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Ground Squirrels Marie Kubiak

1.1 Introduction are inquisitive and highly active so enclosures should be secure – such as large aviaries with narrow spaced mesh. Nest Ground squirrels make up the subfamily of Xerinae, within boxes should be provided (at least one per animal) with hay the Sciuridae (squirrel) family and include a variety of substrate and branches, tunnels, hides and wheels ­provided well-known species such as the groundhog and marmot. for enrichment and to encourage activity. Chipmunks will The species within this subfamily that are more commonly chew plastics, wood, wires and other ­materials and this should kept as pets, and are covered in this chapter, are prairie be taken into account when planning enclosure construction, dogs, Richardson’s ground squirrels and Siberian chip- and when toys or décor are added. They are omnivores and munks. Biological parameters for these species are included can be fed a rodent pellet diet but this should be supplemented in Table 1.1. with seeds, vegetables, insects, and hay. Food may be stored in substrate or nest boxes so it is important to check and clean enclosures thoroughly on at least a weekly basis to prevent 1.2 Husbandry spoilage. Fresh water should always be available and water bottles are generally accepted well. Free range access within a 1.2.1 Siberian Chipmunks house is not advisable due to potential for escape, injury, or damage inflicted to household possessions. In winter wild Siberian chipmunks (Tamias sibiricus) are squirrel-like chipmunks do not exhibit true hibernation but have fluctuat- rodents originating primarily from Northern Asia. Although ing torpor, with several days of dormancy followed by a period common in the pet trade in Europe in the late twentieth and of normothermia, activity, and feeding. In torpor their body early twenty-first century, in 2015 this species was added to temperature drops to around 5 °C and heart rate slows to EU Invasive Alien Species (IAS) Regulation (1143/2014), 4 beats/min. In captivity there is no drive for torpor as tem- resulting in a ban within the European Union on importation, peratures tend to remain stable through seasons and food is keeping, breeding, transport, trade, and accidental or inten- abundant. There is no evidence that absence of torpor has any tional release of this species, though an exemption is made for negative impact. animals to be transported for veterinary care. As such this ­species can only be kept by existingCOPYRIGHTED owners for their natural MATERIAL 1.2.2 Prairie Dogs lifespan, or under licence for medical, research, or­conservation purposes. At present these restrictions remain in place for the Prairie dogs (Cynomys spp.) are large, North American United Kingdom. Pet Siberian chipmunk numbers are declin- members of the squirrel family and have five recognised ing as animals reach the end of their life and no new animals species. Of these only the black-tailed prairie dog (Cynomys are able to be acquired or bred. Other species of chipmunks ludovicianus) is encountered with any frequency as a pet in may be legally kept but are extremely rare as pets. The Pallas the UK. Well-socialised individuals can make good pets but squirrel (Callosciurus erythraeus) and Fox squirrel (Sciurus even the tamest prairie dog can become aggressive during niger), both rarely kept as pets, have also been listed as­invasive their breeding season. species and are subject to the same restrictions. Captive animals require deep substrate to form their Chipmunks are terrestrial though have good climbing ­burrows as well as a large overground area for activity, ­capabilities and will use the full height of enclosures. They ­sufficient to enable a group of animals to be kept together.

Handbook of Exotic Pet Medicine, First Edition. Edited by Marie Kubiak. © 2021 John Wiley & Sons Ltd. Published 2021 by John Wiley & Sons Ltd. Companion website: www.wiley.com/go/kubiak/exotic_pet_medicine

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Table 1.1 Biological parameters (for animals not undergoing torpor).

Body Respiratory rate Heart rate Sexual Body weight Lifespan temperature (°C) (/min) (/min) maturity Gestation

Siberian Chipmunk 50–150 g 5–10 years 37–38 70–80 250–350 8–14 months 30–31 days (Tamias sibiricus) Black tailed-prairie dog 0.7–2 kg 7–10 years 35.3–39 40–60 200–318 2 yrs 30–35 days (Cynomys ludovicianus) Richardson’s Ground 0.4–0.6 kg 4 years 37.5–39.5 40–100 245–275 11 months 23 days Squirrel (Urocitellus richardsonii)

