• Urinalysis should include both fluid and sediment evaluation of a clean voided sample. Microbial culture should be considered if there is evidence of blood cells or bacteria.

• Radiographs of feet are strongly recommended if any signs of pododermatitis or nail cracks are observed (Atkinson et al., 2002). Regular foot trimming and care may require immobilization in certain individuals (i.e., those that have a history of chronic foot problems). See section on pododermatitis. 

• Diagnostic tests for tuberculosis—Periodic testing for tuberculosis in rhinoceroses should be considered, especially if there has been a history in the institution or herd. Intradermal testing can be performed using bovine PPD (0.1 ml ID) in the eyelid, behind the ear, caudal tailfold, or axillary region. Both false positive and false negative results have been found when performing intradermal tuberculin testing in rhinos (Godfrey et al., 1990). Ancillary tests such as nasal swabs, tracheal washes, and gastric lavages for mycobacterial culture have also been used. Serological tests [ElephantTB STAT-PAK®, MAPIA, DPP (dual pathway platform); Chembio Diagnostic Systems, Inc.] are being investigated for use in rhinos. See section on tuberculosis. 

• Other vaccination regimens will depend on regional requirements and exposure risks (consider multivalent vaccination for Clostridial diseases). Contact the SSP veterinary advisor for the most up-to-date information.

Animals being moved between institutions should receive a preshipment examination and testing. This is similar to the routine health procedures but should also include screening for tuberculosis and other requirements dictated by the receiving institution (see quarantine section below).

 

Neonatal Examinations

Ideally, neonates should be examined within 24 to 72 hours of birth to detect any congenital defects. Often the dam can be separated while the calf is manually restrained for a brief, but thorough exam, including body weight, and if feasible, blood collection. Complete blood count, biochemical panel, tests for passive transfer of immunoglobulins [e.g. glutaraldehyde coagulation, zinc sulfate turbidity, radial immunodiffusion plates (equine plates work well in rhinos and can be standardized by testing healthy rhinos), and serum protein electrophoresis], vitamin E level, and banking should be performed. A microchip may be placed behind the left ear for future identification. Particular attention during the exam should be paid to the umbilical stalk for signs of infection, urine leakage, or hernia; passage of meconium, normal rectal/anal anatomy and tone; suckling reflex and neurological status. Regular weights and developmental progress should be documented. Lack of weight gain may be due to inadequate maternal milk production and care, or an indication of health or developmental problems in the calf. Black rhinoceros calves have been successfully hand-reared (covered under Nutrition chapter). In one case, a white rhinoceros calf was orphaned when its dam died, and the calf was taught to drink from a bucket at the age of six weeks. Weakness or other problems resulting in prolonged recumbency can cause decubital ulcers. Treatment of two neonatal white rhinos has been described using serial sedation with butorphanol alone or in combination with detomidine for restraint (Gandolf et al., 2006). Rectal prolapse has been reported in black rhinoceros calves, with surgical intervention required in at least two cases (Pearson et al., 1967; Abou-Madi et al., 1996). Leukoencephalomalacia has also been described in black rhinoceros calves (see disease section for more details)(Miller et al., 1987).

 

Parasites

Internal parasites are more commonly found in free-ranging rhinos than in captivity. Stomach botfly larvae (Gyrostigma pavesii) have been reported in black rhinoceroses (Velleyan et al., 1983). Other parasites reported include nematodes (Diceronema versterae, Parabronemia round— associated with stomach nodules), Draschia megastoma, multiple species of Kiluluma, Khalilia rhinocerotis and pinworms (Oxyuris karamoja). Tapeworms (Anoplocephala sp.) can cause asymptomatic infestation in both captive and wild rhinos (Miller, 2003). One case of neosporosis led to acute fatal myocarditis in a neonatal white rhino calf and abortion in another case (Williams et al., 2002; Sangster et al., 2010).

Ticks are regularly found on free-ranging rhinoceroses, and imported animals should be carefully examined and treated. Multiple species have been identified on African rhinos (Amblyomma hebraeum, Dermacentor rhinocerinus, Rhipicephalus maculates, R. muehlensi, R. simus, R. appendiculatus, R. zambeziensis, Haemaphysalis silacea, Hyalomma truncatum)(Penzhorn et al., 2008). Filarid (Stephanofilaria dinniki) and screwworms (Chrysomia bezziana) can lead to skin lesions in wild black rhinos, particularly prevalent in the axial region (Round, 1964; Penzhorn et al., 1994).

