Toxicology Tuesday, January 15

A common phone call at a vet office is "My pet just ate a house plant; is it poisonous?" This is not a "yes or no" question - the answer depends on the type of plant, what part or parts are eaten, perhaps how much the pet ate, and what type/how big the pet is.

Here is a typical group of house plants (mine):

Ignore the Peace Lily in the back right of this photo - we already covered it in a previous post. The rest came in one of those florist's baskets, a mixed arrangement of foliage plants crammed into a too-small container. It was a "Thank you" gift from Heidi's owners (remember Heidi?) I took the arrangement apart and repotted the plants as small groupings.

Group 1

Group 2

What can you tell us about these plants? Do you know their names, or if they are:

Toxic or Not?
. . . . .

Edit: Wed., Jan. 16

So, from the dearth of responses, I can see this is not a popular topic. Tell you what we are going to do. I'm going to give you some more time to research this one, because it is a toughie, and because I am going to be off the air for nearly two weeks (see next entry.) Here are some close-ups of the six plants in question, and I added some hints to the comments section to help you out.

Answers after I return on January 27.

In Group 1, we have the following three plants:

A. Philodendron

B. Dracaena marginata

C. Dieffenbachia

And, these three plants are in Group 2:

D. Aucuba japonica

E. Parlor palm

F. Syngonium podophyllum

See you in a couple of weeks. Have fun!

. . .

----- Answers -----

It's Jan. 27, I'm back, and here are your answers:

A: Philodendron. A very common household plant, the philodendron is in fact toxic. It, like many of the plants shown here, is a member of the Arum family (Araecea), and the toxic element is an oxalate. (more on oxalates below) Personally, I have had many philodendrons over the years and many houseplant-eating dogs and cats, and I have never had this one be chewed by pets. Neither have I seen a case of toxicity related to Phil in my practices.

B. Dracaena marginata. There are many types of Dracaena, some of which are called "Corn Plants." Most Dracaenas are nontoxic, as is this species.

C. Dieffenbachia. Also called "Dumbcane" for its potential to cause vocal cord paralysis and temporary loss of speech. Listed as toxic, this member of the Arum family also contains calcium oxalates.

D. Aucuba japonica goes by many common names, including Gold Dust Plant, Japanese Aucuba, and Spotted Laurel. It is toxic, too, but here the agent is a glycoside found in the fruit and leaves.

E. The Parlor Palm's Latin name is Chamaedorea elegans, but it is sold as Neanthe bella. (Go figure.) It is nontoxic.

F. Syngonium podophyllum, or Nephthytis, is often called Arrowhead Plant, Arrowhead Vine, or Goosefoot Plant. It is related to Philodendron, and as another member of the Arum family, contains oxalates, making it toxic to pets.

What does all this mean for your pets and mine?

The glycosides found in the Gold Dust Plant are minor toxins. Mild GI upset, vomiting and diarrhea, might be seen if a pet ingests this plant.

Calcium oxalates, the toxic principle of three of the above plants, and the Peace Lily seen in the back right of the first photo, cause oral irritation, drooling, vomiting, difficulty swallowing, and perhaps a loss of voice from vocal cord paralysis. It is rare that a pet would ingest a sufficient quantity to cause serious health risks or death, however.

I am not concerned about keeping any of these plants in my house with my 4 cats and 2 dogs. Interestingly, the two plants receiving the most abuse from my plant-loving cats are the Parlor Palm and the Dracaena, the two nontoxic plants. Is that because they have tried the others and found the bitter taste and oral irritation to be repellent? Is it because the thin leaves look and feel like blades of grass? Or, have we just been lucky? In any event, I do try to keep my cats from chewing the plants, not so much for the cats' sake, as for that of the plants.

The take-home lesson from this exercise is to Know Your Houseplants. You can see this is a challenge, since one plant can have many different common names and even the scientific names may vary. Please, if you have house PETS and house PLANTS, take the time to learn the names of your plants. Do it now, before Fido shreds that thing you got as a housewarming gift from Aunt Fern.

I have two reference books, one by the Sunset publishing house (you can find it at the big box hardware stores) and one by the American Horticultural Society, and I wish I had more. You need at least two books, because no one book will have photographs of every species or variety of houseplant out there. When you buy or receive a new plant, save the care tag that comes attached to it, or at least write down the name.

Toxicology Tuesday, January 8

No hints this week, just a question:

Toxic or Not?