Enclosure size requirements have been detailed as increase body condition but can lead to obesity or disruption 2 × 2 × 2.5 ft (L × W × H) per animal (Pilny and Hess 2004) to normal intestinal function if fed in excess. but this should be regarded as an absolute minimum and 4 × 4× 2.5 ft would be considered more suitable as a mini- 1.2.3 Ground Squirrels mum to allow animals to display normal behaviour. An area of deep substrate should be provided to allow creation Ground squirrel species are uncommon as companion ani- of burrows and can be hay, shredded paper, or soil. Artificial mals though Richardson’s Ground squirrels (Urocitellus rich- burrows and shelters such as drain pipes or wooden boxes ardsonii) (RGS) are occasionally kept. This species is native can be provided for hide and sleeping areas. Cage bars to the grasslands of the Northern United States of America should be no further than 1 inch apart to prevent escape. and Southern Canada and do cross over territory with prairie An elevated observation shelf should be provided as prairie dogs. In the wild, female familial groups exist with solitary dogs are inquisitive and will often climb to investigate males only being tolerated during breeding. In captivity they activity in the surrounding area (Pilny and Hess 2004). can be maintained in social single-sex colonies or mixed sex Plastic should be avoided as it is likely to be chewed. colonies with males being neutered. Though destructive and Chosen toilet areas will be well defined allowing easy daily with a tendency to bite defensively, RGS tend to make good cleaning of urine and faeces and a litter tray can be placed companion animals with regular handling and interaction. in the chosen site. A warm room or supplemental heating Captive animals have similar requirements to prairie is necessary to provide temperatures of 20–22 °C as prairie dogs, though as a smaller species enclosures can be less dogs may enter torpor at cooler temperatures (Johnson- extensive, with 3 × 2 × 1.5 ft advised per animal. Cage bars Delaney 2006). Torpor is not obligatory in prairie dogs but should be no more than 0.75 inch apart. The observation is a facultative response to temperature drop and lack of shelf should not be placed more than 18 inches above the available food and water. Although body temperatures ground as RGS are not good climbers. Ambient tempera- reduce, they remain significantly higher than ambient tures of 18–25 °C are advisable but they are adapted to cooler environmental temperature at approximately 19 °C even in temperatures and will not enter torpor unless temperatures deep torpor bouts. These deep torpor bouts are interspersed drop to below 7 °C (Michener 1983). In the wild RGS are with periods of activity and normothermia when environ- obligate hibernators and will spend up to nine months of mental conditions improve (Lehmer et al. 2001). As torpor the year in true torpor, with body temperature dropping to is facultative there is no need to replicate the conditions in close to environmental temperature as heart and respiratory captivity and to date no adverse effects have been reported rates slow dramatically (Michener and Koeppl 1985). Brief with absence of torpor in prairie dogs. periods of around 12 hours of warming to normal body tem- Prairie dogs are hindgut fermenters and require a high perature occur during this torpor (Michener and Koeppl fibre intake to maintain intestinal health. Where a normal 1985). In captivity temperatures are stable and food is read- appetite is present, provision of a variety of grasses, hay, flow- ily available and torpor rarely occurs. These less harsh con- ers, herbs, fresh vegetables and leaves and occasional inverte- ditions aid overall longevity but the lack of torpor and high brates is appropriate (Orcutt 2005). Pelleted diets designed for metabolic rate all year round may be associated with higher rabbits or rodents can be convenient food source for owners rates of neoplasia seen in RGS in captivity. but should make up no more than 10% of the diet, with high RGS are omnivorous with their dietary requirements fibre material making up the majority of food provided. Seeds intermediate between prairie dogs and chipmunks. Seeds and grains can be offered in small quantities as treats or to should be limited to occasional treats to avoid obesity.

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1.3 Clinical Evaluation

1.3.1 History-Taking

A full review of husbandry is essential as inappropriate conditions are common causes of health concerns. Contact with other animals, diet, previous medical history, enclo- sure size and set-up, and reproductive status are all key information. It is prudent to ascertain familiarity of indi- vidual animals with handling before attempting restraint. For individual health complaints, the duration of symp- toms, number of animals affected, and any changes made to environment in the period preceding clinical disease should be ascertained.

1.3.2 Handling

Chipmunks are fast moving, adept at climbing and jump- ing, and rarely habituated to handling. It is often easiest to catch them in their enclosure or carry box with a small towel and gently grasp them around the neck and thorax with one hand for examination. Avoid restraining the tail as degloving injuries can result. Many prairie dogs and RGS are familiar with handling and are comfortable being restrained by owners. For more reluctant animals, firm restraint with one hand around the neck and one underneath the abdomen, or wrapping the patient in a towel may be necessary. Prairie dogs in particu- Figure 1.1 Female prairie dog. lar can inflict painful bites with their long incisor teeth and secure restraint is advised before any procedures are car- ried out.

