Leptospirosis

Leptospirosis is a zoonotic disease transmitted by the spirochete bacterium Leptospira spp.  The bacteria is shed in the urine of an infected host which can include mice, raccoons, skunks, deer, sheep, dogs and even humans. The bacteria remains viable in the environment as long as it is moist, so it is most prevalent in Florida during the wet summer months.

Dogs most commonly come in contact with the bacteria by licking urine off the grass, or drinking from puddles in the yard that have been contaminated with infected urine. Clinical signs are jaundice (yellowing of the skin, eyes), bloody urine, fever, lethargy, vomiting, inappetance, and kidney failure, and death. The incubation period in dogs is 2-20 days. In humans the signs include lethargy, fever, severe headache, chills, muscle aches, vomiting, diarrhea, and jaundice, and death. The incubation period in humans is 4-14 days. People who are exposed to contaminated water such as surfers, and professionals who are exposed to contaminated urine such as veterinarians, and slaughterhouse workers are most at risk.

Diagnosis is made from blood samples and fresh urine in early infections.
Treatment if caught early, is with antibiotics such as penicillin, and doxycycline. Penicillin is given initially to control shedding of the bacteria in the urine, then doxycycline is used to get rid of the carrier state. The key is prevention. There are no vaccines available for humans, but there are effective vaccines for dogs. The canine leptospirosis vaccine contains the 4 most common serovars, and is included in most distemper/parvo vaccine combination protocols. There are many veterinary practices that do not include leptospirosis vaccine in their annual vaccination protocol and 3 years ago we had 4 cases of leptospirosis. Two of the dogs were not current on any vaccines, and the other two came from veterinary hospitals that did not include leptospirosis in their vaccine protocol. We were able to save two of the dogs. This also posed a significant risk to the owners’ health. We advised them to avoid contact with their dogs’ urine and confine the area where their dogs urinate to limit the area that could become contaminated. This past month we had 2 young dogs with unexplained kidney disease that were had not been vaccinated against leptospirosis by their previous vets. Their owners spent some anxious moments while we waited for the leptospirosis titers to come in.

We strongly recommend that all dogs be vaccinated against leptospirosis annually to prevent this potentially fatal disease.

Heartworm Disease

The hot summer months and humidity bring with it mosquitoes which can transmit many diseases to pets and humans. Heartworm disease is prevalent in dogs and to a lesser extent cats and ferrets. Mosquitoes feed on the blood of warm blooded animals. Mammals infected with heartworms have circulating larvae in the bloodstream. When a mosquito ingests blood from a heartworm infected animal, the larvae mature and develop in the host. The larvae eventually migrate into the heart and pulmonary vessels where they mature and cause clinical signs of heartworm disease.

The clinical signs of heartworm disease in dogs often to do not become evident until  late in the course of the disease. These  signs include coughing, exercise intolerance, lethargy, collapse, and even sudden death.

Heartworm disease diagnosis in cats can be challenging. The disease in cats tends to cause signs that mimic asthma. Coughing is the predominant sign, but vomiting and acute sudden unexplained death has been reported. There is no treatment for heartworm disease in cats because cats go into anaphylactic shock when the worms die. The object of heartworm treatment is to kill the heartworms which could induce anaphylaxis. The drugs that are used to treat heartworm disease are also toxic in cats.

Heartworm disease is preventable in all the affected species. The heartworm prevention comes in many forms including : chewable monthly tablets, monthly topical applications that have flea prevention included, and now a 6 month shot for dogs.

Heartworm treatment is expensive. Heartworm prevention is inexpensive and safe. Heartworm disease can cause permanent damage to the pet’s heart. Pets that are not on heartworm prevention, especially in Florida where the mosquito is the state bird, are likely to result in the pet becoming infected with heartworms. I tell clients it’s the proverbial, “ You  can pay me now or you can pay me later!”

There is no reason for an animal to develop heartworm disease. Yearly heartworm blood tests and monthly heartworm prevention will ensure our pets will not contract this potentially deadly disease.