Here's a close-up photo to help you:

And, even closer:

Yep, that's right, we're not talking about the seeds here (which are safflower seeds, by the way) but the mold that is growing on them. And the answer is, most likely TOXIC.

This is a lesson from my own backyard. Last winter, I left a lid off the metal garbage can where I store bird seed, and it got wet. I didn't notice, and popped the lid back on. As the contents of the can got lower, I dumped fresh seed on top, never noticing the developing toxic stew at the bottom of the can. Finally, one day, I scooped out a bunch of seeds and noticed they were discolored. Upon further investigation, I discovered the mold. Yuck!

I started to dump the can in a corner of the yard when I realized that my opportunistic dogs would surely discover this bounty and feast on it. Bad idea. I gathered up what seed I had already spilled on the ground and put it all in the garbage. Come spring, I thoroughly scrubbed and bleached the can before using it again.

Molds are crazy things, a real mixed blessing and curse of Nature. Some of them give us wine and cheese and penicillin. And, some of them can kill us. I don't know precisely which mold this was, but I am guessing some species of Aspergillus, a ubiquitous environmental mold, and one commonly found in various grains.

Moldy corn was discovered to be the culprit in an outbreak of fatal liver disease in dogs in 1959, which was termed hepatitis X back then. It was similar to cases in cattle and swine which had eaten moldy feed. Further study revealed aflatoxins from Aspergillus to be the cause. More recently, in December of 2005, there were several outbreaks of liver failure among dogs which was traced back to aflatoxin contamination of one brand of dog food. (This is not the same thing as the big, multi-brand pet food recall from last year.)

More than 100 dogs died of liver failure from the 2005 episode. Clinical signs are vague - anorexia, lethargy, and vomiting - the same as a hundred other diseases. Later, dogs develop jaundice (icterus = yellowing of the skin and mucous membranes) and blood in the stool or vomitus. Many victims suffer an acute death before developing any signs. Treatment is supportive, and fatality is high. There is no antidote.

I have never seen this particular problem, but I did see two dogs from the same family who got into the garbage and ate moldy cream cheese. The owners had been away and returned to find one dog having severe seizures. We began treating it, but the dog had such severe brain damage it didn't survive. The owners went home, then returned with the second dog, who had just started having seizures as well. It was then they found the cream cheese container. With supportive care, we were able to save the second dog. Why did these dogs have seizures instead of liver failure? I'm guessing it was a different kind of mold.

Take home lesson from today's subject: Don't feed any moldy foods to any animals, and if you do have bird seed, cream cheese, or other foods get moldy, be sure to dispose of it where your pets can't find it.

Toxicology Tuesday, December 18

Holiday decorating involves many seasonal plants. This week, see how many of these Christmas plants you can identify, and more importantly, if you know whether they are

Toxic or Not?

A.

B.

C.

D.

E.

F.

[Bonus points if you can rate them in order, most toxic to least.]

A. Christmas Cactus - Nontoxic
B. *Mistletoe - Toxic
C. Poinsettia - Nontoxic
D. Norfolk Island Pine - Nontoxic
E. Holly - Toxic
F. I didn't know for sure, so I asked you! I thought this was some kind of juniper species, and most of you agreed. If we are right, then as far as I can tell, it is nontoxic to our pets.

And now, for the bonus round:
Mistletoe is the most toxic plant in today's post. All plant parts are considered poisonous, but especially the berries. It can cause severe gastroenteritis (vomiting and diarrhea), a decrease in heart rate and blood pressure, difficulty breathing, erratic behavior (hallucinations in people), seizures, coma, or even death. Holly is the second most toxic plant, primarily causing a severe, self-limiting gastroenteritis if a pet eats the berries. (I saw this once in a puppy, but it is not very common.)

As for the poinsettia, it has gotten a bum rap over the years. Urban legend has the poor poinsettia plant rated someplace between bubonic plague and nuclear war in its severity. In truth, it is basically nontoxic. A pet who ate an entire plant may experience significant vomiting and diarrhea, and it is possible that an ultra-sensitive individual might develop a mild skin rash from contact with its milky-white sap, but that is all. So, feel free to bring this lovely plant into your home and don't panic if Fido or Fluffy try a little taste.

*[Thanks to the US Forestry web site for the photo of mistletoe.]

Since the next two Tuesdays are Christmas Day and New Year's Day, Toxicology Tuesday is going on hiatus for the holiday season. It will be back in 2008.

Happy Holidays!

