Signs of Glaucoma in Animals

January is National Glaucoma Awareness Month. Although this was primarily started to promote human eye health, I think we should also include animals. Glaucoma in all species, means an increase in ocular pressure that can damage the optic nerve. In a normal eye, the fluid of the eye, aqueous humor, drains out of the eye at the same rate it is being produced keeping the pressure between 15 and 25 mm Hg for dogs and cats. (Note: The normal range will vary depending upon species and the instrument used to measure the pressure.) In glaucoma, the drainage is blocked causing the pressure to sky rocket. It this condition isn’t treated immediately, blindness often results.

The most common sign of glaucoma in dogs and cats is a raised third eyelid.  Dogs and cats have an extra eyelid that originates from the side of the eye nearest the nose and spreads outward. Other signs include redness, swelling and unequal pupil size (anisocoria). Glaucoma is very painful!  Animals will often squint, rub their faces on furniture or paw at the effected eye.  I have seen a few tear profusely as well.

I see glaucoma most commonly in cocker spaniels and Labrador retrievers in Arizona. When I practiced in Minnesota, I saw it in Chow chows, Basset hounds and Siberian huskies as well as cockers and labs. With so many breeds being crossed to create designer breeds, I expect to see more cases as this disease appears to have a genetic component.

Glaucoma can also be caused by other medical problems.  Uveitis which means inflammation of the uveal tract of the eye is a common cause of glaucoma. In Arizona, tick fever and valley fever are common causes of uveitis. Other causes of glaucoma include cataracts, trauma and cancer.

If you notice these signs in your pet, please seek medical assistance immediately. Waiting, even a few hours, may mean the difference between sight and blindness.  I know of a dog who lost vision in his eye after only 60 minutes of increased pressure.


-Balas, M. ‘Keep your sights on animal eye health’. Pet Talk. OREGONLIVE, Jan. 15, 2014.

Ingested Batteries Are Harmful to Pets

Everything these days seems to have some sort of battery.  Smoke detectors, hearing aids, computers, mobile phones, remote controls and even car keys all have batteries. Unfortunately, batteries are extremely toxic to animals. Most batteries contain a strong acid or alkaline material that will burn any tissue it contacts. Some batteries emit an electrical current that causes severe electrical burns. Batteries may also contain heavy metals such as zinc, mercury and lead which are poisonous. 

When I examine a dog for possible battery toxicity, I start with a thorough physical exam paying special attention to the mouth.  If the ingestion is recent, I often see a black chalky material in the mouth.  I also look for ulcers which are areas where the normal gingiva is burned away exposing the underlying tissues.  Next, I take X-rays of the entire gastro-intestinal tract of the animal. Because of the metal, batteries show up well on X-rays. In my experience, dogs who bite a battery will usually spit it out without swallowing any of the battery.

Treatment centers around removing the battery and then treating the damage.  In most cases, I do not induce vomiting for fear of causing more burns to the esophagus, stomach or mouth.  Instead, I remove the battery as quickly as possible through surgery or endoscopy then I treat the patient with anti-ulcer medications, analgesics to help with the pain and a special diet. 

If you think your pet may have ingested batteries, please bring them to a veterinarian right away.  Waiting may cause gastro-intestinal ulcers to perforate. 

-Lee, Justine A. Top Ten Small Animal Toxins: Recognition, Diagnosis, Treatment. ACVIM 2010 Proceedings

5-FU (Efudex, Carac, Adrucil and Fluoroplex) Cream Will Poison Animals

As a veterinarian, I always worry about my patients coming into contact with medicated creams from their owners.  One of the worst is 5-Fluorouracil (5-FU) which is used in humans to treat basal cell carcinoma and actinic keratosis of the skin. The patient applies a cream containing 5-FU to the affected area. Unfortunately, 5-FU is highly toxic to animals. Common brand names include Efudex®, Carac®, Adrucil® and Fluoroplex®.

Dogs and cats are exposed when they lick the cream off the human or get the cream on their fur and then lick it. I have also heard of people who forget to wash their hands after applying 5-FU and accidentally transfer it to their pets. Once 5-FU gets into an animal’s gastrointestinal system, it is rapidly absorbed. Common early symptoms include vomiting, bloody diarrhea, severe abdominal pain, problems with balance and seizures. With time, this toxin will destroy the animal’s bone marrow resulting in anemia, leukopenia (lack of white blood cells used to fight infection) and thrombocytopenia (lack of platelets used to clot blot.)  Death often results from infection, failure of several organs or bleeding into the brain.

Please be extremely careful with 5-FU around animals. Most cats will die from exposure to a small amount. Dogs have a slightly better prognosis with 25% survival. To prevent accidental exposure:

1) Keep all medications in a safe, animal-proof cabinet.
2) Wash your hands thoroughly after handling. 
3) Keep the area covered with a waterproof bandage to prevent accidental exposure.
4) Dispose of all bandages, packaging supplies, etc., immediately in an animal-proof container.
5) Do not let your pet lick your skin after application. 

