Authors: Nadine Lamberski
Categories: Article
Source: Fowler's Zoo and Wild Animal Medicine, Volume 8
Authors: Nadine Lamberski
The family Felidae consists of at least 36 wild cat species. These felids are morphologically similar with rounded, flat faces, facial whiskers, large eyes, and large ears. They have the widest range of body sizes of all living carnivore families, weighing 1 kilogram (kg) to 300 kg. They occupy diverse habitats and are distributed naturally throughout the world except Antarctica and Australia, where they have been introduced by humans.
Felid taxonomy has been intensively studied and yet remains controversial. The number of genera recognized is variable. Although in the past four genera were lumped together, currently at least 12 genera are recognized based on several studies of morphology and genetics.^31^ Taxonomy and biostatistics for felids may be found in Table 47-1 .TABLE 47-1Taxonomy and BiostatisticsCategoryNative RegionGenus and SpeciesCommon NameLongevity (Years)Adult Mass (kg)Gestation (Days)GENUS FELISLCEurope, Africa, AsiaF. silvestrisWild cat195.0–8.064–67LCNorth Africa to Indochina, Sri LankaF. chausJungle cat203.0–1663–66NTNorth Africa, Arabia, AsiaF. margaritaSand cat13.92.7567VUSouth AfricaF. nigripesBlack-footed cat121.3–2.363–68GENUS OTOCOLOBUSNTIran to ChinaO. manulPallas cat162.5–4.566–75GENUS LYNXLCNorth AmericaL. canadensisCanada lynx178.0–18.062–74LCEurope, AsiaL. lynxEurasian lynx2418.0–30.067–74CRSouth EuropeL. pardinusIberian lynx139.0–27.060LCNorth AmericaL. rufusBobcat324.0–18.060–70GENUS CARACALLCAfrica, Arabia, AsiaC. caracalCaracal179.0–18.078–81NTWest Africa, Central AfricaC. aurataAfrican golden cat215.5–16.075GENUS LEPTAILURUSLCAfricaL. servalServal237.0–18.066–77GENUS PARDOFELISVUSouth Asia, Southeast AsiaP. marmorataMarbled cat122.0–5.066–82ENBorneoP. badiaBornean bay catNo data3.0–4.070–75NTSoutheast AsiaP. temminckiiAsian golden cat239.0–16.091–95GENUS PRIONAILURUSLCSouth Asia, East AsiaP. bengalensisLeopard cat173.0–7.065–72VUIndia, Sri LankaP. rubiginosaRusty-spotted cat180.9–1.665–70ENSouth Asia, Southeast AsiaP. viverrinusFishing cat175.0–16.063–70ENBorneo, Sumatra, MalayaP. planicepsFlat-headed cat141.5–2.556GENUS LEOPARDUSNTCentral America, South AmericaL. colocoloPampas cat163.0–7.080–85LCNorth America, Central America, South AmericaL. pardalisOcelot208.0–18.079–82NTCentral America, South AmericaL. wiediiMargay242.6–4.076–84VUCentral America, South AmericaL. tigrinusLittle spotted cat or oncilla231.5–3.074–76NTSouth AmericaL. geoffroyiGeoffroy's cat232.0–5.072–78VUSouth AmericaL. guignaKodkod or guiña142.0–2.572–78ENSouth AmericaL. jacobitaAndean mountain cat16.54.0No dataGENUS PUMALCNorth America, Central America,South AmericaP. yagouaroundiJaguarundi153.5–1070–75LCNorth America, Central America, South AmericaP. concolorPuma2429.0–100.090–96GENUS NEOFELISVUAsiaN. diardiSunda clouded leopard1115.0–30.085–95VUAsiaN. nebulosaClouded leopard2015.0–23.085–93GENUS PANTHERAENAsiaP. uncialSnow leopard2125.0–75.090–103ENAsiaP. tigrisTiger2665.0–306.093–112NTAfrica, AsiaP. pardusLeopard2723.0–91.090–105NTSouth America, Central AmericaP. oncaJaguar2830.0–121.093–105VUAfrica, AsiaP. leoLion27120.0–250.0100–120GENUS ACINONYXVUAfrica, Middle EastA. jubatusCheetah2035.0–72.090–95**CR, Critically Endangered; EN, Endangered; VU, Vulnerable; NT, Near Threatened; LC, Least Concern.
