Felids are a large group consisting of 37 species in the genera Felis (small cats), Panthera (large cats), Neofelis (clouded leopards) and Acinonyx (cheetah). Some species of exotic felids such as tigers, lions, bobcats (Felis rufus), caracal (Felis caracal), servals (Felis serval), and serval hybrids have become have become popular pets.
Felids are a large group consisting of 37 species in the genera Felis (small cats), Panthera (large cats), Neofelis (clouded leopards) and Acinonyx (cheetah). Some species of exotic felids such as tigers, lions, bobcats (Felis rufus), caracal (Felis caracal), servals (Felis serval), and serval hybrids have become have become popular pets. I do not condone the ownership of exotic felids as pets. However, this information is aimed at providing veterinarians who are presented with these animals the basics of their natural history, husbandry/nutritional requirements, preventative medicine and common presentations.
All exotic felids in the pet trade should be captive bred and should have been acquired from a licensed breeder. Veterinarians should be familiar with the specific county, city, state and federal laws that determine the permit requirements for legal ownership. For example, Georgia requires either a Wildlife Exhibitor permit, or a Wild Animal License, in addition to a USDA permit. Among other things, USDA permits require a "program of veterinary care". Veterinarians are discouraged to sign on as "program veterinarians" without careful knowledge of the requirements of a program veterinarian, the facilities and husbandry and a strong client-veterinarian relationship. For more information on USDA licensing, visit http://www.aphis.usda.gov/ac/
Safety and Restraint
Exotic felids come armed with large teeth and claws and powerful limbs. They are agile, quick and find it easy to free themselves from physical restraint. The staff should be aware of how to handle these animals when they present to the clinic. Owners should be encouraged to bring the animals contained in adequate carriers (not on a leash) and in a manner in which they can be removed from the container if needed. Most felids are easy to train and owners should be encouraged to use positive training methods (ie: clicker training) to manage their animals. This will minimize the stress associated with veterinary care and, in some cases, aid in simple veterinary procedures. Small felids (<10 kg) can be physically restrained (with the help of a net and gloves) for hand-injection of anesthetic agents. With few exceptions, a thorough physical exam cannot be performed on a conscious animal under physical restraint. It is important to inform owners that if they not consent to sedation/anesthesia for a physical exam, there are important aspects that will be omitted (ie: dental exam). Squeeze cages are useful for larger cats. In some cases, such as tigers in an outdoor enclosure, administration of anesthetics may only be possible with pole syringes or via darts. Safety protocols should be designed prior to the exotic felid appointment or visit. If in the clinic, protocols that deal with cage escapes, etc, force the staff to think about the equipment and action necessary if these situations arise. When on a mobile visit, it is important to visually inspect the grounds, doors, cage locks, fencing equipment, etc prior to initiating a procedure in order to anticipate an emergency.
Housing: Exotic felids require large spaces to allow them to display a range of natural behaviors related to foraging and territoriality. Most felids are solitary, but some are social or can adapt to small groups. All felids are good climbers, swimmers and jumpers. Some felids are arboreal and require vertical space in order to feel secure. Adequate fencing and other containment facilities are part of all permitting requirements. Large outdoor enclosures are preferred as they allow exercise, exposure to ultraviolet light, the maintenance of natural circadian rhythms and improved ventilation. Problems associated with outdoor enclosures include traumatic injuries from other animals (ie; feral dogs), escape, vandalism/theft, and exposure to feral cats. Many pet felids are kept 100% indoors. Owners should understand the pros/cons of indoor/outdoor facilities as it related to the species at hand. When housed outdoors, the substrate should be easy to clean; however, felids housed on concrete flooring often suffer from chronic degenerative joint problems and food pad ulcerations. A mixture of substrates is ideal.
Small cats should receive 4 to 8% percent of their body weight daily. Large cats require only 1.5 to 3 percent of their body weight in food daily. However, young growing cats may require 10 - 25% of their body weight in food each day. Non-domestic fields are prone to obesity in captivity and therefore, it is best to keep them at a "lean" body weight. Exotic felids are carnivores. The domestic cat can be used as a similar physiologic model. Diets aimed for exotic felids should contain products that are high in quality and prepared with hygienic standards. Salmonellosis and other bacterial enteritis have been reported in cats fed diets that were not handled appropriately. Diets prepared for felids should be balanced. Muscle meat alone can lead to secondary nutritional hyperparathyroidism. Many balanced commercial diets are available for felids and should be used as the base of the diet; however, they do not promote natural feeding behaviors. Other items, such as large bones (that can be chewed but not swallowed), small prey, or animal hides can serve to enrich these behaviors. If a home diet is prepared, a minimum of 1% calcium and taurine supplementation is required. Examples of companies that provide balanced commercial diets: Dallas Crown Horse Meat-Based Frozen Carnivore Diet, Nebraska (Animal Spectrum Inc.) Premium Canine and Feline Diets, Milliken Toronto Zoo Feline/Canine Diets, and Natural Balance Zoo Carnivore Diet. Frozen meat diets are usually the diet of choice at most zoos and larger institutions. Dry diets have been shown to be nutritious, but cats may shun them due to their texture or palatability. Mazuri (Purina) and Eukanuba are good dry diets for exotic cats.
