MSVC 2019 Introduction to Pet Pig Practice Matthew Edson, DVM, MICP Owner, Rancocas Veterinary Associates Mount Holly, NJ / Tuckerton, NJ

Introduction Miniature pigs, also known as pot-bellied pigs, teacup pigs, micro-mini pigs, Vietnamese pigs, Julienne pigs, etc. have become very popular pets. While there are many pig-owning clients out there few practices are willing to see these patients as part of their practice. With a shortage of accessible veterinary resources many owners resort to internet groups and various (and often less-than-accurate) resources for information on caring for their porcine family members. There is great need for increased access to veterinarians willing and able to see mini pig cases. The purpose of these sessions it to provide a basic introduction of miniature pig practice for those interested in adding mini pigs to their practice.

Many shapes and sizes Pot-bellied pigs vary greatly in size. Many prospective pet pig owners seek out “micro mini pigs” in hopes that they will remain small. In our experiences, there isn’t really such a thing as a “micro mini pig”. The pigs in our practice range from adult sizes of 20lbs to 350lbs. It is all too common to have a new pig owner bring their pet in and say they purchased a micro mini pig, tell us its 4 months old, and then discover they actually have a 6 week old pig. Unscrupulous sellers seem to be marketing very young pigs as very small pigs. By the time the owners realize the pig just continues to grow it’s too late to return it (or they can’t contact the seller). The pigs we see that achieve smaller adult size have a tendency to show more congenital issues than their larger counterparts; the suspicion is that breeders are breeding so selectively for small size that other undesirable traits are becoming more prevalent. On average, the pot bellies in our practice are in the 60-120lb range. The pigs at the higher end of the weight range (200+ lbs) tend to be that large because they are grossly overweight, or they are actually production pigs!

Where do these pigs come from (and where do they end up)? Many pot bellies are sourced from breeders. Often times these are local individuals who have either intentionally or unintentionally bred their pigs and have then offered them for sale. In many cases pigs are purchased from out-of-state breeders and shipped in via air carrier. The majority of the “micro mini pigs” we see are sourced from out-of-state breeders which makes it very difficult to rectify situations in which these do not turn out to be so “mini”, or in situations when the pig arrives with either a congenital defect or illness. We often see respiratory illnesses in pigs post-shipping (more on this later). Livestock auctions have also proven to be popular sources for pet pigs. Unfortunately young farm hogs look just like young miniature pigs and many an unsuspecting owner has accidentally purchased a pig that will have a mature weight of several hundred pounds. Mini pigs sourced through auctions have also often been exposed to a myriad of diseases. The most noble and, in this author’s opinion, best source for a new pet pig is via a pig rescue. Many rescues exist and often have hundreds of pigs in need of homes. As with their canine counterparts where puppies typically find homes faster than adults, these sources usually have more adult pigs seeking homes versus

babies. That said, there are also plenty of young pigs in need of homes via rescue organizations. Considering owners often pay over $1000 for young pot bellies from breeders searching for a pig through a rescue is an excellent alternative. One excellent resource is the Pig Placement Network (http://www.pigplacementnetwork.com). Unfortunately, many owners purchase pigs without really understanding their needs. One of the reasons rescues have so many pigs available is that owners purchase them while they’re young and tiny but soon discover that having a large pig in their home presents more challenges than expected. It is extremely important that owners have reasonable expectations when purchasing a pig. Rescues often assist prospective new owners in understanding the full spectrum of pig ownership before they jump in.

Food animal classification/AMDUCA While these patients are brought in as pets they’re still pigs. As such they are considered food animals and are subject to the same drug use regulations that apply to production pigs. Pigs are a considered a “Major Species” which places significant constraints on extra-label drug use. Practitioners must be aware what medications constitute prohibited substances, when withdrawal times apply and must be disclosed, and what the rules and regulations for off-label use are. Those interested in adding miniature pigs to their practice are encouraged to familiarize themselves with the Animal Medicinal Use Clarification Act (AMDUCA) regulations. The AVMA Extralabel Drug Use and AMDUCA FAQ website listed below in the references is an excellent place to start. AMDUCA violations can result in regulatory actions by the FDA which may include written warnings, confiscation of product, fines, or even criminal prosecution. The Food Animal Residue Avoidance Databank (FARAD) offers resources for determining what substances are prohibited and what the withdrawal times for allowed substances are. Their website is located at http://www.FARAD.org. They have also created a app called vetGRAM available for download (free) that makes it very simple to look up needed information even when you aren’t at a computer.

