms of rinderpest?

Answer 13

Rinderpest causes high fever; watery or purulent (pussy) eye and nose discharge; labored breathing; constipation followed by profuse watery diarrhea

Question 14

Can humans get anthrax and how?

Answer 14

Human infections of anthrax occur through direct contact with infected tissue; usually requiring a cut or scratch to allow for infiltration by the disease. Susceptibility to airborne anthrax is low

Question 15

What is the role of wildlife diseases in the ecosystem?

Answer 15

Parasites and diseases act as population control measures; preventing over exploitation of an area and “weeding” out the weaker genes from a population as per Darwinian natural selection

Question 16

Describe the history of rinderpest in Africa.

Answer 16

Rinderpest like any introduced disease decimated the population that had not co-evolved with it. Originally introduced by the Italians who picked it up as they passed through the Middle East. The first outbreak was halted in Sudan in 1884 but a second outbreak in 1889 raged through Africa killing 95% of the cattle on the continent and over 5 000 000 buffalo. In s. Africa; of the ~500 000 buffalo; 50 survived and thus almost all the buffalo on the southern end of the continent are descendants of those 50 buffalo! The only positive result of this pandemic was the eradication of the tsetse fly as there was nothing left for it to feed on

Question 17

What are the 6 main carriers of rabies?

Answer 17

Domestic dog, yellow mongoose, black-backed jackal, bat-eared fox, honey badger and small-spotted genet

Question 18

Where is the highest concentration of anthrax spores?

Answer 18

The highest concentration of spores is in the upper few cm of the soil and in the sediment of water-catchment areas

Question 19

How may the spread of rabies be contained?

Answer 19

If an animal suspected of having rabies; a state veterinarian should be informed. The animal; if drooling; should not be captured. If being destroyed; a head shot should be avoided as examination of the brain is the only method of post-mortem inspection for rabies. There is no treatment for rabies and unfortunately; a suspected animal should be destroyed to prevent the spread

Question 20

How is anthrax spread?

Answer 20

Anthrax spores form upon contact with the air. They spread through several mediums: Scavengers and predators such as hyenas; vultures; lions and jackals may open an infected carcass; allowing for spore formation. They will then ingest the spores; though not necessarily acquiring the disease themselves. The spores will then get deposited in their faeces further away. Vultures may spread the disease particularly effectively by travelling large distances and defecatig or cleaning themselves in water bodies. The spores may also be spread through ticks and flies; particularly biting flies. Blowflies that gather on carcasses may gather the spores and deposit them on vegetation up to 60km away; usually at the preferred feeding height of kudu; making them particularly vulnerable to this disease

Question 21

How is rabies spread?

Answer 21

Rabies spreads through the contact of an infected animal’s saliva and bodily fluids of other animals. This is usually through a bite and rabies causes an animal to lose fear of other animals and become highly aggressive; increasing the likelihood of transmission. Any mammal can contract rabies which means it can spread rapidly. Rabies spreads through a body by being taken up by the nerve supply after entering through a bite wound. The virus travels the length of the nerve supply toward the spinal cord and brain from where it populates the saliva through nerves linked to the salivary gland