Toxicology Tuesday, December 11

The holiday season is a hectic one. Don't add to your worries by putting your pet's health and safety at risk. Be sure to check your decorations and other seasonal items, like these simmering liquid potpourris, to see if they are

Toxic or Not

Answer: Toxic

[To be fair, the Hope Rose product said "non-toxic" on the label on the back of the bottle, but there was no list of ingredients, so I don't know anything about it.]

Liquid simmering potpourris, regardless of the scent or season, contain cationic detergents, essential oils, or both, and are one of the top 10 most common poisonings in cats, as reported to the ASPCA Animal Poison Control Center. Cats are exposed by licking the product directly from the container, or when cleaning their fur after a spill. (Dogs would be equally affected, but this seems to be more a cat thing to do.)

Cationic detergents are corrosive, causing chemical burns of the skin, the mucous membranes of the mouth, or the corneal surface of the eyes. Signs are drooling, severe GI distress, skin or eye irritation, and general depression. Essential oils have similar signs.

DO NOT induce vomiting if your pet ingests liquid potpourri. The corrosives burn on the way up as well as on the way down, and can damage the lining of the esophagus. Instead, dilute the toxin with milk or water and seek veterinary help immediately. Affected cats are usually hospitalized for supportive care, including pain management and supplemental feeding, for several days while the ulcerated areas heal. Prognosis for recovery is good, unless the esophagus is severely affected.

Toxicology Tuesday, December 4

Before my sister had these evergreen shrubs removed from her front yard, I took some photos for the blog. Does anybody know what they are, and if they are

Toxic or Not?

Answer: Toxic

especially to horses. This is Taxus, common name yew, which has many varieties. I don't know which one this is, nor does it matter as the toxicity is the same. With toxic plants, it is always important to specify what part(s) of the plant are toxic and to what species. In this case, the wood, bark, leaves, and seeds are all toxic, but not the fruiting structure, the aril (the red "berry.")

In horses and cattle, which are usually poisoned accidentally when someone throws the tasty clippings into the stall or pasture or if yew bushes are planted next to a fence, even one mouthful can be fatal. There are usually no signs, other than "found dead." The toxic agents, alkaloids called taxines, affect the electrical conduction of the heart, resulting in sudden heart failure and death. Rarely, there may be a delay of one to two days before symptoms - weakness, trembling, difficulty breathing, slow heart rate - are seen.

While yew is also toxic to pets and to birds, it is not commonly eaten by these animals. Cases in dogs are usually related to a bored puppy chewing on whatever is at hand. If you see this happen, induce vomiting immediately and take the pet to a veterinarian, as seizures may occur in dogs. There is no specific antidote for taxines, leaving decontamination and supportive care as the only treatment options.

Toxicology Tuesday, November 20

Are you doing any holiday baking this week? Be careful where you leave those yeast breads and rolls to rise, until you answer this question. Is bread dough

Toxic or Not?

Answer: Toxic

Most of those who commented on this week's post correctly identified bread dough as a potential GI foreign body. As the dough continues to rise in the warm, moist environment of the stomach, it expands to the point of abdominal distension, and may result in bloat (GDV: Gastric Dilatation and Volvulus, a life-threatening complication), or possibly even rupture of the stomach. Signs of GI obstruction include active vomiting or non-productive retching. Remember, though, obstruction is not the same as toxicity (poisoning.)

Many of this week's comments also mentioned the aroma of baking bread, which results from the ethanol produced when yeast ferments. A sufficient quantity of unbaked yeast dough will cause alcohol poisoning, and therein lies the toxicity problem.

Signs of ethanol (alcohol) toxicity include alterations in blood chemistry, ataxia (stumbling and incoordination), depression and abnormal mental status, seizures, coma or death.

Treatment involves removal of the dough by cold water gastric lavage ("pumping the stomach") and supportive care, with IV fluids, monitoring cardiac status, and drugs to control vomiting or seizures, if needed.

Recovery takes 12 to 24 hours, but the prognosis is good with prompt treatment.

Toxicology Tuesday, November 13

During Michigan week, you just know we have to talk about BUCKEYES. We already know they are the greatest college football team in the world, but are they

Toxic or Not?

Answer: Toxic

Most cases of buckeye poisoning involve livestock, including cattle, sheep, pigs and horses, which graze on the young sprouts and leaves of the trees when other forage is scarce. Not every animal which eats the plants shows signs of poisoning, however. The buckeye seed or “nut” is toxic as well, although not to squirrels, which will eat them when more favored foods are not available.

