Bladder Stones
Posted by Aaron
Wednesday, April 29, 2009
Cocoa Bean Mulch
Posted by Aaron
Tuesday, April 28, 2009
This e-mail is making the rounds again, so I wanted to make a point about it. The e-mail states that this poor unsuspecting owner purchased a bag of mulch that said on the bag it was only toxic to cats (first flag - why would mulch say only toxic to cats that eat it?) from Target. Their dog then ate a bunch of the mulch and the next day went for her walk and died on the spot. Although the e-mail is bunk, the general facts are semi-accurate.
Yes, cocoa bean hulls are toxic to dogs and cats. No, Target is not the root of all evil (Wal-Mart is). The e-mail talks about how dangerous this stuff is.
Like all parts of the cocoa bean, the hull contains theobromine. Theobromine is a cousin of caffeine. Dogs and cats don't handle caffeine well. They can tolerate small doses, but not much. Humans, on the other hand, can tolerate quite a bit of it.
Cocoa bean mulch is fantastic. It smells great, degrades into a wonderful humus. Just don't let your dog eat it. Don't use it in the yard where they will be unattended because it does taste good to them.
Chocolate intoxication in a dog looks like a non-coffee drinking person that just shotgunned an entire pot of espresso. Some people could survive it, but chances are that they'll land in the hospital with a heart rate that's through the roof and seizures. The symptoms don't take a day to show up. They show up within an hour and only get worse. These guys get REALLY sick in a hurry and will start to act completely wired out of their gourd pretty quickly.
It's the cocoa itself that's toxic. Milk chocolate is therefore less toxic than dark. Dark is less toxic than baker's. Bakers is less toxic than the whole beans. Hulls probably fall into the baker's chocolate range. It takes several large bars of Hershey's milk chocolate to poison a labrador. By comparison, only one Baker's square will cause big problems.
If your dog eats chocolate you can call the poison control number I have on the front page or call your veterinarian. Have the type and quantity of chocolate ingested ready so we can do the math. We can do calculations to see how much actual caffeine and theobromine they ingested.
Funny story: I once had an owner call me on emergency and say that her dog had just eaten an entire pound of dark chocolate covered espresso beans. Bad, BAD dog. I told her we had to get him to vomit ASAP. She replied, "Oh, he already vomited them up." "Fantastic," I replied. "But then he just ate them all back up again." DOH! BAD, BAD, BAD OWNER! Dogs will never fail to disgust you with their gastronomical tastes. Luckily the dog did well after we had him vomit the beans a SECOND time and kept him away from them. We had to watch him closely, he did have problems, but he survived.
AMH
Labels: chocolate, cocoa, cocoa bean hull mulch, toxicity
Sarcoptic Mange
Posted by Aaron
Monday, April 27, 2009
Historically, this is the mite that people are referring to when they say a dog has "The Mange." The other type of mange mite is demodex. Demodex is sometimes referred to as "Red Mange."
Sarcoptic mange is a condition caused by a mite called Sarcoptes scabiei. There is a video and picture above. There is also a picture of the skin of a dog with sarcoptic mange. This poor stray was found like this and it was the worst I've ever seen. The pictures are painful and no, he didn't survive.Sarcoptic mange is ridiculously itchy. These guys are so itchy that they simply can't stop. On a scale of 1-10 of itch, they are a 12. The itch is usually worse along the ears, elbows, ankles, and shoulders. There is usually a scale or crust over the itchy areas. The pictures above are about as severe as it gets. Usually they are just a little crusty and VERY itchy.
Treatment for these guys has become very easy. My personal favorite is to use Revolution now and then in 2 weeks. That cures them. Other options are Ivermectin injections or oral dose once weekly for four treatments. Dips are a waste of time IMHO. These guys have secondary infection and require antibiotics as well. You can't really use a steroid - at least not at first - because it will make them WAY worse. After the first treatment, you can usually get away with some steroid.
When you first treat them, the itch is worse as the adults die off. This only lasts a day or two, then they feel SOOOO much better.
People can get this one. Pretty nasty once you see the images above. It's quite contagious, but requires fairly close contact with the pet or bedding. As you can see, these little Jabba the Hut guys don't exactly have legs that work well for walking. So they can't crawl across the room to get to you. However, they are able to get from dog to person if you are snuggled up together or if the dog sleeps in bet with you. In people, infection looks like chiggers. They're in the same family. We aren't the intended host, so our body kills them off as soon as they start trying to burrow into our skin. They ITCH like a son-of-a-gun. Your physician can help you with the right treatment, but usually in people it's steroid cream to calm the inflammation because our bodies kill them off so quickly.