1.3.3 Sex Determination

The shorter anogenital distance in female sciuromorphs is key for determining sex. Female prairie dogs have close association of the vulva and anus, male prairie dogs have a clear separation of at least 1 cm (Figures 1.1 and 1.2). Males will only have visible descended testes in breeding season and morphology and pelage does not vary between sexes. Adult male RGS tend to be larger than females, but ­otherwise sexing is carried out as for prairie dogs. Mature male chipmunks have testes descended for most of the year and the prepuce is well defined so sexing is more straightforward. In juveniles and in winter anogeni- tal distance is used to differentiate between sexes.

1.3.4 Clinical Examination

Clinical examination should be carried out in a systematic approach as for any species. Particular areas of focus include dental evaluation – with attention to incisor Figure 1.2 Male prairie dog.

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­structure and uniformity due to potential presence of elo- 1.4.2 Nutritional Support dontoma in prairie dogs and RGS, presence of wounds, For anorexic patients, a high fibre liquid feed designed for assessment of respiratory effort or noise, evaluation of herbivorous species such as rabbits is appropriate for joints (especially stifles) for swelling and reduced range of ­nutritional support, following manufacturers’ recommen- movement, and abdominal palpation for masses. Nail over- dations. A maximum of 10 ml/kg bodyweight can be growth and obesity are common findings. It is prudent to administered at a single feed. Syringe feeding is generally weigh animals at each visit and to be aware of seasonal tolerated well though nasogastric intubation should be variation in weight – males tend to lose weight during the considered for cases where extensive recovery periods are Spring breeding season and all animals gain weight prior to likely or orofacial disease affects feeding ability. expected hibernation in Autumn and subsequently lose this during winter torpor. It is useful for owners to keep records that document the typical weight changes of indi- 1.4.3 Fluid Therapy viduals through the seasons and previous maximum and minimum values. Maintenance fluid requirements for sciuromorphs are estimated to be 50–100 ml/kg/day, based on require- ments for similar sized rodent species (Lichtenberger 1.4 Basic Techniques 2007). Fresh water should be available in sipper bottles or bowls 1.4.1 Sample Collection at all times where animals are voluntarily drinking. Subcutaneous fluids are suitable for mild–moderately In prairie dogs the saphenous and cephalic veins can be dehydrated animals and 10–15 ml/kg can be injected as a used to collect small volume blood samples of less than bolus between scapulae (Johnson-Delaney 2006). 0.2 ml and this may be possible under manual restraint in Intravenous access can be difficult in a hypotensive tame animals. For larger samples the cranial vena cava is animal and patient interference with cannulas is com- accessed under general anaesthesia (Head et al. 2017). A mon. Where used, the cephalic or saphenous veins are needle is inserted just cranial to the manubrium and most readily accessible in prairie dogs and RGS. directed caudolaterally at an angle of 30° from the midline Intraosseous catheters are alternative options in severely (Figure 1.3). The vein is typically superficial and volumes dehydrated animals, or for chipmunks where vessel size of up to 6 ml/kg can be collected in healthy animals (Head limits access, and placement is via the greater trochanter et al. 2017), but this should be reduced to 1.5 ml/kg in of the femur, preferably under sedation and with ongo - debilitated patients. The jugular vein is an alternative in ing analgesia. this species but may not be visible or palpable. In RGS and chipmunks the smaller veins are harder to access and the cranial vena cava is the usual site with 1.4.4 Anaesthesia venepuncture carried out under general anaesthesia. In Fasting before anaesthesia is unnecessary and should be small individuals where sample size required exceeds the avoided. recommended maximum volume, crystalloid replacement Many different anaesthetic protocols have been detailed can be used to restore volume. (see formulary), and an injectable combination is preferred over gaseous anaesthesia alone in prairie dogs and RGS as in all but the most debilitated animals mask or chamber induction is resented. In chipmunks, their small size and difficulty gaining an accurate weight complicates accurate, safe dosing of injectable agents and volatile agents may be used as the sole anaesthetic agent but it must be remem- bered that this provides no analgesia. Once immobilised under volatile anaesthesia, weight measurement can be car- ried out and appropriate analgesics administered based on weight. Endotracheal intubation of sciuromorphs is possible using blind or endoscope assisted techniques but is Figure 1.3 Blood sample collection from the vena cava in a ­challenging so oxygen and volatile agent anaesthesia are juvenile prairie dog. typically provided by mask.