Wild felids are predators requiring large areas of habitat with suitable prey density. Human population growth has negatively impacted both these requirements, resulting in a decline in all felid species worldwide in range and number. Felidae are among the most threatened groups of mammals. Larger species are heavily persecuted because of the danger they pose to humans and livestock. Small cat species are also persecuted and are harvested for the fur trade. The International Union for the Conservation of Nature (IUCN) Red List designates 29 of 36 wild felid species as having a decreasing population trend. Nearly 50% of all felid species are listed in the top three threatened categories, and seven of these species are listed as Critically Endangered or Endangered. Felids characterized as threatened are those that appear to be naturally rare with limited distribution or those that have become threatened because of human factors. The Iberian lynx, listed as Critically Endangered, fits into both categories and may become the first cat species to become extinct in modern times.23, 31
The anatomy of nondomestic felids is similar to that of the domestic cat. Sexual dimorphism is limited with males generally 5% to 10% larger than females. There are 28 or 30 teeth with the following dental incisors (I) 3/3, canines (C) 1/1, premolars (P) 2-3/2, molars (M) 1/1. The incisors are small and are used for nipping flesh from carcasses. Canines are long with a length-wise groove in the enamel and are used to kill prey. The fourth upper premolars (carnassial teeth) are used to slice meat. The reduced dentition allows for a reduced length of the skull and mandibles, which improves efficiency of the muscles that close the jaw. Cats have a more powerful bite relative to muscle mass than any other carnivore except mustelids. Because of their carnivorous diet, cats have a shorter digestive tract with a smaller cecum and a short large intestine.^31^
The forelimbs are used for locomotion and prey capture. To grasp prey, supination of the paw is needed. This increased mobility of the elbow and wrist joints affects running. Canids run faster as they have stiffer forelimbs. The hindlimbs are the propulsers, and the reduction or loss of a clavicle increases stride length. Cats are digitigrade, with five toes in the front and four in the back. The first digit on the front foot is the dewclaw. All felids have retractable claws, the exception being the cheetah, in which retraction is less developed. Cheetahs lack the fleshy sheath protecting the claw.^31^
A key characteristic that was used to separate the big cats (Pantherinae) from the small cats (Felinae) is the presence of an elastic ligament in the hyoid apparatus below the tongue, which was thought to allow the big cats to roar but not purr. Conversely, the bony hyoid of the small cats was thought to allow them to purr but not roar. More recent studies comparing the hyoid structure and vocal abilities dispute this correlation. It has been found that the main difference between the roaring, nonpurring cats and the others was the presence of long, fleshy, elastic vocal folds within the larynx of big cats that resonate to produce a roar. Smaller cats and cheetahs have simpler vocal folds that only allow purring.^31^
Nondomestic felids appear to have an AB blood group system similar to that described in domestic cats. Cross-matching of donor and recipients using standard techniques is important before the administration of transfusions or blood products.^36^
Minimum husbandry guidelines for keeping small (weighing less than 10 kg) and large felids in captivity are available through the Association of Zoos and Aquariums (AZA, www.aza.org) and include recommendations on minimum size specifications, barrier height and width, temperature, humidity, lighting, ventilation, interindividual distances, and sanitation. Additional enclosure features recommended may vary by species and include a vertical component, elevated resting platforms, a heat source, shade, logs or wooden posts to sharpen claws, a visual barrier for cats to hide behind, a den or secure area, varied topography, water features for bathing and swimming, and a shift or secondary holding area to safely move animals from their primary enclosure for cleaning, feeding, or medical procedures. To reduce the incidence of osteoarthritis and pad ulceration, large felids should not be housed for long periods on concrete. Natural substrates or platforms with some flexibility that may be cleaned and disinfected should be provided.^36^
Appropriate safety precautions must be designed into the enclosure and holding facilities to ensure employee and guest safety. These include, but are not limited to, using materials of sufficient strength, covering all openings with mesh or heavy glass, and ability to view all the cats within an enclosure from a safe position. Safety gates provide secondary containment if an animal escapes from the primary holding area. Flares, fire extinguishers, and sound generators may be placed throughout the work area to deter attacks. Keepers may be required to carry pepper spray and communication radios while working with large felids. Escape drills should be held routinely.^36^
The diet of wild felids varies, depending on their sizes. The large cats such as lions and tigers prey on very large mammals, with only two to three species making up the bulk of their diet. Medium-sized felids such as the puma, the snow leopard, and the leopard eat smaller prey but a larger number of different species. The small felids prey on mammals, birds, reptiles, amphibians, and insects. All wild cats hunt and kill their own prey, but some will scavenge opportunistically.^31^
Felids require a much higher proportion of protein in their diet compared with any other mammal, 12% for domestic cats compared with 4% for domestic dogs.^31^ In captivity, a formal nutrition program is recommended to meet the nutritional and behavioral needs of all species. Diets should be developed on the basis of the recommendations of nutritionists such as the European Association of Zoos and Aquaria (EAZA) Nutrition Group or the Association of Zoos and Aquarium (AZA) Nutrition Advisory Group (NAG). The AZA-NAG feeding program guidelines suggest a feeding strategy that includes providing a diet that is nutritionally balanced, that reasonably stimulates natural feeding behaviors, that the animal consumes consistently, and that meets the above criteria and is practical and economical to feed. Domestic cats generally require 80 to 90 kilocalories per kilogram of body weight (BW) per day (kcal/kg/day) to meet metabolic requirements. Diet quantity needs to be altered on the basis of the animal's body condition, life stage, and environmental factors. Amounts of feed may also be based on the National Research Council recommendation of 55 to 260 kcal/BW^0.75^ (Requirements for Domestic Dogs and Cats, National Research Council [NRC], 2006).