Heat Stroke - Hyperthermia

With summer almost upon us, we have recently been reminded what the southern heat can do to our beloved pets. We were involved in a case last year where 2 large dogs were left in a  car while the owner attended classes at a local university. He had the windows cracked and left water in the car for them to drink. The outside temperature was 94 degrees F and the heat index was over 100 degrees F.  Good Samaritan bystanders discovered the distressed dogs and called Animal Control. When they arrived the female dog was dead and the male was unconscious. The officer wet the dog down with cool water and transported him to our veterinary hospital. His rectal temperature was 105 degrees F and he was non responsive. The normal rectal temperature of a dog is 100-102 degrees F. We applied wet towels on his body and turned on a hose with cool water to wet him down. We applied ice packs to his head and groin and armpit areas. An intravenous catheter was inserted and vigorous amount of fluids were administered. An oxygen mask was placed on his nose and his heart rate and temperature were monitored. Once we felt he was stable enough for transport to the Animal Emergency and Referral Center, he was taken there by Animal Control. He unfortunately did not respond and had to be euthanized later that evening. The owner is facing 2 felony counts of animal cruelty.

 Two days later I read of a K-9 police officer in Woodstock, Georgia with 12 years experience, was arrested after leaving his canine police officer in his cruiser. The dog died, and he faces a felony count of animal cruelty, and he has lost his job. This is particularly disturbing because this happened to a person with experience dealing with dogs.

Hyperthermia can occur very quickly in this brutal Florida heat. The temperature in a car can reach 140-150 degrees F in a very short period of time. Dogs do not perspire. They can only dissipate heat from panting and from slight sweating of the pads of their feet. If the ambient temperature is higher than the dog’s core temperature, panting cannot dissipate the heat, and the dog’s internal temperature can rise very rapidly. Signs of hyperthermia are obvious; panting, restlessness, crying, lethargy, red and tacky gums, unconsciousness, and death.

When the body’s core temperature rises above 105 degrees F, serious damage can occur in a very short period of time to the brain, kidneys, intestines, and blood. Once clinical signs begin, they progress rapidly and can result in irreversible organ damage and death.

Prevention is the key. Dogs and other animals should never be left in a car, especially in the summer. In the heat of the day, pets should be allowed to go outside for short periods of time and they should avoid strenuous physical exertion. If they have to be outside, there should be plenty of shade and adequate amounts of water should always be available. We had an English Bulldog present to our hospital 2 years ago on a Saturday morning with heat stroke. The owner had taken the dog out for a walk on a hot morning. The dog began to pant, and collapsed. The owner carried the dog a half a mile to her house before bringing it to our hospital. The dog  presented  unconscious with a rectal temperature of over 110 degrees F. The owner was riddled with guilt. She innocently took the dog out for a walk, and 2 hours later, the dog was dead. Overweight and brachycephalic dogs are more predisposed to heat stroke. Brachycephalic dogs have the “pushed in noses” and they cannot dissipate heat as well by panting.

Dogs are not the only animals that can experience heat stroke. We own 8 horses and during the summer, we are constantly vigilant of the outdoor temperatures and heat indices. Once the heat index reaches 100 degrees F, we bring the horses in their stalls. We have overhead fans and they have automatic waterers in their stalls.

The people that were responsible for their dogs dying of heat stroke are not bad people. They were people who took chances with their pets’ lives and lost. I am not a gambler because I am not willing to lose. Let’s be safe and enjoy our summer with our pets!

Addison's Disease

Addison’s disease, also known as hypoadrenocorticism, is a condition where the adrenal gland does not produce adequate levels of hormones needed to balance metabolic functions. The adrenal gland produces two types of hormones:

Corticosteroids are hormones that allow us to handle stress, the “flight or flight syndrome”. They control protein and glucose metabolism which are the main sources of energy that allow us to cope with stress factors.
Mineralocorticoids are hormones that control electrolyte balance. This in turn affects kidney function.

The cause of Addison’s disease is rarely found, but it typically affects younger patients, typically 4-5 years of age and it affects females twice as often as males. This disease affects dogs, and very rarely, cats.  Clinical signs can range from no signs, to an acute crisis where the patient is presented comatose.  The first signs an owner might notice is a dog that is consuming more water  and urinating more. As the disease progresses, lethargy, inappetance, vomiting and cardiac signs develop as the potassium levels rise.