Yuck.
AMH
Labels: demodectic mange, demodex, mange, sarcoptic mange, video
Anal Sacs - or - "Honey, what's that smell?"
Posted by Aaron
Saturday, April 25, 2009
Ever noticed a time that your dog had a fishy, rotten kind of odor associated with the tailpipe? Perhaps they were scooting on the floor, dragging their anus along your new carpet? These are usually anal sac issues.
The anal sacs are a pair of sacs (usually grape-sized depending on the dog) that sit at approximately 5 o'clock and 7 o'clock around the anus (as pictured above). The sacs are under the skin and between the two anal sphincters. The sacs are connected to the anus via a pair of small ducts. The sacs are lined with glands that secrete the tinny, fishy, nasty stuff that you smell from time to time. It's a unique smell to each dog and helps to explain the age-old question: "Why does my dog sniff the other dog's butt?"
These sacs will sometimes fill up with the material and require emptying or "expressing." If the sacs become inflamed or infected, it is referred to as anal sacculitis. If the infection becomes severe and the actual sac itself begins to break down, then it can become an anal sac abscess. These abscesses will actually rupture through the skin and create a draining tract. They are amazingly painful and fairly nasty! Any dog licking and painful or any dog with a red swelling next to the anus needs to be seen as an emergency so we can get an antibiotic started and get the abscess under control.
Anal sac abscesses that are not properly treated (meaning not given antibiotics long enough or an owner that stops the antibiotics too soon) run a risk of creating these nasty scar tracts in the tissue around the anus called fistulous tracts. These can be a major pain in the rear (literally and figuratively) to treat.
Question: How often do I need to express my dog's anal sacs?
Answer: perhaps never. Some dogs require fairly regular work back there. Others never ever have them done. It completely depends on the individual. If they are licking, scooting, or smelling fishy, they probably need them expressed.
Question: How do I prevent problems?
Answer: IF you have a dog with repeat problems, then you may have to just keep on top of it. However, I've found it hard to predict which dogs will have problems and which ones will just require occasional help.
Question: How do I express my dog's anal sacs?
Answer: Have a veterinarian or qualified technician show you how. It's not too hard. It is fairly stinky and probably best done outside or in the bathtub. However, if you're too rough you can hurt things, so make sure you know what you're doing.
I'm a purist on this one - they are anal SACS lined with anal GLANDS. So when someone comes to me and asks me to express a dog's anal glands, it bugs me. It really bugs me and I usually can't help but correct them. I'm the first to admit I have one or two quirks that people have to put up with and this is one of them.
Many veterinarians will say that they are checking/expressing/flushing anal glands. I have to bite my tongue and avoid the impulse to yell across the room, "They're anal sacs!!!!!!" Anyone who has worked for me has heard me yell across the room something similar to this at least once.
AMH
Labels: anal glands, anal sacs
Toad lickin' Good
Posted by Aaron
Friday, April 17, 2009
Awww, Nuts
Posted by Aaron
Tuesday, April 14, 2009
The title is tacky, but I couldn't resist. Let's talk about neutering.
If you have a prostate, and you have testicles, you WILL have a problem with the afore mentioned prostate. This happens routinely in human males and is why all men over the age of 40 should have PSAs run and digital prostate exams.
The SAME problem happens in dogs. Testosterone causes the prostate to continue developing and enlarging. At some point this may cause the urethra to become pinched off or may get so huge that you can't pass a stool either. Intact male dogs should have a prostate exam completed yearly. There is not a PSA test available for dogs yet.
Neutering removes testosterone and pretty much makes the prostate a non-issue.
Here's a news flash: Testosterone makes you do stupid stuff. Dogs with extra testosterone are more likely to show behaviors like urine marking, dominance, aggression, territorialism, and overactive libido. That's not to say that an intact dog is a "bad" dog and a neutered dog is a "good" dog. No, no. Neutered dogs can still be all of those things. But in so much as testosterone can make bad behaviors worse - it's not worth having it around if you don't need it.
