Ancilóstomos em cães e gatos: sinais, tratamento e prevenção

What hookworms are

Hookworms are thin worms, usually no more than 2 centimeters (under an inch) long. Their large mouthparts grip the wall of the small intestine. The worms feed there and move to new spots from time to time. They release a substance that stops blood from clotting, so the old bite sites can keep bleeding.

Three species matter most in Europe. Ancylostoma caninum infects dogs and does the most harm, because it feeds heavily on blood. It is found mainly in central and southern Europe. Ancylostoma tubaeforme infects cats and occurs across continental Europe. Uncinaria stenocephala, sometimes called the northern hookworm, copes better with cold and is found throughout Europe. It mostly affects dogs and only rarely cats. It takes much less blood and usually causes milder disease.

How dogs and cats get infected

Adult worms lay eggs that leave the body in the stool. In warm, moist soil, the eggs hatch and develop within days into larvae that can infect a new host. Pets pick up these larvae in several ways.

• Swallowing larvae while sniffing, eating grass or grooming after contact with contaminated ground
• Larvae burrowing through the skin, often on the paws, when a pet walks or lies on contaminated soil
• Eating a rodent, or an insect such as a cockroach, that carries larvae
• Nursing from an infected mother, which is an important route for puppies

In dogs, some larvae never reach the gut. They rest in the body's tissues instead. In a female dog, these resting larvae can become active during pregnancy, move to the mammary glands and pass to the puppies in the milk. Routine deworming does not reach these resting larvae, so a mother that looks healthy can still infect her litter. The cat hookworm does not pass to kittens through the milk. Kittens pick up larvae from their surroundings after birth.

Infection is most common where animals share outdoor spaces and stool builds up, such as kennel runs, shelters and yards that are not cleaned often.

Sinais a observar

Healthy adult dogs and cats often carry hookworms without obvious signs. They build some immunity over time, but it is not complete. These pets can still pass eggs and contaminate the ground for other animals. Signs are more likely in puppies, kittens, and animals that are thin, stressed or unwell. Possible signs include the following.

• Pale gums, the main sign of anemia
• Weakness, low energy or tiring easily
• Diarrhea, sometimes with blood, or dark, tarry stool
• Weight loss or poor growth
• A dull, dry or rough coat
• Poor appetite
• Red, sore or itchy skin on the paws or between the toes
• Coughing in young animals with a heavy infection

The cat hookworm can cause bloody or dark diarrhea, weight loss and anemia. Blood loss is a bigger problem in kittens than in adult cats. The northern hookworm rarely causes signs.

Quando é uma emergência

Hookworm disease can progress quickly in very young animals. Puppies infected through the milk can become seriously ill in their first weeks of life, sometimes before any eggs show up in a stool test.

Contact a veterinarian the same day if a puppy or kitten has very pale or white gums, seems weak or unusually quiet, stops nursing or eating, or has black, tarry or bloody diarrhea. Fast breathing or collapse also need urgent care. A small animal can lose a dangerous amount of blood in a short time. Some of these patients need hospital care along with deworming.

Como os veterinários fazem o diagnóstico e o tratamento

Hookworms are usually found with a stool test. In a flotation test, the stool is mixed with a special solution that makes the eggs float so they can be seen under a microscope. Once an infection is established, hookworm eggs are usually easy to find this way. Some clinics also offer a stool antigen test, which can often detect an infection before eggs appear, or PCR, which can identify the species. In a very young puppy with clear signs, the vet may start treatment based on the signs and history, because eggs may not be in the stool yet.

Treatment uses a deworming medicine that kills the adult worms in the gut. Most of these medicines do not kill larvae that are still developing or resting in the tissues, so vets usually repeat the treatment after two to three weeks. A stool test after treatment helps confirm that it worked.

Animals with anemia or dehydration may need extra care while the worms are cleared. This can include fluids, iron and a high-protein diet during recovery. In severe cases a blood transfusion may be needed. The veterinarian chooses the medicine and schedule that suit the pet's species, age, weight and health.

In some parts of the world, the dog hookworm has become resistant to several common dewormers. This has been reported mainly in the United States and Australia. European guidelines describe almost no proven cases in Europe so far. It is one more reason to recheck the stool after treatment when the vet advises it.

Prevention at home

Regular deworming is the basis of prevention. Puppies are often first dewormed at about two weeks of age and kittens at two to three weeks. Treatment is then usually repeated every two weeks until shortly after weaning. After that, many vets recommend regular or monthly treatment based on the pet's lifestyle and local risk. Many monthly parasite preventives also cover hookworms. For a pregnant dog, the veterinarian can suggest a plan to lower the risk of passing larvae to the puppies.

Keeping the surroundings clean also matters. Picking up dog stool promptly and cleaning the litter box every day both help. The eggs need a few days in the soil before they can infect, so removing stool quickly breaks the cycle. Larvae can survive for weeks, sometimes months, in warm, moist soil or sand, so a yard or run can stay contaminated for some time. Keeping cats indoors and stopping pets from hunting or scavenging also lowers the risk.

Regular stool tests show whether the plan is working. Current guidelines suggest testing adult pets at least once or twice a year, and young animals more often.

Risk to people and other pets

Hookworms spread easily between animals that share a yard, run or litter area. When one pet is diagnosed, it is worth asking the vet whether the other dogs and cats in the home should be tested or treated.

Dog and cat hookworms can also affect people. The larvae can burrow into bare skin that touches contaminated soil or sand. This causes a condition called cutaneous larva migrans, an itchy, red, winding line in the skin. The larvae cannot grow into adult worms in human skin and usually die within a few weeks. A doctor can confirm the diagnosis and advise on treatment. In rare cases, the dog hookworm reaches the human gut and causes abdominal pain.

People usually pick up the larvae from contaminated ground. Fresh stool is not infective yet, because the eggs need some days outside the body first. A few simple habits lower the risk. These include wearing shoes outdoors where animals toilet, wearing gloves when gardening, covering children's sandboxes when they are not in use, and washing hands after handling soil or cleaning up after pets.

Rescued and newly adopted animals

Hookworms tend to be more common in animals that live outdoors or in groups, such as street animals and animals in shelters. At Paw Squadron, the first stops after every rescue are the vet and a bath. Each animal gets a checkup, deworming, and treatment against fleas and other parasites. Before adoption, every animal also receives treatment, vaccinations and a microchip.

Deworming kills the adult worms present at the time. Resting larvae can mature later, and a young animal may pick up new larvae before its course of treatment is complete. After adoption, it is a good idea to book a visit with your own veterinarian, bring the health records, and ask whether a stool test or another deworming is due. The vet can then set a schedule that fits your pet.

If you are thinking about giving a rescued animal a home, the Adoptions page shows who is waiting, and the FAQ answers common questions about the process.