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1.4.5 Euthanasia

Humane euthanasia is best achieved with intracardiac injection of pentobarbitone after induction of general anaesthesia. Intracardiac or intraperitoneal injection in a conscious patient is not appropriate. The apex beat of the heart is both visible and palpable in the caudoventral tho- rax and rapid intracardiac injection of 80–160 mg/kg is suf- ficient to euthanase animals effectively.

1.4.6 Hospitalisation requirements

Prey species like sciuromorphs should be kept separate from predators, including cats and dogs, to minimise stress. Where possible hospitalised individuals should be main- tained with their normal social group to maintain social bonds and avoid the negative effects of social isolation. Husbandry within the hospital should approximate con- ditions recommended for companion animals although cage size can be reduced if necessary given the short-term nature of housing. For chipmunks in particular it is impor- tant to check cages are entirely secure due to their ability to escape through small apertures and the ensuing legal rami- Figure 1.4 Hepatic carcinoma in an RGS. fications. Often owners will be able to provide a cage and food and this should be encouraged as familiarity will result in more relaxed patients and a closer approximation of normal behaviour.

1.5 ­Common Medical and Surgical Conditions

1.5.1 Neoplasia

Neoplasia appears uncommon in chipmunks. Two osteo- sarcomas have been described as have a mammary adeno- carcinoma and a single report of hepatic carcinoma (Wadsworth et al. 1982; Morera 2004; Tamaizumi et al. 2007; Oohashi et al. 2009). Spontaneous neoplasia has been reported as uncommon Figure 1.5 Pulmonary metastases of a hepatic carcinoma in an RGS. in Richardson’s ground squirrels with limited case reports comprising a mast cell tumour and several adenocarcino- mas (Yamate et al. 2007; He et al. 2009; Carminato et al. ­squirrels (Spermophilus parryi) (Testut et al. 1996). The 2012). However, this author has seen a high incidence of hepadnaviruses appear to be highly host-specific with no soft tissue and hepatic neoplasms in RGS, with females cross-infection between squirrel species. predominantly affected (Figures 1.4 and 1.5). Excision of A high prevalence of hepatic carcinomas has been masses is advisable where possible for diagnosis and reported in Prairie dogs, presumed to be associated with attempted curative treatment (Figure 1.6). A hepadnavirus hepadnavirus but testing has not confirmed viral presence induced syndrome of hepatitis progressing to hepatic carci- (Garner et al. 2004). Otherwise neoplasia in prairie dogs noma has been recognised in RGS (Tennant et al. 1991) appears uncommon with sparse case reports comprising as well as wood chucks (Marmota monax), Californian lymphoma, lipoma, and osteosarcoma (Rogers and Chrisp ground squirrels (Spermophilus beecheyi) and Arctic 1998; Miwa et al. 2006; Mouser et al. 2006).

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(a) (b)

Figure 1.6 (a) Facial mass in a Richardson’s ground squirrel. (b) RGS following removal of facial mass, determined on histopathology to be a lipoma.

1.5.2 Dental Disease

Sciuromorphs have a typical dental formula of I 1/1, C 0/0, P 1-2/1 M 3/3. Incisors are long and chisel-shaped with a pattern of continuous growth whereas the premolars and molars have closed anelodont roots and do not have a pat- tern of ongoing growth and attrition (Legendre 2003). There are well formed cheek pouches for food collection and storage that extend down the neck (Mancinelli and Capello 2016). Acquired dental disease leading to incisor malocclusion has been described as common in chipmunks and is also regularly seen in other sciuromorphs (Girling 2002). Incisor extraction is preferred over repeat incisor trims due to the stress to the patient and progression of dental changes over time. It is prudent to radiograph those Figure 1.7 Elodontoma formation affecting apices of all four incisors in an RGS. ­animals presenting with incisor malocclusion as elodon- toma presence may be the cause of the coronal alteration. High sugar diets are associated with dental caries, perio- mulated material can obstruct nasal air flow. Elodontomas dontal disease, and tooth decay (Mancinelli and Capello have been widely reported in sciuromorphs in the litera- 2016) and often extraction is the only option remaining due ture, including in chipmunks and the author has also con- to advanced disease at the time of presentation. Trimming firmed presence of elodontomas in several RGS using both or reduction in crown height of premolar or molar teeth radiography and CT imaging (Figure 1.7). Possible inciting should not be carried out as these are closed-rooted teeth. factors include trauma, chronic inflammation, advanced acquired dental disease, and toxin exposure. In prairie 1.5.2.1 Elodontomas dogs a similar phenomenon is observed as a degenerative Elodontomas are a benign but progressive accumulation process in older animals, predominantly affecting the api- of mixed alveolar bone and odontogenic material at the ces of the maxillary incisors and these are more accurately apices of elodont teeth and are considered to be hamarto- termed pseudo-odontomas. Dystrophy of the germinal tis- mas. As squirrels have elodont incisors but closed rooted sue results in development of a plicated mass of dentine premolars and molars, this dysplasia can only affect with damage to surrounding tissues (Mancinelli and ­incisor apices. The resulting space-occupying mass is Capello 2016). Nasal air flow is obstructed and eruption of painful and, when upper incisors are involved, the accu- affected incisors may cease.