It doesn't make you less of a man to have a dog without testicles. Honestly. Nobody cares if your dog is well-endowed. Nobody. However, if it's really that important to you that something hang down between the legs, then there are implants available called neuticals.
AMH
Labels: canine, castration, neuter
Breast cancer in dogs
Posted by Aaron
Friday, April 10, 2009
Today is the Susan G. Komen Foundation 3-day walk around here. Hopefully everyone is aware of the cause and has found a way to support the walk for a cure. I thought I would write a piece about breast cancer in dogs. In many ways it parallels the disease in humans. One of the biggest differences is that we have a way to make a MAJOR dent in prevelance of disease. Breast cancer is very difficult to impossible to treat in dogs given our current access to medicines and practical financial limitations. So prevention is the focus!
I can't count the number of times I have an owner look at me in shock when I tell them that one of the main reasons we recommend spaying female puppies is to reduce the risk of breast cancer. Dogs get breast cancer, just like human females. It is also hormonally influenced and patients that have experienced estrogen surges (i.e. heat, estrus, periods) are more likely to develop tumors. There is also a genetic influence. Breast cancer can run in families.
If a female is spayed before her first heat cycle, her risk of breast cancer is less than 5/100ths of a percent. VERY tiny.
If spayed after the first, but before the second, the risk is about 8% (a 160-fold rise!).
If spayed after the second cycle, the risk is just over 26% (about an additional 3-fold rise. these girls are now 520 times more likely to develop cancer).
So that means over 1 in 4 females intact after their second cycle will have breast cancer. That's HUGE. Not to mention the number of females with uterine infections, uterine cancer, and ovarian cancer. Add all ovarian, uterine, and breast tumors together and intact females are about 33% likely to develop cancer of the urogenital system. ONE IN THREE!
Spaying AFTER a second cycle doesn't really lower the odds, however, femals spayed at a mature age are more likely to have benign tumors than females who are intact at the time of tumor diagnosis. Females spayed at any age will have the ovaries and uterus removed, so those girls can't develop ovarian or uterine tumors either.
So make sure you REALLY want those puppies before you give your dog a 1 in 3 chance of developing cancer as opposed to a 1 in 2000 chance if you spay her as a puppy.
Food for thought.
AMH
Labels: breast cancer, dog, ohe, spay
Prescription drug laws
Posted by Aaron
I have folks get mad at me from time to time when I say that I can't fill a prescription because the pet hasn't had a physical exam within the last year.
Here's the deal.
1) Even in the case of medications that are recurrent and we think we're on the right dose, we may not be. Lots of drugs require monitoring to make sure we're doing the right thing. When I suggest or require blood work for a dog on thyroid supplement, it's not just for poops and giggles. It's because thyroid supplement needs CHANGE OVER TIME. Sometimes they don't. Sometimes they do. I can't predict.
2) Most importantly - IT'S ILLEGAL FOR ME TO PRESCRIBE A MEDICATION TO A PET THAT DOES NOT HAVE A VALID "VETERINARIAN-CLIENT-PATIENT-RELATIONSHIP." This is also known as a VCPR. The same goes in human medicine. If the prescribing physician has not seen the patient within the last year, it's illegal to prescribe. The relationship can be applied to all doctors in a practice. In other words, if any doctor in the practice has seen the pet, then another doctor could, if appropriate, prescribe a medication even if they have not personally seen the pet.
By the way - one veterinarian can't just call another hospital and say, "Hey, would you fill XYZ medication for this pet" if the receiving hospital has never seen the pet. That makes the hospital filling the medication a "pharmacy" and pharmacy laws then apply. Without a registered pharmacist on staff, you're not a pharmacy. Operating as such means big-time fines.
These laws apply to ALL legend drugs. Even the ones that seem harmless. These laws include heartworm prevention!
Oddly enough, there can be two forms of the SAME medication (take, for instance, certain dewormers). One may be over the counter version of the same strength that you could go to the store and buy with no prescription. However, if I happen to buy a different bottle of the stuff (same ingredient, same everything) and it has the magic words, "Caution: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian" then it's illegal for me to sell without all of the i-dotting and t-crossing listed above. Silly, 'eh? Borderline stupid. But, so it is...
So don't get mad at your veterinarian because they say that a physical exam is required for them to fill a medication. They're not just screwing with you. It's not just about money. It's about good medicine, and it's always valuable to make sure you get what you need (nothing less, nothing more). Sometimes it's just plain required by federal law.