Most captive felids are fed commercial meat-based complete diets, so additional vitamin or mineral supplements, including calcium and taurine, should not be necessary. Techniques for proper thawing of frozen diets prior to feeding may be found in the U.S. Department of Agriculture (USDA) guidelines on handling of frozen and thawed meat and prey items fed to captive exotic animals (http://www.nal.usda.gov/awic/pubs/meatprey.pdf). Commercial diets may be supplemented with good-quality carcasses or whole-prey items. If muscle meats or organ meats make up the bulk of the diet, additional supplementation, including calcium, may be necessary. The majority of felids are able to handle the large concentrations of microorganisms present in raw meat. However, guidelines of appropriate bacterial concentrations in received commercial products need to be established for each institution, and commercial products should be tested on a regular basis. Bones may be offered to some species on fast days or twice weekly to promote oral health and to provide enrichment. Fresh water should be made available at all times.
The diet should be analyzed routinely for nutritional content, bacterial contamination, and the presence of foreign material. Several cases of ethylene glycol toxicity from contaminated meat have been reported. The source of the diet components also should be investigated to prevent the transmission of diseases such as spongiform encephalopathies.^36^
Many felids, particularly cheetahs, leopards, lions, and tigers, may be trained to cooperate with veterinary procedures. Behaviors that are particularly helpful include shifting into transport crates, obtaining regular body weights, close visual inspection and oral examination, measurement of temperature, heart rate, and blood pressure, administration of injections or other medications, positioning for abdominal ultrasonography for pregnancy monitoring, and collecting blood or other biologic samples.
Felids less than 10 to 15 kg in body mass may be restrained safely in a net for short procedures such as administration of injections. Heavy gloves may be used, but most felids are capable of biting through them. The majority of cats are darted or confined to a small area or restraint device and hand injected. Commercial squeeze cages are available for restraining and transporting larger felids and work best when incorporated into holding facilities (LGL Animal Care Products, Inc., Bryan, TX; Research Equipment Company, Bryan, TX).^36^
A variety of drug combinations have been used safely to induce anesthesia in felids (Table 47-2
). In general, smaller species require a higher dosage of anesthetics compared with larger species on the basis of kilogram of body weight, and free-living individuals may require higher dosages compared with their captive counterparts. The drug combinations most often used include a dissociative (ketamine or tiletamine), and an α2-agonist (xylazine, medetomidine, or dexmedetomidine), benzodiazepine (diazepam, zolazepam, or midazolam), opioid (butorphanol), or a combination of these. These drugs may be antagonized with yohimbine (0.04 to 0.3 milligram per kilogram [mg/kg], intramuscularly [IM] or intravenously [IV; slow]), atipamezole (0.1 to 0.45 mg/kg, IM), naltrexone (0.05–0.25 mg/kg, IM or IV), and flumazenil (0.01–0.02 mg/kg, IV or IM). Tiletamine and zolazepam (Telazol, Fort Dodge, Fort Dodge, IA) may be used safely in many felids but should be used with caution in tigers. Adverse reactions, including death and neurologic disease (seizures, ataxia), have been anecdotally reported; but controlled studies are lacking. Regurgitation or vomiting during induction or recovery may occur when α2-agonists are used. Food should be withheld from adult felids for 12 to 24 hours and water for several hours prior to anesthesia to decrease the chances of regurgitation and aspiration during induction and recovery. Species-specific protocols have been reported.5, 10, 18, 28, 29, 38
TABLE 47-2Combinations of Injectable Anesthetic Agents Used in FelidsGeneric NameDose (mg/kg)RouteAntagonistCommentsKetamine0.2–2.0IV or IMN/ANot recommended if used alone, best for supplementation or maintenance of anesthesiaKetamineXylazine3.0–10.00.3–1.0IMN/AYohimbineMay need to use higher dosages than those listed for small felidsKetamineMedetomidine (or dexmedetomidine)2.0–6.00.03–0.07 (0.015–0.035)IMIMN/AAtipamezoleSupplements may be needed after 45–50 minutesKetamineMidazolam5.0–10.00.1–0.3IMIMN/AFlumazenilUse in small felids or debilitated catsFlumazenil may not be necessaryKetamineMidazolamButorphanol3.0–5.00.1–0.30.1–0.4IMIMIMN/AFlumazenilNaltrexoneUse in small felids or debilitated catsNot recommended for healthy large felidsFlumazenil may not be necessaryTiletamineZolazepam1.6–4.2 or up to 11.0 in small felids (combined)IMN/AProlonged recoveryUse with caution in tigersCan reduce dosage by adding ketamine or medetomidineMedetomidine (or dexmedetomidine)ButorphanolMidazolam0.03–0.04 (0.015–0.02)0.1–0.40.1–0.3AtipamezoleNaltrexoneFlumazenilSpontaneous recoveries after 40–50 minutes Supplements needed for procedures >30 minutesFlumazenil may not be necessaryKetamineMedetomidine (or dexmedetomidine)ButorphanolMidazolam1.0–2.00.03–0.04 (0.015–0.02)0.1–0.40.1–0.3IM or IVIMIMIMN/AAtipamezoleNaltrexoneFlumazenilKetamine may also be given intravenously soon after inductionMay get spontaneous arousalFlumazenil may not be necessaryIV, Intravenously; IM, intramuscularly; N/A, not applicable; dosages for antagonists listed in text of chapter.