The toxic element is called aesculin, and poisoning affects the nervous system. Incoordination and staggering, weakness and trembling, dilated pupils, depression or hyperexcitability, coma and death may all result from buckeye poisoning. GI signs are also common: dogs may have severe gastroenteritis (vomiting and diarrhea), while horses exhibit colic.

There is no specific antidote. Like many poisoning cases, treatment is limited to decontamination and supportive care.

A fact that is well-known to Ohio State fans was not documented in any of the literature I read. Ohio Buckeyes, while toxic to many species, are, without a doubt, absolutely FATAL to Michigan Wolverines!

Toxicology Tuesday, November 6

Perhaps you have been doing what I have been doing lately, planting spring flowering bulbs. And perhaps you have been wondering, "KatDoc, are these daffodils ..."

Toxic or Not?

Answer: Toxic
Many spring flowering bulbs may cause mild to moderate GI irritation, but daffodils (Narcissus) are the worst of the true bulbs. (It is not my intention to discuss other flowering plants with rhizomes, corms, or tubers in this post.)

Remember when talking about toxic plants, we need to be specific about what part or parts of the plant are toxic. In the case of the daffodil, all parts are considered to be poisonous, but the toxic agents, chemicals known as alkaloids, are concentrated in the bulbs.

The primary signs are vomiting and diarrhea, but hypothermia, tremors, convulsions, and death have been reported. Contact dermatitis (skin inflammation) has been seen in people, particularly among workers in the flower industry, from the calcium oxalate crystals found in the sap, but not pets.

There is no antidote for alkaloid poisoning. Treatment consists of decontamination, IV fluid support, and additional medications for seizures, if needed. The signs may last from a few hours to a day.

Additional spring flowering bulbs that may be toxic (agent):

Tulips - mild vomiting and diarrhea, contact dermatitis (allergens)
Crocuses - vomiting, diarrhea (unknown)
Snowdrops (Galanthus) - vomiting, diarrhea (alkaloids)
Hyacinth - vomiting and diarrhea (unknown agent), contact dermatitis (allergens)
Grape hyacinth (Muscari) - vomiting, diarrhea (unknown)

Toxicology Tuesday, October 30

Once again this week, I took a wrong turn in the grocery store and got lost in the produce section. While I tried to find my way out, I wondered whether these avocados* were

Toxic or Not?

*(Here, we are talking about the flesh of the fruit only, not the bark, leaves, rind, or pit.)

Answer:

Toxic, to birds, particularly psittacines (parrots)

OK, I’ll confess. This post was a bit sneaky. First of all, everybody should know by now that KatDoc doesn’t do bird medicine, so you are forgiven if you didn’t think “avian” when you read this one. Secondly, the people who noted that I specified only the fruit recognized there was some trick to this question.

The point I wanted to make with this week’s quiz is to help you become discriminating researchers when you look up toxic plants on the Internet or in various pet publications. Most of these sources just run a list of plant names, without specifying what part or parts are toxic, what species may be affected, and whether the toxicity is limited to mild GI distress or is more severe.

In this week’s case, avocado bark, leaves, rind, and pits have all been implicated in various toxicities in a number of different species. Dogs may experience vomiting and diarrhea. Horses, physically unable to vomit, develop colic, which can be fatal. Goats have been reported to develop mastitis (inflammation of the udder) from eating avocado leaves. Cattle, rabbits, rodents, cats and fish are also among the listed species affected by the plant parts, but only birds seem to be severely affected by eating the fruit.

Respiratory distress, congestion and fluid accumulation in the tissues around the heart can lead to death in several avian species. My various sources listed parrots, budgies, cockatiels, canaries, and ostriches specifically. The toxic agent is a fatty compound called persin. No treatment was mentioned, nor could I find a toxic dose.

Here’s an interesting fact: The Guatemalan type of avocado (Persea americana) is toxic, but the Mexican variety (P. dryminfolia) apparently is not. According to my reading, the most commonly available avocados in the US are of the Guatemalan variety.

Finally, critically evaluate your source before freaking out when Fido steals the guacamole. All the legitimate references I checked (ASPCA’s Animal Poison Control Center, U of Penn, Wikipedia) reported nothing more than GI signs in dogs, but one unnamed site called avocados “highly toxic” and “deadly” for dogs, without citing their source or giving any data. Question everything you read (including this blog!) before jumping to conclusions on the safety of anything your pet eats.