Pig persona Mini pigs are exceptionally smart creatures. They can be quite sweet, however they can be equally as stubborn too. They are very trainable. Pigs take to litter training quite well and the majority of indoor pigs in our practice are either using a litter pan or are fairly well house trained. Most of the pigs we see can “sit” and perform other simple tricks. They are HIGHLY food motivated creatures which can be used to facilitate training. Their love of food does contribute significantly to their obesity risk, though. Leash training can be accomplished with the use of a harness. While we have had a small number of pigs successfully trained to the use of a collar, the anatomy of the pig makes keeping these securely on the pig very difficult unless they are excessively tight. Owners with young pigs should use caution if keeping harnesses on for an extended period of time as we have had young, growing pigs grow into harnesses that were not re-sized and have resultant wounds (primarily in the axillary region). In general pigs like to do what they want to do when the want to do it unless they have incentive to do otherwise. This can make them exceptionally challenging patients.

Diet The number one issue that comes up with miniature pigs is their diet. Pigs have been selected over many generations to grow quite efficiently with minimal intake. Pot bellies should be fed a

commercial miniature pig diet. Many brands are available but the most popular and widely available diet is manufactured by Mazuri. They offer a variety of life stage formulas as well. Young micro pigs are generally fed ½ to 1 cup of feed twice daily. Average sized adults (60-100lb) sustain themselves well on 1 to 1 ½ cups twice daily. It is quite common to find that owners are feeding commercial hog grower (“pig feed”) or even dog food. These pigs are very frequently grossly overweight. Treats must also be closely controlled. While occasional fruits and veggies are an excellent addition to the diet excessive amounts quickly result in undesirable weight gain. We generally recommend using something like Cheerios as a treat and limiting the amount to just a few (<10) of these daily. Pigs sometimes enjoy grazing on fresh grass, but feeding grass clippings is not recommended. It is very easy to get a pig to gain weight but nearly impossible to get them to lose weight effectively. Overweight pigs placed on a diet tend to be quite cranky and demanding of food. Their poor response to being on a diet often forces owners to fold to their food demands thus making the dieting process very difficult. The best way to keep a pig in shape is to be vigilant about maintaining a healthy diet versus trying to get them to lose the weight later on (not an easy task).

Environment There are plenty of indoor pigs out there. They’re relatively easy to litter train and/or house train. Pigs do need their outdoor time, though, and a suitable yard is necessary. Not only does the yard need to contain the pig, it also needs to keep out predators. Dog attacks on mini pigs are all too common. This can even occur via the owner’s dog, even if the dog and pig have been fine prior. We caution clients against leaving pigs and dogs alone together. Pig owners need to accept that rooting behavior is a staple of the pig’s life. Pigs can and will completely dig up a lawn. Owners should expect that this will occur while roaming outside! Pigs also “nest” and will take blankets, rugs, pillows, etc. to nest in. Owners should be aware of this behavior and perhaps restrict pigs to areas of the home where they cannot access things they aren’t allowed to have. Zoning regulations can be quite strict when it comes to pigs. Many (most?) jurisdictions consider pigs, even minis, livestock and thus do not allow them in residential areas. Any prospective pig owners should ensure they’re allowed to keep a pig at their home. There are many instances of pigs needing to be rehomed due to zoning issues. Pigs can be difficult pets and are often opinionated. They may not be the best choice for inexperienced pet owners or those with young children.

Basic maintenance care Mini pigs do require some basic maintenance care. Hoof trimming is one of the most important of these. There are some pigs that walk on firm/abrasive enough substrate frequently enough that they do wear down their hooves adequately that trimming need not be done very frequently (maybe twice yearly). The average pig does require more frequent hoof care. We typically keep patients on a once every 3-4 months schedule. Overgrown hooves can become deformed and make walking difficult. Once hooves are misshapen it is often difficult or impossible to get them back into a normal configuration. Often times we trim pigs every 6 weeks while trying to regain normal hoof contour. Tusks are trimmed in males >1-2 years of age as needed to keep them from overgrowing.