Anesthesia of exotic felids is fairly straightforward. The same principles used in domestic cat medicine apply. Pre-anesthetic fasting for 12 hrs is recommended. As a general rule, keeping the animal stress-free or relatively calm will translate to needing to use less anesthetic and provide a smoother anesthetic induction. There are a variety of protocols that have been reported for exotic felid anesthesia. In general, the protocols designed for domestic cats are applicable; however, there are some exceptions. Telazol should not be administered to tigers as it can induce seizures and death. Common injectable agents used in non-domestic felids include: ketamine / xylazine; ketamine,/xylazine/ diazepam, ketamine/diazepam, ketamine / medetomidine; or medetomidine alone. The reader is referred to the Further Reading section for references on specific dosages. Inhalant gas induction, without previous pre-medication, are not recommended. Alpha-2 agonists can induce heaving and/or vomiting in most cats. Once induced, isoflurane or sevoflurane in 100% O2 can be utilized to maintain anesthesia. When referring to published drug dosages, it is useful to know if the protocol was utilized only to render an animal recumbent for subsequent intubation and inhalant anesthesia, or if the dosage was used to achieve immobilization throughout the animal handling procedure (ie: field anesthesia). Anesthesia monitoring should be performed in the same manner as with domestic cats.
Often owners request de-clawing, canine teeth extractions and other surgical procedures aimed to make it "more convenient" to own exotic felids. I strongly disagree with these procedures, as they are not performed for the benefit of the animal, and in most cases, can interfere with the animal's natural behavior and cause secondary health problems. The following is a direct quote from Dr. Laurie Gage (USDA Large Felid Specialist): "The problem with most declawing techniques is that P-3 is damaged or removed with the claw. That leaves the cat with P-2 bumping abnormally into the pad for the rest of its life. Usually after about 10 years of age, these cats, the larger of which may reach an adult weight of over 200 kg, will tend to walk back on the posterior portions of their feet, avoiding the pressure of walking normally on their toes. They are prone to pad ulcerations, they tend to gradually develop arthritis in other joints from walking abnormally, have been known to develop back problems, and they almost always seem foot-sore. Cats use their claws for balance and for grasping. They derive a certain amount of enrichment from using their claws. Depriving them of their claws because they have an owner that has no idea of how to handle or manage them seems unjustified. Ovariohysterectomy and castration can be accomplished as in the domestic cat; however, in some species vasectomies are preferred as they do not interfere with secondary sexual characteristics (ie: manes in lions) or social behavior. When performing a vasectomy, it is wise to submit the resected vas deferens for histopathologic confirmation.
Preventative medicine should include all aspects of husbandry and nutrition. Veterinarians should review the husbandry practices used to keep these animals and physically examine exotic felids at least annually. Some owners start off with great husbandry (especially when their new pet is a kitten), but later begin to "cut corners" (ie: feeding road-kill as it is less expensive, forgoing vitamin supplements when feeding home-made diets, etc). Other conditions that can be identified are dental disease (not uncommon if fed soft commercial diets), osteoarthritis and chronic renal failure. If the owner is acquiring new animals, quarantine methods should be applied (at least 30 days without contact). If the owner is breeding, further consideration should be given to the preventative medicine of kittens (same schedule of examination, vaccination and deparasitizing). The following preventative medicine protocol is the minimum needed:
• Annual physical exam
• Annual baseline bloodwork (CBC, Biochemistry, Urinalysis)
• If this is the first vist, or if the risk factors dictate it (ie: exposure to feral cats), blood collection for:
o Feline leukemia, Feline immunodeficiency virus testing (Cornell University Animal Health Diagnostic Laboratory, Ithaca, NY)
o Feline infectious peritonitis testing (Washingont Animal Disease Diagnostic Laboratory, Pullman WA)
o NOTE: domestic cat test kits are not appropriate for non-domestic felid disease testing.