Diagnosis is made based on clinical signs, urinalysis, and bloodwork. The classic Addisonian has an elevated potassium and a decreased sodium. The ratio of sodium to potassium typically drops below 25. Kidney values will begin to elevate as the disease progresses. Not all Addisonian patients fit this classic presentation and the clinician must be open to the possibility of Addisosn’s disease in a young dog that presents with unexplained signs of kidney disease even with normal electrolyte levels. Confirmation of the disease is made with a blood test called an ACTH Stimulation test. ACTH (adreno corticotropic hormone) is a hormone produced in the pituitary gland in the brain that stimulates the adrenal gland to secrete corticosteroids and mineralocorticoid hormones. Addisonian patients have low corticosteroid levels and do not stimulate post acth administration.

Treatment is usually very successful. A patient in crisis is given intravenous fluids with sodium chloride, and corticosteroids. Mineralocoricoid supplementation is begun and can be accomplished with an oral medication called Florinef,  or an every 28 day injection called Percortin. Dogs tend to do better with the injection. Care must be taken with future stresses such as surgery, and low dose oral steroid supplementation may be needed for life.

Dogs can live normal happy, productive lives with Addison’s disease as long as they are managed appropriately. The most famous human that had Addison’s  disease was President John F. Kennedy.

Allergic Skin Disease

One of the most frequent reasons pet owners visit their veterinarians for, is to treat and consult over allergic skin disease. The most common clinical signs are: scratching, licking and chewing at their skin and feet, shaking their heads, scales and flakiness of their skin, discoloration of the hair and skin, and hair loss (alopecia).

There are many causes to allergic skin disease:

Inhalent  allergies occur when a patient has an allergic reaction to things that are in the air. The most common of these is pollen. Pets that have inhalant skin disease tend to have clinical signs that are seasonal, or are worse at certain times during the year. This is by far the most common cause, and pets tend to chew at their feet, have ear infections, and scratch to the point where secondary bacterial infections develop which aggravates the itchiness. Most pets develop skin infections as a result of scratching and licking. The itchiness comes first. This is why it is important to identify the cause of the discomfort and not just treat the infections.

Food allergies are an important component in the skin puzzle. Oftentimes they are not the sole cause of the problem, but they contribute to the symptoms. Pets that have food allergies tend to develop these at early ages and have hairloss in the backside , under the tail. Food elimination trials can be implemented to address this potential cause skin discomfort.

Ectoparasites, ie. fleas and ticks are a smaller proportion of the allergic puzzle with the advent of effective products to control  them. Thankfully, we see very few cases of flea bite dermatitis anymore. It is important to exercise good preventive measures to control fleas and ticks, especially in allergic pets.

Contact dermatitis occurs when a susceptible pet is exposed to something they are allergic to by direct contact. The most common areas of the body affected are the feet. A pet that is chewing at their feet and nowhere else, is likely allergic to the grass they are exposed to. Another common sign is redness in the groin area because it is the most hairless part of the body and the part most likely to contact the grass, when a pet lays down. Other possible causes of contact dermatitis are rugs, or towels and even the laundry detergent used to clean the pet’s bedding.

Treatment is aimed at controlling the itch. This is achieved with topical sprays and shampoos, antihistamines, and sometimes steroids. Steroids should be used with caution, and only on a short term basis because of potential long term side effects. Antibiotics are used to control secondary infections and must be continued until the infection is cleared. This could take 2-6 weeks.
Underlying conditions such as hypothyroidism need to be addressed and treated as well.

Diagnosis is made by trial and error, and allergy testing. This can be done with blood testing (RAST) and intradermal skin testing, usually done by a dermatologist. Food trials can be done without expensive testing by trying novel diets. The definition of a hypoallergenic diet is one protein and one grain. If a food trial is instituted, the pet must get nothing other than the food for 30-45 days for an objective assessment to be made.

Anterior Cruciate Injuries

Anterior cruciate injuries are the most common cause of acute lameness in dogs. Cats can develop ACL injuries but do so much less frequently.  Large breed, and overweight dogs tend to be more predisposed. The anterior cruciate ligament is one of two ligaments that help stabilize the stifle or knee joint. Injury can occur in a young active dog, or an overweight dog that has abnormal stresses on the dynamics of the stifle. An injury typically occurs when a dog twists his leg, either running around a corner, or mis-stepping in a hole in the back yard. This is a common injury in professional athletes like football players and skiers.