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Treatment options attempt to alleviate the secondary Dilated cardiomyopathy is reported as common in prairie ­respiratory consequences of elodontomas or pseudo-­ dogs of over three years of age (Funk 2004) and may present odontomas and include extraction of incisors and associ- with respiratory signs. Treatment follows that of the domes- ated dysplasia, or surgical creation of a dorsally or laterally tic mammals but response to therapy appears to be poor. placed stoma to allow air flow into the sinuses, bypassing the compressed nasal passages (Bulliot and Mentre 2013; 1.5.4 Arthritides Smith et al. 2013). Surgery is more challenging in squirrels and chipmunks compared to prairie dogs given the smaller Stifle swelling, new bone formation, and altered range of patient size and disproportionally narrower nasal passages. movement have been seen by the author in several geriat- ric RGS and less commonly in prairie dogs (Figures 1.9 and 1.10). Management using meloxicam and glucosa- 1.5.3 Respiratory Tract Disease mine/chondroitin appeared to assist with mobility along- Although respiratory distress is commonly associated with side husbandry modification to house affected animals in elodontoma presence, upper and lower respiratory tract infec- a single tier cage. In one case acupuncture in a prairie dog tions are also seen as a cause of dyspnoea. Primary pathogens with osteoarthritis resulted in a perceived marked have been implicated, e.g. Pasteurella multocida in prairie improvement by the owner but given the variable presen- dogs (Figure 1.8), and Pasteurella haemolytica in Siberian tation of osteoarthritis further data would be needed chipmunks (Astorga et al. 1996). However, in many cases, before making a recommendation for this treatment especially in chipmunks, husbandry failings leading to stress modality. and immunosuppression are thought to be the primary incit- A single case of mycobacterial synovitis has also been ing factor for development of opportunistic bacterial pneumo- seen by the author but no infectious joint conditions have nia. Ideally therapy is based on a firm diagnosis made from been reported in the literature to date. radiography, and culture and cytology of a tracheal or bron- choalveolar lavage sample. In many cases this is not possible, due to patient status or size, and broad spectrum antibiotic therapy alongside nebulisation is a compromise made. Metastatic hepatic carcinoma can cause severe pulmo- nary changes with dyspnoea that is non-responsive to sup- portive or attempted treatment options.

Figure 1.9 RGS with stifle osteoarthritis. On clinical Figure 1.8 Mucopurulent nasal and ocular discharge in a examination there was a marked reduction in the range of juvenile prairie dog with acute pasteurellosis. movement of both stifles.

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Figure 1.11 Conspecific bite injuries in a prairie dog following a territorial dispute. This animal was euthanased after confirmation of an open scapular fracture.

Figure 1.10 Normal appearance to stifles of an adult prairie dog.