Vector-borne parasitic infections occur in endemic areas. Trypanosomiasis can infect black rhinoceros and lead to anemia in tsetse fly-endemic areas. Evidence of tick-borne disease has been documented in black rhinoceros due to Babesia bicornis sp. nov. and Theileria bicornis sp. nov. (Nijhof et al., 2003). In addition, antibodies to heartwater (Cowdria ruminantium) have been found in both African species where the Amblyomma ticks are present (Kock et al., 1992).

Capture and translocation or importation may exacerbate potential parasitic infestations and increase the risk of introduction of novel pathogens to a new environment. Therefore, careful screening for external and internal parasites, prophylactic treatment of wounds with fly repellant, pour-on tick treatments (coumaphos, flumethrin), and judicious use of antiparasitic medications (pyrantel pamoate, fenbendazole, ivermectin, praziquantel) should be considered. Check with the SSP veterinary advisor for current recommendations.

 

Quarantine

Due to the size, strength, and temperament of a rhinoceros, it may be logistically difficult to maintain isolation from other animals during arrival and quarantine. The Rhinoceros TAG/ SSP Recommended Preshipment Protocol for Rhinoceros lists a comprehensive battery of tests for health assessment prior to shipment. Since most zoological institutions will not have the facilities available to safely house and manage a newly arriving rhinoceros, it is important that the receiving institution work closely with the sending institution to ensure that all (or as many as possible) of the listed tests are conducted and results reviewed before shipment. Following the preshipment protocol may help compensate for some of the quarantine compromises that may be required. Regardless of preshipment test results, every attempt should be made to maintain some degree of physical separation of the incoming animal from the resident rhinos after arrival.

Current quarantine practices recommend a minimum 30 to 90 day quarantine period for most mammalian species in zoos and aquaria. Social concerns, physical facility design, and availability of trained rhino staff may dictate a modified quarantine protocol. Specific quarantine guidelines and protocols at each institution should be reviewed jointly and decisions made by the veterinary and animal management staff. Recommended procedures to consider as part of a comprehensive plan for rhinoceros quarantine include:

• Thorough physical examination including a review of all organ systems.

• Blood collection for CBC (including blood smear examination for hemic parasites), serum chemistry panel, fibrinogen, serum protein electrophoresis, and serum bank.

• Fecal collection for parasite screening (direct, flotation, sedimentation) conducted weekly for the first three weeks.

• Fecal cultures for Salmonella spp. conducted at least weekly for the first three weeks.

• Any procedures that were not completed prior to transport or that may be due, such as vaccination, serologic screening, or TB testing.

It should be emphasized that the quarantine test requirements should be strongly considered regardless of the results of preshipment testing. The stress of transport and quarantine may result in health changes (for example, Salmonella shedding) that were not detected during testing at the sending institution.

 

Hospitalization and Critical Care

In most cases, hospitalization is impractical with adult rhinoceroses. Most animals will be treated in their holding areas. Rhino calves may be hospitalized in adequate large animal holding facilities if the severity of their medical condition warrants. Barns or holding areas that incorporate species-appropriate restraint devices facilitate medical treatment. Some of the following medical problems require active intervention, including sedation, immobilization, injectable drug therapy, and/or fluid therapy. Although it has been achieved, fluid therapy in rhinoceros presents logistical challenges. In addition to the intravenous route, it is possible to improve hydration using rectal enemas with warm physiologic solutions or even tap water. Animal and staff safety should be a priority in any planned intervention.

 

Diseases

Tuberculosis

Mycobacterium bovis and M. tuberculosis have caused infections in captive rhinoceroses (Stetter et al., 1995; Miller, 2008). Although not currently reported in free-ranging rhinoceroses, there was a recent report of M. bovis infection in a black rhinoceros brought into captivity in South Africa (Espie et al., 2009). Initial infection may be asymptomatic or result in progressive weight loss and emaciation, with coughing and dyspnea occurring in the terminal stages. Nasal discharge may be present but is not a consistent sign. Most infections are pulmonary. Antemortem testing includes intradermal tuberculin test, tracheal and/or gastric lavage for mycobacterial culture, and serological tests (see preventive health section for details). Retrospective analyses of serum from M. tuberculosis-infected black rhinos showed positive results using the ElephantTB Stat-Pak® (Duncan et al., 2009). Treatment has been attempted using isoniazid, rifampin, ethambutol, and pyrazidamide (Barbiers, 1994; Duncan et al., 2009). However, assessment of successful response is limited. Concerns for other collection animals, staff and public health need to be considered prior to initiation of therapy. Since this is a reportable disease, notification of the appropriate state veterinary officials should occur promptly once a diagnosis is made. Consultation with the SSP veterinary advisor is also recommended.