-Lee, Justine A. Top Ten Small Animal Toxins: Recognition, Diagnosis, Treatment. ACVIM 2010 Proceedings
-Peterson, ME, Talcott PA. Small Animal Toxicology. Elsevier, St. Louis, Missouri, 2006.

Comment on Taming Feral Cats

Great job Barb! I would wait until you can handle the kittens before introducing them to the others. I understand your dilemma about the Revolution but I think you did the right thing by treating them. To help them trust you again, I would try bits of cooked chicken for a special treat.  Play with them using feathers on a string to draw them out and then reward them with the treat.  Good luck and congrats again on getting the colony registered.

Comment on Taming Feral Cats

Three months have gone by.The kittens are about 6 months old.The first three caught are now playing with me with toys. They are not allowing contact.I am taking your advice and not forcing it. The male leader will play and run up to my feet and then smell them and run away.I am spending about an hour every morning with them. I feed them while I am in the room all of them come out to eat. The male now waits for me in front of the door waiting for breakfast.I had a tough choice to make last week..I needed to put their revolution on them. The only way was to chase them into their original cage. I managed to get it on them The smallest runt Echo hissed and hissed then stared crying, it broke my heart.I am not sure weather it was the right decision, they were distant about a week and the last one caught is not coming back out yet.I thought it was better they are healthy and pest free for now.Otherwise all the money spent at the vet for worming and flee medication I feel would be wasted.My other cats will come to the door when the kittens are playing. One comes in walks up to the kittens and hisses in a non threatening way then turns and walks out.I wondering if I should wait until I can handle the kittens before I let them into the rest of the house. I don’t want to have to chase them again it seems to undo my progress.And just another update the mom and brother from another litter as well as the other feral cats stopping by to eat are now a registered colony and my city is paying for every cat I catch and release to be spayed/neutered.

Marijuana Toxicity in Pets

As more states legalize the use of marijuana, more and more pets will be exposed and poisoned.  The psychoactive chemical is known as THC (delta 9-tetrahydrocannabinol). Hashish is a form of marijuana with a higher concentration of THC than the regular variety. Here is what to look for in a pet, usually a dog, who has ingested marijuana:

1) Low Dose – lethargy, un-coordination, urinary incontinence, abnormal startle response (patient starts to lose balance then over-corrects), bradycardia (slow heart rate) and dilated pupils.

2) Medium Dose – extreme lethargy that borders upon sedation, vomiting, inability to walk.

3) High Dose – unconsciousness, seizures.

If your pet has been exposed to marijuana, please bring them in for veterinary care immediately.  If less than 30 minutes has passed, your veterinarian may be able to induce vomiting.  If clinical signs are already present, then administering activated charcoal will help your pet absorb less toxin. Since THC is absorbed into the fat, clinical signs can last for several days depending upon the dose and body condition of the animal.  Please be honest with your veterinarian as marijuana toxicity can look like poisoning from several different kinds of sedatives.

Brooks, Wendy. Marijuana Toxicity, The Pet Health Library, VIN, 2/11/03 and revised on 11/4/12.

Organosphate Kills Two Cats and Almost Claims Two Dogs

Organophosphates are commonly used to kill insects and pests in homes and gardens throughout the world. Unfortunately, many people don’t realize this highly effective compound is also highly effective at killing animals. Here is what happened to my friend. She agreed to share her story in order to educate people and hopefully, prevent future poisonings.

My friend took her dogs, Alfie and Pippa out for a run.  Instead of completing their normal walk, they decided to take a shortcut through the lot of a vacant home. The backyard was full of leaves and had a wood crib used to store firewood. Alfie and Pippa found something interesting under the crib. My friend had to pull them away to continue their walk. A few steps later, my friend found her two cats, Crissy and Jasmine . . . dead.

She took her dogs home and then went back to care for her cat’s remains. She returned a short time later to find Pippa sick.  The dog was “vomiting and trying to poop at the same time.” Because of her animal experience, she rushed Pippa to her veterinarian immediately. Her veterinarian diagnosed organophosphate toxicity. While Pippa received treatment, my friend went home to check on Alfie, worried that he may have gotten into it too. She found him down in his create covered with vomitus and diarrhea.  Since organosphospates are attracted to fat tissue, thin animals are affected more quickly than heavier animals. Thanks to the quick diagnosis and treatment with atropine, both dogs survived. 

To prevent another poisoning, my friend searched the vacant yard.  Unfortunately, she found nothing. She suspects the yard may have been sprayed for weeds or perhaps a poison was left to kill field mice and wood rats.

Organophosphates are highly effective and dangerous chemicals.  Please use them with great care to prevent more accidental victims.  If you pet is exposed, bring them to a veterinarian immediately.  This is not something you can treat at home.  The victim needs atropine which is an injectable antidote.   From personal experience with my own patients I can tell you it is a horrible way to die!