• Annual fecal exam (more frequent if housed outdoors and especially if exposed to other felids)
• Vaccination with:
o Feline rhinotracheitis
o Feline calicivirus
o Feline pankeukopenia
1 ml SQ of a killed virus vaccine should be given at least at 9, 12 and 16 wks of age and considered annually; however, due to concerns over vaccine-associated sarcomas may dictate that vaccine titers may be examined annually and a decision made to vaccine based on risk, exposure to other cats and antibody titers. A canary-pox vectored subunit vaccine should be used to vaccinate felids against canine distemper. This disease has killed several captive felids. Canine distemper vaccines (modified or killed) should NOT be used to vaccinate felids. Vaccination against feline leukemia or FIV is not recommended at this time, but has been used in some zoological collections to manage situations where these diseases where a problem. Please consult with a non-domestic feline veterinarian before vaccinating. Exotic felids, like their domestic counterparts, are susceptible to canine heartworm and should receive preventative in the same frequency and dose.
Other Diseases of Felids
In addition to the diseases mentioned above, the following have been reported in exotic felids:
• Feline Upper Respiratory Disease Complex—caused by a combination of organisms including chlamydia, herpesvirus, and calicivirus.
• Gastritis is commonly seen in cheetahs, caused by a Helicobacter bacteria and captivity-associated stress.
• Pyloric stenosis (tigers only) which have required surgical Z-Y plasty to repair the problem and have recovered uneventfully.
• Metabolic bone disease is still reported in young growing exotic felids due to diets with inadequate levels of calcium and lack of exposure to sunlight.
• Ethelyene glycol poisoning was reported in cats fed a particular commercial diet emphasizing that commercial diet quality should be carefully monitored.
• Intervertebral disk rupture occurs in large cats and is diagnosed and treated in the same manner. Mostly reported in tigers.
• Venoocclusive disase of cheetahs and snow leopards. This is a slowly progressing disease of the liver that results in the fibrosis of the hepatic sinusoids. Clinical signs relate to liver failure. There are a variety of diseases associated with cheetahs and veterinarians who plan to work with this species should build a library of articles and books on the subject.
• Bovine spongiform encephalopathy was reported in felids in Europe. Imported non-dometic felids that have been fed cattle carcasses might be at risk for developing BSE.
• Foreign body ingestion/obstruction
The most commonly kept pet primates are squirrel monkeys (Saimiri sciureus), spider monkeys (Ateles geoffroyi), capuchin monkeys (Cebus sp) and marmosets (Sanguinus, Callithrix sp). In some instances chimpanzees (Pan troglodytes), baboons (Papio sp), and macaques (Macaca sp).
Health and Nutrition
All primates should be fed a diet of at least 16% protein (New World primates require 25%). Some primates, like the leaf-eaters have specific requirements for diets high in fiber (a combination of commercial diets high in fiber ie: "leafeater monkey biscuits" and browse or vegetables). If allowed, primates will eat 2-4% of their body weight in food and it is not true that "offering them a wide variety and letting them choose" is an intelligent strategy. As a rule of thumb, the appropriate commercial diet should make up no less than 50% if the total diet of a primate, supplemented by produce. Most primates require vitamin C in their diet (1-25 mg/kg/day). New World primates require vitamin D3 if not in direct sunlight for at least 30 min/day. Marmosets have even higher requirements, thus the high prevalence of metabolic bone disease in these animals.
Most of the following details on diet and husbandry have been adapted from details written by Dr. Anne Baker for the AZA Husbandry Standards.
Of the Prosimian primates (Tarsiidae (tarsiers), Lorisidae (galagos, pottos, lorises), Lemuridae (lemurs), Cheirogaleidae (mouse lemurs), Indriidae (avahis, indris, sifakas), Daubentoniidae (aye-ayes)) only lemurs appears to have made it into the pet market on a regular basis.
Diets of lemurs in the wild include primarily fruits supplemented by leaves (Hladik, 1979). Animals in a captive setting have been successfully acclimated to a diet of commercially prepared primate diets in combination with fresh fruits (apple, orange, banana, grapes, etc., vegetables (cabbage, kale, spinach, cooked carrot and sweet potato, etc.), and leaves (eugenia, hibiscus, mulberry, maple, etc.) The addition of browse seems to be very important for these species. Lemurs can synthesize Vitamin C endogenously. While activity patterns tend to peak in early morning and late afternoon, feeding occurs throughout the day. Food should be offered twice per day in a fashion which prevents contamination with feces. Presentation of food should also allow for arboreal (Varecia) and terrestrial (Lemur catta) activity patterns.
