Canine parvovirus is one of the most potentially devastating viruses facing shelter populations. Control of this virus requires an effective vaccination program, quick recognition, quarantine, and thorough environmental disinfection. This non-enveloped, single-stranded DNA virus is resistant to extreme heat, cold, and dry conditions, and can remain in the environment for months to years.

Parvovirus attacks the epithelium of the small intestine causing severe, bloody diarrhea and life-threatening dehydration.  Other clinical signs include vomiting, lethargy, loss of appetite, and a high fever. The virus also targets the bone marrow, causing a low white blood cell count and a weakened immune system.  Although this virus can cause disease in any unvaccinated dog, it most severely affects puppies because they are immunologically vulnerable and very susceptible to infection after the waning of their maternal antibodies.  Furthermore, Parvovirus is easily transmitted in a shelter setting through exposure to infected feces and fomites.  Viral shedding can occur in infected animals before the appearance of clinical signs, making the control of this disease even more difficult.

Vaccination is essential in preventing the spread of parvovirus. 
 
A strategic vaccination program is the most important factor in the management of this disease. The modified live vaccine protects against all strains of parvovirus and is effective within 3-5 days. All adult dogs and puppies over 4 weeks should be vaccinated immediately upon arrival to the shelter.  Because of maternal antibody interference, puppies should be revaccinated every 2 weeks until they are about 5 months old.

Until puppies are fully vaccinated, they are very susceptible and should be protected from potential exposure.  Puppies should not be walked through the shelter or outdoor enclosures used by the general population.  Staff members should always wear clean gloves when interacting with the puppies and when cleaning their kennels. If possible, puppies should be sent to foster or adopted out of the shelter as soon as possible to minimize their risk of exposure.
 
Animals with a high risk of infection should be isolated in order to protect the rest of the shelter population. The incubation period of this virus is typically about 3-4 days, but can extend up to 2 weeks.  Therefore, a quarantine period of 2 weeks is sufficient to reveal whether an animal will show signs of disease.

To Quarantine or Not to Quarantine

The in-house fecal ELISA snap test is a quick and reliable way to diagnose all current strains of canine parvovirus.  Only animals showing clinical signs or with a history of recent exposure should be tested.  Although PCR testing of fecal samples at a specialized laboratory can distinguish between the different strains of the virus, it is unnecessary in a shelter setting and will not change the treatment plan. Because of the virus’s effect on the bone marrow, a low white blood cell count identified by a blood smear is characteristic of parvovirus infection.  Lastly, necropsy may reveal segmental enteritis, the classic pathological presentation of this disease.

​When an animal has been exposed to parvovirus, it is important to assess the risk of infection and determine whether the animal should be put into quarantine.  The likelihood of infection after exposure depends on the presence of maternal antibodies, the animal’s vaccination status, the amount of environmental contamination, and the proximity to the infected animal.  Antibody titer testing is useful when deciding whether to quarantine asymptomatic dogs that have been exposed.  Clinically healthy adult dogs with a history of vaccination are at low risk of infection and should not undergo titer testing. 
 
Titer testing doesn’t require an outside lab- you can order the kits yourself at (http://vaccicheck.com) and perform them “in-house.”  They require a small amount of blood and, at the time of this writing, cost approximately $16 per test (you must purchase a whole kit containing 12 tests).  See below for how you can use titer test results to identify low-risk and high-risk dogs. The cost of the tests are well worth the chance to say, “This dog is at low risk for parvo virus and can be adopted out now! No quarantine needed” (not to mention the decrease in length of shelter stay)!
 
Snap tests used in combination with titer testing in exposed puppies can help determine their infection status. For example, a puppy with a positive snap test and a positive titer is most likely infected and should be separated from other dogs.  A negative snap test and positive titer without clinical signs of disease (i.e. puppy appears completely healthy) is likely protected and low-risk. A puppy that is not shedding virus but is also susceptible to infection would have both a negative snap test and a negative titer.  The virus may be in the incubation period, and the puppy should be quarantined for two weeks.  Puppies should be bathed before entering quarantine to prevent self-infection from virus particles on the fur.  Staff members should use gloves, shoe covers, and gowns when cleaning the kennels.  Disinfecting equipment should be specific to each individual kennel to avoid cross-contamination. Dogs that do not show clinical signs after two weeks can safely re-enter the general population. 
 
Disinfection of Shelter

Because parvovirus can survive in the environment for years, thorough disinfection is a vital step in the control of this disease.  Ineffective cleaning practices can lead to persistent infections in the shelter.  Household bleach (5% sodium hypochlorite) at 1:32 dilution will successfully kill parvovirus, but only if the surface has been pre-cleaned! It is important to remove all organic matter from the surface being disinfected, as it inactivates the bleach.  Two disinfectants that are more effective in the presence of organic matter in comparison to bleach include potassium peroxymonosulfate (Trifectant) and accelerated hydrogen peroxide (Accel).  Outside enclosures present a more difficult challenge for environmental decontamination. Grass or dirt pens can be flooded, dried, and sprayed with Accel. However, because these methods are not completely effective, susceptible puppies should not use outdoor enclosures that have had recent viral exposure. 