Charlie, aka "Chuckles,"
a 21 year old Chestnut-fronted Macaw,
says, "Don't eat avocados!"

photo by Charlie's human mate, Julie Zickefoose
[Thanks, Zick!]

Toxicology Tuesday, October 23

I broke open my piggy bank for this week's post. But, if I leave them on the floor where the dogs can swallow them, are these pennies

TOXIC OR NOT?

Answer: Toxic

Pennies minted after 1982 are made of 99.2% zinc with only a thin copper coating. Once in the stomach, the stomach acids begin to dissolve the zinc, and it is absorbed and transported to various organs.

Initial signs are associated with the local irritant effect of zinc oxide on the stomach lining. Anorexia, vomiting, diarrhea and a general depression are seen consistently even with short-term exposure or low levels of ingestion. Long-term exposure or higher levels lead to systemic signs. Kidney failure has been reported, but the most common syndrome is Acute Hemolytic Anemia.

Zinc causes damage to the cell membrane of the red blood cells, and the immune system begins to remove these damaged cells. Hemolysis, the break-down of red blood cells, leads to icterus (jaundice, a yellow coloration of the skin and eyes) and anemia, a decrease in the number of red blood cells in the bloodstream.

Treatment involves removal of the penny (pennies), either through surgery or the use of an endoscope, IV fluids and other supportive therapy, blood transfusions in cases of severe anemia, and sometimes chelation therapy, using calcium EDTA to speed removal of the zinc from the system.

Other sources of zinc are the locking nuts on older pet carriers (newer ones are plastic) and other types of zinc-coated hardware, zinc pieces from board games, ointments like Desitin and zinc oxide sun blocks, batteries, some paints and medicated shampoos.

Toxicology Tuesday, October 16

With Halloween upon us, you may be considering glow-in-the-dark jewelery for your little goblins. But wait - what if the pets get a hold of them? Are they

Toxic or Not?

Answer:
Non-toxic.

If glow jewelry was poisonous, would I let our favorite Boston Terrier wear it?

"Mether! Look what KatDoc brought!
All for me!"

"Where did they go?
Did I frighten them away?"

Glow sticks and jewelry contains an oily substance called dibutly phthalate. While its bitter taste may cause some hypersalivation, particularly in cats, it is generally considered safe for pets and children. Unusual behaviors, such as hyperactivity or agitation, may result if the pet is upset by the taste. Rinse the pet's mouth out with water, and offer some soft food. Remember to remove any of the oily substance from its fur, so that it isn't re-ingested as the pet grooms itself.


Warning:
Glow in the dark jewelry has been known to bring out the Gremlin in even well-mannered pets, so please supervise them when they are wearing the latest in dog fashion.

Toxicology Tuesday, October 9

[Next week, I promise we will go back to the True/False format, and stop with the hard stuff. My sister says "It doesn't matter what the toxic principle is, if your pet eats poison, take it to the vet. You are being too picky with this series." But, the Science Chimp says "Knowledge is Good," or words to that effects, so bear with me one more time.]


The last poison in our rodenticide series is bromethalin, found in brand names like Rampage and Real Kill.


Remember the questions:

1) What is the toxic principle? (How does it kill?)
2) What are the signs/symptoms of poisoning?
3) Is there any treatment?
4) How bad is it - (On a relative scale of Fair - treatable if caught in time, Poor - might not survive even with treatment, or Grave - likely to be fatal even with treatment)

Give it a try, answer any or all questions, in part or in total. No one is laughed at for wrong guesses, and all attempts at answering will receive praise and public accolades.

Answer:

Bromethalin is a neurotoxin, and the signs are related to dysfunction of the CNS (Central Nervous System), primarily brain swelling. These signs are highly variable, depending on the dose ingested. Low doses in dogs lead to depression, anorexia, vomiting, and tremors, which may not show up for several days. Paresis (muscle weakness) or paralysis may also occur. High doses can cause a hyperexcitable state, tremors, increased reflexes, running fits, and localized or generalized seizures. In cats, the signs include depression, ataxia (incoordination), abdominal swelling, paralysis, and convulsions. Death can result from either high or low dose toxicity in both species.

These signs are non-specific; they are seen in many kinds of neurologic disease. If you don't have a history of exposure to the toxin, it might go undiagnosed, as it wouldn't show up in any of the routine laboratory work. It can take up to 4 days for initial signs to show in a dog, and may progress for one or two weeks before death from respiratory failure.

