foal care
MARQUIS® (15% w/w ponazuril) Antiprotozoal Oral Paste Caution: Federal (U.S.A.) law restricts this drug to use by or on the order of a licensed veterinarian.
For The Treatment Of Equine Protozoal Myeloencephalitis (EPM) In Horses For Oral Use Only BRIEF SUMMARY Before using MARQUIS, please consult the product insert, a summary of which follows: INDICATIONS MARQUIS (ponazuril) is indicated for the treatment of equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona. WARNINGS For use in animals only. Not for use in horses intended for food. Not for human use. Keep out of reach of children. PRECAUTIONS Prior to treatment, a complete neurologic exam should be completed by a veterinarian. In most instances, ataxia due to EPM is asymmetrical and affects the hind limbs. Clinicians should recognize that clearance of the parasite by ponazuril may not completely resolve the clinical signs attributed to the natural progression of the disease. The prognosis for animals treated for EPM may be dependent upon the severity of disease and the duration of the infection prior to treatment. The safe use of MARQUIS (ponazuril) in horses used for breeding purposes, during pregnancy, or in lactating mares, has not been evaluated. The safety of MARQUIS (ponazuril) with concomitant therapies in horses has not been evaluated. ADVERSE REACTIONS In the field study, eight animals were noted to have unusual daily observations. Two horses exhibited blisters on the nose and mouth, three animals showed skin reactions for up to 18 days, one animal had loose stools, one had a mild colic on one day and one animal had a seizure while on medication. The association of these reactions to treatment was not established. ANIMAL SAFETY SUMMARY MARQUIS (ponazuril) was administered to 24 adult horses (12 males and 12 females) in a target animal safety study. Three groups of 8 horses each received 0, 10 or 30 mg/kg (water as control, 2X and 6X for a 5 mg/kg [2.27 mg/lb] dose). Horses were dosed after feeding. One half of each group was treated for 28 days and the other half for 56 days followed by necropsy upon termination of treatment. There were several instances of loose feces in all animals in the study irrespective of treatment, sporadic inappetence and one horse at 10 mg/kg (2X) lost weight while on test. Loose feces were treatment related. Histopathological findings included moderate edema in the uterine epithelium of three of the four females in the 6X group (two treated for 28 days and one for 56 days).
Think about the environment when considering what is going inside the animal, he suggested.
The Work Up
The first consideration is whether or not the animal has a contagious disease. Is there just one sick animal or are several ill? The age and breed can give clues about the problem. A congenital condition is likely to show up pretty soon after birth, whereas diseases, such as bacterial pneumonia, are likely to occur from two weeks to four months. Weanlings tend to have upper airway and lower airway Streptococcus or rhinopneumonitis. Certain breeds are also more likely to have genetic issues that could cause respiratory conditions. For instance, Arabian or Quarter horse foals with chronic lung issues could have immunodeficiency syndromes. Both are more likely to have selective immunoglobulin M deficiency, while Thoroughbreds and Standardbreds are more likely to have agammaglobulinemia. If a genetic etiology is suspected, consider having the animal tested. Take a step back and really look at the animal, he suggested. Not just the chest, but also the face. Look at facial symmetry and patency of nares. Is there a discharge? It is not unusual for a foal to have sinus issues or a foreign body. “Keep an open mind when you approach these respiratory cases. It might not just be the lungs; it could be the sinuses,” he said. When auscultating the chest, use a re-
Hyperactive Airway Syndrome The foal might have hyperactive airway syndrome if it is in severe respiratory distress: huffing, puffing for every breath, nostrils flaring and has an abdominal lift. The ultrasonography might show consolidation and broad-based comet tails and inflammation, polyphonic crackles and wheezes that might be unresponsive to antibiotics. The animal is being hyperreactive to viral or bacterial pneumonia. Frequently, there is a lot of inflammation in the respiratory tract and exposure to dust in the barn just triggers more inflammation and a cascade of negative events. They tend to be weanlings, but some are older foals that are still on the mare. “I hit them with steroids and I hit them hard,” said Nathan Slovis, DVM, DACVIM. The goal of treatment is to resolve the compromised oxygen uptake. Use intranasal oxygen and bronchodilators, as well as the steroids to reduce the inflammation, he suggested. And ensure strict environmental controls.
For customer care or to obtain product information, including a Material Safety Data Sheet, call 1-888-6374251 Option 2, then press 1. ®MARQUIS is a registered trademark of Merial. ©2016 Merial, Inc., Duluth, GA. All rights reserved.
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breathing bag or cover the nares with your hands to cause hyperpnea, he suggested. “You don’t need a bag for a rebreathing exam. Put your hand over both nostrils, hold it off for a short period—don’t squeeze the nostrils just put your hand over them. Cup them. No need to squeeze. And after they resist, let go and start listening.” Try to better describe what you hear, he suggested. Don’t just use the term “harsh sounds,” it’s not specific enough. “As veterinarians, we should describe it. Is it polyphonic crackles or wheezes? Polyphonic is audible sound with a wide range of frequency that is characteristic of inflammation affecting the larger and smaller airways. It will sound like music,” he said. Is it tubular, a sign of significant consolidation where the air is only moving in the larger airways (main stem bronchi)? Are there increased bronchovesicular sounds, like rustling leaves in the wind? Bronchial sounds are louder than tubular sounds with a wide range of frequency. Do you hear crackles and wheezes? Crackles usually are associated with mucus or secretions; wheezes signal more bronchoconstriction. Consider all the clinical signs. Coughing, wheezing, respiratory rate, flared nostrils, abnormal breath sounds, discharge and fever are all common in foals with respiratory conditions. Look at the abdomen during inhalation and exhalation. Some veterinarians rely on radiographs, but Dr. Slovis does not find them as helpful as ultrasonography. “I don’t like to do ra-
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Issue 3/2017 | ModernEquineVet.com