The typical presentation is a dog that is presented three legged lame, and toe touching. There is usually no pain elicited and the knee may or not be swollen.

Diagnosis is made on clinical history and the presence of an anterior drawer sign. An anterior drawer is when the is abnormal forward movement of the tibia in relation to the femur. This sign can be difficult to elicit in a nervous dog because the tensing of the muscles could artificially stabilize the stifle. Sedation sometimes is required. ACL pull or tear is suspected in any dog that presents with acute, non painful, toe touching lameness. I normally recommend a series of therapeutic laser treatments in our office and send the dog home with glucosamine chondroitin sulfate/ MSM supplements, non steroidal pain medication,  and orders for strict rest, leash walks only, and no running or jumping for at least two weeks. The rule of thumb is if the dog is still lame after two weeks, surgery is usually required to stabilize the joint. If this is not done degenerative joint disease or arthritis sets in very quickly.

There are several surgical options to stabilize the knee joint after an ACL tear:

Extracapsular repair- The stifle is opened and inspected and any remnants of the torn ligaments are removed. If the meniscus is damaged, it is removed, and any bone fragments are cleaned away. A large suture is placed around the back of the joint and inserted in the front of the stifle. This stabilizes the knee. This procedure is best used in smaller dogs that don’t have to support as much weight.

TPLO (Tibial Plateau Leveling Osteotomy)-  This is considered by many, the best way to stabilize the stifle after acl rupture. It is a complex surgery requiring specialized equipment, and many radiographs. This is done by a surgical specialist.

TTA(Tibial Tuberosity Advancement)- This procedure is also complicated, but considered by many to be the preferred method of repair. It is less invasive than the TPLO, but also requires specialized equipment and expertise.

Rehabilitation is important to the ultimate success of any procedure. Rest, and leash walks are a must for 4-6 weeks post surgery. Icing the joint can reduce swelling. Passive range of motion exercises can be begun in 2-3 weeks. Light exercise can be introduced slowly.  Full return to normal function can be expected in 2-3 months.

Fleas

Fleas

We are blessed to live in the semitropical climate of Florida. It is a paradise for humans, but it is also an ideal environment for fleas. Fleas are a year round problem in South Florida. It is important to understand the flea life cycle in order for us to adequately protect ourselves and our pets against these biting pests.

There are 4 stages in the life cycle of the flea:

Egg:  A female flea can lay up to 40 eggs per day. Eggs incubate in warm temperatures of about 65-85 degrees and high humidity. Female fleas lay their eggs on the pet where they fall off into the environment
Larva:  eggs hatch into larvae which feed on the “flea dirt” or flea feces left behind by the adults in the environment. This stage is the stage that picks up the tapeworm eggs that later become infective to the host.
Pupa:  This is the cocoon stage of the flea. They can remain dormant in the carpet for months, waiting for the ideal environmental conditions, and a nearby viable host to feed on, before they emerge as adult fleas.
Adult: Fleas can survive for months without a bloodmeal. Once a suitable host is found, they aggressively attach and feed. A female flea will begin to lay eggs about 24-48 hours after feeding, and continue until she dies. The average life span of a flea is 4-6 weeks and the average time from egg to adult is 21 days.

Fleas can spread several diseases to pets. The most common is tapeworms. A dog or cat will ingest a flea in the process of grooming. If that flea was carrying tapeworm eggs, it will develop into adult tapeworms in the intestine of the host. The eggs are shed in the pet’s stool in egg packets or segments that the pet owner can readily see. The flea larvae then ingest the eggs and the cycle continues.
Flea control must occur on the pet as well as in the environment. Environmental sprays do not kill the egg, larva l, or pupal stages, so if there is a severe infestation, the environment should be resprayed in 3 weeks, when the eggs hatch into adults.

There are many effective products for flea control on the pet. Topical flea applications and oral flea prevention are common and effective.  It is important to coordinate flea control on the pet and the environment to effectively keep these pesky parasites out of our lives.