Resources needed to be a pig friendly practice Equipment wise there isn’t all that much a typical small animal practice needs to add to adequately service the basic needs of miniature pigs. Getting pigs physically into the office can sometimes be a hurdle. Not all patients are leash trained and they are often best carried in in large dog carriers. A small wheeled platform can be helpful to set these carriers on to easily push them into the office. Slippery floors can be very off-putting for pig patients. Being cloven hoofed animals they lack the traction to adequately move about on slippery surfaces. Thin rubber mats (like those used on top of platform scales) can be laid out on slippery floors to allow pig patients to stand comfortably which greatly reduces their stress level. We’ve also used sections of carpet remnant for this purpose and dispose of any soiled pieces as needed. In agricultural practice hog snares are used to handle pigs. We do not recommend their use in pet pigs. Plastic pig boards can be helpful, though, in containing pot bellies in outside environments. A pair of equine hoof nippers and a battery powered Dremel tool with a flexible shaft and grinding wheel are needed for hoof care procedures. OB wire is used to trim tusks in males. Keeping a box of foam ear plugs in the office to facilitate maintaining the hearing of both yourself and your staff is highly recommended. Medications commonly used will be discussed in a later session, but many of these are readily available in most practices. Vaccines will be addressed later in this document.

Physical exam and what to look for Upon entering the office we try to start by getting the pig’s weight. In most cases the pig is contained within a crate or carrier. We put the pig-containing carrier on the scale and record the total weight. After transferring the crate to an exam room and letting the pig out we proceed to weigh the empty carrier and subtract the empty weight to get the pig’s weight. This is much easier than attempting to get the average pig to get/stay on the scale. Barring any owner objections we write the carrier weight on the carrier in permanent marker so we know for future visits what to subtract from the total weight to get a patient weight. Our exams typically start by allowing the pig to walk about the room while obtaining a history from the owner. As previously mentioned, obesity is a common issue in pet pigs. It is uncommon to see thin pigs unless they’ve come from a bad environment, are suffering from an underlying illness, or are elderly. Owners holding large ziplock bags of unhealthy treats are good candidates for a diet discussion! As the pig walks about ensure they show no signs of lameness and appear to be aware of their surroundings. Overweight pigs frequently become “fat blind” as excess facial tissues can sink over their eyes restricting or completely obstructing their vision. TPR Obtaining vital signs can be quite challenging in uncooperative patients. We typically begin with placing a stethoscope on the pig’s thorax to see if they will tolerate this. In small patients holding the patient while performing the exam generally works best. Picking up the patient, allowing them to relax, then listening to heart and lung sounds after they’ve stopped squealing is the general approach. Scratching a pigs belly often takes their attention off the task at hand and sometimes facilitates the physical exam. Temperature measurement is saved for after heart and lung sounds as some pigs truly resent this- understanding that this may be increased if the prior exam process has stressed them out.

SKIN Pigs have coarse haired skin. “Dandruff” is a common finding and does not seem to bother the pigs themselves but is a common owner concern. Many pig breeders and online resources recommend using products on the pig’s skin to reduce this. In many cases these products simply grease up the pig and don’t seem to help a whole lot in the long run. We’ve had some success with adding omega fatty acids to the diet in helping with this. The most common skin condition, especially in young pigs, is sarcoptic mange. Pruritic pigs with thickened red lesions on the legs, face, and underside should be highly suspicious for sarcoptes. Skin masses have not been a very common finding in our experience but these do occur. Unfortunately, many of us are accustomed to looking at canine and feline skin masses. Lesions in pigs do not necessarily share the same visual characteristics as they do in other small animals. Cutaneous mast cell tumors and cysts are represented most. FNA of any visible masses is recommended. HOOVES Ensure hooves are not overgrown. Pigs can be mule-footed (a single or fused hoof or single digit vs. the normal cloven hoof) and this appears to be more common in smaller pigs; likely a consequence of generations of selective breeding for small size. Ectopic hoof tissue originating from the interdigital space is also commonly seen. Further detail on hoof care will be covered in a later session. EYES Entropion is a common finding in miniature pigs. Many pig eyes appear surprisingly normal even with significant entropion. Over time corneal ulcers do tend to develop and surgical correction is recommended if this is discovered. “Fat blindness” occurs in overweight pigs when tissues dorsal to the eyes drape down over the eyes obscuring vision. Surgical correction in the form of a “face lift” is sometimes needed to restore vision. A small amount of brown material at the medial canthus is a normal finding. Owners can wipe this area with a damp cloth to keep the pigs face clean. Doing a fundic exam in pigs is not easy in most patients and the examiner must use caution putting their face in close proximity to the pig’s. Pigs are quite good at using their firm nose as a defense mechanism. EARS Dark waxy debris in the external ear is common. We encourage owners to clean the external ear with a moist cloth. When owners request we clean ears in the office we soak a 4x4 with ear cleaner and wipe the internal pinna. We will use cotton tipped swabs to get in crevices of the pinna but try not to insert these into the ear canal. The anatomy of the ear canal makes it easy to push wax into the canal versus remove it. We typically do not put cleaner or other liquids into the ear canal. TEETH/ORAL CAVITY Tusks in male pigs grow to the point at which they can be seen above/below the lip margins between 1-2 years of age. These can become quite long. The lower tusks can grow to a length at which they curl back into the pigs face. Infections/abscesses can form where the teeth irritate or enter the skin. Long tusks can also cause trauma to other pigs, pets, or people. These are trimmed as needed (usually every 2 years) to keep them from becoming overgrown.