Anesthesia may be maintained with supplemental ketamine (IV or IM), propofol (IV), or inhalant anesthesia (sevoflurane, isoflurane, or halothane). Rapid administration or high doses of ketamine (IV) may induce seizures. Rapid administration of propofol (IV) may result in apnea. Supplemental oxygen is recommended when using injectable anesthetic agents. This may be delivered through the nares, via a face mask, or through endotracheal intubation. Endotracheal intubation is strongly recommended, especially for procedures lasting more than 30 minutes.
Additional anesthetic complications include hypoxia, hypoventilation, hyperventilation, apnea, hypotension, hypertension, bradycardia, arrhythmias, seizures, hypothermia, hyperthermia, and cardiac arrest. Arousal may occur after 40 to 50 minutes when medetomidine is used as the primary anesthetic drug in combination with low doses of ketamine or with a combination of midazolam and butorphanol. This may occur with few premonitory signs, so the clinician must be prepared by having intravenous ketamine or propofol readily available or have an inhalant anesthetic available to maintain anesthesia. A recovery crate should be available in the same room where the procedure is performed if the animal has been removed from its enclosure. This greatly improves safety if there is spontaneous arousal of the animal or a rapid recovery is needed.
Venipuncture sites are similar to those of domestic felids. Blood samples may be obtained from the medial and lateral saphenous, jugular, cephalic, or femoral veins. Lateral tail veins may be accessed in larger felids and are located at the 2 o'clock and 10 o'clock positions. This is a particularly useful site if the cat is confined in a squeeze cage. Reference ranges for hematologic and biochemical values for a variety of captive felid species are provided by the International Species Information System (ISIS): Physiologic values in captive wildlife (ISIS, 2002; Apple Valley, MN).
Felids are susceptible to many infectious and noninfectious diseases. Table 47-3 lists several felid species and the common diseases observed in captivity. Some conditions in captive animals may have a genetic predisposition or may be precipitated by chronic stress. Stress causes a reduced immune response that increases susceptibility to infectious diseases and may be associated with noninfectious diseases such as gastritis and AA-amyloidosis in cheetahs. Stress also has an adverse effect on reproduction and results in a higher tendency for self-mutilation or overgrooming.^33^ Treatment modalities for the diseases below may be extrapolated from domestic feline medicine.TABLE 47-3Common Diseases for Select SpeciesSpeciesCommon Infectious DiseasesCommon Noninfectious DiseasesLion—Biliary cysts or tumorsSpondylosisLymphomaPyometraTiger—Biliary cysts or tumorsSpondylosisChronic renal diseaseJaguar—Ovarian and mammary cancerClouded leopard—Neoplasia especially pheochromocytomasCheetahHelicobacter* gastritisHerpesvirus dermatitisRenal secondary amyloidosisGlomerulosclerosisVeno-occlusive diseaseSnow leopardPapillomavirus associated squamous cell carcinomaVeno-occlusive diseaseFishing cat—Transitional cell carcinomaBlack-footed cat—Renal amyloidosis, gastrointestinal amyloidosis, or bothPallas' catToxoplasmosisHerpesvirus infection—*K. Terio, unpublished data.