1.5.5 Traumatic Injury

In rut, male prairie dogs may compete for territory, inflict- ing bite wounds on other animals – typically affecting the tail base, scrotum, and dorsum. Most wounds are relatively superficial but may require suturing. Intradermal sutures are advisable to prevent premature suture removal by the patient. Occasionally territorial disputes can result in more serious injuries (Figure 1.11) Figure 1.12 Intervertebral disc rupture in a geriatric prairie Significant trauma has been seen following a fall from dog following a fall. Hind limb paresis was present initially but cage tier, or drop from owners’ hands. Limb and spinal function returned over a three month period. fractures have both been seen by the author, as well as intervertebral disc rupture in a geriatric prairie dog follow- have been identified in wild populations and subsequently ing a fall (Figure 1.12). in wild caught individuals introduced into the pet trade. Yersinia pestis is the bacterial cause of bubonic plague and prairie dogs and ground squirrels are both highly sus- 1.5.6 Miscellaneous Infectious Conditions ceptible. An outbreak has been reported in captive prairie Siberian chipmunks were found to be a significant host for dogs collected from the wild for the pet trade and wild pop- Borreliosis (Lyme Disease) in one study of an introduced ulations may also suffer high mortality in outbreaks population in France (Vourc’h et al. 2007) and may serve as (Phalen 2004). The peracute form of disease results in rapid a reservoir of infection. death, whereas in slower progressing cases only lethargy Historically many prairie dogs are wild caught as free- and anorexia may be evident. Post-mortem examination living populations are extensive, not currently under can be unrewarding but in some cases lymph node enlarge- threat, and captive breeding is hard to achieve at commer- ment or abscessation may be evident. Where outbreaks cially viable levels. Sporadic infectious disease outbreaks of high mortality occur in imported animals, or those in

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contact with recently imported animals, Yersiniosis should Cryptosporidium muris has been reported in pet Siberian be considered as a potential cause and a post-mortem car- chipmunks (Hůrková et al. 2003). The rodent tapeworm ried out in a laboratory with suitable biosecurity measures Hymenolepis nana has been reported as a cause of protein to manage the potential zoonotic risks. losing enteropathy and death in prairie dogs and it should be Tularaemia is caused by the bacterium Francisella tular- noted that this is zoonotic (Thas 2010). Endoparasitism still ensis, and both prairie dogs and ground squirrels are sus- remains rare in captive animals and so prophylactic use of ceptible. Humans can be infected by direct contact with antiparastic agents is not advisable. Faecal ­microscopy to animals, aerosol inhalation, bacterial contamination of an detect endoparasites is advisable for new ­animals, or those open wound, or indirectly through arthropod vectors. exhibiting signs consistent with endoparasitism. Granulomatous infection of liver, spleen, lymph nodes, Prairie dogs have fast growing nails due to the need for lungs, and bone marrow results (Phalen 2004). Disease extensive digging in the wild. In captivity trimming of nails has not been reported in the UK but is established in North may be necessary to prevent overgrowth which often America and parts of Europe. An outbreak in North results in fractures at the nail base and mild–moderate America was reported to have resulted in extensive mor- haemorrhage. Guillotine type nail clippers tend to work tality in wild-caught prairie dogs and prairie dog to human well and cautery materials should be available in case of transmission was confirmed. Clinical presentation was high inadvertent damage to the vascular core of the nail. mortality with a predominance of oropharangeal lesions noted at post-mortem examination (Avashia et al. 2004). 1.6.1 Neutering Technique Prairie dogs have been infected with Monkeypox follow- ing contact with rodents imported from Ghana. Symptoms It is important to note that legislation mandates that pre- included pyrexia, coughing, conjunctivitis, lymphadenopa- cautions must be taken to prevent Siberian chipmunks thy, and dermal pox-like lesions. Disease was transmitted from breeding. This can involve maintaining this species as from prairie dogs to humans, including veterinary staff single individuals which is often well tolerated, as single resulting in flu-like symptoms and a papular rash (Guarner sex groups or utilising surgical neutering. Little informa- et al. 2004). Prairie dogs are also susceptible to cowpox, tion is available on chemical contraception in this species. resulting in similar lesions. All three species can often be maintained as single sex As a result of the zoonotic disease outbreaks associated groups though during their breeding season (‘the rut’) prai- with prairie dogs, it is now illegal in the USA to capture, trans- rie dogs in particular can become aggressive to conspecifics port, sell, or release into the wild any of this species (Phalen and human handlers, necessitating separation. 2004). No trade restrictions currently apply in the UK. Where animals are being kept as a mixed sex group then Mycobacterium avium avium has been reported in an neutering of males is the simplest way to control breeding. RGS (Juan-Sallés et al. 2009). The individual presented Open inguinal canals in these species necessitate a closed hypothermic and dehydrated, and died. Granulomatous castration technique and the author prefers a midline inflammation within the lungs and lymph nodes was noted abdominal approach with retraction of testes into the abdo- at gross post-mortem and extensive inflammatory changes men prior to ligation and removal. This results in a single associated with acid-fast bacteria were noted on histologi- incision compared with two scrotal incisions and has reduced cal examination of spleen, liver, mediastinal fat, pleura, potential for post-operative infection as scrotal wounds tend and peritoneum in addition. Polymerase chain reaction to be heavily contaminated due to their ventral and peri-anal (PCR) analysis supported M. a. avium as the causative bac- position. Wound closure is in three layers with intradermal terium (Juan-Sallés et al. 2009). skin sutures used to minimise wound interference. Females can be spayed following a similar approach to other small mammals but elective neutering of females is 1.6 Preventative Health Measures less commonly carried out. Elective neutering is best carried out in prairie dogs at an A variety of endoparasites have been reported at low levels in age of less than one year, and in summer time when ani- wild prairie dog populations (Pfaffenberger et al. 1984) and mals are at their lowest body weight. In older animals, or at wild chipmunks have reported infestations with Brevistriata winter weight, large adipose deposits make surgery more skrjabini and Syphabulea maseri in their natural range challenging. (Schulz and Lubimov 1932; Pisanu et al. 2007). A wider vari- ety of nematodes (Ascarids, Trichostrongyles, Oxyurids, and 1.6.2 Radiographic Imaging Trichurids) have been reported, as well as Eimeria coccidia, in regions where this species is considered a non-native Radiography is invaluable for investigation of dental lesions species (Chapuis et al. 2012). Asymotomatic carriage of and is best carried out under sedation or general anaesthesia