Callitrichidae (marmosets and tamarins) and Callimiconidae (callimico), differ from the remainder of the South America primates in size, social groups, and diet, and will be considered separately. A commercially available balanced primate diet for South American species should form the basis of the diet (50 % minimum by volume of diet offered). Unlike other primates, the marmosets and tamarins cannot synthesize Vitamin D. If the canned diet prepared specifically for marmosets is not used, Vitamin D3 supplements should be given. The remainder of the diet should be a mixture of fresh fruits and vegetables, the composition of which should be frequently changed to stimulate interest and activity. DO NOT feed mice.
Cebidae (howler monkeys, Alouatta; owl monkeys, Aotus; spider monkeys, Ateles; wooly spider monkeys, Brachyteles; uakaris, Carajao; titi monkeys, Callicebus; capuchins, Cebus; saki monkeys, Pithecia and Chiropotes; woolly monkeys, Lagothrix; and squirrel monkeys, Saimiri): Food consumed by New World primates in the wild include all manner of plants and animals, and many genera may correctly be classified as frugivores, herbivores, omnivores, or combinations thereof. Most of these species may be acclimated easily to a captive diet containing a wide variety of commercial diets (primate chows, and monkey biscuits) and "natural" appearing items such as fruits (grapes, raisins, orange, apple, etc.), nuts, vegetables (lettuce, spinach, cabbage, corn, carrot, etc.), mealworms, and crickets.
Colobinae (Colobus, Presbytis, Pygathrix, Rhinopithecus, and Nasalis)
The nutritional needs of Cercopithecines (baboons, drills, mandrills, macaques, guenons, mangabeys, talapoins, patas monkeys, swamp monkeys) are well studied and documented, and there are many commercially prepared primate diets available that will serve as a basis for these needs. The addition of fruits, vegetables, nuts, seeds, grains, insects, etc. as well as fresh browse will greatly augment and enhance the commercial "monkey biscuit". Cercopithecines take almost anything which is digestible and not actually poisonous.
Of the great apes, only chimpanzees are seen as pets. Chimpanzees are omnivorous and their diet should include commercially prepared canned diets and chows, fresh fruits, vegetables and leafy greens, and occasionally eggs and live insects.
Quarantine and hospitalization
All primates should be quarantine for at least 30 days. Depending on their history and previous preventative medicine, this period may need to be lengthened. The social needs of primates should be taken into consideration whenever isolation is necessary. There are several training methods that are successful in those animals in need of frequent biological sample collection. Owners should be encouraged to research and read training methods that decrease animal handling, that decrease animal stress and allow for medical procedures with the safety of the veterinary staff in mind.
The following tests are recommended during quarantine examination:
• CBC (blood collection can be accomplished from the femoral vein (in smaller primates), the saphenous vein, cephalic, jugular or the decubital vein).
• Serum chemistry
• TB testing: inject 0.1 ml. of Old Tuberculin intradermally into one eyelid near the edge or into the abdominal skin or both; 0.05 ml. can be used in small NHPs, e.g., marmosets . Usually the eyelid is preferred as it is relatively easy to observe. If the abdomen is used, the hair should be clipped without traumatizing the skin and the injection site noted. The abdominal skin test is most commonly used when retesting suspect NHPs. The advantage of using the abdomen is that any induration can be measured and a saline control injection can be used. Observe the animals for reactions at 24, 48, and 72 hours postinjection under good lighting conditions. The initial readings may be made by a trained technician. Any reactions or suspected reactions are to be observed and interpreted by the attending veterinarian. The following grading systems should be used: 0=no reaction, 1=bruise (extravasation of blood due to injection) 2=varying degrees of erythema on the palpebrum with minimal swelling, 3=moderate swelling with or without erythema, 4=obvious swelling with drooping and erythema, 5=marked swelling with necrosis and eyelid closed. Erythema and edema of the injected eyelid show a positive reaction to the test. If abdominal skin is used, the following grading scheme applies: 5-10 mm=suspect, >10 mm=positive. Tuberculous NHPs infrequently become anergic to TST. Tuberculosis should be considered and further testing performed on animals that have unexplained weight loss or nonhealing wounds. Additional testing may include: culture swabs of nonhealing wounds, chest radiographs, gastric lavage with culture and other methods as they are validated. The veterinary clinician is obligated to recommend that all people exposed to an animal that has a questionable tuberculosis test result seek medical attention.
• Fecam examinations (3 negatives); particular attention should be paid to entamoebas and protozoas in the great apes.