There is no antidote to bromethalin. It is rapidly absorbed into the system, and reaches peak blood levels a mere 4 hours after ingestion. If ingestion is observed, immediate decontamination (as discussed in previous posts) is the first course of action, and may be of some benefit. Otherwise, treatment is mainly supportive, including cautious use of IV fluids, diuretics, and steroids and mannitol to reduce brain swelling. The prognosis is grave in pets which are exhibiting symptoms.

Bormethalin was the second most common rodenticide I found when I shopped several local stores. About 75% of the products readily available were Vitamin K antagonists and about 25% contained bromethalin. I only found one store that carried one brand of cholecalciferol (Vitamin D) based mouse poison.

To sum up our three main types of mouse and rat poison:

1) Brodificoum, bromadiolone, and warfarin: Deplete the body's store of Vitamin K, causing bleeding problems. Antidote is Vitamin K. Prognosis: Fair. A good chance for recovery if treatment is started in time. Most common poison on the market.

2) Cholecalciferol: Vitamin D. Causes mineralization of soft tissues, especially the kidneys. No antidote, but early and aggressive treatment can speed the excretion of excess calcium, limiting the injury to major organs. Prognosis: Poor. Even with treatment, kidney or heart damage may leave animal with long-term health problems. Least common product available.

3) Bromethalin: A neurotoxin causing nonspecific signs. No antidote. Prognosis: Grave. Death is likely even with treatment. Second most common product.

So, how do you get rid of mice? Sticky traps are non-toxic, but I think we all agree that it is a cruel way for a critter to die. Old fashioned snap-traps are easy, quick, painless and non-toxic. If you can't stand to take the mouse off the trap, toss it - they're cheap. Unless you have a tiny pet, there is limited injury to "non-target organisms." Or, get a cat. I have one I will rent you.

Toxicology Tuesday, September 25

Last week's "essay question" style Toxicology Tuesday wasn't as popular as previous "True/False" or multiple guess quizzes, but let's give it another try. I'll even give you some hints this week.

Here is a different type of rodenticide (mouse/rat poison): cholecalciferol. We know if it poisons mice and rats it is toxic to dogs and cats, since they are mammals, too. The question is how does it affect them?

What is the toxic principal/how does it poison? (Hint: Last week, we had a toxin that altered Vitamin K metabolism, this week is another poison that involves a vitamin.)

What signs might you see?

Is there a treatment?

How poisonous is cholecalciferol/what is the prognosis? Remember our scale of: Fair - treatable if caught in time; Poor - might not survive even with treatment; or Grave - likely to be fatal even with treatment. (Another hint, last week's anticoagulants had a Fair prognosis, this week is different.)

Be bold, be brave - jump in with your guesses. Partial credit is awarded for any attempt to answer, and please show all your work. Neatness counts!
==========================================================

ANSWERS:Cholecalciferol is Vitamin D3. Not only is it found in rodenticides like Rampage, Quintox and Rat-B-Gone, it is also found in multivitamins and some calcium supplements like Viactiv. While it is possible for a pet to be overdosed on Vitamin D3 by eating vitamin or mineral supplements, the risk is much greater from ingesting rodenticides containing cholecalciferol.

Vitamin D3 is a fat soluble vitamin. It is necessary to maintain the delicate balance of calcium and phosphorous in the body. Calcium is not only needed for strong bones, it is a major part of the electrical system of the heart muscle. Excessive intake of Vitamin D3 leads to abnormal calcium and phosphorous levels, irregular heart beats, and the mineralization of soft tissues. In other words, calcium is deposited in the soft tissues of the body, essentially “turning them into bone.” The GI tract, skeletal muscle, heart and blood vessels may be affected, but the kidneys are usually the primary problem.

Clinical signs are vomiting and diarrhea (sometimes bloody.) The bait pellets are blue, so blue vomitus is a key finding. Other signs, including increased water intake and urination, lethargy, and muscle weakness, may be seen in the first 48 hours after poisoning. High doses results in acute renal (kidney) failure. Death can occur in severely affected animals. Those which survive may have long-term consequences, including chronic renal failure and cardiac arrhythmias.

If an animal is observed eating this type of poison, immediate attention is mandatory. It must be treated immediately after ingestion by decontamination (induce vomiting, gastric lavage, administer cathartics and activated charcoal) and must be monitored for physical symptoms and any changes in blood calcium, phosphorous, and kidney levels. If there are no physical or biochemical changes in four days, the prognosis is good for recovery.