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for optimal positioning. Whole body laterolateral views are superimposed (Figure 1.7). Computed Tomography can commonly used for survey radiographs (Figure 1.13). A provide greater detail on size and location of lesions prior to series of views (typically dorsoventral, laterolateral and left planning any surgical intervention. and right oblique views) are used to assess dental anatomy Radiographs are also valuable in detection of articular fully. Elodontomas or pseudo-odontomas are best evaluated changes, intraabdominal soft tissue masses, detection of on slightly oblique lateral views where incisors are not lung lesions, and evaluation of extent of injuries.

Figure 1.13 Laterolateral survey view of an adult prairie dog.

Formulary

Medication Dose Dosing interval Additional comments

Anaesthesia Buprenorphine 0.03 mg/kg SC 30 mins prior to induction Ketamine 10 mg/kg IM Midazolam 1–2 mg/kg IM (Pilny and Hess 2004) Medetomidine 0.1–0.3 mg/kg IM (Johnson-Delaney 2006) Diazepam 1–5 mg/kg IM (Johnson-Delaney 2006) Ketamine 40 mg/kg IM ACP 0.4 mg/kg IM (Sinclair 2007) Medetomidine 0.1 mg/kg IM Reversal with 0.5 mg/kg atipamezole Ketamine 2–5 mg/kg IM Butorphanol 1 mg/kg IM Ketamine 85 mg/kg High ketamine doses may lead to protracted recovery Xylazine 10 mg/kg IM (Olson and McCabe 1986)

Analgesia Butorphanol 2 mg/kg SC q2–4h (Sinclair 2007) Buprenorphine 0.05–0.1 mg/kg SC q6–12h (Smith and Burgmann 1997) Meloxicam 0.4 mg/kg SC or PO q12h (Wright et al. 2017) Tramadol 10 mg/kg PO q12h (Mayer 2012)

Antibiotics Enrofloxacin 5–10 mg/kg PO once daily (Morrissey and Carpenter 2004) Chloramphenicol 50 mg/kg PO q12h (Morrissey and Carpenter 2004) Metronidazole 20 mg/kg PO q12h (Adamcak and Otten 2000) Trimethoprim sulfa 30 mg/kg PO SC q12h (Collins 1988) Doxycycline 2.5 mg/kg PO q12h (Morrissey and Carpenter 2004) Avoid oral penicillins, cephalosporins and clindamycin

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(Continued)

Medication Dose Dosing interval Additional comments

Antiparasitics Ivermectin 0.2–0.4 mg/kg SC q10-14d (Ness 2005) Fenbendazole 25 mg/kg PO q24h for 5d (Allen et al. 1993) Metronidazole 40 mg/kg PO q24h for 5d (Ness 2005)

Miscellaneous Enalapril 0.25–0.5 mg/kg PO q12h (Funk 2004) Furosemide 0.3–0.4 mg/kg PO, SC, IM, IV q12–24h (Mayer 2012)

­References

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