AMH
How do I cut my pet's nails?
Posted by Aaron
Thursday, April 9, 2009
This seems to be something that most owners are very nervous about. It's really not that hard.
The best way to avoid having to trim the nails much at all is to take your dog for regular walks on concrete surfaces (i.e. - daily walks around the neighborhood on sidewalks). Short of that you are probably going to have to trim nails.
- Technique 1 - Use a Dremmel (or other high-speed rotary tool) with the sanding drum on it. Use this to grind the nail back. The heat generated is useful to help drive the quick back. It's also nice because you have a softer surface as opposed to the sharp surface created by the clippers. Many dogs will respond to the heat of the Dremmel and start pulling back when you get close to the quick. YOU CAN STILL MAKE THEM BLEED. It's just a bit harder.
- Technique 2 - Using either form of nail clipper, trim the nail just past the end of the quick.
In either case, keep some Quick Stop powder (or styptic). A pinch of powder on the bleeding end of the nail helps stop it quickly. If you don't have any Quick Stop, an easy home remedy is to use a pinch of flour or corn starch with gentle pressure on the end of the nail. That'll help it clot.
Cats are easy to see where to cut. Take the narrow, sharp, pointy part off. Try not to use human nail clippers. Cat nails are laminar and they will shatter with human clippers. They do better with little nail clippers.
Cool fact: Because the nail is laminar, cat's "sharpen" their claws by pulling successive layers of nail off the end, leaving the harder, sharper point below. Anyone with a cat has found these bits of nail that look like a cast of the end of the nail laying around. When you trim the nail, it has to grow out before it gets pointy enough for them to catch on anything.
Please, please, please, please, please - pretty please - start trimming your dog or cat's nails when they are little bitty babies. Foot/nail phobias are very common in dogs and cats. You have to start young or they may become so nervous about it that they become phobic. I can't tell you how many patients I have that require a wrestling match that potentially includes poop, pee, booty juice (anal sacs), slobber, and teeth. 99% of those patients could have been avoided if we had only started when they were 8 weeks old. It's just like with our own kids - you have to get them used to having their teeth brushed and their nails done when they're little. If you both get used to it when they are babies life is SO MUCH EASIER.
If you're still not comfortable cutting nails - take them to the groomer or your veterinarian starting when they are very young and get them used to it.
AMH
Labels: cat, dog, nail, trim nails
Should I shave my dog/cat for the summer?
Posted by Aaron
Tuesday, April 7, 2009
Easter Lily Toxicity
Posted by Aaron
Labels: cat, easter lily, feline, lily
Poo's Clues
Posted by Aaron
Sunday, April 5, 2009
It's not pretty. We all make it. And it can be a goldmine of information.
To quote the TV show Scrubs: "If you wanna know what's wrong with you, it all comes down to number two!"
Not quite - but it highlights the wonders of stool. Poop. Doo doo. Feces. Stool is what's left over after your body has absorbed what it can from what you eat. The body also adds some fun stuff of its own on the way through.
You wanna know the major reason poo is brown? Stercobilin. It's a leftover metabolite of hemoglobin (the red color to your blood). The bacteria in the gut process it and it turns brown. Thus, COLOR of your poo is valuable. Orange, tan, white, gray, or black all mean something. (orange = jaundice? Black = digested blood or pepto-bismol? gray/greasy = undigested fats?)
In our companion pets, presence or absence of diarrhea is pretty important. Most dogs and cats eat a very regular diet. They should, therefore, produce normal, regular stool. Anything that speeds up the transit of stuff through the gut, the composition of the stuff in the gut, or interferes with the digestion of the stuff in the gut can create abnormal stools.
For instance: Giardia - this is a little single-celled parasite that infects the small intestines. It sits down on the lining of the gut and essentially clogs the works up. Food can't be digested. It makes it downstream to the colon where the colon bacteria throw a big kegger of a party and you get blow-out diarrhea. Similarly, Inflammatory Bowel Disease (IBS in people) or intestinal tumors may cause the gut to fail in absorption of nutrients with the same outcome I mention above.