Summary

Parvovirus can be treated in shelters that have the resources and isolation capabilities necessary to prevent an outbreak.  The treatment is mainly supportive care incorporating anti-emetics, intravenous or subcutaneous fluids, and in severe cases, blood transfusions. Because of the weakened immune system, antibiotics are given to prevent secondary bacterial infections.  Animals should be isolated for 2 weeks following recovery, since viral shedding can occur up to 14 days after the resolution of clinical signs.  If quarantine for that length of time is not feasible, you can feel reasonably confident that the dog is no longer shedding if two parvo snap tests, run after resolution of clinical signs and several days apart, are negative.  In shelters that do not have the ability to treat animals with parvovirus, humane euthanasia is sometimes performed to avoid endangering the rest of the shelter population.
 
Parvovirus poses a great challenge to shelter veterinarians.  This highly contagious and resistant virus can rapidly spread through a shelter, potentially threatening the lives of many young animals.  Fortunately, this disease can be successfully managed through widespread vaccination, strict hygiene practices, and quick isolation of sick animals.  A well-trained and dedicated staff that routinely monitors the health of all puppies can help prevent devastating outbreaks.  By implementing these management strategies, shelters can save lives and protect their most vulnerable population.
 
 
References
 
American Veterinary Medical Foundation. Canine Parvovirus. 2015. <https://owl.english.purdue.edu/owl/resource/747/08/>.
 
Baker Institute for Animal Health. Cornell University College of Veterinary Medicine. Animal Health Article: Canine Parvovirus. 2014. <http://www.vet.cornell.edu/baker/about/articles/CanineParvovirus.cfm>.
 
Koret Shelter Medicine Program. UC Davis Veterinary Medicine. Canine: Parvovirus (CPV). 2015. <http://www.sheltermedicine.com/library/canine-parvovirus-cpv>.
 
The Merck Veterinary Manual. Canine Parvovirus. Merck Sharp & Dohme Corp. 2009-2015. <http://www.merckvetmanual.com/mvm/digestive_system/diseases_of_the_stomach_and_intestines_in_small_animals/canine_parvovirus.html>.

Cats are the ultimate creatures of habit. Unlike dogs, many cats never leave their homes from kitten hood until the day they arrive at a shelter. Not only are cats afraid and mourning the loss of their familiar surroundings, their keen senses pick up a variety of stressors in the shelter. Cats are stressed by the unfamiliar smells (cleaning agents, other animals) and unfamiliar sounds (barking dogs, people working, children) of their new environment. Faced with this extreme stress there are three options; fight, flight, or freeze.

The confinement of the cage takes away the option to flee, so cats must either fight or freeze. Housecats and feral cats both employ these two defense mechanisms, which makes distinguishing these two groups rather difficult. With a keen eye to feline behavior and body language, shelter staff can be trained to distinguish between these two groups.  

Feral cats are defined as those that have had no previous socialization with humans. These animals are born in the wild, and do not have a place as human companions. Confinement and human interaction are incredibly stressful for these animals, and they should be removed from the shelter as soon as possible. Many areas have trap-neuter-return (TNR) programs that work to return these animals to managed colonies. If a TNR program is not available, euthanasia is the most humane option, as rehabilitation of adult feral cats is not possible.

Well-socialized or ‘friendly’ cats are those that have been raised as companion animals. Many times these animals will still be friendly and interact with humans despite the change in environment. However, some of these animals may be particularly sensitive and will either freeze or fight when placed in a cage. Contrary to popular belief, often the most aggressive cats are former housecats who are simply scared for their lives. Many housecats will also freeze and refuse to interact, and thus may appear ‘feral.’ It is important to distinguish these felines as previously socialized so that they may be rehabilitated, either in the shelter or in a foster program, and made available for adoption. It is also important to prevent well-socialized cats from being returned to an outdoor colony where they would not be able to survive. 

Cats will typically take several days to a few weeks to start showing their normal behaviors, but research has shown that within the first four days stress levels decrease significantly. Attempts should be made to do several behavior evaluations of new intakes during this time period. One single observation will not give you an accurate indication of the cat’s previous socialization. Simply assessing the cat’s level of stress will not provide much information, but there are body language cues that can begin to be observed from day one.

Begin your observations by simply observing the cat in the cage. Cats who are in the front one-third of the cage, or who approach the front of the cage at any time are very likely to be previously socialized (Figure 1). The next step is to take a pen or soft toy and rub it behind your ear to pick up your scent. Slowly open the cage door and gently present it to the cat, making sure to keep your eyes soft and blink frequently. If the cat allows, you can try to rub the toy or pen gently along the side of the muzzle and cheeks.