Felids are susceptible to the same infections carried by domestic cats. They are also susceptible to diseases transmitted by other animals, for example, viral diseases such as canine distemper, rabies, and avian influenza; bacterial infections that cause tularemia (caused by Francisella tularensis) or tuberculosis (caused by Mycobacterium bovis); and protozoal diseases such as toxoplasmosis (caused by Toxoplasma gondii).6, 7, 9, 16, 22, 35 Many infections are zoonotic; therefore, good hygiene practices are essential when working with felids. It is also very important to limit exposure of captive felids to feral and domestic cats and dogs, free-living carnivores, bats, rodents, and other small mammals. The common viral diseases in felids are summarized in Table 47-4 . Helicobacter gastritis may be a significant bacterial infection that results in regurgitation, vomiting, weight loss, and ill thrift. Although all felids may be affected, the clinical disease is most often observed in cheetahs. Management of this condition is well documented in the literature. Additional bacterial diseases include those caused by Mycoplasma spp. and Chlamydophila psittaci, which are part of the feline respiratory disease complex, and enterocolitis caused by Campylobacter spp. Salmonella spp. may cause disease but is often passed in the feces of asymptomatic animals secondary to a raw food diet. All felids are susceptible to infections by dermatophytes, especially Microsporum canis and M. gypseum. Treatment with griseofulvin resulted in toxicity with bone marrow suppression and death in cheetahs.^36^ Coccidioidomycosis (caused by Coccidioides immitis) has been reported in nondomestic felids in regions of the world where this pathogenic fungus resides in the soil (southwestern United States and northern Mexico). Bovine spongiform encephalopathy (BSE) has been reported in felids in Europe.^27^ The cats had been fed cattle carcasses or animal products, including blood and bone meal produced in BSE endemic areas.TABLE 47-4Selected Viral Diseases of FelidsDiseaseEtiologyEpizootiologySignsDiagnosisManagementFeline panleukopenia virus (FPV)ParvovirusHighly contagious virus shed in all secretions and excretionsShed in feces up to 6 weeks after recoveryIllness lasts 5–7 daysMortality is highest in cats <5 months of ageCan be subclinicalPeracute cases referred to as fading kittens Acute cases show fever, depression, anorexia, and dehydrationVomiting and diarrhea may be presentPresumptive diagnosis based on panleukopeniaConfirm by demonstrating FPV antigen in fecesTest kits for canine parvovirus antigen may detect FPV antigen during the acute phaseVirus is resistant to inactivationCan survive >1 year in a suitable environmentVirus is inactivated by 6% household bleach (sodium hypochlorite)Vaccination using inactivated or killed virus recommendedLate pregnancy booster with killed vaccine recommended for cheetahsFeline rhinotracheitis or feline herpes virus (FHV)Feline herpesvirus IHighly contagiousVirus shed in saliva and ocular and nasal secretionsEasily spread by fomitesHigh morbidity, low mortalityCheetahs and Pallas' cats very susceptibleOften self-limiting and may resolve in 14–28 daysCan have co-infections with calicivirus, Chlamydophila psittaci, Mycoplasma spp., or bothSerous ocular discharge, conjunctivitis, blepharospasm, sneezing, and nasal dischargeSecondary bacterial infections may occurKeratitis may be seen, especially in kittensUlcerative dermatitis is common in cheetahsKittens may develop acute severe infections that lead to blindness or pneumoniaPresumptive diagnosis based on clinical signs, especially in cheetahs^40^ Swabs of conjunctiva, nasal, or oropharyngeal region for viral isolation (VI), polymerase chain reaction (PCR), or fluorescent antibody (FA)Immunohistochemical staining (IHC) or VI of tissuesSkin lesions may respond to cryotherapyUse of modified-live virus vaccines may induce the disease in nondomestic felidsOnly killed vaccines should be usedVaccination will not prevent infection but may decrease severityCats may become chronic carriers with intermittent shedding of virusVirus viable in environment for 72 hours after a shedding animal has been removedFeline calicivirus (FCV)Calicivirus^13^Highly contagiousVirus is shed in saliva and ocular and nasal secretionsCan also be spread by fomitesHigh morbidity, variable mortalityUncomplicated cases may resolve within 2 weeksCan have co-infections with herpesvirus, Chlamydophila psittaci, Mycoplasma spp., or bothSneezing, ocular and nasal discharge, and oral ulcers of the gingiva and tongueCan have pulmonary involvementSecondary bacterial infectionsOropharyngeal and conjunctival swabs of lesions for VI or real time reverse transcriptase PCR (qRT-PCR)Affected tissues for VI, qRT-PCR, IHC, or FAUse of modified-live virus vaccines may induce the disease in nondomestic felidsOnly killed vaccines should be usedVaccination will not prevent infection but may decrease severityVirus may survive up to 14 days on inanimate objectsRecovered animals may shed virus for months to yearsFeline coronavirus (FCoV) has two feline enteric coronavirus (FeCV), which infects the intestines, and the fatal feline infectious peritonitis virus (FIPV), which causes the disease feline infectious peritonitis (FIP)Coronavirus group 1Highly contagious among cats in close contactShed in feces of healthy catsShedding frequency varies from rare, intermittent, or persistent (best documented in cheetahs)Also