Procyonids and Viverids


Chapter 49

Procyonids and Viverids



Edward Ramsay



Biology


Members of the families Procyonidae and Viveridae are small- and medium-sized, mainly nocturnal members of the order Carnivora. Although the two groups are taxonomically distant, they share susceptibilities to several important infectious diseases and are handled similarly by veterinarians. Only a few procyonid and viverid species are commonly exhibited by zoos or kept as pets.


Procyonids are arctoid or canoid carnivores, more closely related to canids than felids; all but one species, the red panda, are native to the temperate and tropical New World (Table 49-1). Raccoons are the best known and most widely distributed member of this family. In addition to their distribution in their native North and Central Americas, feral raccoon populations have been established in Japan and Eurasia. The raccoon has been the best studied member of the Procyonidae family because of its almost ubiquitous presence in a wide variety of rural and suburban habitats.



Other members of family Procyonidae are the arboreal kinkajous and olingos, the diurnal coatimundis, and the secretive ringtail cats. Red pandas are an exceptional species in this family—they are the only strictly herbivorous members of the family, and their taxonomy has been a subject of debate. The species has been variously assigned to its own family (family Ailuridae), grouped with the giant panda in the family Ailuropodidae, and assigned to the family Procyonidae. It is the only procyonid native to the Old World, living in the mountainous regions of Nepal, northern Southeast Asia, and central China.


Members of the family Viveridae are feloid carnivores; they are more closely related to felids than to canids and are predominantly forest dwellers. The family contains approximately 36 genera and 70 species, and most are small and nocturnal. They are widely distributed in the temperate and tropical regions of Eurasia and throughout Africa (Table 49-2). Mongooses have been introduced to the Pacific and Caribbean islands for pest control but are now considered a detrimental introduced species. Few members of this family are routinely exhibited outside of their range states. The diurnal, social meerkat is the most widely exhibited viverid species. Banded and dwarf mongooses are also popular exhibit animals, mostly in Europe. The binturong is the largest viverid and is frequently kept in captivity.




Unique Anatomy and Physiology


Most procyonids and viverids have elongated, slender bodies and long tails. Kinkajous and binturongs have prehensile tails. Both families are anatomically conservative, quadripedal mammals, with most species having five digits per limb. Several species in both families have semi-retractable claws. The digitigrade viverids have a “waltzing trot” gait, whereas plantigrade species such as the binturong have a more shuffling gait.


The soles of red pandas’ feet are covered with hair and possess a central pad scent gland that may be mistaken for a skin lesion. The red panda forelimb also possesses an enlarged radial sesamoid bone, termed the “panda’s thumb.” This bone is slightly movable and is used to grasp and hold bamboo, their principle food.


Kinkajous have a long, narrow tongue adapted to eating fruit and honey. Procyonids, including the red panda, lack a cecum, whereas the viverids, with the exception of Nandinia spp., have a cecum. Male viverids possess a baculum, and gender identification is not difficult in these animals, with the exception of the immature female fossa (Cryptoprocta ferox). The young female fossa undergoes a period of masculination during when the animal has an elongated clitoris, which contains an os clitoris, and may have scrotumlike swellings. The os penis disappears at maturity.


A notable anatomic feature of the viverids is their enlarged perianal scent glands. These glands vary in size and complexity among the species. The glands’ secretions are used to mark territories and may also be used as a defense. The perianal glandular secretion from the genera Civetticitis, Viverra, and Viveriricula is known as “civet” and is used in the manufacture of perfume and medicines.



Special Housing Requirements


All procyonid and most viverid species are good climbers and should be housed in enclosures with climbing structures. Most are hardy animals and adapt to a variety of climates, but the tropical species should be provided with indoor enclosures and heat during harsh winters. The red panda is native to high mountain habitats, so enclosures should be provided with cool areas or air conditioning in regions with hot, humid summers. Pregnant and parturient red pandas should have a variety of denning boxes, as some females frequently move cubs between boxes.


Many mongooses are good burrowers and will spend considerable time digging. Natural substrate should be provided for these species.



Feeding


Procyonids are generally omnivorous, eating a wide variety of food items. Commercial dog kibble is the basis of most captive raccoon diets and is given along with a variety of fruits and vegetables. Obesity caused by overeating and lack of exercise is also a common problem in captive raccoons. The kinkajou is mainly frugivorous but also eats insects and small vertebrates. The ringtail cats are the most carnivorous of the procyonids, and the red panda eats almost exclusively bamboo in the wild. In captivity, red pandas are typically fed a mixture of commercial “primate” biscuits, fruits, vegetables, and bamboo. If at all possible, bamboo should make at least 50% of the diet. Viverids are mostly carnivorous but, depending on the species, will eat varying amounts of vegetable matter. The binturong is the most frugivorous member of this family.



