July 2014 – Dr. Nelson's Veterinary Blog

You Make The Diagnosis: Eye Problems in Welsh Corgi

Welsh Corgi or the Pembroke Corgi are prone to certain eye problems. Thankfully, the beautiful dog pictured below does not have any issues. As you can see, she has beautiful eyes. Name the common eye diseases in this breed. These diseases may be inherited, congenital or acquired.

Diagnosis:

Distichiasis which means abnormal eye lashes that create problems when they rub on the cornea.
Cataracts.
Persistent pupillary membranes which look like a spider web in the eye.
Retinal dysplasia and detachment.

Source:

-Ketring, Kerry. Breed Predispositions of Eye Disorders. VIN Associate Database, 10/27/2005.

You Make The Diagnosis: Common Dog Parasite

Last week, a client brought in a fecal sample from their puppy. The dog had been given a medication to kill internal parasites called fenbendazole. What are the long white worms called? How did the pup get them? (The intestinal parasites or worms are the things that look like spaghetti noodles.)

Diagnosis: Roundworms ( Toxocara canis)

Roundworms are a common problem in puppies. They can become infected from their mother’s while in the uterus (transplacental infection) or while nursing (transmammary infection) or by eating the infective larval form of this parasite. Once inside, the larva migrates through the pup’s body until it reaches the lungs. The pup coughs and then swallows the larva back into the gastrointestinal tract. Eventually, the larva matures into an adult worm in the small intestines and starts laying eggs to infect a new generation of dogs.

***Note: Roundworms can infect humans. Please check your pet’s feces for parasites at least once a year.

Source: -Rothrock, Kari and Shell, Linda. Ascariasis/Roundworms (Zoonotic) VIN, Associate Database, written 4/25/2006 and revised 9/19/2013.

Immune Mediated Hemolytic Anemia (IMHA) in Dogs

Immune mediated hemolytic anemia (IMHA) is a life-threatening disease in dogs. This disease is also called autoimmune mediated hemolytic anemia because the dog’s immune system actually makes antibodies against it’s own red blood cells. If large numbers of antibodies attach to a red blood cell, it will lyse or burst open inside the bloodstream. Red blood cells with only a few antibodies on their surface will be destroyed by the spleen or liver. Either way, red blood cells are destroyed causing anemia.

Dogs with IMHA usually come into the clinic breathing fast and hard. It is more common in females than males. Their gums are often pale with a hint of yellow (jaundice) due to the release of hemoglobin normally found inside the red blood cells. To diagnose this condition, a drop of blood is mixed with a drop of saline. The antibodies on the surface of the red blood cells make them stick together and clumping will be observed. To me, it looks like pepper.

Once the diagnosis of IMHA is made, I try hard to classify it as either primary or secondary. Secondary means the immune response was caused by something like infection, drugs, parasites, poisons, insect stings, cancer or vaccination with a modified live vaccine. In Arizona, I see a lot of IMHA caused by tick fever (Erhlichia). Primary means that no inciting factor is found. In my experience, these cases are associated with a poorer prognosis.

The goal of treatment is to stop the destruction of the red blood cells with immunosuppressive therapy. If the patient’s anemia is severe, a blood transfusion may be required. Transfusions are only given in critical situations because the new red blood cells will stimulate the patient’s immune system even if they are cross matched. In secondary IHMA, the inciting cause is treated when possible. In dogs who do not respond well to drug therapy, surgical removal of the spleen will often help.

Females are more prone to this disease than males. According to the literature, the following breeds are predisposed: cocker spaniel, collie, English springer spaniel, French poodle, Irish setter, miniature schnauzer and old English sheepdog. In my experience, I see it in these breeds plus Yorkshire terriers and Pomeranians.

Source:

-Vasilopulos, R. & Mackin, A. Immune Mediated Hemolytic Anemia (IMHA). VIN Associate Database, updated 11/10/2005.

You Make The Diagnosis: Rare Blood Disorder In Dog

Pictured below is the blood from a female cocker spaniel. She was anorexic, lethargic and breathing harder than normal. When I looked at her gums, they were pale. Her eyes, gums and skin, had a faint yellow tint. I placed a sample of her blood in a purple top tube. The EDTA in this tube prevents clotting so the individual cells can be analyzed. The sample immediately formed what looked like pepper in the tube. What is this condition called? What causes it?

Diagnosis: Autoagglutination

Autoagglutination means clumping of the red blood cells. See the dark specks in the sample that look like pepper? These are red blood cells that have stuck together. This condition is caused when the dog’s immune system starts making antibodies against their own red blood cells. The antibodies make the cells stick together. When the blood circulates through the spleen, it removes the antibody tagged red blood cells. This dog was lethargic and breathing heavily because she was anemic. The yellow color is called icterus or jaundice. It is caused by all the hemoglobin released from the red blood cells.