Dental disease in pigs is a much overlooked problem. Oral examination is not easy in these patients and thus many times significant oral disease is left unchecked. Almost all senior pig examined in our practice have significant dental tartar accumulation. Over time we’ve found that a large percentage of older pigs anesthetized for surgical procedures (often unrelated to the teeth) have dental disease that has progressed to the point where there are multiple diseased teeth that require extraction. Holding a treat over a patient’s nose will often cause them to open their mouth giving time for a brief view of the oral cavity. Restraint for other procedures such as hoof trims allows for time for an oral examination as well and we routinely do this whenever possible. We have begun performing routine dental cleanings as needed in our pig patients. These are performed under general anesthesia using an ultrasonic scaler. Checking for oral masses is important as well. Squamous cell carcinoma has not been a common finding in our practice but has been noted in older pigs. MUSCULOSKELETAL Inguinal hernias appear with some frequency in young pigs. Umbilical hernias appear to be less common in our experience. Routinely checking for hernias during a patients first exam ensures the opportunity to repair these during a spay/neuter procedure is not missed. Arthritis is a common finding in older pigs. Assessing joint pain is difficult in this species as they typically do not cooperate well for orthopedic exams. Be alert for lameness and joint swelling. Intervertebral disc disease is the primary rule out for an overweight pig that cannot rise or stand in the hind end. These pigs are typically very painful (think IVDD Dachshund). REPRODUCTIVE We recommend spaying and neutering all pet pigs. Intact males can become quite aggressive and display many undesirable sexual behaviors most owners would prefer not to experience. Partially descended or abdominally retained testicles do occur in pigs. There have been reports of neoplasia in cryptorchid testicles that were not removed. Pigs become fertile around 3-4 months of age. Female pigs also tend to have less undesirable behavior when spayed. Of more importance, however, is the high incidence of reproductive tumors in intact females. A 2010 study looked at 32 reproductive tracts removed from pet pigs during ovariohysterectomies. 75% of these had diffuse cystic endometrial hyperplasia; 43% had smooth muscle tumors1. The risk of pyometra is ever present in intact females as well. The procedure is significantly easier to perform in small, young pigs (<6 mos.) than large and/or older pigs. Female pigs cycle every 21 days and gestation is almost always exactly 3 months, 3 weeks, and 3 days.

NORMAL ADULT VITAL SIGNS Low High

Temperature 98 102

Heart Rate 60 120

Respirations 10 30

Vaccination protocols

Typical vaccinations for pet pigs include tetanus, erysipelas, leptospirosis, and parvovirus. While rabies is very uncommon in pigs many practices, including ours, vaccinate for this. We vaccinate with tetanus toxoid, a combo vaccine for Bordetella, Pasteurella, and Erysipelas (RhiniShield TX4), and rabies. The first two vaccines are given and then boostered in 3-4 weeks and repeated on a yearly basis. Rabies is given yearly. It is prudent to split these up in smaller pigs. Regionally other risk-based vaccines may be indicated. Severe vaccine reactions are rare but lethargy for the 24 hours after vaccination is relatively common, especially in smaller pigs. I believe the lepto portion of the vaccine is the culprit so if this is not a concern in your area avoiding it may be prudent. The pigs that present for this after vaccination are almost always febrile, respond well to NSAIDs, and are fine within 24 hours.

Parasite control Routine deworming is not recommended. Bi-yearly fecal samples are used to determine if there is an internal parasite concern that needs to be addressed. In our experience, 95% of these samples come back “no parasites seen” in our pet pig population. Routine administration of parasiticides contributes to parasite resistance and should be avoided.

REFERENCES

1. Uterine Lesions in 32 Female Miniature Pet Pigs. M. Ilha - S. Newman - S. Amstel - K. Fecteau - B. Rohrbach - Veterinary Pathology - 2010 2. Extralabel Drug Use and AMDUCA: FAQ https://www.avma.org/KB/Resources/FAQs/Pages/ELDU-and-AMDUCA-FAQs.aspx