On the other end of the spectrum, constipation can also be important to identify. Anytime the stool is not allowed to pass before too much water is reabsorbed by the colon, you get constipation. Severe cases of constipation result in an inability to pass stools known as obstipation. Fiber, most specifically insoluble fiber, stimulates the colon muscles to contract and helps keep the poo on the move. Fiber is fantastic stuff. It's as important to our geriatric pets as it is to us people. Most of us don't get enough fiber, our colons turn in to saggy bags and we have all kinds of problems with constipation when we get old. FEED YOUR COLON FIBER. Seriously.
Constipation is a problem we see more often in cats. Cats are known to have motility problems in their colons and they just don't move things through very well. In advanced cases, this lack of movement wears out the colon muscles and in severe cases, the colon stops contracting and becomes very, very large. Those guys sometimes need surgery to remove the colon. Less severe cases can be managed with diet and medications to convince the colon to contract better.
One VERY important thing that your veterinarian should be asking you for each year is a stool sample from your dog or cat. Just because you have an "indoor" cat or dog doesn't mean you shouldn't have the stool checked. I've found roundworms in the stools of "indoor" only cats on several occasions. Each time the owner was shocked to hear this. Roundworms are important because they are zoonotic - meaning WE can pick them up! Cat's can continue to self-amplify whatever they have since they always use the same bathroom (litterbox), so sometimes little infections become big infections.
A fresh stool sample can be processed and looked at under a microscope. The type and number of bacteria, parasite eggs, parasites, types of white cells, and presence of starch or fats can all give clues as to the overall health of your pet. Even more critically is the issue that some of these parasites are the type that WE CAN GET THEM. Roundworms, hookworms, and giardia to name a few.
Anytime you visit your veterinarian for diarrhea in your pet - MAKE SURE AND BRING A SAMPLE. It makes life so much easier.
See - you never knew poo could be so cool.
AMH
Help! My male cat can't pee!
Posted by Aaron
Saturday, April 4, 2009
This is an emergency.
Kitty cats are prone to lower urinary tract disease. As I mentioned before in the diet post, we haven't quite managed to get feline nutrition figured out. Whether the problem is more diet related or genetic remains to be seen. Regardless, inflammation or infection of the lower urinary tract in cats is fairly common. It is most commonly referred to as FUS (Feline Urologic Syndrome) or FLUTD (Feline Lower Urinary Tract Disease).
In this post I want to specifically deal with the cat straining to urinate. In a female of any species, it's fairly hard to cause an obstruction of the urethra. It's shorter than the male and tends to flair out towards the end of the urethra. In the male, however, there's a lot more urethra to consider (in most species) and it tends to stay fairly consistent in diameter or actually get SMALLER towards the end. In dogs it has to go through a bone near the end of the penis (called the os penis).
Male cats are a little bit special in regard to the penile urethra. The urethra isn't that much longer than in the female, but the trick is that the urethra gets a bit smaller towards the end. This is important in cats because in cases of FUS the urinary bladder becomes so inflamed that bits of mucous, white cell debris, and usually some crystals or small stones are all formed as part of the inflammatory process. When you mix all that goo together, it can form a plug. When that plug travels down the urethra, it gets caught up towards the end (where it becomes smaller) and obstruct the urethra. Obstruction = BAD. BAD = Emergency.
So, the moral of the story is that ANY MALE CAT STRAINING TO URINATE MUST BE SEEN ON AN EMERGENCY BASIS. Not later, not tomorrow morning, not after work. NOW. Any animal straining to urinate should be seen quickly so we can properly identify the reason, rule out emergency causes and start treatments so the poor dears can feel better quickly.
AMH
How do I know my pet needs his teeth cleaned?
Posted by Aaron
Friday, April 3, 2009
Dental disease is a BIG issue with our pets. Thankfully, advances in Veterinary Dentistry have made our ability to deal with dental disease light-years ahead of where it was even ten years ago.
When I graduated, I only knew how to scale a dog's teeth. I kind of knew how to probe the teeth and really had no idea how to properly extract a tooth or do a local anesthesia block properly. I'm nearly ashamed to admit it, but honestly I just didn't know any better. It's sad, really, because Texas A&M prepared me in just about every way but that. Dentistry just wasn't a priority back then.
Fast forward to today. Night and day. The equipment available, the training available, dental x-ray - it's all relatively new. I've had to work HOURS and HOURS of continuing education to get to where I am now. Today, I'm pretty darned good at it (if I may say so).