The response displayed to this brief interaction can give you great insight to the previous socialization of the cat. Behaviors that strongly indicate previously socialized cats are rubbing, kneading, chirping, playing, and coming to the front of the cage. Sniffing and blinking are weaker indicators, as they could just be signs of a more relaxed and curious cat without suggesting previous socialization. Feral cats are very unlikely to show any of the strong behaviors. While hissing, spitting, or lunging at the front of the cage are simply indicators of an angry cat and do not give us insight on their level of socialization. 

By repeating this interaction at least daily you should be able to have an assessment of the cat within about three days. If you are able to take more time (the seven day mandatory stray hold in Wisconsin makes for a perfect opportunity), you can begin to try and rehabilitate any cats of which you are still unsure  A great trick is to use canned tuna or baby food to slowly ‘clicker train’ the cat to be more relaxed (see resource below). Alternatively, really shy or reactive cats can be placed in foster or a staff office. For some cats just getting out of a cage dramatically changes their behavior.

It is important to remember that when dealing with animal behavior, your assessments will never be perfect. However, as you continue to work with and observe the cats in your shelter, you will gain an appreciation for the types of behaviors displayed by feral and socialized cats. By improving your methods of determination you will be able to save more lives by more accurately placing each animal on the pathway to its best outcome.

Resources:

Slater, et al. Practical Physical and Behavior Measures to Assess the Socialization Spectrum of Cats in a Shelter-Like Setting during a Three Day Period. Animals. 2013. 3. 1162-1193.

http://www.aspcapro.org/resource/spay-neuter-feral-cats/aspca-research-cat-feral

http://www.alleycat.org

http://www.clickertraining.com

Written by Natalie Morgan

4th Year Veterinary Student Extern

July 2015

Heat Stroke and Our Animal Companions

We’ve all seen the countless headlines that tell the stories of animals who suffer the dangerous effects of Mother Nature’s extreme heat, but what exactly are those effects?  How can we, as animal caregivers, recognize an animal suffering from heat stroke and give them the help that they need?  How can we prevent heat stroke?  The following article aims to tackle these commonly encountered questions.

Introduction: When an animal’s core body temperature begins to climb, the body is normally able to counteract that increase by dissipating some of that excess heat through various mechanisms such as panting and sweating from the paw pads.  Heatstroke, however, refers to the life-threatening condition in which the core temperature climbs so high and begins to have many negative effects on the body’s normal functions and regulation that the body can no longer regulate its temperature and a very serious cascade of events unfolds.  Heatstroke is characterized by a core body temperature above 104 degrees F, central nervous system dysfunction (such as convulsions, confusion, or coma), and organ dysfunction.  The latter two result from the cells that make up those organs getting overheated and becoming damaged, thus no longer being able to do their job.  Heatstroke is more common during the summer and in hot, humid climates.  Additionally, it tends to be much more common in dogs rather than cats, though has been seen in both.  Animals that are outdoors during hot weather and do not have access to shade and water can all too easily develop heatstroke, as well as exercising them in hot, humid conditions.  Both of these situations can commonly be encountered in a shelter setting, whether the animal was picked up as a stray on a hot day, was rescued from a hot car from which it was frantically trying to escape, or if shelter animals are walked excessively in very hot weather.  If an animal presents to your shelter with a history of any of these situations, or if you are suspicious of heatstroke in an animal in your shelter on a hot day, the following is a list of signs you should look for:

Treatment of Heatstroke: 

When an animal presents to a shelter with signs similar to those listed above, it is very important that the animal is seen by a veterinarian as quickly as possible.  Their health should be rapidly assessed, beginning with their airway, breathing, and circulation (the ABCs).  These animals may require oxygen support if it is available at your shelter.  After assessing the ABCs, it is necessary to cool them down.  This can be performed by anyone, and should involve spraying the animal with cool water, placing a fan in front of them, and/or placing them on a cool metal table.

It should be stressed that the use of ice should be avoided. Placing in animal in an ice water bath or using ice packs to rapidly cool the animal’s temperature results in constriction of the blood vessels in the skin and thus the animal is less able to dissipate heat from the body.  In addition, contact with ice can be painful for the animal and also causes the animal to shiver, which is further increasing core body temperature.  Finally, active cooling should only be performed until the animal becomes comfortable.  Shivering and low body temperatures should be avoided.  Further treatment after cooling the animal should be performed only by a veterinarian.

References

1.      Scott I Johnson, DVM, Maureen McMichael, DVM, DACVECC and George White, DVM, DACVECC. “Heatstroke in small animal medicine: a clinical practice review.” Journal of Veterinary Emergency and Critical Care. 2006. 16(2) pp 112-119.

2.      “The Prevention and Management of Heat Stroke in Dogs.”Animal Medical Center of Southern California. SDG Publishing, 2015. Accessed July 12th, 2015. http://www.animalmedcenter.com/news-and-press/article/the-prevention-and-management-of-heat-stroke-in-dogs

3.      “Hot Weather Tips.” Pet Care. ASPCA , 2015. Accessed July 13th, 2015. < http://www.aspca.org/pet-care/hot-weather-tips>