reported in domestic cats, African lion, mountain lion, leopard, lynx, jaguar, European wildcat, sand cat, serval, caracal, and Pallas' catTransmitted by the fecal–oral route through direct contact or by fomitesSigns of FeCV can last 2–5 daysThe more severe FIP form is fatalMost deaths in domestic cats 3–16 months of age, uncommon after 5 yearsFeCV may be subclinical or may result in mild diarrhea that may be chronicSigns of FIP are fever, vomiting, diarrhea, and modified transudate effusions with high protein content. Development of FIP depends on two host virus mutation and low immunityFIP is not considered directly transmissible from cat to cat but outbreaks with increased mortality from FIV do occur in groups of unrelated domestic cats in shelters and catteriesShedding is detected by PCR of feces (three samples a month apart recommended for domestic cats, 5 samples within 30 days for cheetahs)^11^ Serologic tests do not differentiate between the two forms of the diseaseTiters >1 : 1600–3200 are suggestive of FIPFalse-positive titers may result in cats recently vaccinated (<4 months)Antibody testing is only useful as a screening tool to detect presence or absence of virus in a collection, recognize potential carriers or shedders when introducing new cats into an antibody-negative collection, and as an aid in the clinical diagnosis of FIPIHC on effusions or lesions is the current gold standard for FIP diagnosisCats that recover remain carriersPrevention is by limiting exposure to infected cats and their fecesMost cats develop an immune response when exposed and recoverVaccination results in variable efficacy and is not sufficient to control outbreaks of FIPVirus is readily inactivated by detergents and disinfectants but may survive up to 2 months in a dry environmentFeline immunodeficiency virus (FIV)LentivirusVirus shed in saliva. Primary mode of transmission is bitesMore prevalent in malesMost infections reported in older captive animalsReported in free-living puma and bobcatsEndemic in certain lion populations in eastern and southern AfricaMost often asymptomatic in nondomestic felids, but may include oral cavity disease, anemia, skin infections, weight loss, vomiting, diarrhea, or neurologic diseasePresence of serum antibodies (Western blot or enzyme-linked immunosorbent assay [ELISA])Western blot available for domestic cats, cougars, and African lions and may be more sensitive than domestic cat FIV based ELISAIsolation of virus from blood cells and salivaPCR developed for lionsRoutine testing recommendedSegregate positive catsInfection is lifelongVaccination available, but may not be necessary if able to prevent exposure to feral catsFIV is labile outside the host and is readily inactivated by common disinfectantsFeline leukemia virus (FeLV)RetrovirusVirus may be found in saliva, tears, urine, semen, vaginal fluids, and fecesOronasal contact with saliva or urine is the most common mode of transmissionVertical transmission possibleTransmitted to nondomestic cats by contact with or ingestion of domestic feral catsPersistently viremic cats develop fatal diseasesReported in cheetah, Iberian lynx, leopard cat, European wildcat, and cougarTypically asymptomatic and transient in nondomestic felidsInfected cats may experience a prolonged period of clinical latencyImmunosuppression, anemia, chronic inflammatory conditions, enlarged lymph nodes, secondary infections, persistent fever, lymphoid or myeloid tumors, or reproductive problemsProgressive infection or regressive infection are the outcomes reported in domestic catsSerologic antigen tests available include immunofluorescent antibody (IFA) or ELISA, false-positives and false-negatives occurConfirmatory test with VI or real time PCR (qPCR) (blood, bone marrow, and tissues)Routine testing recommendedSegregate positive catsSome cats are able to clear the virus, but others remain persistently viremicVaccination available, but may not be necessary if able to prevent exposure to feral catsVirus unstable outside host, but may survive for up to a week in dried biologic depositsVirus inactivated by detergents and common disinfectantsFeline papillomavirusPapillomavirusSpecies and site-specific infectionsReported in domestic cats, Asian lion, bobcats, Florida panther, clouded leopard, Canadian lynx, and snow leopards15, 30 Proliferative lesions in the skin or oral cavityPapillomas in snow leopards may undergo malignant transformation to squamous cell carcinomaPCR of excised lesion developed for snow leopardsRoutine screening for skin and oral lesionsRemove using surgical excision, laser surgery, or cryosurgery and prevent virus from contacting adjacent tissueVaccine for snow leopards under developmentCanine distemper virus (CDV)MorbillivirusHighly contagiousAerosolization of respiratory exudate or contact with other body excretions and secretionsVaccine-induced disease using modified-live virus reported in other carnivores but not felidsNot all felids develop diseaseMortality reported in captive lions, tigers, leopards, and a jaguar and in free-living lions, lynx (Canadian and Iberian), and bobcatsInfections may be subclinical or fatal. Respiratory, gastrointestinal, integumentary, and central nervous system signsHyperkeratosis of foot pads and myoclonusImmunoflourescence of conjunctival scrapings, or buffy coat smearsPaired sera by viral neutralization or IFA test. ELISA may detect immunoglobulin G (IgG) and IgM. Antibodies in cerebrospinal fluid (CSF) may be more