In animals with clinical signs or elevated calcium levels, treatment consists of IV saline solution, furosemide (a diuretic) and prednisone to increase excretion of calcium in the urine. Diets low is calcium and phosphorous and oral phoshate binders are also part of the treatment process, which may last 6 weeks or longer. Prognosis in these cases is poor, due to the potential for chronic, lifetime kidney and heart damage.

The toxic dose starts at 0.5mg/kg body weight. This is the equivalent of 6 grams (about ½ tablespoon) of the typical 0.075% concentration bait in a 20 pound dog. (Another source gave a much higher level, 12-20mg/kg, as the toxic dose.) Secondary poisoning, from eating a mouse or rat which died from cholecalciferol poisoning, has not been reported.

This is not a common poison, at least in my area. I had to go to 10 different stores to find one example of a Vitamin D3-based rodenticide. I have only seen one case of cholecalciferol toxicity in 21 years of practice.

Toxicology Tuesday, September 18

This is Toxicology Tuesday with a Twist. I’m not going to insult you by asking you if rat and mouse poisons are toxic or not. You know they are. What I am going to do is present you with three different types of rodenticides over the next three weeks and ask you the following questions:

What is the toxic principal? (That is, how does it poison – kidney failure, liver damage, etc.)

What signs might you expect to see?

What, if any, treatment is available?

How toxic is it/what is the prognosis? (On a relative scale of Fair - treatable if caught in time, Poor - might not survive even with treatment, or Grave - likely to be fatal even with treatment)

This week, we are looking at D-Con and other brands of mouse poison that contain brodifacoum, bromadiolone and diphacinone.



Are you ready for the challenge? Try it; see how much you know, or can guess.
***************************************************************

Answer: By far, the most commonly available rodenticides are the anticoagulants. The toxic principal of these agents is to cause depletion of the body's store of Vitamin K. Since this fat soluble vitamin is necessary for the manufacture of several clotting factors, running out of Vitamin K means losing the blood's clotting ability, and the development of bleeding problems. Warfarin was the original product, and is still available, though not common. It fell out of favor because it requires rodents to feed multiple times in order to ingest enough poison to kill them. Those early animals which didn't receive a fatal dose bred, leading to the creation of warfarin-resistant populations. The second generation products, like brodificoum, kill with one feeding, thus eliminating the resistance problem.

It typically takes 3 to 5 days for an animal to run out of Vitamin K, so the signs don't show up right away. Bleeding can be obvious - blood in the urine, stools, or vomitus, bloody nose, bleeding from the gums, excessive bleeding from a minor wound or from clipping a toenail too short - or it can be more subtle. Pinpoint spots of blood under the skin called petechiae may be seen. (Birding note: The Yellow Warbler got his Latin name, Dendroica petechia, from the fine red streaks on his breast.) Bleeding into the joints can cause lameness, internal bleeding may cause shock with no external signs of injury.

In cases of known ingestion, treatment consists of decontamination (induce vomiting, gastric lavage, use of cathartic agents, and administration of activated charcoal) and monitoring blood clotting values. If the blood tests show toxic changes, the pet is started on Vitamin K therapy. If the pet is already symptomatic, Vitamin K treatment is initiated immediately and continues for up to 30 days, while monitoring blood values regularly. Severe cases may need blood or plasma transfusions.

On my "how bad is it" scale, the anticoagulants have a Fair prognosis. With early and aggressive treatment, most pets are likely to survive this poisoning.

Because of the wide variability in the types of anticoagulant agents and the differences in individual pets, it is impossible to give a rule of thumb for how much poison is significant. Take ALL pets who ingest any kind of mouse or rat poison to the vet immediately, and bring the package with you, even if it is shredded or damaged. Important information may still be obtained from the label.

This final question always comes up: What if a cat (or dog) eats a mouse (or rat) who has eaten poison? In the majority of cases, there is not enough of the active ingredient in the rodent to affect the pet, however, barn cats who eat a lot of poisoned mice could accumulate enough poison to develop bleeding problems.

Toxicology Tuesday, September 11

Toxic or Not?

Answer: Not toxic (But, see discussion in the Comments section)

Toxicology Tuesday, September 4

A recent visit to the produce section of the grocery store had me wondering ... are these vegetables

Toxic or Not?