​

Salmonellosis

Salmonella infection can cause enteritis and fatal septicemia in captive and newly captured wild rhinoceroses (Windsor and Ashford, 1972; Kenny et al., 1997). In a retrospective survey of captive black, white, and greater Asian one-horned rhinos in the U.S., 11% reported positive cultures, usually associated with clinical signs (Kenney, 1999). Research has shown that asymptomatic black rhinoceroses can carry and intermittently shed Salmonella in their feces (Miller et al., 2008). Clinical infection may result secondary to transport, changes in diet, immobilization, concurrent disease, or exposure to a large number of organisms. Lethargy, anorexia, signs of colic, diarrhea, and death may be observed. Successful treatment using trimethoprim-sulfamethaxozole and supportive care is possible if initiated early. However, treatment of asymptomatic animals is NOT recommended.

​

Leptospirosis

Leptospirosis usually presents with depression and anorexia. Other signs may include hemolytic anemia (not present in all cases), hemoglobinuria, signs of colic, and development of skin ulcers. Fatality rates are high in clinically affected black rhinos although successful treatment with trimethoprim-sulfamethaxozole and ceftiofur has been reported (Neiffer et al., 2001). Diagnosis is based on high antibody titers (microagglutination test – MAT) and confirmed by detection of leptospiral organisms in urine or tissues (fluorescent antibody test). Low levels of antibodies have been observed in free-ranging and non-vaccinated black rhinos without evidence of disease (Jessup et al., 1992). Preventive measures include annual vaccination of black rhinos with a multivalent large animal product, rodent and wildlife control programs, and good husbandry to minimize contamination of feed and water. Abscesses and systemic anaphylactic reactions, including hives and skin sloughing, have occurred following leptospirosis vaccination in the black rhinoceros. Those individuals with a history of systemic adverse reactions should forego regular vaccination.

 

Gastrointestinal Infections

Colitis of unknown etiology and secondary endotoxic shock led to the death of an adult black rhinoceros. Clostridial enterocolitis has been observed in black rhinoceros with signs of diarrhea, lethargy, and colic. Fatal cases of enterotoxemia due to Clostridial enteritis have occurred in black rhinoceros (Ndeereh et al., 2012). See salmonellosis and GI torsion, impaction, and ulcers for other GI conditions.

 

Encephalomyocarditis Infection (EMC)

EMC viral infection usually results in acute death due to myocarditis (Gaskin et al., 1980). The southeastern/Gulf Coast states in the U.S. are considered an endemic area. Diagnosis is usually based on virus isolation at necropsy from heart, spleen, or other tissues (http://www.merckvetmanual. com/mvm/index.jsp?cfile=htm/bc/53600.htm). Prevention should target rodent control, although experimental vaccines have been proposed. A commercial vaccine is not currently available. 

 

Fungal Pneumonia

Fungal pneumonia is usually due to Aspergillus spp. and primarily observed in black rhinoceroses secondary to immunocompromise from concurrent disease, broad spectrum antibiotic therapy, or corticosteroid use (Weber and Miller, 1996). Clinical signs may include weakness, weight loss, epistaxis, or other signs consistent with pneumonia. Diagnosis is challenging, although serology and bronchoscopy, with cytology and fungal culture, may be useful. Fungal pneumonia in the black rhinoceros is often associated with elevations in serum globulin, above levels generally observed in other chronic diseases (S. Citino, pers. comm.). Long-term treatment with antifungal drugs (e.g., itraconazole) is expensive and has unknown efficacy. Definitive diagnosis is often made at necropsy.

 

Anthrax

Death due to anthrax has been observed in wild rhinoceroses. Most cases result in sudden death. Foamy discharge from the mouth and nostrils can be seen and may appear similar to EMC infection. Diagnosis is based on identification of anthrax bacilli in blood or tissue smears. Vaccination of ranched rhinos has been used in some endemic areas of Africa. Sporadic outbreaks in domestic livestock occur in the U.S., although there have been no reports of rhino mortality in these areas (e.g., Texas).

 

Skin Conditions and Dermatopathy Syndromes

Black rhinoceros have a disproportionate number of skin conditions among the captive rhino species. Skin disease may be the most common health problem of black rhinos with over 50% having at least one episode during their lifetime (Munson and Miller, 1999). There are several distinct syndromes reported in captivity.