But enough about me :)
We're not terribly concerned about how the teeth "look." Pretty, white teeth are a human thing, but not so much with our companion pets. Periodontal disease is the big problem. I'll post again about the specifics of periodontal disease.
So how do you know? The best way to know is to stop in and have your veterinarian check the teeth. He or She will be able to help you really get a good look and decide if a cleaning (prophy) is necessary.
If you're at home and want to check the first question is: Does your pet's mouth smell like a garbage dump? And secondly: Are there things growing on your dog's teeth that look like they came out of a swamp? If the answer to either of these is yes - see your veterinarian.
If your dog doesn't smell like last weeks leftover chicken carcass that's been out in the sun sealed up in a black bag then the next step is to "Flip the Lip." Merial (a drug company) launched this campaign a couple of years ago and it's a great way to present it. When I'm in the room and look at the teeth, I'll usually show the owner as well. At least 80%, maybe 90% of the owners have never actually looked at the teeth! The answer - Flip the Lip. Look at all of the teeth. Signs that there are problems:
- Red gums
- Exposed roots
- Tartar build up covering the teeth
- Any teeth that move when you touch them. They shouldn't do that :)
- Broken teeth
- Foul odor
Any of these problems and the answer is YES - your pet needs evaluated. At this point, "brushing the teeth" isn't going to fix the problem.
In my next post, I'll talk about what a dental prophylaxis actually involves.
AMH
Gone Fishin'
Posted by Aaron
Wednesday, April 1, 2009
I saw a patient tonight at the emergency room who had fallen off a cliff, drowned, and was spectacularly brought back to life by his teenage owner. That's the story, at least, and he's sticking to it.
Reynolds is a typical young, knucklehead black lab that went out fishing with her owner today at Denton Creek. The boys had hiked out a bit to get to a deeper part of the river to fish. Reynolds was, as usual, having a great time and was running around as they hiked down beside the creek to find the right spot.
Somehow Reynolds managed to loose her footing while she was walking along the bank and tumbled down to the creek below. She apparently hit her head on the way down and when she hit the water, she was stunned and immediately sunk. Her owner, Joe, jumped off the bank into the water and had to go under to get her back to the surface. He swam back to the bank and by then she was not breathing and her eyes had gone blank.
Joe somehow kept his cool, lay her out on the bank and began to squeeze her chest when he noticed she wasn't breathing. He kept with her for a minute or two and she suddenly started breathing again. She hacked up some water and was disoriented for a few minutes. They both had to find a way out of the mud and hump it back up the hill to get out. It was then a hike back out of the woods and to the car.
By the time they got to me at the emergency room, Reynolds was 100% herself. She seems absolutely fine on examination. I'm sending home a couple days antibiotic to protect her from any pneumonia from inhaling the creek water.
In the initial story, the fall was down a short hill into a creek. By the time I published this story the fall was twenty five feet and the water three feet deep. By tomorrow, I'm sure it will be a fifty foot fall from a rocky cliff into the deep, black, frigid waters below. It doesn't matter. It's a really cool story and deserves to be told. Way to go, Joe.
AMH
Things That Fly and Sting
Posted by Aaron
'Tis the season for all the bees and wasps to start coming out. We're seeing them in droves here in Texas and soon the entire country will be warm enough.
Bees and wasps do the same things to our pets that they do to us. Most pets will experience a little bit of swelling, pain, and maybe even some fluid weeping from the site of the sting. Wasp stings can HURT like a son of a gun! Remember, wasps don't leave the stinger behind. Bees do.
First aid for bee stings are the same for our pets as they are for us. Remove the stinger, keep it clean. Cold compress can help. You can use products like Benadryl spray or cream to help with the swelling.
Dogs and cats can have severe adverse reactions. Facial swelling, hives, difficulty breathing, or vomiting/diarrhea can all happen with severe reactions. These are the exception, though. Most pets only suffer localized pain and swelling.
As a good rule of thumb, you can give Benadryl (diphenhydramine) at about 1mg/pound of weight as a first aid drug. Benadryl comes as a 25mg capsule or caplet and also as 12.5mg/tsp liquid. 25 pound dog gets one tablet. 6 pound dog gets 1/2 tsp. Pretty much any time you suspect an allergic reaction, you can give diphenhydramine. You should also call your primary care veterinarian or local veterinary emergency room if you suspect ANY kind of significant reaction outside of a little pain and swelling.
AMH