Introduction

Five rhino species survive across Africa and Asia. They are distinguished by their massive size, thick protective skin, and horns composed of keratin—the same protein as found in human hair and nails. The rhinos once roamed the savannas in large numbers but in more recent years have become the victims of climate and habitat change as well as of poachers who scour the African continent in search of ivory. Until recently, some 125,000–150,000 rhinos were living in the wild, mostly in sub-Saharan Africa, Zambia, Tanzania, Uganda, and parts of southern Africa. These numbers have now disturbingly declined to about 27,000, including 16,000 White (Ceratotherium simum) and 7,000 Black (Diceros bicornis). 

Traditionally, both African species have been classified or named by their color, but in fact both have grey skin and it is other characteristics that distinguish them. The “White” comes from a misheard Afrikaans word for “wide” (wijd). The White rhinos are bigger, the males weighing between 3,000 and 6,000 pounds. They have a wide, square lip suitable for grazing, a flatter back, and a large head held low. They are almost all “southern” because all the “northern” White rhinos have died off—except for the two surviving females that are “under human care” in zoos. The other African species, the Black rhinos, are smaller; have an arched back; hold their head higher; have a pointed, hooked lip to grab leaves and browse; and weigh less than the White rhino, between 1,700 and 3,500 pounds. The remaining three rhino species are Asian: the Indian, Javan, and Sumatran. They number about 4,000 and are also mostly endangered.  

Rhinos are solitary herbivores that graze in the savannahs and prune shrubs, and in doing so, they create pathways that other animals use. They are quite agile, reaching speeds of about 20 mph on land and 5 mph underwater. They rely heavily on water for drinking, cooling, and skin protection, often wallowing in mud or shallow pools for hours daily. They communicate through a variety of snorts and huffs, even by marking their territory with their droppings. They are aggressive because they have bad eyesight and assume that every moving blurry spot is a potential threat, but they are docile once they have become accustomed to humans. Their brains are small, their intelligence is believed to be low, and they are easily distracted or baited into traps by smart predators. As they lack sweat glands, they are vulnerable to overheating or insects, and as their legs and underside are less protected, they are targets for hyenas or lions.

The diseases of rhinos

Rhinos are susceptible to a variety of diseases, broadly categorized into infectious (bacterial, viral, parasitic) and non-infectious (metabolic, nutritional). The health problems can differ significantly between wild and captive populations. Skin diseases, particularly in captive populations, are common when there are inadequate mud wallowing opportunities. Mud baths serve crucial functions beyond thermoregulation, as they protect against parasites and maintain skin health. Without them, rhinos develop cracked, infected skin, requiring topical and systemic antibiotic treatment. Foot problems also plague captive rhinos because their feet are sensitive and concrete floors fail to naturally wear down their nails, causing pain and infection so that they need to walk on soft ground and undergo regular trimming under sedation.

Bovine tuberculosis is a significant concern, especially in South African national parks; rhinos can be infected for years without showing clinical signs but may easily infect new populations. Hemorrhagic septicemia (HS) is another possible cause of death for Javan rhinos, likely transmitted from water buffalo in national parks. Arboviral diseases such as Shuni, Sindis, Middelburg, and West Nile viruses are transmitted by mosquitoes and can cause severe fatal neurological diseases. Also sometimes causing sudden death are clostridial diseases, often associated with environmental conditions such as drought followed by intensive rainfall. Rhinos can also be infected by filarial worms, tick-borne protozoas, parasites, trypanosomiasis (sleeping sickness), and a variety of other diseases.

Saving the threatened rhino

Wound care innovations have provided opportunities for rhinos injured by poaching or other trauma. A recent series published in South Africa has shown that medical grade honey is useful in the therapy of gunshots and dehorning by poachers. Rhinos attacked for their horns often survive initial assaults but require extensive reconstructive surgery and long-term wound management. Poaching for meat and ivory has become a primary threat to rhinos, threatening them with extinction. Although poaching incidents in Africa have declined, they remain too high for sustainable survival, and a concerning spike in early 2025 saw ninety-one rhinos killed in South Africa.

Veterinarians have worked on developing new techniques for treating massive facial trauma, including skin grafts and innovative pain management protocols. Some programs include proactively removing horns under anesthesia to deter poachers, but this is undoubtedly a controversial practice. In 2004, scientists successfully achieved the first IVF (in vitro fertilization) pregnancy by transferring a lab-grown white rhino embryo into a surrogate mother, suggesting assistive reproductive techniques could revive species such as the northern White rhino, of which only two females remain alive. Female rhinos have gestation periods of 15-16 months and typically produce only one calf every two to three years, making each new reproductive event precious. However, addressing the full spectrum of threats—poaching, habitat loss, climate change, and emerging infectious diseases—requires sustained international cooperation, adequate funding, and integration of local communities into conservation efforts.