Autoagglutination is the clinical sign for an disease called immune mediated hemolytic anemia. This condition is more common in females than males.

Scorpions Pose Threat To Pets

In Arizona, the bark scorpion ( Centruroides exilicanda and Centruroides sculpturatus) is the most common type of scorpion. These insects hide during the scorching daytime temperatures then come out at night to hunt. They sting their prey with their tails, injecting a potent venom.

Scorpion venom contains a potent neurotoxin that can cause disorientation, hypertension, paralysis, convulsions, excessive tearing and salivation, muscle fasciculation and even contortions. Animals who have been stung by a bark scorpion also cough. I am not sure why this occurs but the cough helps me make the diagnosis. I read an account of one veterinarian who was stung on the finger by a bark scorpion. He said his throat felt like it was full of grit. Perhaps the animals are experiencing the same thing.

Treatment for scorpion stings is primarily symptomatic which means treating the symptoms as they occur. Most pets require medication to control pain, seizures and hypertension. Some animals will have severe muscle spasms. I saw a marmoset monkey that had a bad habit of eating scorpions. This little monkey had full body contortions that started with her face and spread backward. There is an antivenin designed for children that also works in animals. The monkey I mentioned made a complete recovery about 20 minutes after receiving the anitvenom although she slept a lot for the next day and seemed stiff.

Besides using the venom to catch food, scorpions also use it for defense. The venom is extremely painful to most mammals. Once injected, it attaches to sodium channels of the nervous system that transmit pain. Grasshopper mice have a modification to their sodium channels that blocks this from occurring allowing them to feast on scorpions. If stung, they might groom the area but are otherwise unharmed. I obviously need to get grasshopper mice for my garage where this scorpion was found!

Sources: -Johnson, Jay. Scorpion Envenomation and Treatment in Chelonia, Association of Exotic mammal Veterinarians Conference 2013. -Rowe, Ashlee, et al, Voltage-gated sodium channel in grasshopper mice defends against bark scorpion. Science Oct. 2013; 342 (6157):441-6. -Shell, Linda. Scorpion Envenomation, Canine Associate Database, Vin 6/5/2010.

EPA’s Prohibition of Second-Generation Anticoagulants Creates New Problems for Pets and Children

In 2008, the Environmental Protection Agency (EPA) decided to ban the use of second-generation anticoagulants in products used to control rodents. Anticoagulants kill pests and pets by causing the animal to bleed to death. This ban will go into affect in 2015. To comply with this ban, many manufacturers of rat baits and other rodenticides have switched to using a neurotoxin called bromethalin. Unfortunately, this compound has no known antidote. When children or animals consume this product, it kills by causing swelling of the brain due to salt accumulation. Common clinical signs include weakness, depression, vomiting, tremors and eventually seizures.

Why I consider this poison worse than the anticoagulants is because there is no antidote. If the poisoning is caught right away, within 10 to 15 minutes, vomiting is induced. After that, the patient is given repeated doses of activated charcoal to absorb the poison. Once bromethalin causes brain swelling, these patients require several days of hospitalization. So far, I have only seen this toxicity in dogs. The last one required a week of intensive care to recover.

In contrast, vitamin K1 is the antidote for anti-coagulant toxicity. The poison takes much longer, often three to five days to cause death giving much more time for treatment. Even though the vitamin K1 treatment is usually eight to twelve weeks, it is still much cheaper.

As I stated above, most but not all of the manufacturers of rodenticides have switched to bromethalin. d-CON decided to return to use of first generation anticoagulants in their products. I applaud this decision as it will give me more time to treat my patients and make it less expensive for their owners. However, I would prefer people use other methods to control rodents. Here are a few suggestions that have worked well for me:

Remove all food sources that attract rodents. This includes pet food and fruit dropped from trees.
Make the environment less hospitable to rodents by cleaning up debris and removing overgrown vegetation.
Do not kill snakes or other rodent predators.
If you have to catch rodents, use a humane trap.

Source: -Scheidegger, Julie. ‘d-CON complies with EPA, but sticks with anticoagulant rodenticide. Toxicology expert cites 65 percent increase in bromethalin exposure calls since EPA banned second-generation anticoagulants’ dvm360 July 2014, p. 10.

You Make The Diagnosis: Common Schnauzer Blood Disorder

Pictured below on the left side is a blood sample from a Miniature Schnauzer who presented for vomiting. Abdominal X-rays showed an empty stomach with no other abnormalities. We drew blood from the dog, placed it in a serum separator tube then spun it in a centrifuge. After the spinning finished, the yellow colored material in the tube separated the cells in the patient’s blood (Dark red area below the yellow plug) from the serum. Instead of the normal clear straw-colored serum, this dog’s serum was pink. Name the condition, what medical diseases are often associated with it and how is it treated? (Please note: The serum on the right is slightly red in color because some the red blood cells ruptured during the blood draw and spinning.)