rewarding than serumViral isolation, qRT-PCR, or IHC of tissuesExclude potential reservoirs (domestic dogs, raccoons)Vaccinate susceptible felids using recombinant vaccineRabies virusLyssavirusBites of infected animals (carnivores or bats)Contact of saliva with mucous membranes or open woundsAerosol in an enclosed environmentFatal disease within 2–7 days of illnessSalivation, abnormal behavior (aggression) or neurologic signs (paresis, seizures)Recommend euthanasia and shipment of head to a qualified laboratory for FA or VISerology used to monitor response to vaccinationReportable diseaseZoonotic diseaseVaccination recommendedLimit exposure to wild carnivores and batsLyssaviruses are not stable in the environment and are inactivated by common disinfectantsAvian influenza (AI)Type A influenza virus, subtype H5N1, further classified as highly pathogenic (HPIA) or low pathogenic (LPAI) according to its virulence in poultryTransmission occurs through the respiratory and oral routesReported in domestic cats, tigers, leopards, and Asiatic golden catsDirect contact with affected birds or were fed raw poultryCat-to-cat transmission has been documentedFever, respiratory distress, severe pneumonia, rapid deathNeurologic signs (circling, ataxia) may be observedSubclinical infections also occurOropharyngeal, nasal and/or rectal swabs or fecal samples for RT-PCR and/or VIPostmortem samples of lung and mediastinal lymph nodes for VI or RT-PCRReportable diseaseZoonotic diseaseEach institution should have a highly pathogenic avian influenza (HPAI) preparedness protocolDo not feed poultry products to nondomestic felids especially in countries with known or potential outbreaksVirus is sensitive to standard disinfectantsVirus may persist in cool aquatic environments (>100 days) or indefinitely if frozen
Significant protozoal infections include coccidiosis (caused by Eimeria spp.) and giardiasis (caused by Giardia spp.). These may result in severe enteritis, especially in kittens. Many healthy felids are seropositive for Toxoplasma gondii antibodies. Kittens and immunocompromised animals may develop acute generalized toxoplasmosis. High neonatal mortality in Pallas' cats from toxoplasmosis has hampered conservation efforts. Prophylactic treatment of breeding animals and neonates is recommended. Cytauxzoon felis is a protozoan that infects blood cells.4, 12, 24, 41 It is transmitted by the lone star tick (Amblyomma americanum). The natural reservoir is the bobcat that becomes a persistent carrier after developing mild or subclinical infection. The disease may be fatal in untreated domestic cats, and a fatal infection in a white tiger has been reported. Babesia felis, originally identified in wild cats from Sudan, has been reported sporadically from various countries.1, 4, 20, 24, 41 South Africa appears to be the only country where feline babesiosis is a significant clinical entity. The infection is assumed to be tickborne, but the vector has not been identified. Concurrent infections may contribute to clinical disease. Ascarids (Toxocara and Toxascaris) are common in captive animals and may be difficult to eliminate. The ova are highly resistant in the environment. Repeated testing and treatment of animals while in quarantine may prevent the introduction of ascarids into exhibits. In chronically infected cats, routine treatment may be needed to limit worm burdens. Disease caused by Dirofilaria immitis (heartworm) has been diagnosed in a black-footed cat.^8^ Prophylactic treatment is recommended in endemic areas.
Noninfectious diseases are often related to husbandry, diet, or breeding management. Obesity is a significant cause of morbidity in captive felids and may predispose to metabolic conditions such as diabetes mellitus. “Stargazing” has been associated with hypovitaminosis A in young lions.^39^ Common dental diseases include gingivitis, calculus accumulation, fractured canines, and fractured molars. Focal palantine erosions have been reported in 15 wild and captive species but is more prevalent in captive animals.^42^ Degenerative joint disease and spondylosis are common in geriatric felids, especially the larger species.^19^ Chronic renal failure is common in geriatric felids.^37^ Renal amyloidosis is particularly common in black-footed cats and cheetahs.^34^ Veno-occlusive disease is a slowly progressive liver disease, which results in the fibrosis of the hepatic sinusoids or veins and eventually occlusion of the vessels. It has been reported in cheetahs and snow leopards. Myelopathy has been diagnosed in cheetahs in Europe, and leukoencephalopathy has been diagnosed in cheetahs in North America.^27^ Pyometra has been reported in lions, tigers, and a leopard.^21^ Lions seem to be at an increased risk for developing pyometra compared with other species. Ovariohysterectomy may be warranted in nonbreeding female lions. The use of progestin-based contraceptives has been associated with endometrial hyperplasia and uterine and mammary adenocarcinoma. Nonsteroidal anti-inflammatory drugs (NSAIDs) should be used cautiously. Aspirin, acetaminophen, and ibuprofen may cause toxicity, and caution is advised when using other formulations such as carprofen, deracoxib, naproxen, etodolac, and indomethacin. Meloxicam has been used in nondomestic felids with no reported adverse effects.^25^ Barbiturate and thiafentanil toxicity has been reported in felids fed carcasses of animals that had been euthanized or anesthetized with these agents.