• Fecal culture for Salmonella, Shigella and Campylobacter
• Serology for the group of diseases of interest, which will depend on previous history, exposure to other primates, and species at hand. For example, the macaques should be tested for Herpes B, measles (previous vaccination may result in positive result), SIV, STLV, and SRV. DO NOT send blood or biological samples to any lab without first confirming that they will handle biological samples from primates. Some labs which specialize in primate testing are: Bioreliance http://www.bioreliance.com
• Vaccinations: Rabies (Imrab-3; annually until adulthood; every 3 years thereafter), Tetanus toxoid 0.15 ml/kg (two injections 4-6 wks apart; 3rd dose one year later; booster every 5 years; start youngsters at 2-3 months), for great apes: polio (Human OPV vaccine), Human DPT vaccine (Diptheria, Pertusus, Tetanus), Human MMR vaccine (Measles, Mumps, Rubella) and the human varicella zoster offers some protection.
• Thoracic/abdominal radiographs are highly recommended to establish a reference with which to compare in future.
Capture, restraint and immobilization techniques
Successful anesthesia of primates depends on understanding how the animal is typically handled, whether it is trained to get into a restraining device, its disposition, etc. There is no "recipe" for anesthetizing primates, but rather anesthetic protocols should vary depending on the situation. A review of primate anatomy and physiology is recommended for practitioners attempting to anesthetize primates, as they are significantly different from the carnivore model. In general, administering tranquilizers (ie: oral diazepam; injectable midazolam 0.05-0.15 mg/kg IM) might prove useful, especially in animals that are not used to unusual situations. By far the most popular injectable anesthetic used on primates is ketamine. It has a wide safety margin; however its effect will vary significantly depending on the species at hand. It is best to consult with someone who has experience prior to using it. Other injectable anesthetics are medetomidine: ketamine (0.05: 2 mg/kg) combinations, Telazol (which requires lower volumes, but creates prolonged anesthetic periods (4-6 mg/kg)), propofol (2-6 mg/kg IV) or induction with inhalant gases. An extensive review of the pharmacological properties of these drugs and their effects on primates are beyond the scope of this document. Two major resources for the private practitioner on this extensive topic include: The Veterinary Clinics of North American: Exotic Animal Practice, Analgesia and Anesthesia, Jan 2001. Edited by Darryl Heard. Primate Anesthesia. Horne, W.A. p 239-266 and Zoo and Wild Animal Medicine, 5th ed. Edited by Fowler, ME and Miller RE.
Diseases of interests
• Rule of thumb: DO NOT mix monkeys from different continents. Most diseases that are asymptomatic in one group can be serious or fatal in another.
• All primates can develop tuberculosis, Shigellosis, Salmonellosis, E. coli enteritis, Tetanus, Campylobacteriosis, Helicobacteriosis, Literiosis, Strep pneumonia and a variety of other bacterial pneumonias, Blastomycosis, Coccidioidomycosis and Cryptococcosis.
• Lemurs-Diabetes mellitus; Black lemurs: periarticular hyperostosis; ruffed lemurs: trichobezoars, all lemurs: hemochromatosis.
• Marmosets-wasting marmoset syndrome, a syndrome causing weight loss, alopecia, diarrhea, colitis and anemia thought to be caused by low-protein diets, zinc deficiency or chronic parasitism; Herpes hominis; Herpesvirus tamarinus; Marmoset poxvirus, Paramyxovirus, myxoviurs (influenza) Types A, A2; Measles; Paramyxovirurs sanguinus; Callitrichid hepatitis or Lymphocytic chroriomeningitis virus (LCMV);
• Squirrel monkeys: Herpes samiri: host species; Measles; Encephalomyocarditis virus; Yellow fever
• Spider monkeys: Herpes ateles: host species; Yellow fever
• Macaques—Herpes hominis, Herpes simiae (Herpesvirus B, Cercopithecine herpes 1): all macaques should be considered reservoirs; some Herpesvirus B free colonies have been established, but a negative test does not prove a macaque is free of this virus; particular zoonotic concern; Monkeypox; Simian immunodeficiency virus; Hepatitis A
• Chimpanzees and other great apes: Measles, poliovirus, respiratory syncytial virus (pneumovirus), influenza (orthomyxoviurs), parainfluenza III (paramyxovirus), adenovirus, cardiovascular disease, rheumatoid-like arthritis, psot-Shigella reactive arthritis, hypertrophic osteoarthropathy, Legg-Calve-Perthes disease, rickets, oral papilloma (chimps), hypothyroidism, diabetes mellitus.
Warnell School of Forestry and Natural Resources & the Southeastern Cooperative Wildlife Disease Study at the College of Veterinary Medicine, University of Georgia, Athens, GA 30602; firstname.lastname@example.org