Diagnosis: Hyperlipidemia

Miniature Schnauzers are prone to a condition called hyperlipidemia which means ‘too much fat in the blood’. In my experience, patients with hyperlipidemia are prone to pancreatitis, diabetes mellitus and inflammatory bowel disease. This condition improves with a low fat diet. In a few dogs, I have to prescribe additional therapies to control it.

Unfortunately, many dog foods marketed as low fat aren’t. Pet food manufacturers list the amount of fat in the food either ‘as fed’, ‘guaranteed analysis’ or ‘metabolizable energy’. I use the metabolizable energy because it tells me how much of the fat will actually be metabolized by the patient. I had a client who didn’t want to feed a prescription diet. They found an over-the-counter diet with a minimum of 8% fat in the guaranteed analysis and fed it to their dog. He developed pancreatitis after two weeks on the food. Although the guaranteed analysis was 8%, the fat actually measured well over 30% in metabolizable energy.

Children’s Hospitals & Clinics of Minnesota

On August 6th I have the privilege of serving as a conversationalist at CHA’s Table Talk in St. Paul. We will have a wonderful time and raise money in support of Children’s health. One of the great programs Table Talk helps fund is Pets Assisting With Healing (PAWH).

Animals bring a world of medical benefits to human health. The simple presence of animals in children’s hospitals helps the kids heal both mentally and physically. All attendees will receive a coupon to download a copy of Coated With Fur: A Vet’s Life. I hope you will join us and support CHA. More information is available at www.cha-stpaul.org.

Watch Out For Cane Toads

This morning I was out walking my dog when we came across a toad sitting under a bush. In Arizona, the Sonoran Desert toad comes out during our summer monsoon season. These toads are part of the Bufo genus of toads commonly called cane toads. The marine variety are found in Florida and Hawaii while the Colorado River toad, the other common name for the Sonoran Desert toad, is found in the desert southwest. Unfortunately, these toads were also introduced into Australia.

Bufo toads secrete toxic substances from their salivary glands. I have read reports of teenagers in Arizona dying after they licked a toad to get high. When a dog licks or picks up a toad, the dog absorbs the toxins through the mucous membranes of the mouth. It must burn because dogs will whine, paw at their mouths and salivate excessively. Their gums are bright red. After about 20 to 30 minutes, the dogs start to have problems walking. As the full effects of the toxin are felt, dogs start to seizure. The toxin can also cause life-threatening cardiac arrhythmias. Thankfully, the toxin is short lived, usually about an hour.

If your pet contacts a cane toad of any variety, flush the area immediately with water. For the mouth, I have my clients use a garden hose to run water through their pet’s mouth for ten minutes before coming into the clinic. ***Caution: Never place anything in an unconscious animal’s mouth as it may aspirate.*** I always recommend monitoring the pet with an EKG for at least an hour to check for abnormal arrhythmias.

Sources: -Shell, Linda. Bufo Intoxication, Toad Poisoning, VIN Associate Database, 3/25/2010. -Wooden, Bill and Wooden, Beth. Sonoran Desert Toad (Bufo alvarius), Arizona-Sonora Desert Museum, https://www.desertmuseum.org/books/nhsd_desert_toad.php

Pet Food Label Confusion

In my experience, all pet people want to feed their beloved pets good food. But how do you know if a food is right for your pet or not? How do you separate the facts about the food from the advertising claims? As a veterinarian, I recommend studying the nutritional adequacy statement which is required by federal law. Here are the three questions it answers:

Is the food complete and balanced? If the label uses the term ‘complete and balanced’ it contains everything the pet needs in the proper amounts to meet all of its nutritional requirements and maintain health.
For what stage of life is the food designed? For example, is the food designed for puppies and kittens or adults?
What method was used to determine the protein, fat, fiber and moisture content of the food? ‘Guaranteed analysis’ and ‘as fed’ are the most common methods. The package will usually use the method that presents its product in the most favorable light. I always ask for this information in ‘metabolizable energy’ because it tells me how much of the foodstuff is actually converted by the pet into energy. For example, I had a client with a dog who needed a low fat diet. The owner bought what they thought was a low fat diet based on the guaranteed analysis value of 10%. The diet was actually well over 30% fat in metabolizable energy and therefore, not appropriate for this patient.

Source:

VIN News Service staff writer, ‘Profusion of pet food choices cooks up confusion’. VIN News Service 6/2/14.