• Superficial necrolytic dermatopathy (SND)—This has also been called ulcerative skin disease, vesicular and ulcerative dermatopathy, and mucosal/cutaneous ulcerative syndrome (Munson and Miller, 1999; Dennis et al., 2007). More than 40 black rhinos have been affected. Initial signs are epidermal plaques or vesicles that progress to ulcers, often over pressure points, ear margins, coronary bands and tail tip. Oral or nasal ulcers may develop concurrently. Clinical signs are intermittent and, during episodes, rhinos may also be anorexic, depressed, lame, have oral or nasal bleeding, and lose weight. Affected animals may have decreased albumin and hematocrits. In most cases, the skin lesions are associated with other concurrent health issues, including GI and respiratory disease. Research suggests that the underlying cause may be an imbalance of dietary essential micronutrients with related metabolic changes. Management includes symptomatic treatment such as topical or systemic antibiotics, topical ointments, and hydrotherapy. If lesions become extensive, it can be fatal. Treatments with cryotherapy and steroids have been successful, but rhinos treated with systemic steroids can develop fatal fungal infections. Occasionally, lesions may resolve spontaneously.

• Eosinophilic granuloma syndrome—This syndrome usually presents with oral and nasal non-healing ulcers and granulomas (Pessier and Munson, 2004). Cytology shows a predominance of eosinophils associated with lysis of collagen and mineralization. Development of significant ulceration may lead to epistaxis or oral bleeding. A similar syndrome has been described in domestic cats. Although lesions may resolve spontaneously, usually over one to seven months, they may recur. Treatment has included corticosteroid therapy, which can result in fungal pneumonia, or local cryotherapy. Laser therapy has been used to treat ulcers but may exacerbate hemorrhage. Supportive care is recommended in severe cases. Eosinophilic granulomas in wild rhinos are typically associated with Stephanofilaria dinniki.

• Neoplasia—Squamous cell carcinoma (SCC) has been treated by surgical excision in a captive white rhino (Goodman et al., 2007). A greater Asian one-horned rhinoceros with SCC of the horn has also been successfully treated with surgery and radiation (Greer et al., 2010). Cutaneous melanomas have been reported in both black and greater Asian one-horned rhinoceroses (Wack et al., 2010).

• Fungal—Malassezia pachydermatis and Candida parapsilosis were identified in black rhino and successfully treated using natamycin solution.

• Environmental—Dermatitis may be due to inadequate access to wallows.

• Other—There has been a rare single case of primary vitiligo reported in a black rhino that began around the nares at two years of age and progressed to include multiple areas without evidence of the other syndromes (Takle et al., 2010). These cases illustrate the importance of biopsy and culture for identifying the etiology of and directing treatment in dermatologic cases in rhinos.

 

Pododermatitis and Chronic Foot Problems

All species of rhinoceros are susceptible to developing pododermatitis due to inappropriate substrate or other husbandry conditions in captivity. Abrasive substrate, long-term indoor housing in northern climates, and limited access to a wallow contribute to chronic foot trauma in captive rhinos (von Houwald, 2005). Management of the condition includes improvements in husbandry and medical/surgical interventions. Medical treatment may be in the form of oral antimicrobial medication and topical use of copper sulfate and oxytetracycline. Regular hoof trimming and surgical debridement of necrotic lesions, along with use of collagen products for granulation tissue stimulation, can lead to improvement in appearance and comfort of the animal. In addition to the factors mentioned above, nutritional imbalances (e.g., zinc) are also being investigated. Black rhinos have also been reported to develop laminitis that may or may not be related to idiopathic hemorrhagic vasculopathy syndrome (Fig. 3.13; Nance, 1998). Frequent foot trimmings, analgesics, and antibiotics are needed to manage this condition, similar to laminitis in domestic horses

​

Corneal Ulcers and Keratitis

Corneal trauma and secondary infection can result in corneal ulceration and perforation. Surgical management of a melting corneal ulcer using a conjunctival graft has been described in a greater Asian one-horned rhino (Gandolf et al., 2000).

​

Horn Problems

Horn avulsion, cracks, or other trauma can occur as a result of acute or chronic rubbing, pressure, self-induced, or conspecific fighting. This may lead to myiasis, abscessation, osteomyelitis, or pain with behavioral changes. Radiographs, thermography, or fluoroscopy can be used to assess the extent of the damage. Treatment may involve debridement, antibiotics, wound treatment, and fly control (Suedmeyer, 2007). A squamous cell carcinoma of the horn in a greater Asian one-horned rhinoceros was diagnosed and managed with partial amputation and radiation therapy (Greer et al., 2010). The horn is attached to the basal dermal layer not unlike the laminae of the horse’s hoof wall and therefore perturbations in blood flow can presumably lead to laminitis. See Sullivan paper on Vitamin A. 

​

​

​​

​