Answer: Toxic to both dogs and cats

Onions, leeks, and garlic are all members of the Allium family, and are common toxins in dogs and cats, along with chives, scallions, shallots and the many wild native and domesticated ornamental Allium species. Alliums contain a variety of organosulfides, chemicals which, when metabolized, are converted to highly reactive oxidants. These lead to oxidative hemolysis, or break-down, of red blood cells.

Organosulfides may be found in all parts of the fresh plants, in raw or cooked foods, or in liquid, powdered, or dehydrated preparations. As little as 5gm/kg of onions in cats or 15-30 gm/kg of onions in dogs may result in clinical signs of toxicosis. That’s about 1 ounce in a 10 lb cat or 5 to 10 oz in a 20 lb dog. Poisoning may occur from a one-time binge, or the effects may be the result of cumulative ingestion if there is a constant source available (i.e., a dog who regularly “grazes” on Allium species found in the yard or garden.) Some dogs, notably Japanese breeds, have an inherited defect making them more susceptible to onion toxicosis, and certain medications can also increase the risk of toxicity.

Signs of onion toxicosis are related to the anemia which results from hemolysis (destruction) of red blood cells: rapid heart beat and respirations, weakness, exercise intolerance, pale or yellow color to the gums, depression, decreased appetite or activity, or a dark color to the urine. These symptoms may be noted within one day if a large amount was ingested, or it may take several days for signs to develop in cases of chronic exposure.

There is no specific antidote for this poisoning. Treatment is primarily decontamination (inducing vomiting and administering activated charcoal) in cases where ingestion is known to have taken place in the last 1-2 hours and supportive care. Severe cases of anemia may require a blood transfusion.

Note: Some people give their pets garlic pills or supplements as a flea preventative. This practice a) could potentially lead to toxicosis and b) doesn't work for fleas anyway. (Flea prevention post is coming up.)

Note 2: Some people sprinkle onion or garlic powder on their pet's food as an appetite stimulant. This practice a) sometimes works, but b) should be used with caution - tiny amounts, infrequently, and not in pets who are increased risk for toxic effects (Japanese breeds, on sulfa drugs, has other risk factors for hemolytic anemia.)

Note 3: Baby food is sometimes used to encourage a pet's appetite, especially in cats, and baby food often has onion powder in it. Whether or not this is enough to cause any toxicity is a matter of debate. I personally think it would only be a problem if the cat ate nothing but jars of baby food for some time.

Aside: In vet school, we called this "White Castles' Syndrome." If you aren't from Ohio, you might not get this joke. If you have eaten White Castle burgers (aka "sliders") you have my sympathy.

Toxicology Tuesday, August 28

How do you answer this week's Toxicology quiz?

Toxic or Not?

What do all these products have in common? Each of the above items (except the Hartz product) contains 45-65% permethrin, a synthetic insecticide. (The last item contains phenothrin, a similar agent.) Permethrins have a good margin of safety in dogs, but even a small amount of any of these products are TOXIC to cats.

Pyrethrins are the natural pesticides derived from chrysanthemum flowers, which are very safe and which break down quickly. They can be used in cats and young animals with little to no risk of injury. (Note: Anything is potentially toxic to an animal with a sensitivity to that agent.) Man-made pyrethoids like permethrin last a lot longer and are safe for dogs. The packages always bear warning labels saying not for use in cats, though some are more obvious than others. There are at least 18 different permethrin products available, and it doesn't matter if you get one from a veterinarian, the Internet, a pet store, or any other source - permethrins extremely toxic for cats.

Permethrin toxicity is one of the most commonly encountered poisonings in cats. While some cases occur accidentally, most are caused by owners who deliberately ignored the package labels, applying it to cats in spite of the cautions. I can’t count the number of permethrin toxicities I have treated over the years, and every case was caused by operator-error. Excuses were usually “I just put on half; I only used a little,” and so forth. NOT FOR USE ON CATS means none, never, ever, not even half the tube, not even a little bit, none whatsoever.

Other cases are the result of accidental application, or rarely by cats coming in close contact (grooming, cuddling) with dogs who have had these products applied. My cats frequently snuggle up with my dogs – I won’t have a permethrin product in my house.

Signs may appear within a few hours but can take up to 72 hours to show up. Muscle tremors are most common, and seizures may occur. With aggressive (and expensive) treatment (decontamination, IV fluids and medications like methocarbamol for tremors and diazepam for seizures) the prognosis is good.

If you accidentally apply a dog product to your cat, bathe it in Dawn dish detergent immediately and contact your vet. If your cat is already symptomatic, skip the bath and go directly to an emergency service for intensive care.