Restraint and Handling


Captive procyonids and viverids may be trained to enter tubes or small kennels for capture and transport. Some small species may be briefly restrained with nets and heavy gloves, but chemical restraint is necessary to safely perform physical examinations and diagnostic procedures (Figure 49-1). The largest issue surrounding restraint of meerkats, and possibly other small, social viverids, is aggression associated with reintroduction of animals into a group, especially if they had been kept separate from the group overnight. Several strategies have been employed, including ensuring return of an immobilized individual to the group the same day, immobilizing several members of the colony at the same time (not just the animal requiring medical attention), and dusting animals to be reintroduced and others in the colony with talcum powder.




Chemical Restraint, Anesthesia, and Surgery


Most studies of procyonid and viverid immobilization have used a combination of a dissociative agent (ketamine or tiletamine) and either an α2-adrenergic agonist (xylazine or medetomidine) or a benzodiazepine (zolazepam) injected intramuscularly (Table 49-3). With the disappearance of medetomidine from the North American market, dexmedetomidine has been substituted into protocols at approximately 50% the dosage of medetomidine. The wide range of dosages listed for immobilizing members of both families most likely reflects differences in immobilization of captive and free-living (trapped) animals.



Chamber induction with isoflurane in oxygen is also a widely used induction protocol for all species weighing less than 10 kilograms (kg). Anesthesia is typically maintained by inhalation agents such as isoflurane following endotracheal intubation. Surgical procedures are performed similar to protocols used for domestic carnivores.



Diagnostics


Physical examination, radiology, and other diagnostic procedures are similar to those performed in domestic carnivora. Blood samples may be obtained from the jugular, cephalic, femoral, or saphenous vein, but obtaining blood samples from obese individuals may be difficult. Hematology and clinical chemistry values for procyonid and viverid species are generally similar to those for dogs and cats, with a few exceptions (Tables 49-4 and 49-5). Red pandas commonly have lower serum or plasma sodium concentrations (130–135 milliequivalents per liter [mEq/L]) and chloride concentrations (100–105 mEq/L) than those seen in domestic carnivores. In the author’s experience, healthy red pandas also may have low hematocrits (30%–35%). Enzyme activities for aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and creatinine kinase (CK) are generally greater in procyonids and viverids than those observed in domestic carnivores (see Table 49-5). The cause for this is unclear but may be a result of the procyonids and viverids being restrained and immobilized prior to the blood samples being obtained.



TABLE 49-4


Hematology of Selected Members of the Families Procyonidae* and Viveridae














































































































Raccoon Kinkajou Red Panda Slender-Tailed Meerkat Binturong
RBC (106/µL) 8.74 ± 1.2 8.76 ± 2.6 8.49 ± 1.2 9.56 ± 1.5 7.49 ± 1.5
Hemoglobin (g/dL) 12.2 ± 1.5 14 ± 2.8 12.3 ± 1.7 13.0 ± 1.9 16.4 ± 7.4
Hematocrit (%) 36.8 ± 5.4 40.5 ± 8.1 39.3 ± 5.1 41.0 ± 6.2 45.9 ± 8.5
MCH (pg/cell) 14.2 ± 1.4 17 ± 4.4 14.9 ± 1.7) 13.7 ± 1.4 21.7 ± 1.9
MCHC (g/dL) 32.9 ± 2.2 35.3 ± 3.0 31.6 ± 3.2 31.6 ± 2.7 36.5 ± 15.3
MCV (fL) 42.8 ± 5.2 48.8 ± 14.2 46.3 ± 5.2 43.5 ± 3.4 62.9 ± 7.8
WBC (103/µL) 9.84 ± 4.1 8.41 ± 3.1 7.42 ± 3.0 6.65 ± 3.6 12.7 ± 5.0
Segs (103/µL) 4.84 ± 3.7 4.76 ± 2.3 3.79 ± 2.5 4.39 ± 3.0 7.65 ± 4.0
Bands (103/µL) 0.44 ± 0.7 0.08 ± 0.01 0.16 ± 0.5 0.12 ± 0.12 0.11 ± 0.36
Lymphocytes (103/µL) 3.94 ± 2.0 2.85 ± 1.5 3.1 ± 2.0 2.07 ± 1.4 3.68 ± 2.3
Monocytes (103/µL) 0.33 ± 0.3 0.27 ± 0.2 0.27 ± 0.3 0.22 ± 0.2 0.57 ± 0.5
Eosinophils (103/µL) 0.78 ± 0.5 0.64 ± 0.7 0.15 ± 0.2 0.13 ± 0.1 0.41 ± 0.6
Basophils (103/µL) 0.06 ± 0.04 0.1 ± 0.06 0.13 ± 0.11 0.08 ± 0.01 0.05 ± 0.14
Platelet count (103/µL) 470 ± 160 449 ± 76 576 ± 189 389 ± 169 333 ± 115

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Aug 27, 2016 | Posted by in EXOTIC, WILD, ZOO | Comments Off on Procyonids and Viverids
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