Felidae exhibit a high degree of variability in estrus cycle characteristics, including duration. All felids have induced ovulations, but some have spontaneous ovulations. The occurrence varies across species and between individuals within a species. It occurs frequently in clouded leopards, fishing cats, and margays but rarely in cheetahs, tigrinas, and ocelots. Pallas' cats are very sensitive to photoperiod; tigers, clouded leopards, and snow leopards are moderately affected; and ocelots, tigrinas, margays, lions, leopards, and fishing cats are not influenced by photoperiod. Clouded leopards and Pallas' cats exhibit seasonality in gonadal activity, but margays, cheetahs, and oncillas cycle year round. Suppressed ovarian activity and estrus occurs in cats housed in a group (e.g., cheetahs). All cats have a zonal placentation.2, 3
Many felid species do not reproduce well in captivity. Assisted reproductive techniques such as artificial insemination are important for managing zoo species.14, 32 This technique is challenged by the variable responses to ovulation induction therapies. Fecal cortisol may be measured and reflects the adrenal status and stress levels of animals managed under different husbandry conditions. These data improve the understanding of how social and environmental factors affect the well-being and reproductive fitness of animals. Contraception of felids is sometimes necessary to facilitate management needs or because of concerns over the health of the animals.
The AZA Wildlife Contraception Center (2012) makes the following recommendations for felid 1.Gonadotropin-releasing hormone (GnRH) agonists are considered the safest reversible contraceptives, but dosages and duration of efficacy are not well established for all species (caution has to be exercised in their use in lions because of prolonged response with questionable reversibility at certain doses). Side effects are generally similar to those associated with gonadectomy, especially the potential for weight gain.•Suprelorin (deslorelin) implants (female or male)•Lupron® Depot injection (female or male) 2.Ovariohysterectomy or ovariectomy (females) or castration (males) may be considered if permanent sterilization is an option.3.In felids, progestin contraceptives are associated with progressive uterine growth that may result in infertility, infections, and sometimes uterine cancer; mammary tissue stimulation may result in cancer. If a progestin is used, treatment should only be short term and should be started before any signs of proestrus. Progestins should not be used in pregnant animals.
Routine, periodic, or opportunistic health examinations should be part of the preventive medicine protocol for felids. Many institutions perform examinations under anesthesia every 2 to 4 years, but this frequency is dependent on the individual animal's age, life stage, health status and medical history, and species and the resources and philosophy of the holding institution. Animals that are trained as part of an operant conditioning program may be visually examined, have blood collected, and receive vaccinations without anesthesia or the need for remote delivery equipment. These examinations may be substituted for one under anesthesia in many cases if dental examination and prophylaxis and thorough palpation are deemed unnecessary. Routine health examination should include an assessment of body condition, body weight determination, complete physical examination, evaluation for ectoparasites (ticks, fleas, flies), blood collection for complete blood cell (CBC) count with manual differential and hemoparasite examination, serum biochemical panel, and serum for banking. Recommended serologic tests include those for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV). Additional tests that may be necessary based on species, geographic location, or potential for disease exposure include those for Toxoplasma gondii, feline coronavirus (FCoV), and canine heartworm (Dirofilaria immitis). Serologic tests to monitor response to vaccination may be useful for feline parvovirus (FPV), especially in cheetahs, and for the rabies virus.^26^ Vaccine titers for feline herpesvirus (FHV) or feline calicivirus (FCV) are predictive of protection, except for highly susceptible species such as cheetahs. If a cheetah has a low or negative titer to FPV or FHV, more frequent vaccination should be considered. Urinalysis should be performed, if possible. Survey radiography and abdominal ultrasonography may be valuable if resources are available to establish reference information or to diagnose occult conditions. Fecal examination for parasites is recommended at this time if a regular program for parasite surveillance (once to twice yearly) is not already in place.
Vaccination protocols for carnivores have been recently reviewed.^17^ Vaccines recommended are divided into core vaccines (recommended for all felids) and noncore vaccines (optional, depending on the specific disease risk of the species and institution, not generally recommended). Vaccine-associated sarcomas have rarely been reported in nondomestic felids. Because of the lack of serologic studies and difficulty in performing challenge experiments on nondomestic felids, specific information on the length of protection from vaccination is lacking. Specific recommendations for vaccination frequency cannot be made, although most institutions vaccinate adults every 1 to 3 years using the core vaccines. Core vaccines include rabies (killed, e.g., Imrab 3, Merial; or recombinant canarypox-vectored, e.g., PureVax Rabies, Merial) and feline panleukopenia, calicivirus, herpesvirus (killed, e.g., Fel-O-Vax PCT Plus, Boehringer Ingelheim). Noncore vaccines that should be considered only in species at risk include canine distemper virus (CDV) (recombinant canarypox-vectored, PureVax Ferret Distemper, Merial) and FeLV (killed).
Animals that are being shipped to a new institution should be evaluated using the procedures described earlier. The preshipment examination and test results allow the receiving institution to discuss disease risks associated with the acquisition in advance with animal managers. Results should be compared with the results of the quarantine examination at the receiving institution. Examination and testing during the quarantine period provides vital information following the stress of shipment and change in environment. Biologic samples should be stored for future testing or studies, as needed.
Quarantine should occur in an off-exhibit area away from other animals, especially other carnivores (collection and free-living). Dedicated tools and equipment and personal protective equipment (removable outer wear, gloves) should be used. If dedicated footwear is not an option, a footbath may be used. Quarantine period for all felid species is typically 30 days, but this may vary depending on the source of the cat or institutional practices.