Skip to main content

Pet Health Library

Parasites

  • Lung flukes in North America are parasites called Paragonimus kellicotti that infect the lungs of dogs after they have eaten an infected crayfish or rodents that have eaten infected crayfish. Eggs are then released by the parasite into the dog’s sputum to be coughed out or swallowed and released in the feces to continue the life cycle. Lung flukes can be found anywhere in North America but more commonly around the Mississippi River and Great Lakes. Infected dogs can be symptom-free or may develop cough with sometimes bloody mucus, pneumonia, pneumothorax, lethargy and weakness. Diagnosis can include locating eggs of the parasite from feces or mucus from the lungs. X-rays can also reveal cysts in the lungs caused by the parasite. Treatment requires one of 2 commonly used anti-parasitic medications: Praziquantel or Fenbendazole. Although zoonotic, these parasites won’t transmit directly from dogs to humans.

  • In North America, many parasitic lungworms infect cats. Cats can become infected by swallowing infective stages of parasitic lungworm. The exact means of becoming infected varies according to the life cycle of the particular parasite. Signs can include coughing, heavy breathing, wheezing, sneezing, poor appetite or anorexia, weight loss, fever, enlarged lymph nodes, and ocular or nasal discharge, and may be more prominent in kittens due to their immature immune systems. Although the success rate of treatment depends on the severity of symptoms and the number of parasites present, the prognosis for recovery is generally good.

  • There are many species of lungworm that can cause respiratory problems in dogs. Infection is acquired through either: ingestion of an intermediate host such as snails or slugs, ingestion of animals that have been infected by eating these animals or depending on the species, from an infected dog by contact with saliva, nasal discharge, or contaminated food and water bowls. Lungworms can be found throughout North America and the world with certain species seen in certain areas. Clincal signs can range from asymptomatic to tachypnea, coughing, sneezing, wheezing, respiratory distress or exercise intolerance. The degree of clinical signs is usually proportional to the strength of the dog’s immune system. Diagnosis involves history, physical exam, x-rays and organism identification through either baermann fecal examination or BAL/bronchoscopy. Treatment involves use of specific antiparasitic drugs for various lengths of time depending on type and severity of infection. Prognosis is good but re-infection can occur.

  • The bacterium that causes Lyme disease can be transmitted to dogs through the bite of an infected tick, most commonly the deer tick (black-legged tick), which is found in the midwestern and eastern United States and throughout Canada. The disease typically causes pain and swelling in the affected dog's joints along with decreased appetite and fever. The kidneys are sometimes affected, in which case the disease is often fatal. Diagnostic testing, treatment, and ways to prevent Lyme disease in your dog, including instructions for tick removal, are explained in this handout.

  • Metronidazole is given by mouth or injection and is used off-label to treat certain anaerobic bacterial and protozoal infections and gastrointestinal conditions in dogs, cats, and other animals. Give as directed. Side effects may include nausea, vomiting, diarrhea, regurgitation, decreased appetite, tiredness, and drooling. Do not use in pets that are allergic to it, are debilitated, or are pregnant or nursing. If a negative reaction occurs, contact your veterinarian.

  • Milbemycin oxime + afoxolaner is a heartworm disease preventive that also treats certain internal parasites and controls fleas and ticks in dogs. It is also used off-label to treat mite infestations in dogs. This combination drug is given by mouth as a flavored chew tablet. Certain dog breeds are more sensitive to milbemycin oxime than others; your veterinarian will advise you on the safety of milbemycin oxime use in your dog. If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately.

  • Milbemycin oxime + lufenuron is a heartworm disease preventive that also treats internal parasites (e.g., whipworms, hookworms, and roundworms) and controls flea populations in dogs. Milbemycin oxime + lufenuron is given by mouth as a flavored chew tablet. At prescribed doses, this medication is well-tolerated; when used off-label at higher doses for treating mites, side effects have been observed. Your veterinarian will advise you on the safety of milbemycin oxime + lufenuron use in your dog. If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately.

  • Milbemycin oxime + lufenuron + praziquantel is a heartworm disease preventive that also treats certain internal parasites and controls fleas in dogs. This combination medication is given by mouth as a flavored chew tablet. At prescribed doses, this medication is well-tolerated. Certain dog breeds are more sensitive to milbemycin than others; your veterinarian will advise you on the safety of milbemycin use in your dog. If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately.

  • Milbemycin oxime + praziquantel is a heartworm disease preventive that also controls tapeworms, hookworms, roundworms, and whipworms in dogs. It is given by mouth as a flavored chew tablet and must be given with a meal to ensure adequate absorption. At prescribed doses, this medication is well-tolerated. Your veterinarian will advise you on the safety of this combination product’s use in your dog. If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately.

  • Milbemycin oxime + spinosad is a heartworm disease preventive that also controls hookworms, roundworms, whipworms, and fleas in dogs. Milbemycin oxime + spinosad is given by mouth as a flavored chew tablet. At prescribed doses, this medication is well-tolerated. Your veterinarian will advise you on the safety of this product’s use in your dog. If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately.